Sonic Frontiers preamps tube eaters??

Just wanted to find out from member owners of Sonic frontiers preamps if they experienced frequently replacing tubes (within months) due to noise (tube rush noise).

The reason I asked is I was told recently by a reputable tube vendor (no need to mention names here)that Sonic Frontiers preamps (SFL and Line series) tend to develop noise even after being replace with NOS tubes. In addition, that by design the unit runs the tubes (6DJ8, 6922, 7308 etc) to their max limits which is the reason for their short life.

He even claims that there are a lot of post on the web about this. I've tried the AA and Agon to look for such specific threads but found not enough evidence pointing to this problem. He claims that the original tubes that came with these preamps were really Russian 6N1P which are very hard to find (re-labeled as 6922)????

Have had mine (Line 2 SE)since 2003 and yes I've gotten tube rush noise (very faint on one side). But this problem can be move to the other side when that tube is moved. Thus the reason for shopping on NOS tubes. The unit performs flawlessly with the exception of the very faint tube-rush noise on ONE side.

Hope to hear from SF preamp owners and Thanks in advance.

I've owned a SF Line 3 for about 10 years and never experienced either premature tube burnout or tube noise. In fact, the Line 3 is amazingly quiet and I've only replaced one 6922 tube so far.
I think I know who you might have spoken with, and that particular vendor doesn't seem to like 6922 tubes, period. If he is the same guy, he did not even want to assist me in retubing my previously owned Line 3 SE. However, that is his choice and I can't really blame him considering the high price of the various NOS versions of that particular tube. To answer your question, I have not heard of SF Line preamps being known as tube eaters and the Line 2 SE and Line 3 SE I owned did not do so. There are other vendors who would be more than willing to help you retube, and you should also not overlook new tubes, which may be quieter in some instances. Also look into which tubes are more important sonically, since if memory serves, you may only need two of the higher priced NOS 6922's in that preamp to get the most for your money, you could use new manufacture tubes in the other 4 spots. Searching here and on AA may give you the answers you want.
I don't know about the Line series, but I had an SFL-1 and now have an SFL-2. They are both very quiet and easy on tubes. I have used new and NOS tubes and had no problems whatsoever.
I have an SFL 1 and have had same tube in it for a year, and it is on 24/7 unless I am out of town, swapping wires or power goes out............if anything I am surprised this tubes has lasted so long, I am using a NOS Valvo Amprex tube from Holland.
I also have a Line 3SE and have had no premature tube failures, in fact I have been using the orig. NOS tubes for several years with very quiet operation. I've had the occasional low level tube rush but nothing note-able from more than a few inches away. This is a great sounding and very reliable unit. You only need the really good NOS tubes in 4 locations... all else can be simply good/reasonably priced.
I have the line one, I haven't experienced any problems with the pre eating tubes.

Jojass402, when you say NOS do you actually mean new, or used? Do you have a tube tester? Do you test the tubes when you receive them?

If used, how much life is really left in the used tubes you are buying?
I own a SFL2 and wouldn't consider it a tube eater. It does run them a tiny bit harder but nothing to worry about. Don't get freaked out about this as a set of tubes are going to last many many years. As mentioned above there are critical locations where you want your best tubes. I get a little his but I can only hear it a few inches away from the speaker and it doesn't bother me.
Thank you fellow members for voicing out your experiences whch makes me feel better. I too don't really have a problem with this unit. I just thought I might try replacing my noisy tube and get them from
a reliable vendor/s for a change. BUT this particular vendor have been true to his words in the past with good recomendatons from fellow goners.

I was quite surprise and caught off-guard when he mentioned that Sonic Frontier preamps eat tubes by design (meaning they get noisy after a few months).
He did not even have any to sell BUT in the end of the conversation he mentioned to check back in 2 weeks. He recommended sticking to 7308s Siemens NOS tubes from germany which will cost around $200. for the pair (which I thought were within fair price).
Another source which I was looking into is Chris Johnson's "Parts Connexion".
Heck the price is also in that neighborhood. Don't mind spending that kind of money as long as I get a pair of QUIET, expected Sonics, and the reliability
these tubes were designed for.

Jea, I bought these previous pair of tubes from another well known vendor in
S. California (NOS Siemens CCA 7308) which performed fantastically for a few months then one side went "tube-rush" on me. No, I do not have a tube tester.
Tube testers are not cheap let alone choosing the right brand and model that does a good job checking the tubes.

I'll ask another favor- and this may already be on some thread here at Agon but since we're at the subject matter- Which vendor would any of you good folks recommend to buy these tubes from? Antique Electronic Supply?? Upscale Audio???, Parts Connexion??? Tubestore?? Tube Depot??? VTS?? Bio??
Vacuum tube valley??? Angela Insruments??? Tubemonger?? Decware???

