New Aleph Mini PCB GB - Page 21 - 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 19th March 2005, 09:46 PM   #201
diyAudio Member
 
Join Date: Feb 2004
Location: Racine, Wisconsin
I have read this (1-198) post and I'm on the wiki but this AADD is killing me....

Is the final version a 30w/C design?

It can also be built as a 10w?

Are most all class A designs regulated?

Is that so the current source remains relatively stable?
  Reply With Quote
Old 19th March 2005, 10:04 PM   #202
diyAudio Member
 
Join Date: Sep 2001
Location: Salt Lake City
This weekend I'm building just one channel of the mini to prove the board. I will also provide some specs of the operating unit. In a week or so we may convert a friends Aleph 3 to a 30 with the other set of boards if time allows. I DO have to work also.....

What did you mean by regulated supplies in class A amps? The current source is actually modulated by the audio on the output.

Mark
  Reply With Quote
Old 19th March 2005, 10:50 PM   #203
jleaman is offline jleaman  Belgium
Banned
 
Join Date: Apr 2002
Send a message via AIM to jleaman
He is probably thinking when i started we were talking about regulated power-supply's. To witch i might do in my aleph mini's
  Reply With Quote
Old 19th March 2005, 11:09 PM   #204
diyAudio Member
 
Join Date: Sep 2001
Location: Salt Lake City
Cutting them apart is easy but very touchy as the thinest blade I had was a hacksaw blade. The bandsaw blade was way to thick to cut these boards. Pre-milling, perfing, or slitting these will be mandatory. Also, if you polish the tinning before you solder with 0000 steel wool the solder adheres very well. I use Kester Electronic Silver solder for everything I do here.

Mark
  Reply With Quote
Old 19th March 2005, 11:32 PM   #205
diyAudio Member
 
Join Date: Feb 2004
Location: Racine, Wisconsin
Quote:
What did you mean by regulated supplies in class A amps?
What I mean is that the typical chip amp is built with an unregualted power supply. Transformed, rectified, capped and then on to the chip without regulation. The talk of regulation kind if disappeared after page 10 of this thread.

So, one more time...

Is it true of most class A amplifiers to be unregulated power supplies, or is it more common to regulate power?
  Reply With Quote
Old 19th March 2005, 11:40 PM   #206
jleaman is offline jleaman  Belgium
Banned
 
Join Date: Apr 2002
Send a message via AIM to jleaman
Quote:
Originally posted by Mark A. Gulbrandsen
Cutting them apart is easy but very touchy as the thinest blade I had was a hacksaw blade. The bandsaw blade was way to thick to cut these boards. Pre-milling, perfing, or slitting these will be mandatory. Also, if you polish the tinning before you solder with 0000 steel wool the solder adheres very well. I use Kester Electronic Silver solder for everything I do here.

Mark

I hope brian puts on cut lines and that the pcb place makes it easy to snap them : O ) NOt may of us have a band saw. But a exacto Knofe worked for tbe Gain clone kit's.
  Reply With Quote
Old 19th March 2005, 11:57 PM   #207
diyAudio Member
 
Join Date: Sep 2001
Location: Salt Lake City
"Is it true of most class A amplifiers to be unregulated power supplies, or is it more common to regulate power?"

Chip,
One can go either way with these amps. The most common though is un-regulated. Keep in mind that the front ends(input devices) are regulated. Mark Levinson and Krell have made and sold all regulated class A power amps. Keeping in mind that there is a pretty constant current draw regardless of output power I donno how much improvment you'd realize.... I thinkit would be small though. Probably the most two common DIY supplies are both CLC and CRC type supplies. With a very well made and oversize toroid and large amount of capacitance the supply tends to be pretty well regulated to begin with. Its also possible with a CLC eupply tog et the ripple so low that its impossible to measure accurately. My Aleph 2's for example have 58,000 mfd -6mh-58,000 mfd supplies. All thats on the DC is some noise and one would need a screen room to be able to even measure the ac ripple on the dc rails.

Mark
  Reply With Quote
Old 20th March 2005, 01:21 AM   #208
diyAudio Member
 
Join Date: Sep 2001
Location: Salt Lake City
I just posted a fresh batch of photos on Brian's gallery.
One thing for sure... this is one tight little board! If you use 1/4 watt 1% resistors they will have to be stood on end. I don't really mind this practice at all myself. Over the years I've seen MANY pieces of pro gear from Dolby and others that have been done just this way. What I did do was to alternate the positions of the bodys of them so that should they get bent over there will be less likelyhood of them touching. All in all I don't have any problems with doing it this way.

One more thing we all need to get straight here and perhaps develop is a resistor value chart for this "universal board" showing the values of the resistors used in the different Alephs. Since this test circuit is going to be a Mini-A I am goig to make R-12, 14, and 16 750 ohms. R-13 will be 47.5K, and R-17 at 392. I will leave the feedack values just the way they since we are sticking with the balanced input. I will leave out R-6 for now since my input fets are very well matched, but we can all go back and explore tunning that value once this board is up and running. I will need advice from Brian and others on this matter so those that are qualified to chime in please do so. I would like to see a chart developed to refer to for the correct values for those positions depending on what model Aleph you want to build. It will make it alot less confusing for those that are new to this project.

Thanks!
Mark
  Reply With Quote
Old 20th March 2005, 01:31 AM   #209
jleaman is offline jleaman  Belgium
Banned
 
Join Date: Apr 2002
Send a message via AIM to jleaman
Im doing the chart but lack of brians ability to email it to me i have not done it yet along with the part's list : O )
  Reply With Quote
Old 20th March 2005, 03:56 AM   #210
diyAudio Member
 
Join Date: Feb 2004
Location: Racine, Wisconsin
Thanks Mark! Nice pics too!

http://www.briangt.com/gallery/miniALEPH-prototype
  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
mini-aleph versus aleph-3 rmgvs Pass Labs 7 4th February 2010 04:18 PM
Mini Aleph Board & Aleph 2 Parts List gpsmithii Pass Labs 3 16th January 2010 04:58 AM
Aleph Mini / Aleph 3 PCB ready (?) croccodillo Pass Labs 5 27th July 2009 02:51 PM
Difference between Aleph J and Aleph J Mini ppmmcc Pass Labs 5 17th May 2008 07:10 PM
WTB: Aleph-mini PCBs and transistor set for Aleph 30 needtubes Swap Meet 4 6th November 2005 07:29 PM


New To Site? Need Help?

All times are GMT. The time now is 01:33 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