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.

Pass Aleph 2 dual power modes?
Pass Aleph 2 dual power modes?
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 13th February 2018, 01:35 AM   #11
Blues is offline Blues  United States
diyAudio Member
 
Blues's Avatar
 
Join Date: Sep 2003
Location: The Milky Way
Quote:
Originally Posted by raman15 View Post
Haha...Thanks folks for your responses. Brought a smile to my face.

There is no going back here. However I do see the schematics for the Aleph 5 and 2 are almost identical except for the bias and output stages. My thought was that can I offload these to a separate board and call it "configuration board" and very easily switch from Aleph 2 to Aleph 5? 300W in savings will help ...

Your thoughts.....
Replace your power transformers with ones that have dual secondaries. You can have switchable secondaries so you have both +/-45Vdc for Aleph 2 and Aleph 5 +/-35Vdc supplies.

__________________
Life simplified! Leap into the Warpspeed wormhole... http://www.6moons.com/audioreviews/warpspeed/1.html
  Reply With Quote
Old 13th February 2018, 01:49 AM   #12
Eric is offline Eric  United States
diyAudio Member
 
Eric's Avatar
 
Join Date: Nov 2000
Location: Central PA, USA
Pass Aleph 2 dual power modes?
Now THAT's an elegant solution. There are two possible solutions: changing rail voltage and changing bias current. I was trying to think of a simple way to change bias, but I like this suggestion for the transformer better.
__________________
My DIY Basement Theater, Aleph-X Amps, Avro Open Baffle Speakers, LDR based BA-3 pre, Pearl II, highly modded Technics SL-1200, F4, a40, several ACAs, FHXL, Tang Band 1772 bass-reflex
  Reply With Quote
Old 13th February 2018, 02:04 AM   #13
raman15 is offline raman15  United States
diyAudio Member
 
Join Date: Aug 2017
Location: New England
Quote:
Originally Posted by aspringv View Post
I'm not intrinsically against any of those things...

Thinking aloud here, but if you've a transformer with split primaries, you could have a selector switch that wires the transformer for 120/240V operation, thus halving the voltages on the rails when in 240V mode. That's about the cleanest solution I can think of.
Aaaah...Less is more! The KISS (Keep It Simple Stupid) principle. Yes the toroids are dual primary....and I have one unit open to the reconfigure the PSU board. Easy enough to test. Thanks Aspringv and Blues! I will try this out soon(hopefully) and post. The cost of 1 switch and an extra Thermistor is so minimal .....or maybe a pair of lightly used 750VA yoroids may show up for sale.

its been 30 years since i last dabbled in electronics, built amps etc. and this was and is so much fun. Life gets in the way.

btw on another note......if you own a pair of nice speakers and an Pass aleph...do crank up Muddy Waters "Folk Singer" ...or Miles Davis "Assenseur pour L'echafaud" ...or Diana Krall's "A Case of You" live in Paris........absolutely transcending....
My apologies for being all over the map
  Reply With Quote
Old 13th February 2018, 03:09 AM   #14
aspringv is offline aspringv  Australia
diyAudio Member
 
Join Date: Sep 2010
Location: Perth, Western Australia
Pass Aleph 2 dual power modes?
...and if you ever move country you'll be all good as well!

I'd maybe wait for another member or two to chip in on that idea. I'm no guru, but I can't see any reason it wouldn't work.
  Reply With Quote
Old 13th February 2018, 03:39 AM   #15
xrk971 is offline xrk971  United States
Got Foam?
diyAudio Member
 
xrk971's Avatar
 
Join Date: Oct 2012
Location: Metro DC area
Pass Aleph 2 dual power modes?
If you like the sound of the Aleph, then you like the harmonic signature of SE Class A amps, dominant 2nd harmonic, lower third harmonic, not much else. Try the Ranchu Aksa Quasi Class AB amp. It has the same harmonic structure (Hugh designed it to mimic a SE Class A amp). It runs 120mA bias from +/-35v supplies and is much more green.

The Dacz layout is proven and tested. Great sounding amp.

Very simple quasi complimentary MOSFET amplifier
__________________
XRKaudio https://www.etsy.com/shop/XRKAudio
  Reply With Quote
Old 13th February 2018, 04:18 AM   #16
aspringv is offline aspringv  Australia
diyAudio Member
 
Join Date: Sep 2010
Location: Perth, Western Australia
Pass Aleph 2 dual power modes?
Looks like the primary switching is a go-er. Feeding 120V to a transformer configured for 240V?

Edit : and thanks for the musical suggestions - I've an aleph 2 ish clone at home, so I'll get amongst your suggestions.
  Reply With Quote
Old 13th February 2018, 05:07 AM   #17
2 picoDumbs is offline 2 picoDumbs  Australia
diyAudio Member
 
2 picoDumbs's Avatar
 
Join Date: Sep 2013
I recently had some transformers custom made like this, but there are multiple taps on the secondaries.
__________________
"If you leave this point unattached to some circuitry, an ideal constant current source will emit a small lightning bolt which will travel until it connects to something." Nelson Pass
  Reply With Quote
Old 13th February 2018, 07:19 AM   #18
Zen Mod is offline Zen Mod  Serbia
Official Court Jester
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
Pass Aleph 2 dual power modes?
before doing anything with rails , make a test with variac

I'm pretty sure that you're going to have troubles with DC offset at output
__________________
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 14th February 2018, 04:47 AM   #19
Andersonix is offline Andersonix  Sweden
diyAudio Member
 
Andersonix's Avatar
 
Join Date: Jan 2004
Location: Marin County, California
Pass Aleph 2 dual power modes?
A totally different way to save a lot of energy would be to switch on and off the amp using a 'music sensor' circuit like Martin Logan uses f.ex.
  Reply With Quote
Old 14th February 2018, 04:55 PM   #20
Nelson Pass is offline Nelson Pass  United States
The one and only
 
Nelson Pass's Avatar
 
Join Date: Mar 2001
Pass Aleph 2 dual power modes?
If you adjust the bias current and/or rail voltages of the Aleph, you will also
need to adjust the DC offset at the output.
  Reply With Quote

Reply


Pass Aleph 2 dual power modes?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
FS: Pass Aleph P1.7 finished preamp PCB without power supply yoke Swap Meet 1 14th May 2017 12:43 PM
Pass Aleph 5 Power amp for sale georgebrooke Swap Meet 0 23rd March 2015 03:21 PM
Pass Aleph 0s: How to disassemble & assemble it to replace power capacitors? Albert Hong Pass Labs 55 21st October 2013 05:55 AM
Best Power Supply for Pass Labs Aleph (X)Ono dtm1962 Pass Labs 8 15th April 2013 11:04 AM
Aleph-X builders LOOK!! HIGH-power (real!) dual Schottky diodes for sale cocolino Swap Meet 11 5th March 2004 08:56 AM


New To Site? Need Help?

All times are GMT. The time now is 09:55 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki