Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Pass Labs This forum is dedicated to Pass Labs discussion.

Aleph P 1.7 output muting relay...
Aleph P 1.7 output muting relay...
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Thread Tools Search this Thread
Old 20th March 2002, 06:20 PM   #1
Freddie is offline Freddie  Sweden
diyAudio Member
Join Date: Oct 2000
Location: Sweden
Default Aleph P 1.7 output muting relay...

I've read in the service manual that the output muting relay is controlled by the circuits of Q21 and Q22. But where is the output relay? I can't find it anywhere on the schematics, I can't find it on the component placement diagram either. I suppose it is directly after the 10uF caps, and simply shorts to ground so there are no turn on transients, am I right?

Thanks in advance

  Reply With Quote
Old 20th March 2002, 08:50 PM   #2
fcel is offline fcel  United States
diyAudio Member
Join Date: Sep 2001
Location: LA County
I don't mean to bug in here but has anybody installed/design a turn on muting circuit for BOSOZ? Nelson Pass has indicated in the BOSOZ article as a exercise for the reader.
  Reply With Quote
Old 21st March 2002, 12:52 AM   #3
Helix is offline Helix  United Kingdom
diyAudio Member
Helix's Avatar
Join Date: Jul 2001
Location: UK
i guess it justs attenuates the output to the full, by using it's volume control relays
  Reply With Quote
Old 9th April 2002, 01:55 AM   #4
GRollins is offline GRollins  United States
diyAudio Member
Join Date: Feb 2001
Location: Columbia, SC
The mute relay runs off of the Mute + and Mute - coming from Q21 & Q22. Q21 switches on and off more or less instantly once the rail comes up or drops. Q22 provides the delay on turn-on via the cap at the gate. The relay itself is not shown (at least not on the power supply schematic with the rest of the circuit--I didn't bother looking for it elsewhere), but it's not too hard to hook up a relay to Q21 & 22, then apply ground to the outputs. The IRF610 and IRF9610 have sufficient current capability to drive any reasonable relay coil for this application.
The circuit tickles me, because it's such an elegant way to use up out-of-spec parts from the gain stages.

  Reply With Quote
Old 23rd October 2002, 03:43 PM   #5
Klaus is offline Klaus  Germany
diyAudio Member
Join Date: May 2002
Location: near Frankfurt/Main
Default Voltage of mute relaiy?


I do not understand all details of the voltage losses of this damned FETīs...

Could anyone please tell my the Voltage rating of the mute relay coil, thanks!

  Reply With Quote
Old 23rd October 2002, 08:41 PM   #6
Jens is offline Jens  Germany
diyAudio Member
Join Date: Feb 2001
I believe 48V types, but both output relays serial - like the input relays.

  Reply With Quote


Aleph P 1.7 output muting relay...Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
muting transistor>relay,can i do this? Rodzilla Analogue Source 2 18th December 2016 08:40 AM
Muting Relay ..... buzzing Baldin Solid State 13 18th May 2009 06:59 PM
Muting relay problem decky Solid State 23 23rd March 2008 08:29 AM
Aleph L Muting Relay Rating PaulyG Pass Labs 3 10th December 2002 01:55 AM
Muting: alernatives to mechanical relay? paulb Solid State 29 31st December 2001 08:37 PM

New To Site? Need Help?

All times are GMT. The time now is 07:30 PM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 16.67%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio