Supratek Owners Thread

Btw,..  the difference between the 2 is pre circuit.  Chard. hey s a traditional resistor loaded circuit, 2stage, direct coupled.   Cab uses some CCS load,  direct coupled as well.  Both are parafeed output as all Suprateks are.   

@budburma   Yep,  I'm here and happy to help.  Shoot Mick an email and ask for my contact info.  A'gon won't let me post it here.  These units carry a transferable lifetime warranty (provided they hav'nt been modded),  so if anything is wrong due to component failure (somewhat rare) it will most likely be covered.  At the very least I can make sure all is in spec and clean/tighten up for you.

Hey Bob,   I have Mick making me a Pre as we speak (or in que at least, lol).   All Cortese models are Phono integrated pre's.  The price difference ($4K / $7K) is whether or not the phono is a standard CR or the more expensive LCR version and the $500 difference between those is whether or not the chasis is Copper/Chrome or Steel.   Having the phono (Cortese) is not going to make a difference in heat vs a Chardonnay,  it will be negligible.  The phono tubes are rated at ~10k hours as well so they will most likely outlive all the other tubes in use too.   If you don't need the phono section though, then you need to look at the Chardonnay or Cabernet.  After discussion with Mick,  I was led to believe that the difference between the 2 is in the capacitors and iron (transformers/chokes) in use, the circuit is pretty much the same.   The power supply I believe is pretty much the same as well except the Chardonnay has the Tube Regulators located on the preamp box (PS box has just the rectifer)  and the Cabernet has the Regulators located on PS box (3 tubes).   Biggest difference being the audio circuit components.  He told me that the Cabernet, even with some more exp. componets is not necessarily better per-se, but a little different. Possibly a bit more nuanced I guess.  Mick will tell you that all the magic is in the circuit design not fancy components, although he does use quality and nice components even in his cheapest builds.   Hope this helps!  

Shibui,..   I would imagine that the only tube you should pull is the Rectifier which will sever the B+ voltage and reduce the risk of a short when trying to measure.    If you measuring the heater voltage,  all the tubes in that circuit need to stay in place to provide the 'running load' to the transformer.   When you start removing tubes,  the load changes and the heater voltage will start to vary a bit, increase.   Best to talk with Mick again if you have not though.

HighStream,  that was my impression from Mick.   That this new circuit really narrows that gap between components and really just makes the perceived change in components just different not necessarily better.

Tubes,.. all the way.  Only SS component currently in is the hybrid PSA-BHK Pre, soon to be replaced with the new Grange beast that Mick is looking to put back 'on-line'.    Will have a  DHT and 6sn7 circuit that can be flipped between along with the LCR phono.  He briefly mentions it in his latest blog post.  Due ~April/May,..  Amp wise I switch between a Decware SE84UFO 25th Anniv.  and Gerus 300B.   Never personally cared for the sound of SS or PP tube circuits.

@gryphongryph    Contact Mick and get my contact info.  I'd like to discuss your issue a little more but feel like we should take the convo off line from this thread.

depends on your system and what your after.   they are 2 different circuits with the later incorporating some CCS.   The Cab's sound a little more hifi or tend show some more contrast in the music than the Chardonnay.  Thusly I would call the Chard. a bit smoother or even handed across the board,  a little less 'jump' factor if you will.   Both sound amazing.  would really come down to personal listening preference and associated gear and or the direction your trying to move from where your at right now..

I would maybe think the Chard but ymmv.  It's always a personal preference at the end of the day.  Can't go wrong with either.  Maybe start with a Chard.,  less exp. and see if you feel like your wanting of anything.  Most likely will be very happy though.

