Very useful Frede, thanks for sharing.

More and more people seem to be migrating back to vinyl, including many younger people fed up with tunny sounding mobile device music.  Black is back.

Have you had any response to the new MC box you are going to build or the 'new' version of the stereo width box?

Dave.

I still use a Beogram 4000/20CL with my Beolab and I find the phono preamp really superbly musical and detailed!

The exact same combination as I use Jacques!  Wonderful to hear isn't it?.

Dave.

Hi.

Is the Phono and the Mic input crossing signals on the priamp? 

I have changed all electrolytic caps(not tantilum) and transistors, but after playing vinyl for 30 mins, i get some awful distortion in the right channel. 

Sounds like a camp fire in the speaker. The speaker is OK.

If I turn the volume down, it's gone. The higher the volume, the higher distortion. Suddenly it can be quiet for several minutes, before it starts again.     

The MIC input has similar noise, AUX and TUNER is perfect.

Did you fit low-ESR capacitors?

Martin

I used mostly general electrolytic capacitors. But sure, you are onto something I didn't think of. I understand you are NOT supposed to use to high spec capasitors, right? All values are directly replacements, with some higher voltages, but all uF has been swapped with same nearest value.

I have used some Nichicon FW Gold Muse caps from 3-100uF. Are they to low-ESR?

Great tip Martin!. Thanks

BR

Frank

Frank Solem wrote:

I have used some Nichicon FW Gold Muse caps from 3-100uF. Are they to low-ESR?

Great tip Martin!. Thanks

 

BR

Frank

 

In which circuits?

Martin

Hi Frank,

I would also recommend you to check the following:

1.

Do you hear the noixe in both channels?  

This is to indentify the source of the noise.

2.

A possible point could be - the polarity of the replaced electrolytics.

Please check that in the 2 pre-amps

If the noise is on both channels - perhaps the problem is in the power supply filters for the 2 pre-amps.

Dillen,

Since the problem is in the phono stage and Mic only, I'm thinking is has to be a problem with preamp 1 or amplifier 2, right side. I have used the gold muse caps on that whole board, exept the four bigger caps,

2x400uf(142&182). There I used 2x 390uF Nichicon, but I cannot see the type.

2 x 160uF(63&89). There I used 190uF Nichicon, cannot see the type.

  I have used the same capacitors on right/left side. Only right side has the problem.

I can see now that I haven't changed the two transistors 86 & 87 in amp 2(Nor the 64&82 left side). in mine they are BC-transistors with TO-18 metal casing. 

I will replace those two transistors pr side and give it a try. Of course, now as I am fiddling with it, it have had no symptoms for one hour... Crystal clear , perfect sound 😎

Thanks for the inspiration, I really value the help. I was getting stuck, but now have found new inspiration :)

Thanks to Classic also, for valid points :)