NOS tubes for Sonic Frontiers Line 1

I just recently bought a Line 1 here on the Gon, Sounds great, but, I would like to do a little experimenting with some NOS tubes. I under stand the back two tubes make the biggest difference.
I would appreciate any suggestions? It now has the Sovtek 6922 stock tubes.

Thanks, Jim
I have not owned the SF Line 1, and connot comment on the specific preferences of that pre. However, two good places to look for info about and comparisons of the various memebers of the 6DJ8/6922 family are:

I don't know the tube complement of the Line 1, but if it includes 12AU7's, IMO, Joe's discussion of that family is a bit short. There are other more detailed threads on AA.

I have a Line 1 (original owner). I recently replaced the tubes with electro-harmonix... which I'm not real happy with. I have one set of matched Amperex gold pin 6922's that I was using in my DAC which I tried in the Line 1. What an improvement. I've played a little with which position is the best. I just started that, but so far any position works well. I'll let you know when I have more definitive answer.

I'm in the process of getting 6 matched pairs of Ei's (which are much more reasonable priced than the Amperex's) to replace the electro-harmonix. The Ei's are suppose to be very good. I'll let you know how that goes (I should know in about a week).

Jeffcott, Thank you for your reply. I did check the forums on AA.

Maggie3, thank you for your reply, you saved me some money, I was going to buy four of the electro-harmonix tubes for LV3, V3, LV2, and V2. I was wondering about tubes for LV1 and V1. I seen on AA post someone had mentioned the Ei`s.
I received an email from a fellow member of the Audiogon and he also recommended the Amperex tubes.

Well I ended up buying two matched pairs of used Amperex PQ 6922 gold pin U.S. made Orange label tubes. Just couldn`t justify the higher priced white label Amperex tubes. I want to thank Bill, a Gon member, for putting up with all my email questions, he was very helpful. And I also would like to thank "Sam 1104" I am sure I was becoming a pain in the butt with all my questions. Sam answered every one. I learned alot from Sam. I highly recommend buying from him.
I am looking forward to getting the tubes and hear how they sound.
I am glad you are enjoying your first steps into tube enjoyment. It can be quite addictive. I fully understand your feelings about White Label USA PQ's, which are the next on my list. I currently have Holland Bugle Boys and Holland Orange Label PQs. Comared to what is considered "the really good stuff", the White USA PQs are actually quite reasonable in price. Enjoy!
Forgot one thing......based upon my experience I have found absolutely wonderful benefits with tubes using good isolation and dampers. I am currently using Townshend Seismic Sinks (need one more for my pre) and Herbie's Tube Dampers everywhere there is a bottle. The benefits of the Sink under my tube DAC was absolutely eye opening. Can't speak for your equipment in terms of reaction to dampers, but in my pre (a PSE HL1) the improvement wrought by putting the Herbies Dampers on a pair of Holland Bugle Boys was really dramatic.
I also have a Power 1. Soon after purchasing it I started tube rolling. Right now I'm using EH kt-88, 2 BB-6922, 2 EH 6922 and 2 BB 7308 in the drivers.

From what I read, the 2 rear drivers have the most impact on the sound, so I started with the 6922's. With my equip (AR LS2MKII w/ 6922 PQ, Jolida jd-100 w/RCA 5751 blackplates and Dahlquist QX-10) the system sounded decent.

Interestingly, when I moved the EH 6922 into the rear drivers the sound stretched vertically, and became much more 3-D. Go figure.

I used to be a professional artist, and since getting into tubes I've discoverded each tube-type I use colors the sound, differently.

So much fun, but oh so costly, sometimes. When my wife returns my charge card I want to try out a matched EIkt-90 quads.

Anyway, enjoy your Power 1. I think mine is boss!
I got my tubes today. Sound, Incredible!! Just can not believe the midrange.
Jeffcott, I ordered the Herbie`s tube dampers. Should get them this week..