@gryphongryph   you should not hear any hum from the supply or speakers, save for a touch of tube rush/hum that is normal for a DHT. That hum/rush will be a touch more than on the SN7 output.  Should really only be heard with ears next to the speakers.   Supply (PS) should be almost dead quiet (again) save for some very slight mechanical hum only heard from a foot away (or closer)..  nothing should be heard from a seated position.   Mick was unfortunate with a small batch of bad transformers.  Only 4 I believe.   I helped repair one,  and while it left my bench and system dead quiet (after 20hrs of listening),  it showed up at the owners with noise again.  Turns out he had a bad umbilical cord that did not present a problem to me at all.  I suspect one of the connectors was a lemon.  Mick's soldering is as good as you'll find anywhere.   Mick sent the customer a new cord and the unit is now reported to be quiet and trouble free.     Try this,... completely remove the umbilical  (unattached at both ends, very important)  and if you have a dental pick or large sewing needle (or something similar and metal),..  wedge it in between each metal contact and the plastic shell hole of the connector.  This will help ensure that there is adequate contact tension.   May help,  may not, but it would be a good place to start trying something to see if it makes a difference.   I also think that sometimes in the manufacturing process a little oil gets left inside the contacts and can cause some light resistance issues as well.   Generally some purposeful plugging/unplugging back and forth a bit with connector pin wipe down (rubbing alcohol) can help that too.    
    In regards to the gain.   A gain switch can be added to the SN7 circuit if need be.   I'm in the middle of a move between states right now so my bench is down for the next 6 weeks,  but would be happy to look at adjusting for you if needed when I'm back up and running.   Best,  Johnny

@gryphongryph  the umbilical is made with solid core wire and thus the stiffness. There is a stateside cable company that makes aftermarket umbilical's for the suprateks,... can't exactly remember the name. Audio Revelation maybe..   In this case the hum is going to be related to either the PS transformer  or the umbilical connection...  I'm pretty sure same for @couger4u     def try adjusting the position if the umbilical a little if the hum reappears,..  I'm of the opinion there is some intermittent / light connection issue in the interface.   I helped another owner with exact same issues and a new umbilical cleaned it right up.   @couger4u   read my earlier post to Gryph about how to temp. adjust/tighten the connectors..   very well may help your issue a bit.   @jtgofish and @luisma31   the TJ mesh should only be around 1.3amp.   Few 300b's  will be above 1.5a. (generally only the 'super' 300b's that are rated for much higher plate V/ dissipation)    The pre runs the 300b very lightly...

@alpha_lam  gotta disagree with you on the  'if you plan to own a supertek, be prepared for a very involved experience',..   you bought a used unit and have issues, you are in the minority of owners out there.  If owning a Supra was 'involved' Mick wouldn't have a business. Especially a biz with tons of units out in the field an such a loyal following.   Yes, stock units will present issues from time to time and yes when I have repaired,  I have found a bad solder joint here and there,  it is not the norm though and honestly they have been much older units that have had some very obvious use and been banged around a good bit.  His soldering is excellent and rarely do I ever find bad joints though on occasion I will.   Regardless,  it happens anywhere in this business and more importantly Mick covers any issue on stock units for their LIFETIME.  That's pretty amazing considering the size of his operation.    I'm not aware of him using electrolytics in the cathode of the DHT, much less anywhere in the circuit save for on PS regualtors or B+ filtering in early models.  I have worked on these units with models going all the way back to 2005,..  always film caps and always one on each side of the DHT filament above the center tap.  It sounds as if this unit was modded and someone didn't know what they are doing based on your description.  When I repair a unit,  you would be hard pressed to tell that the circuit (solder joints)  are not original and had been repaired.   It is entirely possible the unit was modded (which it sounds like from your description).   Not to mention that when that unit left Mick's shop,  I can almost guarantee that it did not have the issues you experience.  That type of imbalance would have been easily caught while Mick QC'd the unit.    Anything is possible so I'll stop short of saying it isn't possible,  but I do want to correct you on your idea that Supra's in general require effort to own.  That is just not true as they are created and made correctly 99% of the time.  

@alpha_lam  The filament is run from a regulated DC circuit not B+,.  regardless,  there is a small electrolytic at the regulator output (5V assuming a 300b DHT) in PS box,..  if you are referring to a cap seen in the pre (not PS box) directly soldered to the socket pins this would not be an electrolytic cap and would not be for filament power filtering but would be a bypass cap.  As mentioned earlier there would be one on each filament pin.   Just trying to help you out here as what you are describing is not making a lot of sense from a circuit standpoint.  At least not how Mick builds his circuits..

