RIAA board on eBay

[Blair]

Has anyone ever built this circuit. I assume by "designed by: Yang" it is referring to the board layout because it looks like many other schematics. Does it look OK?

http://item.mobileweb.ebay.com/viewitem ... 3674679598

Thanks!

Blair

[Geek]

Looks like one o' dem Jadis or L'Audio knockoff boards

[Blair]

Hi Gregg,

I'm not interested in the board really. Just a tried and true circuit for someone asking about a phono stage. He wants point to point, so the design does not matter too much. I can do it.

Got any suggestions using 12AX7s or 6DJ8s?

Thank you!

Blair

[Geek]

Honestly, Shannon's Budgie is by far the best I've heard

Tied for second for my ears is the Marantz 7C and my MOSeiden designed by Linnenberg-Audio.

Cheers!

[Blair]

Anyone try the 6BQ7A in the Budgie?

Blair

[Shannon Parks]

Anyone try the 6BQ7A in the Budgie?

Blair

You'd have to change the biasing to make it work in the Budgie, and then the 6BQ7 isn't linear at all in those conditions. 6BQ7s seem to really want >150V on the plates.

For PTP, you can do the classic RCA 12AX7 circuit, or the RJM 6DJ8 one:
http://usr.audioasylum.com/images/2/269 ... -phono.gif
http://phonoclone.com/diy-pho3.html

Shannon

[Blair]

So,

I did not build that board, but I found this RIAA board with a schematic and built it. It's quiet, so that's good, but the issue is that I cannot put both front tubes in without some odd oscillation like activity in the form of a low pitched repetitive tick/thud. I did this via point to point and the cathode follower feeds an SRPP line stage circuit.

Any ideas of why it is fine with one driver, but not both?

http://item.mobileweb.ebay.com/viewitem ... 9876975749

Thanks!

[Blair]

Got it! The CF after the gain stage was out of phase on the Feeback resistors.

Swapped them and dead quiet.

Thanks!

Blair