Preamp Deal of the Century

Hey Fiddler. No need to for any apologies here, just good to see your Tung-sol roundplates are starting show off and srut their stuff. Tube rolling with any gear can be perplexing at times given all the variables, particularly with the 6sn7 family of tubes. The entire 6sn7 family have a tendency to be prone to microphony and/or noise when employed as a gain tube. Given the incredable resolving capability of the Supratek preamps,and magnified by the high gain of the circuit itself....... you now have gain stage that will allow you to hear the best/or worst of the particular brand tube being employed. Unfortunately...the tube's noise ,hiss,hum,or microphony will be magnified as well. No wonder why Mick Maloney and so many others recommend using the stock EH 6sn7 gain tubes. Mick has done an incredible job of voicing his preamp with the EH 6sn7. I am more than certain Mick is testing,screening and cherry picking the best examples from every lot he orders from Electro Harmonics, culling and discarding the examples that don't make the grade. The EH 6sn7 is far and away the best sounding 6sn7 of current manufacture, leaps and bounds better than the sovtek he was originally working with. The very best examples of new old stock 6sn7's are so hediously expensive to acquire these days...when one factors in the n7's penchant to be prone to hiss,hum and microphony. I would guess the EH 6sn7 is simply a "No Brainer". I do consider myself very very fortunate these days as I have always had a huge collection of nos tubes at my disposal. I spent 14 years in the field as a techie for Dukane {Bell % Howell}. We serviced,repaired and calibrating amplifiers in the big movie theaters,concert halls, churches, schools,colleges, universities etc in Canada. The 6sn7 was employed in the majority of amplifiers back in the day, not to mention jukes, radios and nearly every television ever made.Allowing me the luxury of collecting hundreds on n7's when they were cheaper than cup of coffee. Ever wonder why Tube Dealers use a grade rating system for their inventory of old stock 6sn7's???? "Buyer Beware" is the appropriate warning here! If it is graded as a standard grade tube, or a driver grade tube.... Do yourself a favour and "don't even consider it guys".... as it's just a sure fire recipee for a major disapointment here, particularly if it's to be employed for a gain stage in a high quality preamp! Meaning... preamp grade tubes only here gang!!! Noisey tubes are a major liablity and will only serve to mask much of the micro resolution,nuance and timbre buried under the noise floor. Remove the noise and you will be just amazed at how much more of the musical information you've been missing! When voicing my Supratek with any given brand of nos 6sn7's... I would typically need to go through 6-10 examples to find a matched pair with a noise floor that was low enough for use in the supratek. Some brands...Kenrad Black glass for example[my favourite beside the Tungsol round], had an even higher culling rate! Fortunately, the Tungsol round plates are usually much more consistent here...typically lower in noise and tighter triode sections. Hey Fiddler, now that you have discovered the real magic of the Tung-sol round..... lose that pair over at flea-bay and grab a low noise pair. Life is grand.

Hello Cello. Re: regulators in the supratek. They do indeed influence the sound of the pre,however...their influence is nowhere near the dramatic difference of the 6sn7 or the rectifier choice for that matter.I am using the syrah,not the cortese,however,I think the tube topology of the power supply is identical to both units, wherby the regulators are employed on the power supply chassis of the cortese along with the gz34.The syrah uses the regulators on the chassis of the pre and the rectifier is located on the seperate power supply.We have a large selection of different tubes and types that can be employed here for regulation duty.All of them being employed as a means of further smoothing the ripple of the rectifier.I believe this is why many believe that they have "no" influence on the sound of any given amplifier.The choice of rectifier and regulators can make a profound difference [as I am sure you heard when swapping out the stock 5ar4/gz34]. One can use an original NOS American [beam tetrodes] 6L6,G,GA,GB,GC, 5881, the obsenely expensive WE 350b and many others as well as their nos Euro equivalents like the el-34,el-37,Kt66,Kt-77 etc[read expensive again]. Most all of these tubes will sound a little different than the current modern equivalents like the eh 5881,russian or chineese 6L6's, kt-66 or el34's. I for one, cannot tolerate the russian KT-66,6L6,5881 as regulators in my rig, I do find the current chineese Kt-66 the most relaxed sounding of any of the modern made equivalents.All nos 6L6 will better "any" of the modern equivalents with the possible execption of the original nos 6L6 [metal] which... in my rig sounds very similiar to the sovteks. The tung sol 5881 is the tube of choice here, however the old 6L6g [ST-bottle shaped version only] is also a very nice choice and can be found for typically 20% of the cost of the tung-sols.Regulators will not influence frequency or tone like that of the 6sn7 tube types.Their impact or influence has more to do with air and spatial cues in a sublimal sense.A sound that is more relaxed and effortless in a musical way. Allowing one to hear very fine micro detail, nuance and subtle spatial cues that are burried in the texture of the music.This hidden imformation is definitively masked when the stock tubes are used...This hidden imformation or nuance per say is very clearly resolved ,its just simply "there" and coherent in a natural kind of way with out requiring one to concentrate in order to hear these artifacts in the recording. It seems to pull you in closer to the music and forget about your equipment.Really very obvious when one puts the stock tubes back in.The genelec kt-66 or mullard el 37 are probably the best of all of the types I have listed here and will get you very close to the greatest beamed power tube ever produced, The Western Electric 350b. A side note here for supratek owners... There is another nos tube that I am currently employing for regulation duty in the syrah that I honestly believe can hold its own with the esteemed WE 350b! The best of it is...they can be had for pennies. I will post my thoughts here after I have climatized myself with this particular tube.

Jazzdude. Now that makes more sense. I thought that he must be using both socket types on the same chassis with a switch.

Regarding my last post: I should qualify things for those that are following this thread.My commentary was based solely on the use of vinyl as the source for comparison.

Swampy. What rectifier are you using and does it test strong?