Jea48: Based on your posts are you saying that the 2 and 3 slots yield the greatest results? The reason I ask is I have two sets of two matched pairs (Electron Tube, Russian) and Amperex Greens, as well as a complete set of 6 Amperex JAN 7308 Greens. All of the tubes came from Upscale Audio where the Line 1 was originally purchased. I started playing with rolling the tubes over the weekend, but wasn't quite sure what to do with just a set of 4. Sounds like I can still play.
Please post your observations when you get the Herbie's Dampers. I am interested to hear how you like them and what changes you observe.
The 2 tubes in the far back row Will yield the biggest change in sound, LV1 and V1.
Next is the middle row, LV2 and V2.
Front row, LV3 and V3 least effect.
I learned this from Bill and Sam.

Question for you. When not listening to your SF preamp do you put it in standby or shut it off completely? Looks to me that standby shortens the tube life. Is that right?

Jeffcott, yes I will let you know.

I've had this pre for about 2 years. It's my first tube based piece of gear. The information I've come across during that time suggests that putting it into standby is a trick used by SF to increase tube life ( as opposed to leaving it on all the time). Supposedly it runs at about 10% of the normal operating mode while in standby. I've seen this number referenced by more than one person. The only time I completely shut mine off is when I'm going out of town for the weekend. Mine is tied into my HT rig so between listening to music or just using the HT bybass to watch TV/movies it's on every day. I would think turning it on and off daily would do more harm than just leaving it in standby when I'm not home. Recently music has started to sound a little dull and lifeless so I decided to break out of the extra tubes that came along with it when I purchased it from a gentlemen here on Audiogon. The tube life of the Amperex's is supposed to be 10K hours, that's about 2 years. So I'm going to see what type of changes I can hear from trying out the different tubes, including the stock ones. Hopefully my tubes are still good and I don't have to dip into my stash, but we'll see. I can post my results if you like? It will be a week or two before I will have meaningful information. Please update the thread when you have some info on the tube dampers, I've never heard of them before.
Snipes, I posted a question on AA...Tubes...On 02-05-05.
"Sonic Frontiers Line 1 standby, shorten tube life"? Check it out. Sam 1104, who I bought my tubes from has a line 2 and he turns off his unit also. I am now shutting my Line 1 down at night.
Jea48: I posed the same question to SF tech support yesterday before I read your response. I'll post their answer when I receive it.
Does anyone have a "good" source for a few Amperex 6922 usa PQ's.Thanks>
They came today in the mail. The Herbie`s HAL-0 9 tube dampers. Sound, Tightened up everything. Cleaner, more focused. I do think I lost a tag of the bloom, but I think It needed to.

Sirspeedy, If you have not read "Joe`s Tube Lore" I highly recommend you do. Go to, Audio Asylum...FAQ...Tubes...Joes Tube Lore...6DJ8, 6922, 7308 saga part 1 and part 2. Great info.

I bought my Amerex PQ tubes from "Sam 1104". He has used NOS, and new NOS, NIB 6922. You can see his adds on Audiogon. Send him an email, He knows Tubes!

Here is the reply from SF Tech support concerning what happens during standby. It seems to match up with what has already been posted here and on the AA thread referenced by Jea48, but it's always good to hear it from the source.

First response:

Standby mode leaves the filament of the tubes running, so when voltage is applied to the plate (i.e. when switching on operating mode) the tube is of course already warm. When voltage is applied while the tube is cold, the cathode gets stripped of electrons rather quickly (especially if signal is applied at that time). Kind of like heating and circulating engine oil before cranking the motor in freezing weather.

Second response when I asked for clarification on a few points:

When a tube is running, voltage is applied to:

1. filament, because tube needs heat to run

2. plate, to give the tube a charge

3. grid gets negative bias - think of it as the spring on the accelerator pedal without which the engine would self-destruct

There are other grids in output tubes but just covering the basics here. In standby mode, only voltage #1 is applied. Standby mode increases tube life simply by keeping tube warm all the time. The rest of it is off.

In HT pass-through, tubes are in operate mode in case you want to change inputs back and forth.