I really like the Siemens CCA 7308s as they deliver the kind of PRAT I really enjoy. I've tried several 6DJ8s Elite gold but they got noisy after a few months (1-2 tube out of 6) & nowhere close to the Siemens Prat. Also tried BRAND NEW Sovteks 6922 (3 pairs)- which another vendor claimed I'll get great bottom end- Yes, but found out that was all it was good for (Weak top end but quiet). My sanity check is always swapping-in the original tubes which are dead quiet and good sonics (again but not as good as the 7308s).

Again THANK YOU ALL for your feedbacks- now if I can only find another
helpful vendor who can deliver reliable tubes without me second guessing and not be prompted to get a tube tester..:^)
Line 3SE owner for 5 years, only had to re-tube once last year and I had 6H23 in them before without ever noticing any tube noise thru out the 4 or 5 years of usage. Given the life span I got from the tubes, I would rate it as gentle on the tubes.

Yes, you can get better sound by putting in NOS. But I have been using cheap tubes (EH or NOS Sovtek) in buffer stage with good success.
Jolen1aub, Check out the Amperex US made PQ white lable 6922 E88cc tubes for the critical positions, a bit costly but have been my favorites. For a bit less cash the Mullard 6922/CV2493 low noise GT. Britain tubes are nice too.
Thank you all for responding and re-inforcing the reliable qualitiies of the Sonic Frontiers product.

But the question remains.... now that we know what tubes to get... WHERE is a reliable vendor to buy these tubes from?
(without 2nd guessing their reputation). Another reason we are paying top dollars on these NOS tubes is we expect them to be QUIET, have better sonic performance(maybe), and to be reliable for years.... (10,000 hrs).

Hi Jeff- thanks for chimimg in! Telefunken or Amperex??
last we chat you were in the process of getting
some Teles not too long ago.
Is tubemonger a reliable source for these tubes?
(from your experience?)
Joel, I perfer the Amperex over the tele for the critical positions. The tele are nice but just a tad laid back for me. Tubemonger has always provided good stuff and I have never had any problems with his tubes. AA FAQ page has some good info you seek.

Which Amperex in particular do you recommend?
Are these 7308s or 6922s?
Please let me know and I'll give the tubemonger a try..:^))

And thanks again!

Joel, my favorite is the 6922 PQ white lable US then 6922 PQ white lable from Holland.
I would like to jump in here regarding tube rolling with S.F. I have had some experence in this. All old stock tubes have a flavor or different sonic note. With sonic frontiers amprex orange globe or bugle boys offer a great degree of musically and considering you need 2 quads they also can be had for less money. I also feel that a tube tester is a good investment ( I have 3 different ones ) There is really no warrenty on 50 yr old tubes... but they should arrive in stated condition. I have sold tubes that test strong, and are quite in my pre-amp, but are noisy in another.Those I have taken back and exchanged for another type in order to find the correct match.
I have sold tubes that test strong, and are quite in my pre-amp, but are noisy in another. Those I have taken back and exchanged for another type in order to find the correct match.

Here is a post from Kevin Deal concerning tube rush noise.

Here are a few posts from AA,
tube rush noise
I have been using the Line 3 for over 9 or 10 years and never had any noise issues. I have changed 2 sets of tubes, not because they did not sound good, it is just that I had the itch to make a change. Also, can someone tell me what are the critical locations for tubes in Line 3. Thanks
Magnih, LV2 & V2 then LV1 & V1
This is a very useful thread for me, having an SFL-2 for a year now. May i seek help, too?

I noticed that the previous owner changed the stock sovteks at position LV1-V1 with Chelmer Valve E88CC and at position LV4-V4 with Gold Aero 6DJ8-ECC88 Platinum Series... now this confuses me for 2 things:

1. the manual and the inside panel says that if tubes are changed, the pots LVR1-VR1 needs to be adjusted "for optimum performance"... the warning says "do not..."; so guys, how did you do it? and,

2. the posts did mention LV2-V2 and LV1-V1, is this also true with the SFL-2? Jsawhitlock answered for Line 3; or are the positions in my preamp correct?

I have just gotten hold of NOS Sylvanias which i have now installed in my Power 2 and wished to install, too, in the SFL-2... could you kindly advise?

Send an e-mail to Parts Connexion c/o Chris Johnson, or give him a call.
He should be able to give you the information you require

LV2 and V2 are the most important positions and next is LV1 and V1 for the SFL 2, line 1, line 2 and line 3. Trim pots should be left alone. as the label says.
I had a SFL2SE for about three years. I got it new and had two sets of stock tubes in it over that time. I never tried NOS tubes because I was Never sure how to adjust the trim pots inside the unit. The stock tubes which I sourced from SF always came as matched sets and were burned it a the factory. And most Importantly came with a drawing showing what position I was to adjust the pots to for that specific set of tubes. As far as tube rush after about a year I could notice this but only a low listening levels.I always felt this was a limiting factor for me in trying other tubes because I would have no idea where to set the trim pots. I ended up with a BAT VK 40 SS pre. and to my ears is even better and no problem with tubes.