Ah, I see,.. I’m pretty sure (without seeing a schematic) that cap is feeding a regulator used to increase the cathode voltage of the DHT. It has nothing to do with the filament V if this is the case. The circuit is direct/DC coupled between the 2 stages (sn7/DHT) and the DHT cathode has to be raised beyond what is naturally generated through the cathode resistor/current alone. That cap is not in the audio path at all and should have no noticeable effect on the sound (provided it is installed correctly and working as intended). Obviously in your case, with it being blown, it was effecting the reg that was helping raise the cathode V so yes, it would have thrown the circuit out of spec.
In regards to the transformers, Mick has been using them a long time and found they sounded more ’real’ than most anything else he has tried and lived with. I had the same misgivings as you at first when I realized what they were, very much wanting to see some ’boutique’ brand like lundhal, etc... I have listened to both and others at this point in my Cortese lcr as I couldn’t resist ’knowing’ for myself and being a constant tinkerer the swaps were pretty easy for me. If it makes you feel any better I ended up with the Blue Talema’s back in there at the end of it all. I felt they really provided a more natural presentation of the music. Everyone hears different though. You very well may like a slightly different sound/presentation that swapping them will provide. I do think that if you make the change you will realize with a little time that the Talema’s are really spot on and excellent when used with Mick’s specific circuits. Best,

DC after the reg is already smooth. (that's what the reg does, ;-)) those 10Kuf help knock the ripple down before the reg so it doesn't work as hard and produce as much heat.   Again,.  I suspect it is tied into the supplemental V circuit used to boost the cathode V,.   Anywho,  sounds like you got it sorted and working.

I try all kinds of different configs, including messing with and adjusting the feedback..  can't help myself.   Lundhal,  Jensen, some hammond are what I've tried,  some with air gaps, and some without (purpose built for parafeed).   4:1 and 8:1 ratios are what you need to look for. I  prefer the 8:1 as the circuit already has alot of gain.   Keep in mind that these are configured as parafeed (no DC current) so you don't have to worry about any dc current spec on the tranx.   Unfortunately don't have any of the really nice trans like hashimoto, tango, etc..  laying around to try.  Honestly though i doubt I would like them enough more to justify the cost but ya never really know till ya try,.  plus most of those are all big units with air gaps which are not needed..   Anywho,.  feel free to PM if you have any specific questions about the circuit,  I'll try to help the best I can.  Don't want to continue to junk up this thread with repair related posts..  Best,

@couger4u ,   start with no inputs (no sources plugged  in) and only the output connected to your amp.   If you have a couple shorting plugs you can use on the  'selected' input use them. With the vol. dwn if the amp is quiet and there is no more hum from the speakers (there will always be a tiny bit due to the tubes) then your issues lies a source component and the connection between the pre and that/those components.  If you still have the same hum with the vol down and no inputs connected there is an internal issue somewhere in the circuit.   If it is quiet,  try raising the vol (with no inputs connected).  With a non-terminated (no shorting plug) input you will get some increasing noise with an increase in volume knob,  this is normal (with shorting plugs this would be gone).  You should not hear any loud or disturbing hum though.   Once you have confirmed that it is quiet as described above,  start adding components to the inputs,  1 at a time.  .  Your issue is most likely a grounding issue between the 2.     Any 'mechanical' hum you are hearing from the PS is a completely separate issue.   This can be caused (as mentioned earlier) by wall power or its grounding  or also by the grounding from other components that are connected to the same circuit (breaker).   The PS will always have a little hum.  Nothing you should hear from a seat 8-10 feet away though,  however if you get your ear next to the unit you will hear a little or faint buzzing or hum.  Alot of times this is the rectifier (buzz)  or transformer (hum). Some rectifiers are quieter than others but their perceived noise is also very dependant on the wall power in general as well.   Use the supplied regulators and use a good 5AR4 for the rectifier when testing and listening.   While other tube compliments can work,  it is easy to get some interesting results and subsequent mechanical noise (not from speakers) with other tubes.   Hope this helps a little.  Best,

@couger4u   so did you ever clear up the hum that came from the speakers?    Is the only hum your concerned with now from the unit itself (mechanical)?   These 2 different types of noise/hum would point (seemingly) to 2 different issues.   Have you tried to move and plug the unit in at another location in your house or over at a friends house as previously mentioned?    The umbilical itself I would not suspect as causing the hum as Mick mentioned.  I have seen a case where the connection point of the umbilical (to the case)  caused hum in the speakers and if the umbilical was shifted around that hum would cease,..  This (umbilical) is not related to mechanical hum from the PS itself though.    I think you need to completely rule out the power in your house as a cause for the PS mechanical hum you seem to be referring to above though. 