Hopefully this was informative for someone other than just myself. I'm still not 100% clear on whether or not leaving it in standby mode cuts down on the tube life. For example, does 1 hr. in standby mode = 1 hr. of music listening? If not is there a ratio? My tubes supposedly have a 10K hr. life expentancy, is that 10k of music listening or just on?
Well I am now looking at an early 60s matched pair of Siemens E188CC 7308 gold pin NOS tubes. I want to see if I like a warmer sound. Any opinions? This tube rolling could become addictive.
Have any of you experimented with the placement of tube dampers on the tubes? 1/3 down from the top, verses half way down from the top, in the middle. I swear I can hear a difference with the Herbie's tube dampers. 1/3 down tighter, half way down warmer. Is it my imagination??
Tubes came today. Did not get the Siemens E188CC 7803. By the time I made up my mind to buy them they were gone, already sold. I bought a matched pair of Siemens CCa gold pin tubes from the 60s. The sound, different from the Amperex PQs. The CCas are warmer, I think smoother, Still eary to tell. Little hard to do an A/B comparison with tubes. So far I really like the CCa. I will report back in a couple of days.

Well, I like the Amperex PQ tubes better. The PQs are cleaner, quieter, more lively than the Siemens CCa. The CCa is warm and smooth but I found myself dosing off.
Now my search for a matched pair of USA made white label Amperex PQ 6922 gold pin early 60s.
Anybody want to buy a pair of very slightly used NOS NIB Siemens CCa gold pin tubes?

Jea48,Both myself and a pal are on the prowl for 6-12 Amperex PQ 6922's.May the best man win the race!!!
I owe the Siemens CCa tubes an apology. It took about 25 hour of break-in time for the CCa to start to open up and come alive. I now have about 30 hours on them and I am impressed. So much so I cancelled my add on Agon. I couldn't replace them for the $180.00 I was asking. After I get about 50 hours on them I will compare them again to the PQs. I will report back then.

In my system the Siemens CCa sounds best. To think I tried to sell them. Compared to the orange label USA made Amperex 6922 PQs the CCa is cleaner, quieter, more air, larger sound stage, deeper tighter bass. I cannot speak for how they would stand up to the early 60s white lable PQ 6922 USA made tubes. This is after 50 hrs on the CCas.

In another subject I have been emailing back in forth with an Agon member that has a line 1 preamp. The topic was which tube spots were the most important in the Line one. He emailed "Sonic Frontiers" and they told him the second row LV2--V2 would yield the greatest sound difference. I was confused to say the least. I even changed the positions of the CCas and the PQs to have a listen. Needless to say I did not care for what I was hearing. In our emails I asked him to email Chris Johnson at Parts Connexion about the tube positioning. I mean who would better know than the designer. He emailed me back, Chris said the back row first then the second row then the front row. That made sense to me, that explained the difference I heard when I switch the tubes around. I asked him if he would post the great info he got from Chris Johnson, I hope when he gets the time he will. Bill, a fellow Agon member is using a pair of early 60s 7308 Telefunken in the back row. Might have to try that.

My tube placement now in the Line one,

LV1..V1... Siemens 60s NOS CCa 6922 gold pin tubes.

LV2..V2...Amperex 60s NOS PQ 6922 USA gold pin org label.

LV3..V3...Amperex 60s NOS PQ 6922 USA gold pin org label.

My system,

Arcam Alpha 9 CDp
AudioQuest power cord
AudioQuest Diamond X2 ICs

AR ES-1 TT, Rega RB300 arm, Clear Audio Aurum Beta Mk 2 cart
Grado PH-1 phono preamp.
AudioQuest Lapis X2 ICs

Sonic Frontiers Line 1 preamp
AudioQuest Diamond X2 ICs
Audio Research VT 50 power amp
AudioQuest Sterling 3 ...8' pair speaker cables
ProAc Studio 200 loudspeakers

3 dedicated circuits with hosp grade 20 amp levington duplex recepts, on the same phase in the panel.
Well here I am again. I bought me a matched pair of new NOS Early 60s Amperex 7308 PQ USA tubes. The first pair I received early this week. Turns out after just a few hours of time on them, one of the tubes became noisy, Microphonic. I bought them from Mike Miller, "Fat_Cat", here on Agon. I emailed Mike about my problem and Mike immediatley sent me another new pair, which I received today, {Saturday 3/26/05}. That is what I call a quick turn around. He said return the other pair when I got the time. I highly recommend Mike if you are looking to buy tubes with no worry.

