diyAudio

diyAudio (http://www.diyaudio.com/forums/)
-   Pass Labs (http://www.diyaudio.com/forums/pass-labs/)
-   -   threshold SL10 - DC output (http://www.diyaudio.com/forums/pass-labs/35127-threshold-sl10-dc-output.html)

pjmont 31st May 2004 07:41 PM

threshold SL10 - DC output
 
Hello, i have a Threshold SL-10 preamp and a threshold TA300 poweramp, now i have a problem with the preamp :

Only in the left channel i have found one DC of 0,12V, this cause a problem with the poweramp (only the power amp without the pre is ok), and so my left woofer have a strange and unusual movement, even if sound the same one.
What's it? a any broken transistors?

Thank you
Pierluigi (Italy)

Nelson Pass 31st May 2004 11:24 PM

2 Attachment(s)
I am posting the schematic of the high level stage, which
(hopefully) shows a direct coupled output whose DC offset is
adjusted by an op amp. The op amp could be bad, or the
capacitor could be leaking, or some other component could
be failed sufficiently that the op amp can't make the correction.

pjmont 31st May 2004 11:48 PM

Ok many thanks Nelson.
Bye
Pierluigi

tfender 21st February 2012 03:20 AM

Quote:

Originally Posted by Nelson Pass (Post 406184)
I am posting the schematic of the high level stage, which
(hopefully) shows a direct coupled output whose DC offset is
adjusted by an op amp. The op amp could be bad, or the
capacitor could be leaking, or some other component could
be failed sufficiently that the op amp can't make the correction.

Hello
I take an interest that try out , Pre SL-10 , this , I want to know position value aforementioned , and the circuit , Supply , http://www.diyaudio.com/forums/<a hr...i/ob/gregh.png[/IMG]

Thanks
http://upic.me/i/ob/gregh.png

Zen Mod 21st February 2012 03:43 AM

search

it's there

juanitox 27th February 2012 07:44 PM

:) i really love the sound and look of this preamp , the only thing is the hi level stage gain , too much gain for nowadays sources and amp . is there a solution to reduce the gain of this stage without affecting too much the sound ?

i have already put a 30k resistor in series with the volume pot but it is the max i could had before affecting the sound..

any idea ?:spin:

Zen Mod 27th February 2012 08:09 PM

:clown:

didn't I already told you (somewhere ) - just cut that 18K2 in half , for 6db gain reduction

gain is roughly 18K2/750

juanitox 27th February 2012 08:24 PM

hey zen guy sorry it was not me , can you explain how to cut ? i have the scissor ready :D

Zen Mod 27th February 2012 08:26 PM

either solder another one 18K2 across existing one , or desolder existing one and solder 9K1 instead

;)

juanitox 27th February 2012 08:31 PM

you are a killer.. thks :headshot:


All times are GMT. The time now is 08:14 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio


Content Relevant URLs by vBSEO 3.3.2