Hello Gang.It seems most supratek owners have rolled out the stock tubes for various brands of nos tubes to "synergize" their systems. The older gt versions of the 6sn7's seem to be the tube of choice and rightly so.Phono tubes as well. A lot of people just do not realize that the voltage regulators and the rectifiers can have as much or more of an influence on the sound of their choice of tubes.One would think[by reputation and cost] the various nos mullard family of 5ar4/gz34's would be "the" choice for rectification. The lgendary mullards are great to be sure however.... there are a whole slew of nos rectifiers choices out there that can be had for a fraction of the cost of a nos mullard gz-34--- and many of them sound as good or even better! As far as the mullard family of rectifiers go...I personally think the Gz-33 sounds better than the GZ-34 in the syrah and is typically 1/2 the cost.I have an old 5v4g shoulder type rectifier [labelled Philco] that sounds better than all of the mullards...GZ32,gz33 and Gz34! I have 2 nos versions of the 5z4 that also sound terrific. These can typically be purchased for under $10 each.The best of the bunch in my system is the Bendex Redbank 6106. This tube is electrically equivalent to the 5y3g family of rectifier tubes but also indirectly heated with a slow power up to minimilize cathode stripping.Rectifiers "DO" make a difference!Especially in the depth department.When using the bendex.... the bass is better resolved,faster,more articulate and more extended than any of the mullards.The air between the instruments and performers on stage is also noticibly much more apparent.... lending itself to a better focus of each individual instrument or musician.The "tone" thing has more to do with the choice of the 6sn7 of course.However you can refine the "tone" of your nos Tung sol's,kenrads,and sylvanias with a good rectifier.Mullard's are great and will probably outlast you or the preamp... however, there are other nos choices out there that make great music with the supratek.Voltage Regulators??? Yes... they make a difference as well,just not to the extent of the rectifiers.The older 5881's and 6L6g's seem to sound a little more relaxed than the 6L6gb's or gc's,but can also sound a little soft when used with the ken-rad vt-231's or Rca grey glass vt-31's.The genelec Kt-66 as voltage regulators makes almost any 6sn7 sound wonderful[exclude the sovtek]. Of course ---the Western Electric 350b is the "King" of any of the 6L6 family of tubes and if you can afford them[or find them]they are "THE" tube of choice for voltage regulators and will outlive you and the rest of your equipment to boot!You really haven't heard the real tone of your tung-sol rounds until you regulate them with a pair of the Westrex 350b and a good rectifier! But start with the rectifier first.Hey!...wouldn't the world would be a very dull place without music???... enjoy! Cheers David.

Any of the supratek preamps that I have seen 4 sale on the GON seem to sell "immediately" at full retail or close to it [depending on condition]and rightly so.I for one...cerainly would have purchased one on the GON if given the opportunity- just to avoid the 9-10 month wait to have it made.The preamp truly is a world class reference product that can compete head on with anything out there- especially if your system is vinyl based.Some may not like its open tube architecture while others consider it an art form.I personally don't care one [way or the other] what "any" equipment looks like as long as it gets me closer to the music.I have 2 legendary Classic tubed preamps to compare it to and can honestly say the supratek will definitively stand the "test of time" and one day also become a cult classic as well.It certainly betters both my ARC SP-10 mk2 and my Luminesence B through the line stage and has the luxury of a remote to boot.The Supratek also betters the sp-10 when a low output moving coil is employed.I still prefer phono stage of the Lumi in my set up, however,to be candid, it is much like comparing fine wine or fine art. Different strokes for different folks!Chosing one over the other is another matter of perspective when it comes to selling.At this particular jucture in my life I would "never" sell my Luminescence and I would have a tough time selling my ARC sp-10 as well[sentimental reasons].I have owned it and enjoyed it immensly since 1985 and it has always been my benchmark for comparison!One day: one or the other will make it to the classifieds and when it does I suppose the fair market value at that time will dictate its worth.I for one would bet on the Supratek at maintaining its value and high demand.If your looking to buy one and the opportunity presents itself? "BUY IT" Its a no-brainer" The world would be a very sad place without music! Enjoy.

Hello Petland. Regarding the RCA 5u4gb rectifier suppled. It will work- however it is a "directly heated" full wave rectifier and not recommended.I would consult Mick with regards to using it, Indirecty heated rectifiers[recommended] will prevent cathode stripping of the other tubes in the line.The sylvania 5v4g that you mentioned is a good rectifier especially when used in conjunction with the early gt versions of the sylvania 6sn7's. I don't know why the guy would send you a 5u4g.Perhaps that was in error for the other 5932. Enjoy. Cheers David.

HELLO Gang.The preamp will indeed operate without regulator tubes, However... please do not operate the preamp without them. The purpose of the regulators is to smooth out the dc ripple from the rectifier tube to maintain a correct and steady dc voltage to the other tubes.

Hello Gang. What happened to the tube thread on the supratek preamp? Did it get yanked?

Hey Bwhite. To reiterate: Under no uncertain terms would the WE 350b's be justified for regulators in the supratek given their current market value.As mentioned earlier in the tube thread; The only reason I use them in mine is... I had a pair left over from an old pair of theatre amps that I sold years ago.Yes, I do like them as regulators in the supratek.. however the tungsol 5881's or any of the older 6L6 G versions are terrific.Their purpose in the supratek is to smooth the dc ripple of the rectifier and regulate a constant voltage to the gain stage.Early st-bottle shaped 6L6 G'versions can be found for peanuts just about anywhere. The guitar guy's tend to prefer the higher rated GB and GC versions of the 6L6 as the G rated versions cannot handle being ramped up into overdrive and tend to distort far to early for them.I would hazard to guess that well over 90% of the 6L6's were traditionally sold to the guitar amp market.

Hey BWhite. Hearing the differences between regulation and rectification tubes is certainly not odd or strange,its a "good thing" ... as they do infact impart on the sound of the supratek. Your description of the 6L6 metal seems to parrallel mine... as I also find them rather lacking of air and space in the soundfield,and more so than any other tubes I have tried, sovtek included.I have not tried the 5932 however, the GEC kt-66 and the mullard EL-37 seem to be the closest to WE 350b than anything else I've used.These tubes all seem to add more depth and air to the soundfield without changing the tone of the music.Regarding the use of the ecc-32 in your friends Syrah..... very strange....something doesn't add up here, as they work just fine in mine.Have you tested these tubes? What rectifier and regulators was he using with these?