I did get a chance to experiment with the Herbie's Hal O tube dampers on the microphonic tube. I found the Hal O helped control the noise best at just slightly above the top third of the tube. And also where the pads rested against the tube would make a difference. Even the tightness of the Hal O against the tube made a difference. Tighter was better.

The sound, how do they compare to the Siemens cca, I will have to report back later after I get about 50 hours on them.

Hi Jim, Lawrence here, the guys who sent you email regarding which pair of 6922 in Line 1 affected the sound most. As I mentioned to you I have both old Siemens CCa and Amperex 7308 PQ (white label). I been plucking in and out on both type tubes on both my Line 1 and Power 2. At the end of the day, I prefer Amperex 7308 PQ over Siemens CCa. Amperex sounded more full body and a touch of warmness as compared to Siemens CCa. Siemens sound clean, accurate, airy high and better control of bass but overall sound is kind of lean as compared to Amperex full body sound. Hard to put them in word, anyway, I prefer Amperex over Siemens CCa in my system. I let the Siemens CCaa sitting in SFCD-1 at the end of day. And last but not least, the white label certainly sound better than the orange label. Will continue with my experiments and post my opinions if there is new findings.
Lawrence, I like both the Siemens CCa and the Amperex PQ USA white label 7308 tubes. Both have their own sonic character. I have been switching them back and forth for weeks it seems. I do like the rich warm sound of the CCa on vocals. It is a tough call for me to say which sounds better. I do agree the orange label USA PQ 6922 is no match for the early white label USA PQ 7308 tubes. I wasted my money on that one.
What are you using for tube dampers. especially in the back row, LV1-V1?

I read your recent post, why are you thinking about a SS power amp? If you want a more SS sound from your power amp you might want to try electro-harmonix tubes. Email Chris Johnson at Parts Connexion see what he says...

So for now I have the CCa in the back row LV1-V1. The PQ 7308 in LV2-V2. and the orange label PQ in LV3-V3.

I am now looking for a matched pair of Telefunken E188CC early 60s. I want to try them in the preamp next.

My quest for the Telefunken E188CC, I am not having much luck. Them puppies are expensive! I have found a new matched pair of E88CC 6922 gold pin diamond bottom late 60s. Question, are Telefunken tubes like the Siemens and Amperex tubes where the early 60 tubes sound better than the later 60 tubes? I am hesitant toward buying them without knowing... I made that mistake on the orange label Amperex PQ 6922 tubes.

Jim, I suggest the next group of E88CC/6992 you should try out is the Holland made Philips. I managed to get hold of 3 types of Holland made Philips and my comments are as follows:

(1) Philips E88CC SQ - Same construction as Mullard E88CC, from what I know, Mullard have no plant in Holland so Mullard E88CC most likely made by Philips Holland plant. The sound is refine with good details. Soundstage is quite wide but slightly lack the warmest of tube sound.
(2) Philips E88CC CCa Miniwatt SQ - Great tube! details, dynamics and musical engagement first class. Sound have the magnet feel.
(3) Philips 7308 SQ - Quite similiar to no. 2 but slightly lost in details and also bass is slightly lesser. Overall a very good tube.

Okay, that my comments on Philips E88CC, I hope this is useful to you guys out there looking 6922 replacements.

Jim, as for the reasons for getting a SS amp to match with Line 1, I heard one of setup using line 1 with pass labs amp and it sound beautiful and yet have dynamics of a SS amp. I was thinking to myself that maybe it is time to replace the Power 2 with SS amp.

