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.

Official M2 schematic
Official M2 schematic
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 12th June 2018, 08:12 PM   #2731
kbergsson is offline kbergsson  Iceland
diyAudio Member
 
Join Date: Jul 2009
Location: Norway
Silasmellor I have the Diyaudio powersupply solution (8x 18000uf) in my F6 and unshielded 400VA trafo. Had some supply noise at first then remembered to do grounding excactly as 6L6s F6 build guide. My F6s are now totally silent on my 100+db Altecs.
Did you get your Kemets from surplus in Holland? I got mine there (tunasto) for a good price. Jonny Canuck, correkt 47000uf long life PEH200. Mouser has them as well but they are expensive. Mine are as said from surplus but according to datecodes all between 2 and 3 years old, seem to be unused.
I have some screens for the edcors on the way, if necessary, but they will be placed furthest from the trafos.

Last edited by kbergsson; 12th June 2018 at 08:21 PM.
  Reply With Quote
Old 12th June 2018, 09:23 PM   #2732
silasmellor is offline silasmellor  Denmark
diyAudio Member
 
Join Date: Nov 2016
Location: Denmark
Official M2 schematic
Yes, I saw the link to that surplus store in another thread and snatched up some of those caps there as well. They are in mint condition, so a very nice find! How do you plan to connect them? I am thInking to use a dual 300va, 19v secondaries, and use 4x2 ohm (5w) between cap banks to bring ripple down further. Psud2 says that should give around 23v after the last caps.

I also use the grounding scheme from the guide. From psu board, via cl60 To chassis. Each amp board connected to +/-/gnd.. The noise is very faint with me ear next to the woofer, but I can see higher order harmonics in the fft which bother me (though i am not sure they are audible). I’m not sure if it is radiated noise from the transformer getting into the Jensen’s, but that’s currently my hypothesis.

Looking forward to more pictures, my build is still some way off, so I am curious how this works out (great I am sure).
  Reply With Quote
Old 12th June 2018, 09:33 PM   #2733
coolnose is online now coolnose  Europe
diyAudio Member
 
coolnose's Avatar
 
Join Date: Sep 2009
Link?
  Reply With Quote
Old 12th June 2018, 09:53 PM   #2734
kbergsson is offline kbergsson  Iceland
diyAudio Member
 
Join Date: Jul 2009
Location: Norway
It will be similar to your plans i.e. I have some 0R1 10w wirewounds as R in CRC, so 47000uf-0R1-47000uf and maybe 10uf large Wima as bypass per rail. The trafos I got are 2x 300VA dual 18V seconaries. I dont have any simulation sw. So If I like the sound is will be ok, If not Ill have to try something else
In the F6 I use shielded input cable with shield connected to gnd cable at input connector. I have used Tubes for a long time so if I dont hear noise I dont care
It will take some time to finish as I have not bought a chassis yet, and dont want to dissassemble my F6 to test the M2. I like the F6 to much

The store is Electrodump.nl i think.

Quote:
Originally Posted by silasmellor View Post
Yes, I saw the link to that surplus store in another thread and snatched up some of those caps there as well. They are in mint condition, so a very nice find! How do you plan to connect them? I am thInking to use a dual 300va, 19v secondaries, and use 4x2 ohm (5w) between cap banks to bring ripple down further. Psud2 says that should give around 23v after the last caps.

I also use the grounding scheme from the guide. From psu board, via cl60 To chassis. Each amp board connected to +/-/gnd.. The noise is very faint with me ear next to the woofer, but I can see higher order harmonics in the fft which bother me (though i am not sure they are audible). I’m not sure if it is radiated noise from the transformer getting into the Jensen’s, but that’s currently my hypothesis.

Looking forward to more pictures, my build is still some way off, so I am curious how this works out (great I am sure).

Last edited by kbergsson; 12th June 2018 at 10:09 PM.
  Reply With Quote
Old 13th June 2018, 05:48 AM   #2735
coolnose is online now coolnose  Europe
diyAudio Member
 
coolnose's Avatar
 
Join Date: Sep 2009
Thanks!
  Reply With Quote
Old 13th June 2018, 10:15 AM   #2736
kbergsson is offline kbergsson  Iceland
diyAudio Member
 
Join Date: Jul 2009
Location: Norway
As Im an assembler of kits and not a designer, I must give credit to ZM ( his nice 2M clone ) and older FW powersupply designs as inspiration for my simple CRC.
  Reply With Quote
Old 13th June 2018, 02:27 PM   #2737
Skylar88 is offline Skylar88  South Africa
diyAudio Member
 
Join Date: Jun 2017
Location: South Africa, PTA
Quote:
Originally Posted by kbergsson View Post
The store is Electrodump.nl i think.