Hello Bwhite. Could be a weak rectifier and/or weak ecc-32's. Gentlemen... please do yourselves a very big favour , you "must" get yourselves a good calibrated tube tester!!! Absolutely indispensible,especially when considering the tube rolling everyone is doing here! Most any tube that tests anything less than 90% shouldn't even be a consideration. Even if one is purchasing nos tubes,a good calibrated tester is "imperative" as many NOS tubes right out of the box can fail to meet spec.To be blunt and honest! I think you will be somewhat surprised when you test some of these tubes you are using in the supratek. Matching the 6sn-7's per channel is paramount for top preformance in the supratek.... not to mention.... section to section matching of each of these tubes- which is even "more" important [in all triode tubes]! Check the strength of any rectifier you are using as these will have a large impact on the overall sonics of the preamp.Making a comprehensive evaluation regarding the sound of various tubes makes, types, and vintages of these tubes in any circuit is pretty much flawed without knowing these parameters.For example... A strong rectifier of the same type will sound very different than that exact same tube that tests even 10% less than the stronger one. Do not mean to sound so derogatory gang, however some things are a given and need to be addressed here .....Cheers David

Hello Georgia. Each and every NEW tube needs to be run in for a period of time to settle in. Some more than others.

Hey Gang. I'd take bets the Syrah 4 sale here doesn't last the weekend.

Hi Fiddler. I have an order in for the welbourne labs attenuator,unfortunately they are in a back order position at present. Anyone tried it in a supratek yet? Thanks for the tip on the Mundorfs.

My tube compliment mirrors slowhands exactly, except for the regulation tubes. I use western electric 350b's in place of the tung sol 5881.

Hello Brian and Jazzdude. The early 6L6G[shoulder shaped bottle] are very good and quite a bit better than the later GB's or GC'c types in my syrah. Brian.....Email me off line regarding the WE 350b's. Cheers David.

Very good analogy from Jazzdude,No one should use any directly heated rectifiers with the supratek preamps. Although the guy's assessment is bang on about the sound of a ux-280.

ASA. Do you "really" want to go there? Come on now : I know your a much bigger man than this. Just leave it be brother .All of you here have a very Merry Christmas and all of the best in the New Year. Sincerly David.

Congratulations Bob. Amazing huh.The best of it all is: Like a fine wine or all fine tube equipment for that matter, it can only get better with age, as the transformers,caps, resistors,wire etc, need a steady dose of frequency modulation [read music] to settle in!Really comes into its own at about 6 months. Enjoy

Devils Advocate? Interesting analogy and some food for thought here.How does one qualify as a "Devils Advocate"?? Perhaps... we can post an internet polling station here, and all of us "insecure members" can vote for you or whomever else aspires to assume this distinctive title "The Internet Devils Advocate" Yeah! Who knows... you could become really famous here on the Gon ... Maybe even become a "Legend in your own Mind". You would get my vote.

Hello Gang. ASA, any Canada geese hanging out with the gulls there? Your Clear Side anology and its relationship with up stream and down stream components is bang on here. Yes...I do hear this attribute and you are correct in your analysis. I have employed the black Kenrads in my pre for that very reason. They do offer more of a textured soundscape and sound a little more organic in my rig when compared to most of the others. However, this does depend on the genre of music that I am listening to at the time, as well as amplifier choice[tubes in my case]. In my honest opinion: Ones choice of gain tube[6sn7]in the supratek is not a liabilty [per say],but a very flexible option to have when fine tuning with any given high resolution system . The Clarity of the supratek, will definitively allow one the abilty to hear the changes in the source,the componentry,wires,tubes etc,.An Example: the RCA redbase 5692 is far and away the tube of choice when used in my Luminescence B.....the Kenrad by comparison, would rank way down the list of nos tubes in that particular pre.Vice versa for the syrah[go figure]as mine does not seem to respond well to the 5622,at least in my rig. I have marched over [with my syrah in tow] to quite a few friends places [as well as a box of nos 6sn7's]and in every case, the syrah has removed a blanket of fog in each and every one of these systems[all very musical and high end by anybody'standards]By doing so,I have learned a great deal about the "voice" of the supratek and how it synergizes with different components. Example: One friend uses the Conrad Johnson MV-52 amplifier employed with nos mullard el-34's [beautiful little amp BTW]to drive JM labs model??? The Kenrad is "NOT the tube of choice in his system as we both preferred the syvania wgt's by a wide margin.The sound was a great deal tighter with the sylvanias in the syrah when listening to live blues and jazz. Another friend uses the meadowlark Shearwaters driven by mfa 120b monos in triode. These amps are running Genelex KT-88's and are wonderful sounding instruments. Here; the Kenrads sound incredible in the supratek.The stage is huge, literally holographic,with instruments and voices in full scale.A really enjoyable experience to be sure, made his Audible illusions 3a sound anemic,thin,and 2 dimensional.[Yes....he has ordered one] Prior to inserting in the syrah,his system was always very impressive in a "hifi sense" being that it resolved a heck of lot of imformation from the source with good dynamic range,great bass as well as clarity. I direct comparison with the Syrah, it sounds like good "hifi" but the Syrah gets you way closer to the event making the the 3a sound like its broken. I am a firm believer in getting the tonal balance right, first and foremost,then tuning the system to yeild as much resolution as one can achieve in a given room.The supratek is the heart and soul of each and every system I have heard it in! Enjoy.

