Another Aleph J arriving - 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 23rd February 2014, 07:41 PM   #1
diyAudio Member
 
BobEllis's Avatar
 
Join Date: Sep 2003
Location: Upstate NY
Default Another Aleph J arriving

Feeling proud of myself for actually making progress. I got my ground bus bar (3" x 12" x 0.125") drilled out for the main cap connections and mounted the power transformers. I bought brackets to mount them vertically but since they fit (barely) laying flat that's the way to go.

I'd hoped to finish this amp today, but life has interfered, and I am waiting on a few parts. Resistors for the CRC, fuse holders for each transformer, and some hardware scheduled for delivery next Wednesday.

I can see that I am going to have to do the cap screw heat sink mounting mod - Otherwise I'll never get the front panel attached or be able to adjust the amps.

Nothing particularly special about the board setup, I used the store BOM other than using Fairchild IRFP240s and BC546C I had on hand. I bought the jfets a long time ago from ampslab and was pleasantly surprised to find at least 4 pairs with idss around 10 mA matched within .03 mA out of 20 pieces. I was also able to make 4 perfectly matched sets for my F5T.

There's not a lot of room to spare. Transformers are Antek 4220s. Smoothing caps are 68,000 F/50V. Chassis mount 25W 0R1 resistors will mount on the ground bus. I realize that's an "old school" power supply. Rectifiers and AC connections will be on the front panel.

Progress will be even slower for a month or two, as the surgeon says I can't lift more than 10 pounds after much needed back surgery. I may have to turn my daughter into my amp mechanic so I can listen to it during my recovery.
Attached Images
File Type: jpg IMG_1192.jpg (682.6 KB, 531 views)
  Reply With Quote
Old 23rd February 2014, 08:01 PM   #2
Marra is offline Marra  United Kingdom
diyAudio Member
 
Join Date: Nov 2009
Location: Near Lincoln
And I thought mine was a tight fit.
Nice work Bob.

Last edited by Marra; 23rd February 2014 at 08:10 PM.
  Reply With Quote
Old 23rd February 2014, 08:02 PM   #3
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
schweet

good luck with back surgery

I'm prolonging mine , now for more then 10 years now .....

in fact - not prolonging , still being in shape not exactly bad enough

__________________
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 23rd February 2014, 08:20 PM   #4
6L6 is offline 6L6  United States
diyAudio Member
 
6L6's Avatar
 
Join Date: Oct 2010
Location: Denver, Colorado
Tie all your grounds to one point on that gorgeous piece of copper. It should be silent.
  Reply With Quote
Old 23rd February 2014, 08:33 PM   #5
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
even if I would split it in two - having full dual mono that way
__________________
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 23rd February 2014, 08:34 PM   #6
diyAudio Member
 
BobEllis's Avatar
 
Join Date: Sep 2003
Location: Upstate NY
Thanks, guys.

ZM, I've put it off as long as I can stand. Actually I can't stand much, so it's time. I've managed to work the "No brain, no pain" theory to my advantage. Problem is I can't be on my feet for more than about 15 minutes or my legs go to sleep and I fall down. My personal doc/good friend is an avoid surgery if at all possible guy but has been pushing me to get it done for a couple years. Same guy did wonders for my neck, so I'm expecting good results.

I should be back making dodo posts in a week or so...
  Reply With Quote
Old 23rd February 2014, 08:37 PM   #7
diyAudio Member
 
BobEllis's Avatar
 
Join Date: Sep 2003
Location: Upstate NY
I may split the ground busses with my F5T, I have the same caps and copper bar for it. We'll see how this one goes.
  Reply With Quote
Old 23rd February 2014, 08:49 PM   #8
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
be sure to check in here , as soon you arrive home
__________________
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 23rd February 2014, 09:15 PM   #9
NYCOne is offline NYCOne  United States
diyAudio Member
 
Join Date: Jul 2010
Blog Entries: 1
It looks great.

If you have the time/inclination, more photos are welcome.
  Reply With Quote
Old 23rd February 2014, 09:50 PM   #10
diyAudio Member
 
BobEllis's Avatar
 
Join Date: Sep 2003
Location: Upstate NY
I'll post progress pictures when I start making progress again.
  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 (Single Ended) + Larvadin (no Memory Distortion) = Ultimate Aleph? tiefbassuebertr Pass Labs 19 25th January 2014 02:15 AM
Russian triodes ГИ-15Б arriving in a few days tricomp Tubes / Valves 16 6th July 2012 06:55 PM
A mint Kenwood KA-907 amp is arriving, I need help/info/advice on restoring it. Kuja Solid State 5 21st November 2011 11:46 PM
e-mail notifications not arriving every time halfgaar Forum Problems 7 17th May 2011 08:48 PM
PCBs for Aleph 2, Aleph 3, Aleph 4 and Aleph 5 amplifiers kristijan-k Swap Meet 64 12th September 2002 07:55 AM


New To Site? Need Help?

All times are GMT. The time now is 11:28 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