@couger4u    In regards to the gain control.  This is essentially a volume control placed at the end of the signal chain.  The main (front panel) volume knob is placed on the input, before the 1st tube stage.   If the 'gain' is engaged and the knob is fully counter-clockwise,. it is the same as not being in the signal.   As Alpha is saying,  if the noise is inherent in the circuit (and there's always some though typically very low),  the relationship between the noise and vol. controls (including gain control) will be the same.  ie,  lowering the gain will seemingly lower the noise but you would need to raise the main vol. back up (thus essentially increasing the noise) to make up for the lost gain.   One thing to keep in mind here,..   the pre's are very high gain to begin with.   It takes very little input to get a big/healthy output,  so the hotter the input signal from your source,  ie, 2+ Volts,   the less range you will get out of your vol. knob (regardless of using the gain control). This is also compounded by the amp sensitivity.  The gain control is useful in situations where the amp has a very high sensitivity and if the source has a hot output in the >+2v range..   You must be careful though to not reduce the gain so much that for a hot input/source you end up allowing too much signal (Vol. knob turned way up) into the 1st stage of the circuit.   This is when/where you will start to get some induced distortion as Alpha mentions.   If your curious as to test the inherent noise of the pre in relation to your amps sensitivity,..   turn the gain off,  if your pre has a gain switch in addition to the gain control knob, use the switch to completely remove the control knob from the circuit;  Once done,  select a input/source but do not 'play' anything.   Turn the volume control up until you start to hear the noise in the circuit.  Mark this spot on the volume knob.   Now,  turn the volume back down,  play something from the source that is selected and raise the volume knob back to the marked spot.  If the pre is functioning correctly and the noise is in the normal range (ie, no problems with the circuit) then the music should be extremely loud at this point and WAY over the noise you heard in the previous test.  As mentioned earlier this is VERY dependent upon the sensitivity of your amp.   If you have a solid state amp that has a very high sensitivity, ie, ~500mv   then   you will start to hear the pre's noise quicker within the volume range,  but the vol. control will also have less range unless the gain control is engaged a little.   A little gain reduction here could be useful but I would caution against using to much,  especially if the source has a very hot/high output.   For what its worth,  I have found that operating the Volume control in the 8-11am range is optimal,.  generally speaking of course).   Hope this helps a little.

The 6J5 pulls half the heater current (.3ma) of a SN7 (.6ma)..   BUT, you have 2 of them per channel vs 1 sn7 so the total heater current draw is the same.  This does not effect the longevity of the tube provided it is being run at or close to the 6.3V spec.    In regards to the circuit and how the tube is driven/operated (ie, B+/bias),  it will be very similar as to how Mick runs the SN7 based pre's.   All in all,  they are all run very conservatively.    You'll find that any NOS tube stock (generally speaking),  especially that from the 60's and before to have very long life in Mick's pre amps,.. Tubes just aren't made like they used to be.   Newer Chinese manf. stuff,  not so much.  They can die (and do) with very few hours on them (comparatively speaking).

I do,..  Cortese LCR,  but am going to move to a Grange when Mick has time to make it.   Also have an older Chardonnay I picked up that I am currently refurbing to bring up to current spec/circuit.   It doesn't have a remote so will probably add that as well.  May keep, may sell once I'm done.  Not sure yet.   I handle most of the state side repairs for Mick to keep owners from having to ship all the way back to AU. My bench/services have been down the last 3 months due to a move but am back up and running now.    Generally speaking, his pre's are very solid and rarely need work.  He did have an issue recently with a bad batch of transformers that caused him a nightmare.  That has since been sorted out though.  I believe that there are a few users that posted here who unfortunately had some of those units (only about 6 in total,  a few made it to the US)..

Hey @markusthenaimnut    I dont believe that I have listened to Chenin specifically.   I have had a few of the older units,  Grange, Syrah and Chardonnay come through.   They all sound wonderful once within spec.   Without seeing the insides,  it's hard to know what was used in the build and or the circuit Mick used at the time.   Some of the older units had Electrolytics in the PS and there is a possibility that it could be close to time for a refresh there.  Any of these like this get replaced with good PP's that will last till the end of days.   Beyond that,  Mick's circuits are solid and I wouldn't expect any issue unless a CCS fet failed (if used) and even those are almost bomb proof.   Back to your question though,..    what I have found is that the older designs (generally speaking) compared to his latest stuff have a little heavier or thicker sound to them.  Not in a bad way but maybe just not quiet as resolving or having that 'nth degree of jump factor.  At this point its really getting down to system dependency and what works better with the associated gear.  I think anyone could live happy with any of the circuits including his older ones,..    The difference is more akin to spice selection when cooking..