I hear you Tom! and a very good point. One hell of a lot of experimentation going on out there without some type of methodology or reference point to work with.And with tubed gear, more often then not, it can lead far too many poor souls into proverbial Bermuda Triange. I have read more hype and BullShit regarding vacuum tubes here and there and everywhere on the net. Too many people that I know personally have rolled different tubes, way to many times until they are so confused and frustrated with how bad their stuff sounds, that they start looking at what to upgrade next. They read somewhere on the net,some inexperienced dimwit professing that the 12abcdxyz is an auwsome tube, and then they go out buy some tired tube pulls or relabelled fakes they saw on ebay, and they don't even own a tube tester nor know how to use one!A simple recipe for disaster if one has little or no experience with tube brands,tube types, vintages, and tube topology. It's really a simple rule of thumb....If your going to invest in NOS tubes,buy a tube tester and learn how to use it. That said: there is no denying that many NOS tubes can transform most any well designed amplifier[vintage,modern, DIY or otherwise]into a magical experience. Examples you say: Try a fresh siemen ecc803/12ax7 [60,s vintage] in any interation of the audio research sp series preamps and most would soil themselves at the transformation.I am not talking tonal balance tweeks here gang, but a whole higher league altogether. For those that use a modern amp with a 12au7 as a driver tube, now try a 60,s vintage mullard [10m series] or mazda chrome plate from the same era and you'll think you have died and gone to heaven.Ever heard an original genelex KT77 in place of an el-34? Now thats an ear opener if the ever was one!It just doesn't get any better than that!Same with the Genelex Kt-88 or Kt-66 to name a few more. Forget the tonal balancing act here gang,its a whole nother order of magnitude better in every which way! Tonal balance changes? Far easier accomplished with speaker placement, room treatments and cables, "NOT" the tubes.

ASA...... Dammit..... ya caught me red handed... Next time, I think I will just leave the Kens at home.

Hello Gang. Re: rolling regulators and rectifiers. Jazzdude's observations regarding soundstage stability and re: equipment employing vaccum tubed power supplies is rather astute and really very relevent here. Most of us with the supratek preamps know the pre is quite sensitive to the tubes employed in it.Ones choice of 6sn7's is usually chosen for it's voicing and its synergy with the partnered amps and speakers in a given room.Ones choice of rectifier and its marriage with the regulation tubes used will also add another spice to the recipe. A rather sublime artifact; that is not so easy to put your finger on right away because they do not directly affect tone or frequency. Soundstage stability is the primary reason why Mullard rectifiers have long been considered the rectifier of choice among tube amp enthusiast,guitar players,hobbyist and collectors alike.When employed in amplifiers using power tubes in the output,this soundstage stability artifact becomes a much larger issue and paramount with ones choice of rectifier. Ask yourself:Why do Mullard rectifiers command 5 to 10 times the price of the modern equivalents or other 5ar4's from the same vintage?[new or used] Collectors and speculators ya say? Think again! The soundstage stabilty thing that Jazzdude is talking about here is "THE" reason.Any competent guitar player with half an ear and a vintage tube amp will tell you the same and the mullard rectifier will last as long as the amp. ASA has really nailed down the sonic signature of the supratek and apptly penned it as being on the "clear side". NOW gang,just for fun....You want to hear "clearly" what Jazzdude is on about??? For those that are presently using a strong testing NOS mullard or bendex rectifier[90% minimum] Choose an appropriate live recording that you are very familiar with and would consider to having large dynamic swings and accompanied by a vocal.Pay particular attention to the precise placement or location and size of the vocalist on the stage. NOW pull your nos rectifier and replace it with the stock 5ar4/gz34,let it warm up a least 1/2 hour and replay it again. In my rig... the precise location of the vocalist will wander or slightly drift from his/or her precise place on the stage both laterally and vertically.The size does not change,but his/her location will drift. With the mullard in place,the vocalist is precicely focused in his/her own place on the stage.There is no drift,wander or shift. This artifact really becomes obvious in size and scale when the accompaning band gets cooking at the same time....drummers kicking,horns are honking,pianos a hammering in time with the vocal.Does everthing remain in scale and in the same place?does the drum kit get a little smaller or the cymbals wander slighty left or right of the drum kit? Or maybe the piano sounds wider on the bottom registers in relation to the upper keys when the band gets going. The piano size and scale [distortion thing] is one that is easily heard and can be very difficult to get right to begin with, let alone listening to rectifiers for chrissakes!However..Of all instrument,the piano is the easiest instrument to hear this drifting thing happen especially if accompanied by a human voice. Geez gang.....I think Im getting a little carried away here.Just try it people,let your ears be the judge!

Cello. While I do not use any of the symposium products,I second your recommendation on their effectiveness.They are terrific with tubed based gear. I have heard the effect first hand in a friends room isolating his magnificent sounding Klimo tube preamp and companion Kent mono amps. Their effect is his rig was not subtle. We have both been promoting the resonance control theory with tubed based equipment for many years. He has spent as much or more on his room than his equipment[read very expensive]and his rig is one of the finest if not "the" finest I have ever heard.The system is vinyl based only and his table is set up out of the room.Every piece of electronics is isolated with symposium pruducts.The noise floor is almost non existant.Music in his room is always magnificent experience.I am still dying to hear my Syrah in his system for comparison.

Hey Gang. I suppose what one might call a tweak,another may call it a component.In defence of stevem and keeping things in perspective, I certainly concur with every point he made in numerical order, as they would most definitevly qualify for a top shelf system for making great music and more often than not will make a major impact to be sure. Heck...I own one of everthing he mentions on the list with the exception the digital dac stuff. However... I have also heard every single one of those components mentioned on the list sound mediocre at best, for a number of reasons[my gear included here gang].I personally believe resonance and vibration control is imperative when one gets to the level of equipment mentioned on that list. Tweaks?? I don't think so Stevem. Optimizing a system of that calibre is paramount and really should be considered the common denominator here.

