Need Aleph L Service Manual - 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 12th October 2014, 08:59 PM   #1
diyAudio Member
 
Join Date: Jan 2008
Location: Salt Lake Silly, Yewtaw
Default Need Aleph L Service Manual

My first pass Labs project was an Aleph L back in about 2002. I had the service manual on one of my computers but lost it at some point. I want to go back to the L for a while and possibly do some mods to it and wanted to know if anyone here could send me the service manual. I moved everything Pass Labs related over to my server a few years ago and I literally have everything Pass Labs except for that. Not sure what happened to it.

Thanks in advance!!
Mark Gulbrandsen
  Reply With Quote
Old 12th October 2014, 09:17 PM   #2
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
.
Attached Files
File Type: pdf Aleph L.pdf (592.8 KB, 245 views)
__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa...© by Mighty ZM
  Reply With Quote
Old 12th October 2014, 10:31 PM   #3
diyAudio Member
 
Join Date: Jan 2008
Location: Salt Lake Silly, Yewtaw
Thanks Zen!
  Reply With Quote
Old 12th October 2014, 11:21 PM   #4
diyAudio Member
 
Join Date: Jun 2003
Location: Wroclaw
Aleph L is a nice preamp, a lot of gain if you need so. Though if you want to go for a little batter the Alph P 1.0 is similar but more relaxed, extended and smoother sounding. Regarldless of the volume control (usuallu any 5K or 10Kat the output will do a job). The input and output caps quality is critical as alwyas in any preamp.

Kind regards
  Reply With Quote
Old 13th October 2014, 02:14 AM   #5
diyAudio Member
 
Join Date: Jan 2008
Location: Salt Lake Silly, Yewtaw
Yes.... I built an L many years ago and it has been sitting on a shelf all this time and I have been using a Grounded Grid preamp. I want to get back to the L again and perhaps do some mods to it....

Best,

Mark
  Reply With Quote
Old 13th October 2014, 03:23 PM   #6
WalterW is offline WalterW  Netherlands
diyAudio Member
 
Join Date: Oct 2012
Location: Utrecht
Cool, thanks for the pdf and mentioning the existence of an 'Aleph L'

I still have to read the whole article, but I particular liked this part:

"The Aleph L is a simple Mosfet stereo preamplifier having four single-ended inputs and two outputs. Its controls consist of an input selector and a level control. The volume control is passive up to the 3:00 o’clock position where the gain is unity. At 3:00 o’clock, the connection from input to output is direct, with no components in the signal path, and past the 3:00 o’clock position the unit becomes an active preamp"

Maybe I can implement something like that in my preamp/ volume control ...

Walter
__________________
Pass F5, F5Tv3, ACA, Aleph J, DDDAC1794, DCB1, BA3-preamp, VFET CSX1.
  Reply With Quote
Old 13th October 2014, 03:53 PM   #7
koja is offline koja  Canada
diyAudio Member
 
Join Date: Oct 2009
Location: Windsor
the passive-to-active concept is phenomenal. i always wondered why "L" never gained much traction and P so quickly took over. maybe this many years later the concept could be revisited and an "L2" could be born to be tried? Does this sound like the greedy boyz' cry?
  Reply With Quote
Old 19th October 2014, 03:18 PM   #8
diyAudio Member
 
Join Date: Jan 2008
Location: Salt Lake Silly, Yewtaw
I am also wondering that. It could have been implemented in his later preamps too.

After a few days of listening to the L again it is actually really good. I likely have more money in the four coupling caps and bypass caps than in any other aspect of the build!

Mark
  Reply With Quote
Old 22nd October 2014, 10:20 PM   #9
MikeW is offline MikeW  United States
diyAudio Member
 
MikeW's Avatar
 
Join Date: Sep 2002
Location: North of Boston
Didn't I send you a preamp?
__________________
MikeW
  Reply With Quote
Old 23rd October 2014, 08:03 PM   #10
diyAudio Member
 
Join Date: Jan 2008
Location: Salt Lake Silly, Yewtaw
Hi Mike W!

Yes you did and I still have it here. I am getting back into this after a grueling eight years of living, breathing and eating Digital Cinema conversions 24/7. I'd like to take your board design and modify it for better coupling caps that are physically much larger. I never felt the small electrolytics were quite up to the task and I wired larger Multicaps with .01 bypasses to the boards. The problem is there are three of them on the output in parallel so more board real estate is needed there. Both at the input and the output.

The other option is building an Aleph X preamp which I have the service manuals for. Those have balanced supplies and shouldn't need output caps.

P.S., All these years I have been using a Chinese Grounded Grid kit with a few upgrades to it. It's actually VERY hard to beat it if you have a good quality set of 12AU7's in it. The sound stage, bloom and clarity of each instrument is uncanny. Now it's time to pick up where I left off.

Mark

Last edited by Mark Allen; 23rd October 2014 at 08:09 PM.
  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
ALEPH 2 Service Manual hifileslie Pass Labs 21 5th December 2014 06:08 PM
Aleph j Service Manual. lykkedk Pass Labs 20 1st December 2010 03:22 PM
Service manual: ALEPH L spersanti276 Pass Labs 3 27th April 2008 07:34 PM
Aleph Service Manual randytsuch Pass Labs 1 12th January 2007 03:15 AM
Aleph L Service Manual mdi Pass Labs 0 18th September 2006 05:25 PM


New To Site? Need Help?

All times are GMT. The time now is 02:52 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