Sjöström Audio DIY forum

Projects => Phono RIAA amplifiers => Topic started by: VesaK on December 20, 2014, 02:06:16 PM

Title: Humming QSXM3
Post by: VesaK on December 20, 2014, 02:06:16 PM
heaveno

At last had time to put this RIAA together, but did not succeed to make it stabil. When starting, voltage jumps to something like 14v. But after maybe 30sec it drops and start to oscillate. DC show 0,03-0,00. If connected to a speaker, it makes low HZ brumming sound.  RIAA has one pair of SSR01/02 superregs as PS.   

Have tried to figure this out but with no success. Please...

Ps. many polyprops and R1 are under the board, cause of size

Vesa
Title: Re: Humming QSXM3
Post by: peranders on December 20, 2014, 02:32:23 PM
I would appreciate an even closer look and not with a flash if that's possible.

Can you list every part you have mounted and what type you have used?

I assume that you have a perfect ± 15 V supply voltage?
Title: Re: Humming QSXM3
Post by: VesaK on December 20, 2014, 06:19:16 PM
Hi

Solved... Had not R2, or short, on place. Sorry...

Now it plays great.

Picture with superregs. Great stuff!

Thanks

/V