P.S Forget about Telefunken, they are over price for their performance. I think the price is so high just because it is rare and not because it is the best. My next group of E88CC/6922 to try is Europe made Tungsram and RTC.
My Telefunken E188CC tubes came yesterday, 5/27/05, in the mail. I just could not wait to give them a try. I installed them in the "Line one" back row , installed the Herbie's Hal-O damper at the same level as the upper Mica Wafer. Turned the system on, loaded a CD, set the CDp to repeat, and let the system warm up for about an hour.
After about an hour I sat down for a listen. First impression the tubes sounded a lot like the Amperex white label early 60s PQ 7308 USA tubes. I listened for about two hours. Listened to about five CDs for comparisons. As I listened It seemed to me the tubes sounded to be a little too dampened, seemed to lack Air...The herbie's Hal-O dampers! I pulled dampers off and begain to listen, there was difinitely a difference. More Air, more life like. But I also noticed the vocals were not as smooth and less focused. Bass was not as deep and full, highs not as controlled as they were with the Herbie's on the tubes. I experimented placing the dampers at different locations on the tubes. To make a long story short I found the sweet spot for at least this pair of E188CC tubes. At the top of the tube, just before the tube curves in, to make the top point.
The sound, I listened for about three hours, These tubes are detailed, focused, with a nice smooth full midrange. Diana Krall's piano sounded accurate, natural, full bodied, with authority. Bass was deep, controlled, and full.
One thing for sure about this tube, it Fast and Lively.

These are the CDs I listened to;

Diana krall "Love Scenes"
Diana Krall "The Girl In The Other Room"
George Jones "Cold Hard Truth"
Dire Straits "On Every Street"
Alison Kraus "Now That I've Found You"

Comparison to the Siemens CCa or the Amperex PQ tubes, that will be the tough part as usual but I think the Telefunken will hold their own. The Telefunken E188CC are keepers.

Jim,I'm glad you are getting a high level of sound from your tube investment.My pal got ripped off on some poor TELE's,so as you know,you must be careful who you buy from.

I just put the Halo Dampers on my phono tubes,last week,with similar results to you,but found that with careful placement on the tubes,and less arm damping,I greatly increased tonal purity.I am in the process of doing some tube rolling,my friend did eventually get Amperex 6922 PQ's,for his phono section,and I am about to empty the bank on some really choice Siemens CCa's.I know I'm paying serious bucks,but I simply have to know,in my own set-up how these fare against my Ediswan 5358's,which have served me well.Good luck!
Sirspeedy, Siemens CCa early 60s tubes, do your home work... Ask lots of questions. Ask for pictures. Here is a Great picture;
Here is a response I posted on another members thread.

09-19-05: Jea48
Gsselling, I spent most of yesterday experimenting changing tubes around in my Line 1. Lately I have been running a pair of early 60s NOS Siemens CCa tubes in the back row LV1 & V1. In the center row LV2 & V2 a pair of Amperex early 60s PQ USA 7308 tubes.
I moved the PQs to the back row and the CCa tubes to the center row. I new I would here a difference and indeed I did.
I listened for about an hour or so. Then I pulled the CCa tubes from the center and installed a pair of Telefunken E188CC tubes. I had interchanged the Telefunken E188CC and the Siemens CCa tubes in the back row enough times I new what to expect in the difference in sonics between the two tubes. I turned the Line one on and let it warm up for about a half hour. I then sat down for a listen......I listened for about an hour. Playing the same CDs I had listened to with the CCa tubes. The differences were still there but on a larger scale. Confused, yes...I pulled the E188CC tubes and reinstalled the CCA tubes. Turned the preamp back on, waited about a half hour and sat back down for a listen. The difference in sound between the two pairs of tubes is definitely more noticeable in the center row, LV2 & V2 than in the back row LV1 & V1.

Last night I sent an email myself to Chris Johnson.

Mr. Chris Johnson;
I know you have probably answered this question in the past several times. I
am of the understanding that the order of importance of tube placement in
the Sonic Frontiers Line 1 and Line 2 is as follows,
LV1 & V1..... most important will yield the biggest change in sound.
LV2 & V2.....Second most important.
LV3 & V3.....least important.

I have the Line one and have been installing the best of breed NOS tubes in
the back row, LV1 & V1. Early 60s Siemens CCa, Amperex White label PQ 7308
USA made, Telefunken E188CC, and Telefunken E88CC tubes.

Someone just posted a thread on Audiogon saying that "Sonic Frontiers" says
the center row LV2 & V2 will yield the biggest change in sound followed by
LV1 & V1.

