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Slight Tube 'Whistle' - Help?

Hi. Two Questions on my preamp:

1. Someone asked me if the pre is "hard on tubes"...what does this mean?

The EH stock tubes became super-hissy after 800 hours...stock replacements on the way. Meanwhile, i put in Amperex 6922 US PQ White labels...better in every way. Silent...until just recently. After about 300 hours with the Amperexes, i now [occassionally] hear the teeniest, tiniest bit of "whistle" thru the R tweeter only. In general, the hiss is super, super quiet (and i have 95 db speakers)...but [sometimes not always] it has gone from effectively silent to a soft whisper now in both channels.

Can a preamp be 'hard on tubes'...and if so, is there anything one can do? Or is the 'teeny R-channel whistle' a symptom of this or something else...or just par for the course with any preamp...particularly one with a ridiculously low noise floor? i cannot get over how much super-soft detailing i can now hear thru ordinary recordings.

2. In trying to figure this out, with the unit on, i tapped each tube out of curiosity...and discovered i could loudly hear it thru each speaker. Is this normal? Should i care since i dont tap my tubes while i listen?

Other than the teeniest, tiniest bit of hiss and this occassional 'whistle', the unit is dead silent...so perhaps this 'tapping' business is a non-issue?? The tube sockets themselves are on their own floating suspension systems underneath in the unit apparently.

If i put an EAT tube damper on each tube, should this stop it? Again, should i care?...is this normal?

Thanks for any guidance!!!!!!!!!
lloydelee21
lloydelee21 OP
1,202 posts
 
hah!!!! Thanks, Mezmo. Thanks everyone for your help. That was very reassuring. I will monitor...there is nothing but silence right now.

...at some point may try the EAT tube dampers. i already use them in my DAC which is very, very to microphonic problems.

jea48
2,944 posts
 
...at some point may try the EAT tube dampers. i already use them in my DAC which is very, very to microphonic problems.
11-13-11: Lloydelee21
Tube dampers will not stop a preamp from eating tubes....

What is the make and model of your preamp?

Special warning to Audible Illusions preamp users:
The one you can say for the Sovtek is that you can run it hard and it can take it - and apparently that’s exactly what AI does. Unfortunately the classic NOS tubes in this family just cant take this kind of treatment and will rapidly fail when used in these units (and some of you guys have the fried tubes to prove it!). So you AI users are probably best off limiting yourselves to the Sovtek, the Russian 6H23N & 6N1P, the 7DJ8 and the E288CC. There may be others the range of tube types and variations is quite literally bewildering but these are the ones I’m aware of that should be able to handle the higher stresses of this brand of preamps. I review the Edicron, Siemens E288CC and 6H23N here but there are other brands for some of these. I’ve seen Phillips E288CCs & Amperex 7DJ8s advertised on some web sites in the past and there are probably others. It might be worth your while chasing them down & evaluating them for yourself to increase the number of alternatives for use in your AI.
http://www.audioasylum.com/scripts/d.pl?audio/faq/joes-tubes.html#6DJ8
lloydelee21 OP
1,202 posts
 
Hi. Thanks the preamp is the new CJ GAT.
jea48
2,944 posts
 

Hi. Thanks the preamp is the new CJ GAT.
11-13-11: Lloydelee21

I would contact Conrad Johnson...
lloydelee21 OP
1,202 posts
 
Yes, i will. Thanks. Ed in Service is top notch.
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