Microphonic RCA???

[tgourlie]

Anyone ever have the RCA(Monster interlink) from the Turntable to the Preamp become Microphonic?

I have,

Oh yeah and I can also pick up radio stations from one of those interlinks too. Ground?

Anybody have any ideas on what could be going on. Maybe use a sheilded ground cable?

Thanks again

[WMcD]

I never ran into this. I have not fooled with turntables or vinyl for a long time.

I am quite sure this is a matter of a bad connection somewhere.

If I may be pedantic here. Not to be too much of Bullwinkle's Corner and Mr. Know It All.

In the days of crystal radio, there was an alternave to the crystal diode. It was a sewing needle placed to bridge two razor blades, to thereby make two point contacts. One would be enough, probably.

This functioned as a diode. A diode is classic way to decode AM radio signals. The AM signal would average out to zero except for this "one way" conductor which ignors half the signal, so the modulation is recovered.

Also, cranky connection are sensitive to vibration, hence microphonic.

Best,

Gil

[lynnm]

Quick question:

Does your amp exhibit this behaviour with other interconnects?

I doubt that using a shielded ground connection will make a difference.If anything such a hookup could introduce a ground loop.

If however you find that your amp does not behave in that manner

with a different interconnect then my best guess is that one of the

cables is the culprit.

Another thought: How are those interconnects connected to the

turntable? Do they connect via an RCA jack or are they wired directly?

Does this behaviour occur only on the phono setting or does it show up elsewhere?

[pauln]

You probably need to get your interconnects up on spikes so as to isolate them from vibration and better couple the electric flow.

[Duke Spinner]

Bad Solder Joint

[tgourlie]

The noise does not occur in any of the other inputs. Only the

phono. The phono stage uses two 6DJ8's (one for each channel) and

the line level inputs use 1 6DJ8. All of the tubes are also make

noise when tapped lightly. Is that normal for these tube types?

I will also check all solder joints on the inputs. I did clean

all inputs with Ultraconnet as well. Maybe I did corrupt the

solder joints.

Thanks for the help!!

[lynnm]

Don't shotgun when troubleshooting!

Remove all input cables and lightly tap each of the 6DJ8 tubes.

If you get microphonics then the problem is either a tube ( quite

likely BTW ) or some component associated with the tube rather than a

cable.If no microphonic behaviour then connect one cable to the phono

stage and try to replicate problem.If no microphonics then remove that

cable and try its mate in that connection and so on.

What you need to do in this type of situation is to reduce the

variables to an absolute minimum and test new variables singly. If you

attempt to rule out several variables at once you wind up spinning in a

circle and get progressively more confused.

[mark1101]

Tubes can be microphonic to different levels. I have had tubes that produce a slight sound out the speakers when tapped, and some that you can not even touch ANYTHING in the equipment rack without an absolutely abnoxious sound out the speakers. Those are the ones that really piss you off for having spent money on them. Some are silent (out the speakers) when tapped, and get you to elicit a smile. Microphonics is not necessarily by price either as I have learned.

You have to be the judge if it warrants a change out. But, I have no idea if a microphonic tube can pick up a radio station.