Steve. Nice post . "Fine tuning" is the more appropriate word here in this thread. I have a sneeking suspicion that most of us here have "been there and done that".Many of us have experimented with IC's,speaker wire,tubes etc,and can hear the differences these may or may not impart in ones room.I suppose some might call that tweaking,one can call it whatever they want.I would preferr to call it Fine Tuning myself. Are you fine tuning your proacs or are you "tweaking" them??? A superb choice in speakers [by the way] and one that is very dear to my heart![still miss my response 3's to this very day] Interesting......I would classify that type of work as being in the tweaking category and I am certain Stuart Tyler would also call it "Tweaking". He has "voiced" all of his response series speakers to sound as "beautiful" as they do. Steve.... no disrespect here,I am very intrigued to be sure,however; I just don't believe there would be any reward in modding that speaker with a raven ribbon......and yes, I do believe the Raven is a superb driver.Hope you will post your thoughts on your Tweek. Cheers.

Hello Grannyring. Congrats on the supratek choice and welcome to the forum.Regarding Nos tubes: Not much more to add on my behalf as Mr Bwhite's assessment of the nos tubes choices for the supratek is really very accurate. He has pretty much "dialed in" the sonic signature of those tubes.{Kudos to Bryon and very well said!}Regarding phono Tubes: I personally preferr the Amperex 5842 gold pin over the Western Electric 417a [most WE 417a's tend to be a little more microphonic]I also use the mullard GK5's in the phono but the nos RCA's are great as well and their influence have never really been an issue with me.I use a Koetsu Roewood mc,mind you I do preferr the RCA's with the Shelter 501.The voice of the cartridge used in the phono may very well dictate ones choice of tube here as the RCA's are a tiny bit brighter in the treble region. I am really quite certain that any of the nos tube choices mentioned in Bwhites post will literally mesmerize you. Enjoy!

Hello Gang. A while back, I posted an alternative tube that can hold its own with the ultra expensive Western Electric 350B when employed as regulators in the supratek. I have been using a pair of 6F6g [ST bottle shape] from the 1930's in my Syrah for more than a month now.Mine are labelled rogers, however, I believe they were made by National Union[the company that first developed the 350b]. These power pentodes are slightly smaller than the 350b and their internals are almost indentical. Do "not" use the 6F6 metals[developed first] as they do not sound the same as the later glass tubes.These 6F6 power pentodes preceeded the more common 6V6 beam tetrode tubes and were used mostly in old radios and consols of the day.They should be relatively cheap and easy to source with a little searching as there is virtually no demand for these tubes today.The 6F6g will amaze you in the supratek! They sound so much like the 350b its simply a no brainer.

Hey Jazzdude. Discovering wildcat tubes???? Hmmmmmm . I have been working with vacuum tubes ever since building my first tube gear [dyna pas and mk2 amps kits] in grade 9 electronics class [1967].A little story here..... My first employment in the working world was as a techie for Bell & Howell[Dukane] in their microfilm division.One of our biggest accounts was at the Westinghouse plant in Hamilton Ontario[transformer division]. I will never forget walking into their computer room and seeing a gigantic Univac computer that employed more than 18,000 vacuum tubes! Next to the computer room was a storage facility to house their massive tube inventory.The late Archie MacIssac, who was their Chief electrical engineer at the time,He and I became very close friends. Archie saw the writing on the wall regarding the demise of the vacuum tube from a technical perpective and began collecting tubes. His collection was something to behold, facinating, and enormous! Tubes from all over the Globe, dating back to the earliest stuff, including gigantic watercooled Eimac power triodes and pentodes,some of these tubes are worth a small fortune today.Over the years,I too; became a collector of vacuum tubes and now have a rather humble collection of some very rare tubes .However, most of my collection are limited to audio tubes per sey. I also collect vintage tube gear, but have [reluctantly] sold most of my collection off in recent years, due to space limitations and the mess of stuff that aways seems to accompany these things. However...Sure wish I had kept some of that great old stuff today! If one is to collect vacuum tube gear, one better learn how to repair and retube the stuff.I think its a "given" that the tubes employed in most any circuit designs can make or break the way it will sound in any given system,especially if that given system has the abilty to resolve the amplified imformation.Particularly the vintage stuff,but much of the modern stuff as well. Its really a shame, that todays designers are literally "handcuffed" because of the availabilty and the prohibitive cost of many of these great NOS tubes .Unfortunately, for us anyway, many designers of modern tubed gear have really no choice but to "voice" their creations with todays mediocre sounding modern tubes,their hands are tied!That said.... a lot of the modern stuff[not all] can be transformed into a whole higher order with the great old nos valves. After all,vacuum tube research reached it's pinnicle in the 50's and early 60's.It really shouldn't be much of a surprise, given todays superior passive parts[wire,capacitors,resistors,diodes etc]when designed around good linear transformers, that we are now seeing products coming to the market that are pushing the envelope [sonically speaking]at reasonable cost [in todays dollar]. Relative to the "old guard" well established Corporate American companies .Any one remember the cost of the Marantz 7 or model 5's of the era?Astramonical in todays dollar! There has been an underground movement in DYI vacuum tube audio for many years. In this "imformation age" and the ever growing internet, I am certain we will see many more Supratek-like pruducts reach the masses.A really good thing for the open minded Audiophile. [Audiophile?] geez... I really hate that handle. All the more reason to start collecting those great nos tubes before there ain't any more to be had. Hell...ya need to take out a second mortgage to acquire some of these tubes! We will also see more people designing equipment that will employ "alternative" tube types, due to the cost and availablity of the traditional audio triode tubes used in commercial audio equipment.Interesting, how the industry adopted the 9 pin miniature triodes[12au7,12ax7,12at7 6dj8 et] as the the norm in the amplifiers from the 60's to modern day stuff . Considering the stuff of a decade earlier used their octal based family equivalents . The 6sl7's operating characteristics are basically a cross between a 12ax7 and a 12at7.The nearest 9 pin equivalent would be a 5751.The 6sn7 has the same average plate characteristics as the 12au7 but with a hotter filament.The 6BL7 resembles the 6dj8 miniature triode so common in todays equipment but it has slightly less gain and even lower plate resistance.The basic octal base family of dual triodes evolved from the 30's and 40's and were used mainly in WW2 military communication equipment. The 6sn7 was so highly regarded in private industry that Univac employed them in their computers.Later iterations evolved into the 5691[6sl7]and the 5692[6sn7]Given identical circuit topology,these octals elicit a more linear and focused sound than a 12a?7 or 6dj8,are more extended at the frequency extrememes while also expanding the space and perimeter of the soundfield. Given the demand for these nos tubes,the better ones are now commanding prices approaching that of the premium 12ax7's and 6dj8's so common in modern equipment.The circle will turn again and a new bread will emerge using equivalent alternatives to the 6sn7 and 6sl7 octals. Relatively inexpensive octal triodes from the same era with similar electrical characteristics. Take the 6DN7 and 6EM7 for instance. These are great sounding dual triodes that are dirt cheap from any tube dealer not to mention ham fests and flea markets.We can thank the alternative free thinking pioneers of the industry,men like Scott Franklin and Bruce Moore who introduced the magnificent Luminesence octal based preamp in the early eighties. The Lumi's design topology employed many of these octal based triodes, all hand wired, point to point with discrete circuits and fully regulated vacum tubed power supplies.This preamp was such a radical design change from the accepted norm in the state of the art designs of the day.At the time,the ARC sp-10 and the CJ premiere 3 were considered at the edge of the art and the king of the hill .There is no doubt in my mind,the Lumi was the catalyst and the inspiration to much of the octal based triode tube designs emerging today,.....Supratek included.

