LA2A with too much noise - sos

[SIXTYNINER]

hello
sombody know what can be do
for "kill" the hi level noise (not normal) with Teletronix LA2A?
(don't say me - "noise gate) the limiter work fine in compression
but output have too much noise  ,
can be tubes to replace?
any help are wellcome
thanks in advance to any post help about

 

[SSLtech]

Swap the 12AX7 with the sidechain 12AX7. -If not that, replace the 12BH7, but that's perhaps less likely.

Did this just suddenly become noisy, or is it a new build which you just expected to be quieter? (Hint: LA-2a's are not particularly quiet [meaning 'hiss-free'] devices...)

Keith

 

[SIXTYNINER]

hi "cyberkeith"
and thanks for post,
just swapped 12ax7 , but same level of noise
replaced 12ax7 with new one
and noise go a bit down
but remain an high level of noise (much then normal)
probably it is the other tube

 

[[silent:arts]]

mostly the 12ax7 in the audio path.
you are building a D-LA2A, right ?

a few people had some noise issues, all the time it just was this tube.
http://www.nrgrecording.de/nrg/viewtopic.php?t=405&postdays=0&postorder=asc&start=81

 

[SIXTYNINER]

hi volker
thanks for link !
....this unit is an original teletronix
not clone.....

 

[SSLtech]

Can you confirm that by "noise" you do in fact mean hiss, and not hum or something like that?

IT will help us to help you.

Keith

 

[SIXTYNINER]

hi keith
the noise is not hummm
it is a kind of hiss , .....very much near a white/pink noise
replacing the 12ax7 the noise loses around 30%
i'm waiting replacemente for orher 2 tubes
for try to replace tubes  and see
what happen
:-[

 

[hugo]

take some "12ax7wa-r" from tad if tubes are involved. Use a filtered IEC inlet..twist tight the heaters..