Chris will you settle this once and for all. Who best can answer this
question but you the former owner and designer, of the Sonic frontiers Line
1, 2, and 3. Will you please give the reasons why.

Also would you mind if I posted your answer in quotes on Audiogon. I will
only post that part of your answer that you approve.

Thank you very much for your time.

Left my Full name
Audiogon user name jea48
My email address

A simple answer, unsigned:
>"LINE 1, Line-2

Most important.....gain tubes V2, LV2"<
A reply email address,
Information []

Jea48 (Threads | Answers)
(edit my post)
I like amperex holland orange globes in my line 1-- they beat out mullards, valvos, bugle boys, and 50s amperex D getters in my system.

Haven't tried the PQs, siemens or teles, but I've got two sets of orange globes in V1-V4 and the quietest valvos i had in V5 and V6. It's working just fine for me.
Well nothing like starting over. In the last three weeks or so I have acquired two pairs of early 60s NOS Siemens CCa tubes. The first pair about 3 weeks ago. Time enough before I was told the center row was the most important on the Line one. Up to that point I was switching out the back row with the CCa tubes and the Telefunken E188CC, Telefunken E88CC, And a pair of 70s Siemens CCa tubes. I was using a pair of early 60s NOS Amperex PQ 7308 USA made tubes in center row.

As far as the back row the Telefunken E188CC and the early Siemens CCa tubes were the best sounding tubes. The Siemens seemed to be a tad thinner sounding than the Telefunken tubes. The back row. Infact I thought the E188CC tubes sounded great. They were a good match with the Amperex 7308 tubes in the center row.

Then the apple cart was upset. Time to start all over. I moved the Amperex to the back row and installed the Siemens CCa tubes in the center row. The sound, the siemens were very transparent, with plenty of air. Midrange was full and focused. Krall's Piano was the best sounding to date. I liked this arrangement better than having the Amperex in the center and the Siemens in the back row.

I then pulled the Siemens and installed the Telefunken E188CC tubes. Big difference in sound in the center row, than I heard in the back row. The Siemens clearly pulled ahead of the Telefunken tubes imo...The Telefunken tubes lacked the transparency and air of that of the Siemens tubes.

I pulled the telefunken E188CC and reinstalled the Siemens CCa tubes to varify my findings. In my system the CCa tubes sound better. That is in the center row.

I also compaired the Siemens to the Telefunken E88CC tubes and the Siemens sounded better to even a larger degree than the differences heard between the Siemens and the Telefunken E188CC tubes.

The worst sounding tube in the center row was the 70s Siemens CCa tubes. Midrange was warm but not focused. Highs were rolled off. Bass was loose and a little muddy. I bought these tubes early in the game and was mislead by a seller here on Agon. I was told they were from the late 60s.

Yesterday my second pair of early 60s NOS Siemens CCa tubes came. I pulled the Amperex 7308 tubes from the back row and installed the Siemens tubes. I will post back the results later.


I'm using SFL-1 hybrid with telefunken 801s...excellent nos. or you may try RCA black plate


I always find the center row affected the sound most which lead me to post the question in this thread before. I also asked around, Sonic Frontiers, PartConnexion, Line 1 owner etc. Guess I am right that center row V2 and LV2.

You tubes setup are very close to mine now, I have the 60's Siemens in V2/LV2 as it gave a better mid and sounded more muscial. I placed Telefuken in V1/LV1 as it gave better extended high (airy). Amperex 7308 PQ white label is now in V3/LV3.

As I mentioned to you before, 70's (with engaged code inside and metal support between plates) Siemens sounded very warm especially the A frame type. As for the 80's (just a thin metal bar support the halo above plate) Siemens, you cannot forget it. Not worth trying at all. The 60's (no engaged code inside and no metal support between plates) Siemens sounded the best in my system.

I am still having fun playing around with different combinations and I have purchased a rare pair of Brimar CV2492 recently. It will be interesting how it sound.

I just experienced my first NOS tube failure. One of the Siemens early 60s CCa tubes. The bad tube was installed in the center row of the line one, V2, right channel.

