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Retro - A fully symetrical phono stage with RIAA filter

using just the + output and common ? is that correct?
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Connecting unbalanced turntable to the Retro

I just read through most of this thread after which I ordered the bunch. I am very excited to put an analogue stage next to the ancient Buffalo24 digital stage.

There is just one thing I don't fully grasp when connecting an unbalanced turntable to the retro. Like most turntables, it outputs a left and a right RCA connector and a ground wire. And ideally I would like to connect these three cables directly to the retro box.

Russ White describes in the first post of this thread how he tackled this, however I am not sure whether I fully grasp what he is saying:

"You can still use normal RCA inputs with one end of the cartridge output grounded. I have been using it with the cartridge floating. I use XLR with pin 1 connected to the retro GND and pins 2 and 3 connected only to the cartridge outputs. One per channel."

Russ is using an XLR cable and I would like to wait for now with modifying the turntable and therefore would like to use the standard RCA/ground wire cables.

Thus, in the retro box, I am planning on fitting 2 female RCA connectors and one of those ground screws.
The 0 wire of each channel is then connected to the the ground of the turntable, and to the IN- on the retro board and not to the ground of the retro. The other RCA wire goes directly to the IN+ on the retro board.

Why not, connecting the unbalanced signal to IN- and IN+ and directly wire the turntable ground to the retro ground? By connecting it as Russ suggests, the entire turntable' ground is in the signal path, that seems a bit scary..

Since this is all a bit new to me and I am quite eager to learn. Did I interpret the quote of Russ correctly and would that work?

Thanks!
Bas
 
Hi Bas,
you just need to make sure that none of the RCA outputs are connected to the turntable ground. You should check it with a continuity meter. If there is no connection then your turntable will not need any modification.

Thanks! This is exactly what I was looking for. And the floating cartridge is than referring to that is cartridge is not grounded at all.

Cheers,
Bas
 
any more boards being produced?

I'm interested in a pair of Low Z boards—are these still being made? The TP site has them all out of stock, and am not sure if they are going to be in circulation any more.

Assuming they are, have there been newer ICs that should replace the 1632 and 1642? It seems like projects I've made even 2 years ago now have "obsolete" parts in them. :(

Alan