Aleph 5 playing... - 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 18th March 2003, 06:31 PM   #1
Lucas_G is offline Lucas_G  Netherlands
diyAudio Member
 
Join Date: Nov 2002
Location: Netherlands
Default Aleph 5 playing...

I have finally got some pictures of my two new Aleph 5 monoblocks.
They were taken some 10 days ago when I had just started to listen to them.
You will see them in their naked version.
Meanwhile I have added the wooden sides and the aluminium tops and bottoms. The frontplate will be professionally made in a later stage.

Lucas.

In this picture you see the side of it:
The Condis were still not fixed, but hey cvould not fall out...
Attached Images
File Type: jpg aleph5photo6.jpg (63.7 KB, 2753 views)
  Reply With Quote
Old 18th March 2003, 06:33 PM   #2
Lucas_G is offline Lucas_G  Netherlands
diyAudio Member
 
Join Date: Nov 2002
Location: Netherlands
View on the top:
Attached Images
File Type: jpg aleph5photo8.jpg (71.9 KB, 2670 views)
  Reply With Quote
Old 18th March 2003, 06:35 PM   #3
Lucas_G is offline Lucas_G  Netherlands
diyAudio Member
 
Join Date: Nov 2002
Location: Netherlands
Other side:
Attached Images
File Type: jpg aleph5photo9.jpg (63.9 KB, 2600 views)
  Reply With Quote
Old 18th March 2003, 06:40 PM   #4
Lucas_G is offline Lucas_G  Netherlands
diyAudio Member
 
Join Date: Nov 2002
Location: Netherlands
View from underneath:
Attached Images
File Type: jpg aleph5photo5.jpg (55.3 KB, 2542 views)
  Reply With Quote
Old 18th March 2003, 06:42 PM   #5
Lucas_G is offline Lucas_G  Netherlands
diyAudio Member
 
Join Date: Nov 2002
Location: Netherlands
Also upsidedown:
Attached Images
File Type: jpg aleph5photo4.jpg (61.2 KB, 2482 views)
  Reply With Quote
Old 18th March 2003, 06:46 PM   #6
Lucas_G is offline Lucas_G  Netherlands
diyAudio Member
 
Join Date: Nov 2002
Location: Netherlands
Again from underneath you see the 30 VAC transformator (330 VA) with next to it a small heatsink on to which two rectifierbridges are attached.
Attached Images
File Type: jpg aleph5photo3.jpg (46.2 KB, 2366 views)
  Reply With Quote
Old 18th March 2003, 06:52 PM   #7
Lucas_G is offline Lucas_G  Netherlands
diyAudio Member
 
Join Date: Nov 2002
Location: Netherlands
These PCBs are Kristijan's...

I attached folded brass dog-pennings for cooling the 9610s.
Under the PCBs you first get a nylon ring, then an alunminium stripe, then the IRFP 240, then Kapton (non-grease) isolation, then a 3 mm thick redcopperbar, then grease, and finally the Seifert Heatsink, measuring 216 x 150 x 84 mm.
Attached Images
File Type: jpg aleph5photo7.jpg (60.9 KB, 2354 views)
  Reply With Quote
Old 18th March 2003, 06:55 PM   #8
Lucas_G is offline Lucas_G  Netherlands
diyAudio Member
 
Join Date: Nov 2002
Location: Netherlands
Here you can again see how the Mosfets were attached:
(Sorry for the badly focused photo...)

You also see the AC filter inlet, and the thermal 80 degrees Celsius clickson.
Attached Images
File Type: jpg aleph5photo2.jpg (45.7 KB, 2308 views)
  Reply With Quote
Old 18th March 2003, 07:00 PM   #9
Lucas_G is offline Lucas_G  Netherlands
diyAudio Member
 
Join Date: Nov 2002
Location: Netherlands
Here is a final (rather dark) picture where you can see the wooden sidepanels in a still rough state and one of the aluminium grids for the tops and bottoms.
(They have been installed now but I don't have a digital camera. I will post them later...)
Attached Images
File Type: jpg aleph5photo1.jpg (48.2 KB, 2232 views)
  Reply With Quote
Old 18th March 2003, 07:32 PM   #10
Lucas_G is offline Lucas_G  Netherlands
diyAudio Member
 
Join Date: Nov 2002
Location: Netherlands
Some remarks on the components used:

The toroids are 30 VAC 330 VA from Reichelt, Germany. Very cheap (33 Euro) and very silent.

The Condensators are 45 Volt (56 Volt surge) Marcon 16.000 uF. I used 2 sets of 4 pieces in each monoblock, divided by Intertechnik 3,9 mH 0,24 Ohm I-Point chokes.

I use two rectifierbridges for each channel.
The 30 VAC result in a 39 VDC under load.

One channel delivers appr. 30 mV DC offset, the other one is around zero!

I matched all mosfets, and I also matched the 550BC on HFE.

I used 0.25 Watt 0,1% precision resistors made by Welwyn, and 5 Watt MOX resisters made by Intertechnik.

Since I too have 4 Ohm speakers I decided to use the resistorvalues of WuffWaff that he has posted in another thread. This leads to a higher bias.

The Seifert heatsinks reach a temperature of about 47 degrees Celsius at a roomtemperature of 20 degrees. The redcopperbar on which the mosfets are attached reaches 53 degrees.
We can therefor conclude that the redcopperbar is a good solution.


Now on to the sound:

I have borrowed a lot of commercial products in the 1000 up to 4000 Euro segment from a befriended Hifi-shop.

Most sounded horribly clean and sterile with a narrow spacing.
Only a Classé Audio amp was a bit more natural but its bass was weak.

The Aleph 5 is in another class: it lets you hear detail and space in recordings without ever getting harsh.
It is the most natural sound that I have heard.
Thank you Nelson Pass!

Regards to all,

Lucas.
  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
Just playing with my Charlize andy2667 Class D 87 14th August 2008 08:14 PM
Now playing… martyh Analogue Source 2 27th June 2008 02:46 PM
Playing with ROMs Zero One Digital Source 0 13th May 2007 12:18 PM
what's better, a mid playing high, or a tweet playing low??? cody6766 Multi-Way 10 20th February 2005 09:40 PM
Playing with a Magic Eye. Shoog Tubes / Valves 7 13th January 2005 09:33 PM


New To Site? Need Help?

All times are GMT. The time now is 03:48 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