Here is what I experienced. When switching line inputs from the front panel I got a popping sound through the right speaker. Scared the hell out of me to say the least. Also up close I heard a slight fuzzy sound comming from the right speaker. I had pulled the CCa tubes earlier and installed a pair of early 60s Siemens E88CC I had just received. I listened to the E88CC tubes for about an hour and a half. I pulled the E88CC tubes and reinstalled the CCa tubes. I powered back up the Line one, when I pushed the line input for my CDp, thats when I heard the pop... Like a dummy, I pushed one of the other line input buttons to confirm what I had just heard...

I pulled the tubes one at a time and tested them. The bad CCa failed in section 1 of the dual triode tube. Section 2 still tested strong. The puzzling thing is section 1 does not show any shorts or grid emissions. I did not take a listen after the problem, I did not want to take any chances of damaging something.
This tube was from the last pair of CCa tubes I had just bought. I had maybe 150 hours on them.

I then reinstalled the early 60s Siemens CCa tubes that I had installed in the back row, and installed them in the center row. For the back row I installed the Siemems E88CC I had received today. Powered up the Line one, no pops when switching the line inputs system sounds fine.

Any thoughts? I handle the tubes like a new born baby. This is a first for me with an NOS tube.

I know this answer is late to your original question but I used to own a Line 1 which I purchased from Kevin at Upscale Audio. At that time I had asked Kevin for some NOS tube recommendations for it. He suggested an Ediswan 6922 from the 1960's and I purchased a pair. I tried tons of different tubes in my Line 1 but kept putting the Ediswan back in. Ediswan are hard to find on the used market but if you every get a chance, try a pair, they were very good IMO.

Good Luck and sorry for hear of the CCa failure, a hazard of the hobby.

I just replaced the 6922's (all 6) in my Power 2 amp. I put EH 6922 Gold Pins in there, to replace Siemens NOS ECC88's. The EH tubes sound a bit darker, but the bass is much better. I miss some of the openness in the midrange and treble with the Siemens, but I'm very happy with the EH, nonetheless. It's good to find a tube you can be happy with that is also in abundant supply, IMHO.

Also, I can see unequivicolly that the EH Gold Pins are far superior to the standard EH 6922, which was the stock tube in my Blue Circle pre-amp.


I finally got around to buying a pair of early 60s USA made Amperex PQ 6922 tubes. Both tubes were made in 1961.

Another great tube. Not quite as warm as the early 60s Siemens CCa tube but still a very smooth sounding tube. The 6922 PQ is detailed, fast, lots of air, and liquid sounding. Imo the bass is deeper than the Siemens CCa tube. The sound stage is wide and multi layered.

In an earlier post I mentioned the early 60s USA Amperex 7308 tubes. Imo, in my system, the 6922 PQ is a better sounding tube. Vocals are more involving.

My present tube placement in my Line One

Back row early 60s Siemens CCa
Middle row early 60s 6922 PQ USA
Front row early 60s Siemens E88CC

Audio Research VT50 Amp
All "EH"
In my last post I forgot to mention I found the best position for the Herbies HAL-O damper was near the top of the 6922 PQ tubes.. In fact I run the HAL-O dampers near the top on all the tubes in the Line One.
Just an update. I have been running early 60s Amperex PQ white label USA made tubes in my Line One preamp for the last few months. I pulled the two pairs of early 60s Siemens CCa tubes I was running in the middle and back rows mainly because of their value, worth. Can you guys believe what a pair of them are selling for now? I managed to buy three pairs before the price went through the roof.
I have been buying early 60s Amperex PQ tubes on Ebay with pretty good luck. I picked up a nice pair a couple of weeks ago for $87.59. They were made in 1961. They tested close to new. I am running them in row two of the Line One at the present time.

About a month ago I picked up another tube tester. If you are buying NOS tubes used or new, you need a tube tester. I bought a Hickok 6000A for a hundred bucks, what a buy.
Hi guys, this post is off subject but just as important. Did you guys read this thread?
Please respond to the thread if you have, or have not, had problems with your Line 1, 2 or 3 volume control on your Sonic Frontiers preamp. Would like to hear of your experiences.