Pass Labs X2 REV1 Relays? - Page 2 - diyAudio
Go Back   Home > Forums > Amplifiers > Pass Labs

Pass Labs This forum is dedicated to Pass Labs discussion.

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
Reply
 
Thread Tools Search this Thread
Old 7th December 2005, 11:28 PM   #11
diyAudio Member
 
Join Date: Jun 2005
Location: Dallas, Texas
Cool, thanks.

Now the next question - looking at the amp it seems a lot like
an unbalanced to balanced converter. Unless I'm missing
something it does not have the "supersymmetry" circuit.
Therefore, if one has balanced sources, wouldn't an Aleph P 1.7
be a "better" choice ? What would be the benefit of the X2 over
the P 1.7 ?

W.
  Reply With Quote
Old 8th December 2005, 10:06 AM   #12
Buhl is offline Buhl  Denmark
diyAudio Member
 
Buhl's Avatar
 
Join Date: May 2002
Location: Aalborg, Denmark
Default Is the X2 not a X?

No problem !

By the way, I have the same question popping up in my head last night, when I looked through the X2 service manual - I dont se the feedback resistor going from drain to gate of the FETs - so basicly, its two bosoz /BLS stages, where the first one is unity gain, and only handles the balanced input, and the second has 10/17 dB gain, and handles amplification and optional conversion from unbal. to bal.
Is it really true that the X2 is not a "X" ??

Conserning advantages of the X2, it may be the high output voltage swing, I seem to recal the distortion curves of the BLS "manual" showing the voltage swings effect on the FET distortion.

Cheers !
Buhl
__________________
"Calculations? We don't need no stinkin calculations! We just make them really big!" Quote: Nelson Pass
  Reply With Quote
Old 17th December 2006, 08:25 PM   #13
Buhl is offline Buhl  Denmark
diyAudio Member
 
Buhl's Avatar
 
Join Date: May 2002
Location: Aalborg, Denmark
Looking through the x2 manual again, the same questions pops up in my head - does the x2 lack the x-feedback loop ???

Cheers !
Buhl
__________________
"Calculations? We don't need no stinkin calculations! We just make them really big!" Quote: Nelson Pass
  Reply With Quote
Old 18th December 2006, 05:57 AM   #14
Mad_K is offline Mad_K  Norway
diyAudio Member
 
Mad_K's Avatar
 
Join Date: Sep 2002
Location: Norway
Yes, no X, no feedback
__________________
Mads K
  Reply With Quote
Old 26th March 2011, 12:07 PM   #15
diyAudio Member
 
PTSOUNDLAB's Avatar
 
Join Date: Dec 2001
Location: FRANCE / TOULOUSE
Hello

I made a X2 Rev1 preamp but I have an issue and need help if someone can help.

This is the PSU schematic (in red my voltages) http://www.ptsoundlab.com/temp/passx...supplyrev1.jpg

This is the input (in red my voltages) http://www.ptsoundlab.com/temp/passx...dlineinputrev1

This is the output (in red my voltages) http://www.ptsoundlab.com/temp/passx...lineoutputrev1

My problem is that R6 is very very hot (I installed a 10W 1K resistor because a standard resistor burn). And I don't have 60V and 40V on drain of IRF but 84V.
All other voltages seems ok.

I tried with Axicom 2K88 24V relays, and with 2x 3K2 resistors in place of relays.

Could someone confirm that PSU schematic is correct ? (i modified just primary from 120V to 220V E.U. standard, and C1, C2, C3, C4 are 4400F and not 1000F)
TH1 is 10 ohms 3A

Thank you

Pascal
  Reply With Quote
Old 27th March 2011, 09:18 AM   #16
diyAudio Member
 
PTSOUNDLAB's Avatar
 
Join Date: Dec 2001
Location: FRANCE / TOULOUSE
Hello

suddenly I have a doubt ! When on Nelson SM is noticed 1004 for a resistor, is the resistor a 1K004 or a 100x10000= 1 Mohms
If 1004 is 100x10000= 1 Mohms in the SM, i found my stupid error and now I know my problem.
In E.U. we use not really the same codification than in U.S. i think, and in this case I must check all resistors because the last number in the code is the multiplication coefficient.

Could someone confirm ?

Thanks

Pascal
  Reply With Quote
Old 27th March 2011, 12:53 PM   #17
RIP
 
Join Date: Oct 2005
Location: Central Florida
The 4th digit tells you how many zeros to add.
  Reply With Quote
Old 27th March 2011, 03:36 PM   #18
diyAudio Member
 
PTSOUNDLAB's Avatar
 
Join Date: Dec 2001
Location: FRANCE / TOULOUSE
Thank you Bill !

I'm an idiot, I forgot that we don't use same notation in E.U.

Thank you (and thank Nelson)

Cordially

Pascal
  Reply With Quote
Old 30th April 2011, 08:33 PM   #19
diyAudio Member
 
PTSOUNDLAB's Avatar
 
Join Date: Dec 2001
Location: FRANCE / TOULOUSE
Hello

with correct resistor I have correct voltages now.

But I still have an issue if someone can help.

The relay mute don't work. Relays don't engage. I have no voltage on relays pins.
On this schematic are all voltages from ground Click the image to open in full size.

I verified all connexions, and changed by security Q5/Q4 R9/R10 D1/D2 R6/R8

Could someone help me ?

Thanks

Pascal

Last edited by PTSOUNDLAB; 30th April 2011 at 08:37 PM.
  Reply With Quote
Old 3rd May 2011, 02:41 PM   #20
diyAudio Member
 
PTSOUNDLAB's Avatar
 
Join Date: Dec 2001
Location: FRANCE / TOULOUSE
Hello

I think that I found the solution. There is a mistake in the SM
On the schematic there is a 60V CT transformer, but it's ok for the 85V, not for the 95V version. For the 95V version we must use a 80V CT and not a 60V CT like it is noticed on the SM
With a 60V CT we have 100V unregulated and it is not enough to have a difference of 8V between regulated and unregulated voltages.
I have 100V for unregulated and 95V regulated, so I must find a transistor which conduct with only 2 or 3 volts difference.

Does somebody has an idea of which transistor I can use in place of IRF9610 ? It could help to solve this issue quick

Pascal
  Reply With Quote

Reply


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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Pass Labs D1 maartentje Pass Labs 85 14th July 2013 07:10 PM
FS: Pass Labs X-250 jtwrace Swap Meet 0 17th June 2007 02:20 AM
pass labs sss Pass Labs 5 6th October 2003 06:23 AM
My opinion on Pass Labs and Mr. Pass (Nelson) himself b_online Pass Labs 11 21st May 2003 12:39 AM


New To Site? Need Help?

All times are GMT. The time now is 09:59 PM.


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