I built the M2 boards and mounted them on the test heatsinks to make sure they worked properly. In my music room they were quiet without the shield. During final assembly on the workbench, there was low level noise from the computer sitting just a few inches away. I installed the shield and grounded it. When I turned the amplifier on again it was absolutely quiet.
Grounding the shield was something I copied from Zen Mod's Papa's Koan build, his M2 clone, since I had never before used mu metal. After Jeff posted his comments above, I took the time to read about it and agree with him. I stand corrected, grounding the mu metal shield is not necessary. I am sure it does not hurt, so I am not going to take apart my M2 just to remove those grounding wires.
Grounding the shield was something I copied from Zen Mod's Papa's Koan build, his M2 clone, since I had never before used mu metal. After Jeff posted his comments above, I took the time to read about it and agree with him. I stand corrected, grounding the mu metal shield is not necessary. I am sure it does not hurt, so I am not going to take apart my M2 just to remove those grounding wires.
Yeah, I'd still ground it just for safety (like any other metal item in the amp), even if it does nothing for the shielding.
Experimenting last nights with M2 coupling caps and i was sceptical about any difference.
Real situation tests that was clearly audible.
The same 2 songs with strings, accordion, piano , acoustic bass , drums and the voice i do play maybe 50 times or more.
Stepped attenuator at the same precise volume level.
7 different types of caps was soldered and de soldered.
Not all show on the photos , specialy bulky paper in oil etc.
Conclusion : passive is important if you care about colorations of recorded sound from the passives components.
Caps changes was like less or more subtle equalisation. That only caps so i take care about semiconductors test next time.
Thanks to Mr Pass.
Was intructive experience after intellectual reads of many articles.
Truth of the music from my actual audio system.
Real situation tests that was clearly audible.
The same 2 songs with strings, accordion, piano , acoustic bass , drums and the voice i do play maybe 50 times or more.
Stepped attenuator at the same precise volume level.
7 different types of caps was soldered and de soldered.
Not all show on the photos , specialy bulky paper in oil etc.
Conclusion : passive is important if you care about colorations of recorded sound from the passives components.
Caps changes was like less or more subtle equalisation. That only caps so i take care about semiconductors test next time.
Thanks to Mr Pass.
Was intructive experience after intellectual reads of many articles.
Truth of the music from my actual audio system.
Attachments
elna silmic bypassed with 1uF Philips MKC ;
that , and I'm done
zillion dollars cap is better than that combo
that , and I'm done
zillion dollars cap is better than that combo
I wish I'd read the last 2 posts before ordering my parts last night for the Markwart crossover! 😀
Wait a minute...are you talking about using Silmics in the C3 position? I thought the 3300uf was only available in a 10V rating.
naaahh, I have used silmic 3300uF 50V like this one 2PCS ELNA 3300UF/50V RFS SILMIC II High-END HIFI Audio Capacitor MADE IN JAPAN | eBay but it will not fit to teabag boards.
Yes, the UMS is great, even if I invented it myself!
It allows you to bolt output PCB's right to the drilled and tapped heatsink diyAudio chassis!
Sneak alert! IF people wanting UMS boards are patient their dreams will be answered!
It allows you to bolt output PCB's right to the drilled and tapped heatsink diyAudio chassis!
Sneak alert! IF people wanting UMS boards are patient their dreams will be answered!
[
Sneak alert! IF people wanting UMS boards are patient their dreams will be answered![/QUOTE]
If this means the store will be carrying M2 boards, great news. I have often wondered why the store would not want these boards being the M2 is such a wonderful amplifier. Any time Nelson is gracious enough to share one of his designs the store should stock boards. Good for store, good for diy'ers.
Sneak alert! IF people wanting UMS boards are patient their dreams will be answered![/QUOTE]
If this means the store will be carrying M2 boards, great news. I have often wondered why the store would not want these boards being the M2 is such a wonderful amplifier. Any time Nelson is gracious enough to share one of his designs the store should stock boards. Good for store, good for diy'ers.
Even better DiyA Store option M2 essential kit pcb's with the jfets, mosfets and Edcor transformers 
And Silmics 🙂Even better DiyA Store option M2 essential kit pcb's with the jfets, mosfets and Edcor transformers
Whit:
- 2x M2 boards 2mm 70µm UMS compatible
- 1x Power Supply Board 2mm 70µm
- EDCOR PC600/15K
- transformer shielding
- all components (ELNA, WIMA, VISHAY/DALE, PANASONIC, BERGQUIST, and so on...), including 2x 60000µ capacitor bank and 8x HEXFRED TO247
Whitout:
- Main transformer
- Enclosure,
- paired JFET
- RCA or binding posts
for 250 Dollar without postage?
JP
- 2x M2 boards 2mm 70µm UMS compatible
- 1x Power Supply Board 2mm 70µm
- EDCOR PC600/15K
- transformer shielding
- all components (ELNA, WIMA, VISHAY/DALE, PANASONIC, BERGQUIST, and so on...), including 2x 60000µ capacitor bank and 8x HEXFRED TO247
Whitout:
- Main transformer
- Enclosure,
- paired JFET
- RCA or binding posts
for 250 Dollar without postage?
JP