Hello SteveM. A little off topic here in this thread, however, I am very curious. How did you intergrate the raven with the proac? Is it integrated on the original proac baffle in the box? In phase or reverse?I concur with your rather astute analysis regarding Stuart Tylers BBCesque-like voicing of his speakers.[You have very good ears sir] . I too... just love that proac voicing technique, and quite frankly believe it is the reason why they make such beautiful music.I am also a BIG fan of the original 15 ohm BBC version of the roger Ls3/5a, which was obviously tuned or voiced to sound the way it does. I still have a pair in my kitchen, we have listened to them every day for more than 25 years.Many,many times... visitors and guests to our home have been mesmerized by the sound of the LS 3/5a. And most are usually in utter dis-belief when they realize they are actually listening to these diminutive 25 year old little babies.Has your modded proacs been a success in capturing that BBC like magic???? The Raven's are so incredibly transparent and posses that elusive abilty to resolve that very fine micro-detail, akin to the better E stats out there. I have just never heard them "successfully" married to a full range speaker that I could live with. Hell... You can banish me to a desert island for the rest of my days with any one of the proac response series speakers,my Supratek and any decent tube amp! All of proacs just make for beautiful music!I would be interested to hear your thoughts Steve.

Hello Baranyi. What do you consider very cheap for the Berning? No matter how you slice it, It is certainly one of the finest sounding amplifiers money can buy today, and given its power platform,really very versatile. Do you really care if it is a prototype?

Hello Gang.I have been out of town, just catching up on the thread. Swampwalker, hope your progressing on your troubleshooting.... These things can be frustrating, but persevere there brother as you will indeed be rewarded. Jewel.... regarding microphonic 6sn7's??? As bwhite correctly pointed out, many 6sn7's tend to be microphonic in the supratek,noteably the Kenrads, however...your dealer states that: "all nos 6sn7's tend to be microphonic" That is a rather profound statement to be sure, and nothing but total pile of BS.Perhaps it is just because of the sad supply of kenrads in his inventory.Yes, the Kenrads can be microphonic in the supratek but certainly not all of them.They need to be cherry picked. I had to go through a dozen of mine to find a pair that were quiet. The least microphonic and quietest of any 6sn7 types are the rca 5692 [red base].Personally.... I preferr the sonics of the Kenrad vt-231gt's[navy version] or the tung-sol rounds in my rig. That said: any strong testing RCA redbase 5692 will simply stomp the modern chineese or russian 6sn7.These have more air and extension up top and are a little leaner in the bass, but the bass is nice and tight,very fast and has very good resolution.Does not have quite the atmasphere or bloom in the midrange like of the kens or the tung sol rounds but good examples of this tube are very smooth and non-fatiguing.Very system dependent here with regards to tone and synergy. A good example or a case in point: I have a MFA luminescence B that employs a 6sn7 for gain in its line stage... The Lumi tends to be a shade on the dark side of nuetral. Both the Kenrads and tungsol rounds would be my "least" favorite 6sn7 when employed in the Lumi, while the rca 5692 is "far and away" the best 6sn7 type tube in the lumi.The sylvania 6sn7wgt vt231 metals are very similar tonally to the rca 5692 however,these tubes also tend be microphonic in the Supratek and also need to be cherry picked per sey. The tung sol round is an all around great performer in the supratek, as well as the much more common 1930's rca grey glass 6sn7gt's. The RCA's can be sourced just about anywhere as there were more of these manufactured than any other tube ever made. The RCA gt's are tungsol roundish sounding[read sweet] in the supratek, traditionally much easier to source and easier on the pocket book as well. Again... system "synergy" is the key word here. Personally... I find the Tungsol round just a little too "tubey" or sweet sounding in my rig. Your mileage may very of course. Suggestion here: It may be a good idea to acquire a batch of say a dozen of the same 6sn7 type and then cherry pick the best pair and sell off the rest.I know... can get a little costly,but they are pretty easy to sell on ebay or right here on the gon. Slowhand and tubegrover... Sure happy to hear you guys liked the 6f6g's for regulator duty[amazing huh].A great alternative from the insanely priced we 350b.To be candid: I am always a little aprehensive about recommending anything in a public forum as we all have different rooms,amplifiers,rigs and ears. PS: For those sourcing early bottle type 6f6g's for regulation duty in the supratek....these can also be substituted with a 1611 or 1621 tube. These tubes are physically about the size of the we 350's with similiar internals. Cheers David.

Hey Abe, Good score! most everthing on the list can be used with the exception of the 2a3 DTH triodes and all of the miniature 9 pin 12a?7 family of tubes,807's,oda regulators and the 807.

hello Lisbon. The original 6f6 valves[power pentodes] date back to the early 1920's and were actually first produced in all metal form and looked similar to the early 6v6 metal valves that are so common in early guitar amps.Do "not" use these metal types as they do not sound the same. To the best of my knowledge,the 6F6G [Shoulder shaped glass vavles] were produced from the late 20's through to the early 40's. The tube was produced by either Sylvania or National Union and rebranded for many radio companies of the day. Mine say Rogers,however I have also seen them labelled philco,electrohome,RCA,westinghouse etc.There are also quite a few different versions of the 6F6g's with different looking plates and internals.The ones that I am referring to had rounded black plates like the Western Electric 350b.I have seen many with flat black plates as well. I am not sure if I can post a picture on this thread,if you want to see a picture of the internals of this valve,I can e-mail you one off-line. Cheers David.

Hey Bryan.Tell me how you post pictures on this thread?

Hello Gang. RE: The use of 6F6g as regulators. Fiddler and Lisbon,I can certainly understand your apprehension and anxiety here.Consulting tube substitution guides and doing net searches will give you imformation that is simply not applicable here regarding our application in the supratek. Firstly...The 5881, and the 6L6 tubes employed in the supratek are are actually output tubes[beam tetrodes]. They were never really designed for use as a regulator tube.These tubes were originally designed for amplification duty only, re: output stages for amplifiers,radios and TV's. Just like many other common output tube types such as the KT-66,el-34,kt-88,6550,kt-90 etc to name a few . When one referrs to any tube subsitution guide or manual,the manual will give you direct substitions for that one particular tube type that would have similiar voltage curves[among other parameters] for the tube being substitued."IE" for voltage,amperage,bias and output power[wattage]etc. These paramaters are really not applicable here as they are not employed as an output stage tube in the supratek.The duty of these tubes in the supratek were specifically designed and employed as regulator tubes, whereby their application in the supratek are specifically used to smooth the ripple of the rectifier, "not" as an output tube per say. A tube substitution guide will tell you absolutely nothing when referred to in this context. Consulting any tube substitution manual will only tell you what tube can be substituted as an output tube . Example: A typical substition for a 6L6 found in any given manual, would be a 5881,7581,5932,Kt-66,6L6G,6L6ga,6L6gb,6L6gc etc.In actual fact, there are many relatively common power tubes[power tetrodes,power pentodes,beam power tubes] that can be substituted for the 5881/6L6 in the supratek. The 6F6 is a small power pentode and is perfectly safe and suitable for use as regulation duty in the supratek. I personally use the western electric 350b in my supratek only because I've had a pair in my stash for many years.I have also tried nos 5881's, all of the 6L6 itterations, as well as 7581's,5932's,kt-66's,6v6g's and of the 6f6g's. The legendary WE 350b beamer is the "King of the Castle" for regulation duty in my rig and in my humble opinion, the 6F6g [round plate] is the next best thing to it.If I didn't have a pair of 350b's, than the 6f6g would be "THE" tube of choice. I ran a pair of these in my syrah for more than a month. Try em, they are terrific.

Thank you for your kind words Rabelais. I can certainly appreciate Mick's take on using different tubes. For what it's worth,I did asked Mick that very same question the week I received my Syrah. I had a few pairs of the WE 350b,s in my stash and was curious about rolling out the stock 6L6's. His answer was the same. I also asked him the same question regarding swapping out the stock 6sn7s for euro eqivalents like the Mullards,his answer was no to swapping them as well. I have used the we 350b as my regulator choice[ an exact equivalent by the way] for well over a year now and they will "stay" in my Syrah until the day I sell it. My posts regarding tube choices in this thread are simply my observations with respect to how they sound in my system.They are not recommendations per say. Your mileage may vary of course.

Hello Abe. The 6v6 is a beam tetrode similiar to the 6F6 and will work as regulators in the supratek syrah, however, I doubt it will sound better than a 6l6, my experience with any of the metal tube types has always been a disappointment. The early 6L6's and 6F6's were metal tubes as well.Give them a try and see what you think.

Hello Jyprez. Whom would you be referring to sir?

Hello Jpms. I have both NU 350b's and Western Electric 350b's and cannot hear any differnce between them when used for regulator duty in the supratek. As many of you well know,the 350b was never really designed for regulation duty as it was traditionally used as an output tube, and when used as an output tube in an amplifier,it is without any doubt...the king of the 6L6 family of tubes. That said: I cannot hear any difference when used as an output tube either. Like most Western Electric vacuum tubes,the name itself will command premium money.If one can find the NU labeled 350b's at a decent price........grab em while you can! Hey gang..... It is like good real estate, *they ain't making anymore* Cheers

Mrmb. Wow! A very fine system indeed sir,and being a former owner of soundlab A-1's..very close to my heart.While my system is voiced primarily for vinyl,I am certain you would be amazed at the benefit of a top level pre in your rig,whether it is a supratek, one of the Cats or any other pre at that level. I have never auditioned the wadia in my own rig,however....the supratek syrah's line stage was considerably better than my cat sig sl-1 mk2,my MFA luminescence or my ARC sp-10 mk2 when paired with my sony es9000. And I can say for certain that all of the pre's were much more preferable than a direct hook-up to the amps.My experience with a digital source without a preamp in the line was that the music was somewhat thinner dimensionally than real life, missing the body and the bloom of the real thing. The syrah is incredibly transparent and dynamic,and adds nothing of a character or signature per sey. I have never heard the cat amps paired with the cat preamp either so I cannot attest to their synergy and can only surmise they would be a very good match. I did have the pleasure of hearing the magnificent JL-1's mated to the Klimo Merlin pre,[another great pre BTW] powering a pair of proacs former flagship model response 4's and can honestly say I was completely mesmerized with the fidelity, and one of the finest sounding rigs this guy has ever heard. The remote option is also one that I had reservations about as well, but now.... something I couldn't live without. It functions strictly as a motorized pot for gain only and isn't in the signal path. My acquisition of any of the pre's mentioned above, were solely on the merrit's of their phono stages and I can honestly say I enjoyed countless hours with all of them while spinning vinyl. I still use the Luminescence and doubt I will ever part with it. That said:The supratek bests every one of them when used as a line stage and by a wide margin. At the current price of admission...it has no real competition that I am aware of! Perhaps, someone here with much more experience than I have in the digital medium will hopefully chime in here.

