MM phono amplifier C3G tubes

[rclourenco]

To sell has new, my home built MM Phono amplifier.

It is based upon Andre Ciuffoli C3G phono amplifier (amply available by Google search).

Selling due to no use and to pick some funds for the next project.
The amplifier is working and it’s very silent, BUT from time to time it oscillates and I can’t seem to resolve the problem. It’s very random, and some times it plays wonderfully for 20 hours and days in a row, and all of sudden it starts oscillating!!?? (Maybe one of you experts and potentially interested in getting this, can resolve the issue).


The amplifier is based on the fantastic Siemens C3G tube, know for its longevity and fantastic silent. The ones included have scarce hours of work, were bought new and are the gold pin version.

Included (please refer to the photos): Main unit + Separate Power Supply + Connection cables.

Materials:

• Full aluminium chassis, 3mm + 8mm face plates
• High quality Neutrik connectors
• PWS:
  • IE custom made transformer, largely oversized for the needs
  • High B+ rectifier board with Ixys diodes
  • Michael Percy Filaments power supply
• Main:
  • Lundahl LL1660 Transformers: 2 Amorphous + 2 Normal (market value alone on these in excess of 650€)
  • 2 x C-Core chokes custom made by Electric Europe in the Netherlands
  • Mundorf Mlytic capacitors
  • DALE filter resistors
  • All signal resistors Audio Note Tantalum
  • All RIAA capacitors RelCap Styro (new old stock and has used by Audio Note on their top line RIAA)
  • All tube bases are machined teflon with gold pins
  • All internal wiring Vandenhul
  • All signal cabling Belden 8402

Selling the all has is for 1.000€ + Shipping to be calculated depending on the destination (please note that the units are quite heavy with all that iron)
Could think of selling the Lundahl transformers alone (only the 4 pack): total 500€

Thanks for looking.

 

[Koifarm]

Maybe it oscilates because there are no grid resistors.

 

[rclourenco]

Thanks, but i did integrate 1k resistors right on the tube base G1, it improved, but still randomly comes back…

 

[mgomespt]

Hi Rclourenco, I was about to start the same project when I noticed your thread, I'd happily buy it from you as the asking price is more than fair, I'll send you a pm now

 

[mgomespt]

for some reason I cannot message you...can we do it through the comments here? or you can try messaging me?

 

[mgomespt]

Rui, parece que é português e se não me engano mora em Cascais, isso seria ouro sobre azul uma vez que estou em Colares 🙂 um abraço

 

[planet10]

Rui, it looks like it's Portuguese and if I'm not mistaken lives in Cascais, that would be gold on blue since I'm in necklaces 🙂 A hug

English please.

dave
diyAudio moderation team

 

[mgomespt]

Heheh, sure

 

[YouAgain]

Might want to put ferrite beads on all of the grid leads as well as using the grid stopper resistors.
I tried 7788 tubes once and only both resistor and ferrites would cure the oscillations.

 

[rclourenco]

Many thanks for the idea and support!

 

[rclourenco]

Sold
Please delete the thread if you will
Thanks