Correct link: elektrodump.nl

.
  Reply With Quote
Old 13th June 2018, 03:34 PM   #2738
1543 is offline 1543  Germany
diyAudio Member
 
1543's Avatar
 
Join Date: Jun 2004
Location: Ruhrgebiet
Official M2 schematic
Default Get the most out of M2/F6

Had some time to listen to M2 amplifier I build few weeks ago. Soft low end, soft on top. I like the soft low end, but not the lack of details in music. When listening to music the lack of details is very obvious at some songs, however still something special, a bit like water color.

I am using allready transformers (jensen ground isolator) to avoid hum (cause by TV, SAT antenna) in my TV setup. To reduce sound impact of transformer I have placed the passive volume attenuator behind the transformer.

This reduces the THD&N at low freqencies for example by 14db (0db compared to -40db signal level according to jensen datasheets). Also the micro details in music are not lost and setup is more immune to inducted distortion by electric fields.

To get the most out of M2 and F6 I would like to place the volume attenautor also behind jensen / edcor transformers. For M2 this would be possible I guess. Could you help please if this would be feasible and what pot/relay volume attenuator impendance would fit best to match output impedance of transformer and the power transistors.

Any chance to put a dual volume control behind the jensen transformer in a F6? I do not know where to place.
Attached Images
File Type: png M2_Vol.png (86.9 KB, 199 views)
  Reply With Quote
Old 13th June 2018, 04:12 PM   #2739
Mark Johnson is offline Mark Johnson  United States
diyAudio Member
 
Mark Johnson's Avatar
 
Join Date: May 2011
Location: Silicon Valley
Official M2 schematic
The traditional position for a volume control would be "R2". Use a 100K pot to ground, input comes from R1, wiper goes to Q3 and Q4. Since it's DC coupled, if the input signal happens to have any DC offset, changing the volume control can produce a scratchy sound.

You probably don't want to drive the output stage from an impedance that varies with volume control setting. So you probably don't want to install the pot between the secondary and the output stage.

Last edited by Mark Johnson; 13th June 2018 at 04:19 PM. Reason: scratchy
  Reply With Quote
Old 13th June 2018, 04:14 PM   #2740
Russellc is offline Russellc  United States
diyAudio Member
 
Join Date: Mar 2003
Location: midwest
Official M2 schematic
Quote:
Originally Posted by 1543 View Post
Had some time to listen to M2 amplifier I build few weeks ago. Soft low end, soft on top. I like the soft low end, but not the lack of details in music. When listening to music the lack of details is very obvious at some songs, however still something special, a bit like water color.

I am using allready transformers (jensen ground isolator) to avoid hum (cause by TV, SAT antenna) in my TV setup. To reduce sound impact of transformer I have placed the passive volume attenuator behind the transformer.

This reduces the THD&N at low freqencies for example by 14db (0db compared to -40db signal level according to jensen datasheets). Also the micro details in music are not lost and setup is more immune to inducted distortion by electric fields.

To get the most out of M2 and F6 I would like to place the volume attenautor also behind jensen / edcor transformers. For M2 this would be possible I guess. Could you help please if this would be feasible and what pot/relay volume attenuator impendance would fit best to match output impedance of transformer and the power transistors.

Any chance to put a dual volume control behind the jensen transformer in a F6? I do not know where to place.
Odd, I note none of the soft low end or lack of detail.... I guess rooms, ancillaries, and speakers can change things up?
__________________
Pass B-1 preamp, Pass BA3 preamp, Pass F-5 Amp, Pass F-6 Amp, Pass BA-3 Amp, Pass M-2 amp, Pass Aleph J amp, Pass Pearl 2 Phono pre Tekton Enzo, Altec A7, Econowave JBL 2235H & B&C CD
  Reply With Quote

Reply


Official M2 schematicHide 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
First Watt M2 Kovax Pass Labs 154 13th February 2014 05:20 PM
JBL m2 ! Ahmad_tbp Multi-Way 0 7th February 2013 01:14 PM
First Watt M2 chrismercurio Pass Labs 16 18th March 2012 01:53 PM
swans m2 blue934 Multi-Way 0 22nd May 2008 05:56 AM
Audio Note M2 regulator schematic drobert Tubes / Valves 1 10th November 2007 03:09 AM


New To Site? Need Help?

All times are GMT. The time now is 06:15 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