@markusthenaimnut  in regards to your ques. above.  I've been running mine (LCR) for the last 2 years without issue.   The pre will stay on for 8-10 hrs at a time on a regular basis.   No small tube failure yet.    I have found that I prefer the 6n6p in the phono though.  Have used 7308 and the supplied 6h23.    In an earlier conversation with Mick he did mention to me that he had started to see a higher failure rate than expected with the 6h23's he was supplying for a while and recommended switching them out although I'm having no issue with mine yet at the moment,..  It's possible that the one 7308 you put in was already on the fence.   Just about imposible to tell with tubes.   I will say that the heater voltages are always spot on as they are regulated and the circuit does not put alot of stress (V/ma) on that tube (any of them for that matter).   May be nothing more than a bit of bad tube luck.  I do highly recommend trying some 6n6p if you haven't.  A touch less gain but that's rarely a problem in a Supra..  If you feel like somethings out of whack or are overly concerned I'd be happy to take a look for you and make sure everything is in spec.

@luisma   probably isn't but only 1 maybe 2 of the new Grange pre's with their owners yet.   I believe he only shipped the 1st one within the last month.     There's alot going on in that pre and it takes Mick a long time to complete the build.   Hopefully  an owner will post here with impressions but I'm pretty sure I already know how it'll go,.. lol

LOL,  Rumor is correct.  Western part of state in the Blue Ridge Mtns.

If next to each other,  I would give them at least 6' of space.  In that it is a transformer coupled design (output)..  those OPT's will pick up any stray/strong EM.    Generally not a huge concern but the PS is just that and you wouldn't want them practically touching. 

[email protected]

Get a pair of EML 300b’s and be done with it.   Superbly built,  very rugged, sound amazing, have a 5 yr warrenty and are on par with Elrog and WE at a better price.   

PM sent..

Make sure the center/rear toggle in front of the gain knob is positioned towards the front of the pre (or make sure the knob is fully clockwise),..  Other posibility is that the V switch for the DHT is incorrect.   If you are in fact using a 300B (NOT 45),  try the switch in the other position,..  no harm as the 45 only gets 2.5v (not 5v)..    this can also be (very) carefully measured with a dmm by lifting on the DHT out of the socket just enough to probe both of the 'large' pins.  DMM set to DCV.   Should see 5v. make sure the probes DO NOT touch other pins or chassis.    Also make sure your input selector is correct.  if using the first rca /input   selector should be in the 2nd position.

The EML 45's are great,  running a pair of the 45 Mesh on my Grange.  Wonderful tube!

Jack summed it up nicely.  Smooth/classic vs. more dynamic/lively.   Its subtle but instantly noticeable and interestingly both still very much retain that ‘Supratek’ house sound.  Mostly likely due to the regulators.  A feature very few other builders incorporate.  Couple that with the ease of repairs due to P-P wiring and you have sonic pieces of art that can literally be handed down for decades to come and will sound as good if not better 50 years from now with only some very minor maintenance. 

Nah,.. you dont understand the PS, and how its built.  There is very little difference if any between the  chardonnay / cab PS.   The main PS feeds the tube regs which make it what it is and do the major cleaning/stabilization of the V feeding the circuit.  The main difference people see in the 2 models is between the regs either being on the pre or located on the PS.  It is purely cosmetic and he actually makes the cab a lot of times with the regs on the pre chassis.   The PS circuit for both is the same.  Adding in a boutique cap in the PS before the the regs is honestly a waste of money as well.  My opinion on (and his) on using fancy parts in areas that they wont make a difference.  I’ve been lucky to hear a ton of his amps in just as many configs including ‘tricked out’ PS’s etc,..  it aint worth it and the reliability drops. 

The Chrome is plated over a copper chassis.   He used to offer a straight copper that was polished (pics on his website) but did away with it.  There is a ‘antique copper’ finish that is more a copper/hammertone type finish over a copper chassis. It looks really good.   The powder coat finishes are all on steel chassis.  Both will give some level of shielding as they are grounded but the copper gets the edge there.  I think you’d be hard to tell a diff. in SQ between the 2 honestly.   Get what looks best to you or works with your budget.  

