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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.

jojass402
jea48
4,425 posts
 
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.
Dsremer


Here is a post from Kevin Deal concerning tube rush noise.
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Here are a few posts from AA,
tube rush noise
.
jsawhitlock
302 posts
 
Joel, my favorite is the 6922 PQ white lable US then 6922 PQ white lable from Holland.
magnih
10 posts
 
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
jsawhitlock
302 posts
 
Magnih, LV2 & V2 then LV1 & V1
egay's avatar
egay
18 posts
 
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?

Thanks,
.e.
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