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 21st December 2008, 04:29 PM   #31
diyAudio Member
 
t_majerovic's Avatar
 
Join Date: Sep 2008
Send a message via ICQ to t_majerovic
Default Power supply - soft start

Thank you Gyuri. Your solution looks very robust and oversize :-). I'm almost decided to use modified power supply circuit topology from here:

http://www.passdiy.com/pdf/a75p2.pdf

I hope that you are one of lucky people who don't need spend last days in shopping centers to buy something. I wish you happy marry Christmas.
I like Christmas but hate days before because tons and tons of people are everywhere....
  Reply With Quote
Old 21st December 2008, 05:28 PM   #32
Gyuri is online now Gyuri  Hungary
diyAudio Member
 
Gyuri's Avatar
 
Join Date: Nov 2003
Location: Budapest
Szervusz, Tomas!
Well, if we may regard it as fortune, here in middle-east Europe, and yes, here this nowadays fortune, with not buying hardly, but I spend my days with work rather at it.
Nothing is missing otherwise here from the Christmas, only the essence of this, that is the peace, the calmness and the affection.
Let it be from these here for us more!
But this mostly possibly not too our leaders, but depends on ourselves!

Gyuri

Anyway why not we could be friends? Since we are thinking similarly. And why it excludes the opportunity of the friendship if we are thinking some other way?
__________________
Those who would have deserved the life they are all dead already. "Oh, my dead dears!" - Captain Cat
  Reply With Quote
Old 24th December 2008, 10:50 AM   #33
diyAudio Member
 
t_majerovic's Avatar
 
Join Date: Sep 2008
Send a message via ICQ to t_majerovic
Default Hello Gyuri,

Completely agree :-)
  Reply With Quote
Old 24th December 2008, 11:32 AM   #34
diyAudio Member
 
t_majerovic's Avatar
 
Join Date: Sep 2008
Send a message via ICQ to t_majerovic
Smile My Aleph is working!!!! Yeeeaaaaaah....

Hello all

My Christmas began few hours earlier. I bring alive one Aleph 4.0 mono block. It is working without compromises. Sound is very good. Amplifier is hot like hell :-). Heatsing has 60C when room temperature is about 22C. Power supply rails still hold on 51V DC without any variation. Heatsing on rectifier is cold.
I removed thermistor connected between GND and earth which caused a lot of buzzing into speaker (it is used in original schematics). Now speaker is really quite and producing music only.
Output DC drift is under 20mV after 30 minutes amplifier warming.

Input mosfets are matched to 10mV and output mosfets are matched to 100mV.

Once I bring online second mono block make any listening and keep you updated about my impression.

To Nelson Pass: Thank you that you share with us design ideas and schematics. Many thanks.
  Reply With Quote
Old 24th December 2008, 12:36 PM   #35
Gyuri is online now Gyuri  Hungary
diyAudio Member
 
Gyuri's Avatar
 
Join Date: Nov 2003
Location: Budapest
I congratulate you Tomas!
Additional patience, and with its other half full the joy.
With a Christmas greeting!
Gyuri
__________________
Those who would have deserved the life they are all dead already. "Oh, my dead dears!" - Captain Cat
  Reply With Quote
Old 25th December 2008, 08:19 PM   #36
diyAudio Member
 
t_majerovic's Avatar
 
Join Date: Sep 2008
Send a message via ICQ to t_majerovic
Smile Update it's working again!!! Yeaaah...

Gyuri thank you.

Second Aleph 4.0 mono block is alive and fully operational. It's working also without problems. Measured values are almost same like on first mono block.

Yeaaah this year Christmas are amazing.

Next step is solve issue with soft start circuit topology.
See you later.
  Reply With Quote
Old 26th December 2008, 01:23 AM   #37
elac310 is offline elac310  France
diyAudio Member
 
elac310's Avatar
 
Join Date: Nov 2007
Location: Strasbourg
What about this solution?
http://www.transtecrk.de/products_In...begrenzer.html
  Reply With Quote
Old 26th December 2008, 02:21 PM   #38
diyAudio Member
 
t_majerovic's Avatar
 
Join Date: Sep 2008
Send a message via ICQ to t_majerovic
Smile Soft start issue is solved

Thank you elac310.

I keep and tuned up my initial soft start circuit and seems to be working fine. Current limiting resistor should have value 6.5 ohm and 30W. Resistor is bypassed by relay after 10 seconds. Input fuse should be slow type 6A/250V.
  Reply With Quote
Old 26th December 2008, 03:13 PM   #39
diyAudio Member
 
t_majerovic's Avatar
 
Join Date: Sep 2008
Send a message via ICQ to t_majerovic
Post Listening and listening....

Today I spend hours and hours by listening of music on my finished Aleph 4.
My source is DVD player Panasonic DVD-RA71 (little bit obsolete but has good sound). I used output with volume control for headphones and connect it to RCA on Aleph 4.0 (I don't have preamplifier yet) . My speakers are Jamo Classic 8 (4 ohms, yes I know Aleph 4.0 is designed for 8 ohms, yes I know that Jamo is not high end). Amplifier and speakers are connected by standard speaker cable with diameter 3mm.
What about sound? So I should say that I'm surprised positive and also negative way. But in most cases positive way, believe to me. Amplifier and currently used speakers love jazz, blues, world music and instrumental music. It is full of details and air. I can listen music quite or loud and there are still details.. Since today I like Diana Krall, Elvis Costello. Death Can Dance Duality kicked out my breath...full of details, space and dynamics (I should say same about first two CDs.). Well next listened CD was from Michael Jackson two CDs compilation history. Here were coming positive and negative experiences. Older records/songs are without live when music become complicated/more voices, instruments (special electronic instruments) sound is like screaming without details. Also space is like reduced. But for example songs Stranger in the Moscow, Earth song had very nice sound with details, dynamics, space...
I like Enigma so it can't be missing during listening. Today Enigma made for me mixed fillings. Usually I hear a lot of bass. Today Enigma was played with less bass but more details, air and space.

I thing that sound will be improved by adding preamplifier with input selector + volume control and use line out from DVD player. Also better speaker should improve sound quality.

Well I already began to build preamplifier. Here is link: http://jos.vaneijndhoven.net/relaixed/:)
  Reply With Quote
Old 26th December 2008, 03:17 PM   #40
diyAudio Member
 
t_majerovic's Avatar
 
Join Date: Sep 2008
Send a message via ICQ to t_majerovic
Default Here are some pictures

....maybe you know some of them:

http://www.facebook.com/album.php?ai...&id=1386409150
  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
FQA12P20 for use with Passlabs F5 etc dhole Swap Meet 4 13th March 2009 01:23 PM
www.passlabs.com down? Mickey Pass Labs 2 7th February 2008 12:02 PM
Passlabs D1 with DC servo ? shf1107 Pass Labs 9 22nd December 2007 04:46 PM
Passlabs Becomes Complex A'af Pass Labs 17 16th October 2003 03:22 PM
Passlabs Aleph 5 project????? Chamberman Pass Labs 3 14th June 2001 08:53 PM


New To Site? Need Help?

All times are GMT. The time now is 05:15 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