They do take a little time to settle in when new.   You'll notice a nice difference within a couple days (20-30hrs),.  Those Output transformers need a little juice running through them to open up.. The supra's also like to be at stable operating temp to sound their best too (~45 min. on)..  A little congested before that point.   The 6n3c is the Russian eq. of a 6L6..  I personally like the 5ar4 (gz34) and 5u4gb rectifiers but you'll find a big difference of opinion on what people like.  If yours cab is a 6sn7 standard (ie, no DHT),  then your rectifier choices are pretty wide open..  just stick with the typical 5volt heater variety,.

@tksteingraber   You will hear a little crackling when the remote is used due to the motor interacting with the high gain circuit.  You should only hear it while the motor is turning the vol up or down (remote) though.  Should stop once you take your finger off that remote button.    Sometimes if you have a cell phone near (~3') of the pre,  the pre will pickup some rf from the phone and you could hear some cadenced ticking and or a little static in the background.    IF you hear/get the crackling from the volume when manually engaging the control at the unit, I would suspect a dirty pot,  but these are sealed so not much you could do about it other than replace.   If it's silent other than when turning up/down manually,  I would worry with it. Won't harm anything.

I have found that a good 50hrs seems to open up the OPT's,..  I always hear a difference in the first hour as the unit gets hot and temps stabilize.   Tubes can be hit or miss with their own break in,..   some don't require much time and some do,..  doesn't really matter the brand, age, etc..  this is more specifically to the output tubes,  not rectifier or regulator tubes..   If you hear the center or imaging shifting back and forth some,  thats the tubes..   They generally always settle in at some point.  I have had some that were stable for the first few hundred hours and then shift only to restabilize and lock into place.  Kinda crazy but nature of the beast if you will..   GZ34 (5AR4) should last many thousands of hours,..  5k at least if not 10,..   the power supply on your unit is pretty easy on them,.  The dht cabs pull a bit more current but a straight SN7 cabernet is a pretty light load. 

The balance shift is slight.  The control is not implemented in the traditional style where it is another shunt to grd. in addition to the Vol. pot.   Mick does this purposely because there is less degradation to the signal but the caveat is that there is less total shift to either side.  There is also the thought that if you need to shift the balance more than 6db or so left or right (for whatever reason) then something in the setup or associated gear is wrong and needs to be reevaluated.   Alot of pre’s completely omit a balance control these days. I think that is a mistake as there can easily be situations where a slight shift is needed, especially with tube gear.   As tubes age and get hours on them there gain can shift slightly (or more) over time and some balance shift may be required to recenter the image.  Hope this explanation helps clear any confusion.  

The original dual was adjustable on both channels.  His current version 300/SN7 is adjustable on the 300b. SN7 is only main VC.    @Gryphongryph ,  does the gain adjust the sn7 output ?   Regardless,  if your losing a channel when you engage it,  something is up.   Possibly the switch.   If your in the US you can send to me if need be.  Contact Mick for my info.   Swap tubes side to side first though just to be sure.  

The XLR in is transformer based so yes, it is a true balanced input converted by transformer to single-ended for the circuit.    The circuit itself (gain stages) are not balanced.   The output is transformer based as well and able to truly balance the signal or send out via single ended..

There is a 'mute' switch, yes.   but you have to engage/disengage it manually.  Not automatic at startup/shutdown.

Congrats!  I have one here.   A very good circuit without doubt.  

depending upon the 300b tubes you have installed maybe,  maybe not..   you need to measure.  the dimensions of the GF tube are given at the site.   

Honestly @tksteingraber  I wouldn't worry about asking Mick to send replacement sn7's.   Your better off finding some good ole NOS USA (or new/current) ones from a reputable local (US) source and going that route.  Things take such a beating these days during travel and it's a long trip from AU.   A decent pair will cost you about the same as his shipping cost to you..

As @isaacc7 mentioned,  Mick stopped making them back when Covid hit due to an extremely high backlog of Pre's need to be made.  I believe orders have since slowed down a little for him and I'd be willing to bet he would make or certainly consider producing some amps now if anyone was/is interested.   Certainly  reach out to him and inquire if so.   His amps NEVER (very rarely) show up on the the used market.  You can probably guess why,. ;-)