New cables for Thorens TD 160

Al, sounds like a good idea, if I had multimeter.
Suppose I should own one. The shop suggests,
"I don’t think the problem is the cables we put in. It’s possible the tonearm wires are bad but also unlikely.

Turntables have weird, subtle problems because the signal level is very low to begin with but I have gotten very good at sorting them out. "

Remember, I have no idea of the history of this table.
But it sure did look clean, except for those cables, which
were original, though broken.

Agree with Almarg. If you don't have a multimeter then try swapping headshell leads around for 1 channel. eg: connect the red headshell lead to the green pin on the cartridge and the green lead to the red pin on the cartridge and see what happens. I suspect the workshop that did the cables inadvertently connected the + & - leads the wrong way around at the turntable end for one channel.

An interesting thought- that the ground and signal
might be reversed. I just tried reversing the connection
on one channel and no change.

I wonder has anyone seen a signal drop from such a
reversal before? You'd think if the theory were sound
(if you will), reversing the +/- would always lead
(again if you will) to a signal gain or drop.

Anyway, back to the shop.

To clarify my earlier comment, I was not addressing the possibility that the two connections for one channel are interchanged, as the post by Tanathen78 earlier in the thread had already addressed that. As he indicated, that would result in the two channels being out of phase with each other, which would be perceived as vague and diffuse imaging, and probably also as reduced bass (which in turn might contribute to a perception of reduced volume).

What I was addressing was the possibility that the + wire of one channel might be interchanged with the - wire of the OTHER channel. In other words red interchanged with blue, OR white interchanged with green.

That would result in the center pins of the preamp's RCA inputs for the two channels being connected to each other through one of the cartridge's two coils, with both inputs "floating" (i.e., having no definable voltage or impedance) relative to the preamp's ground.

I don't know what the resulting sonic consequences would be, as they most likely would be dependent on the design of the particular phono stage. But it's certainly safe to say that the sound would be far from normal, and it seems quite conceivable to me that the result could be the very weak volume you have described.

I'm hesitant to suggest that you intentionally introduce that kind of reversal as an experiment, however, because another possible consequence that is conceivable to me would be a loud and potentially destructive hum or oscillation (although being careful with the volume control would PROBABLY eliminate any possibility of harm). That is one reason I suggested checking all of the wiring with a multimeter instead. Hopefully the shop will now do that for you.

Regards,
-- Al

I did try switching the connections to the cartridge
every which way. No dice. So it's back in the shop.
We will see. He did note that it's an original Pickering
cartridge, but I knew that...

Hoping for some good news next weekend. Will report.