Hello Joe.Yes, I believe that is the one, however.... It is difficult for me to tell if they are rounded plates in the picture. If they are,and at that money: every Supratek owner should definetely grab a pair. Well done sir?

Tubegroover. The phono stage of the syrah is truly outstanding,and very flexible regarding cartridge choices.Due to the higher gain and loading flexibilty in the syrah, It will better the cat,the sp-10 and the lumi when using mc cartridges with outputs below .5 mv. I have run the phono stages of every one of them through the line of the syrah. Higher output coils or magnets are another story as each one of the above pre's have top shelf phono stages that are very engaging and incredibly good by anybody's standards. My cartridge of choice is the Koetsu rosewood [circa 1980] that I recently had rebuilt by Koetsu. While it was being rebuilt,I used either a denon 103,shelter 501 [briefly] or the low output grado reference[.5mv]. With the denon[.25mv]the syrah won hands down.With the Koetsu,I do preferr the phono stage of the both the sp-10 mk2 or the lumi when loaded below 100 ohms and run through the line of the syrah.With the shelter however...I much preferred the syrah with the cat coming in a close second.The grado sounded simply wonderful through each and every one of them,but did have more weight and the tightest bass through the phono of the syrah.Comparing the phono stage of the supratek to these other great phono stages is not only a testiment to its credibilty but was a revelation of sorts to me and the main reason why I think it has no real competition at it's given price point. Given it's phono stage flexibilty and oustanding line stage all in one package......It is stupid good and really a no brainer!!!!! Mike... There is no doubt in my mind that the Wadia is at a whole higher level than my humble sony cd player,........however.....be prepared to be mesmerized with the analogue experience if your thinking of going there...I'd take bets it will put another big dent in the old savings account once you hear it in that fabulous system of yours.

hey Clipsal. The WE 350b's, though very expensive...are a terrific investment and will only appreciate in value. I concurr with your assessment regarding the bloomy bottom octave when paired with the Kenrads. You must be running full range speakers.You will find the tungsol rounds a little leaner on the bottom end with the 350b's. Very system dependent over-all, especially for those using full range speakers that have extension into the bottom octave. For those with stand mounted monitors or speakers with a leaner bass weight...The Kenrads would only be a big plus.I recently visited a friend with my syrah in tow. He is running a pair of stand mounted proac response 2's and an el-34 based amp.I am was using the early sylvania metal base 6sn7 with the 350b's in my Syrah. Substituting the Ken's in place of the sylvania's really made his system sing in a big way.It added more weight or a foundation to the overall presentation and worked magically with the proacs. I was "mesmerized" with this set up...captured both of us for many hours into the evening. Those proacs really make beautiful music!

Hi Joe. To the best of my knowledge....The 6c45 is a russian military tube with no direct sub. I have a very limited background with russian equivalents. Sorry.

Hello Amandarae. Yes the 6v6 works very well as a regulator in the supratek. Regarding warm up:each and all quality [tubed] preamp stages will take a minimum of 20 minutes of warm up time to come into there own and should be optimum about twice that amount of time. I can see you have figured it out that there is not much point in turning off your SS amp. Regarding the bass balance with the Kenrad black: What speaker are you using? Your phono stage configuration is different then mine however I am really somewhat suprised at your analysis of the red based 5692. Personally... It would be my last pick of nos 6sn7's for the line gain duty in my Syrah.... Funny thing is: it is far and away the choice of tube in my MFA luminescence.Than again, the lumi is somewhat darker sounding the my Syrah. Perhaps this observation is in direct contrast to the Kenrad... because of the bloomy base you are experiencing with the Kenrad. As our own Jazzdude has recommended [more than once I might add]... you mighy want to try a pair of RCA grey glass 6sn7gt's. They are a lot better balanced [tone wise] than the RCA 5692 in the syrah and possess a lot of that organic midband of the Kenrad. Further more, they are a hell of a lot cheaper to boot. In my rig, the 5692 sounds a lot closer to the voice of the sylvania 6sn7gt. Nothing is absolute regarding the voice of this particular octal tube and they certainly all have their own flavor.Do try the RCA grey glass though as they really are sweet and relaxing. Cheers and best of luck.

Amandarae. Wow, You have a lot of very fine equipment in your arsenal. A couple of questions. What speakers are you currently using to voice the supratek???... the logans or the paradigm's. How large is your room and your speakers location in the room. No need for panick sir. Like most new vacuum tubed equipment.....you will need some run in time with the supratek as the transformer,wires and tubes will start to settle in and find its voice after about 100 hours or so. Rolling tubes at this juncture will only confuse the issue further. When I first received mine, I too, felt the same kind of anxiety as it sounded somewhat unbalanced and out of sorts tonally.I was thinking too myself that perhaps I made a big mistake,I was rather disappointed to say the least. So much so, that I put the stock tubes back in the preamp,turned the cd player on repeat and let it play for almost a week before I even went back into the room. The change in tonal balance after 30 or more hours was not suttle to say the least. Not only was it more coherent tonally,but what became immediately apparent was it's superior focus. I don't know the stock 6sn7's that came with your preamp,mine were of chineese origin and are really quite good tonally. A few suggestions to help you get a handle on the voice of the supratek: Tube rolling? Leave the stock tubes in it and roll out the supplied rectifier "ONLY" and replace with a nos equivalent[preferably a mullard]You will probably notice the change immediately however, listen to it for at least 100 hours before changing out the 6sn7's. The 6sn7 will have the largest influence on the tonal balance,more so then any other tube. You will find out that the preamp will improve dramatically after the 100 hour mark and continue to improve even further until 300 hours or more. Once it finds its focus... the tonal balance tweeks and tube rolling flavours suddenly become so much easier to voice in your room.Please, trust me on this, be patient and you will be rewarded. Best of luck.