[Robertod]

Pic3

[Robertod]

pic 1 power,
pic 2 line,
pic 3 phono

[galyons]

Pic3

Per schematic should be:
4 x ECC83 or equivalent tubes
The 2 large blue electrolytic capacitors should be 22uF.
The 4 small electrolytic capacitors should be 220uF.
The 4 green box film capacitors should be 0.22uF.

I cannot read the values very well in the pic. So check the actual components.  They may not be exactly the same, but should be close.

[galyons]

Pic2

Per schematic should be:
2 x ECC82/12AU7 or equivalent tubes
The 2 large blue electrolytic capacitors should be 22uF
The 2 green box film capacitors should be 0.47uF.

I cannot read the values on the electrolytic caps in the pic. So check the actual components.  They may not be exactly the same, but should be close.

[Robertod]

thanks a lot very helpful.
How about the first pic. the one tube for power supply.

Again thanks, cheers!

[galyons]

Pic1

Per the power supply schematic there should be:
1 x ECC82/12AU7 or equivalent tubes
The 2 large black electrolytic capacitors should be 220uF
There should be 2  electrolytic capacitors  100uF
There should also be caps for the 12.6V filament supply.

I cannot read the values on the electrolytic caps in the pic. So check the actual components and let me know the values.  They may not be exactly the same, but should be close.

I would consider changing the electrolytic caps on all of the board due to their age.  If the small electrolytics are Black Gate, leave them. They should be fine.

[Robertod]

Thank you for your info.  I will open up the AN this evening and I'll reply what I find.

[Robertod]

Opened up AN was able to verify the caps only one different was on board with 4 tubes
450v 33uf not 22uf.
large black caps are on power supply are rubycom.
most caps are from rubycom.


thanks for your help

[galyons]

Opened up AN was able to verify the caps only one different was on board with 4 tubes
450v 33uf not 22uf.
large black caps are on power supply are rubycom.
most caps are from rubycom.


thanks for your help

That is an insignificant difference in the 450v caps.  33uf is really only one step up and the caps are for power not signal.  I think you are good to replace the tubes as specified.  25 year old electrolytic caps likely should be replaced.

Cheers,
Geary

[Robertod]

Thank you for all your help. Upgrade tubes and replace caps. thanks.

I was wondering if you can send me a copy of the schematics. if not no prob.

thanks again.

[slaw845@yahoo.ca]

Hello,. I know I am rebooting an old thread but I have the exact same preamp.  An early M1.  Does anyone know if the ribbon cable that was used is worth upgrading in this preamp?  And would any one know what the 12au7 does in the power supply?

[SET Man]

Hello,. I know I am rebooting an old thread but I have the exact same preamp.  An early M1.  Does anyone know if the ribbon cable that was used is worth upgrading in this preamp?  And would any one know what the 12au7 does in the power supply?

Hey!

   Hmmm, I missed the original post. Anyway, I have the Audio Note M1 Phono pre. I bought it new back in 1997 or 98 and have been in my system since.

   I upgraded a few things in there including all the RCA chassis connectors and wire, I used 6-nines single crystal copper if I remembered it right. It sounds better to me. You can try it but I do recommend you don't throw away the original just in case you like the stock better so you can put it back. Other big change you can make in there is the line stage output capacitors, they are 0.47uf, I have been using Jensen PIO copper in there the pass 20 years. Sadly Jensen is no longer around.

  As for the tube in power supply, the pre came with 5814A which is a Mil-spec version of the 12AU7. I have Philips JAN 5814A in mine right now. Hope this help.

Buddy