Simplistic NJFET RIAA

Really can't tell bcs Rush put that together, I only told him about the configuration idea. If he does not read maybe PM him?

It worked great, no hum.
I can find the diagram when I get home tonight and post, but in a nut shell, used a common ground from both supplies in outboard chasis to single point in preamp.
So that was +/- 17 volts for DCB1 and +38 volts (or whatever it was raw) for RIAA and the common ground = 4 wires.

Rush
 
It worked great, no hum.
I can find the diagram when I get home tonight and post, but in a nut shell, used a common ground from both supplies in outboard chasis to single point in preamp.
So that was +/- 17 volts for DCB1 and +38 volts (or whatever it was raw) for RIAA and the common ground = 4 wires.

Rush

Here is my very rough white-out drawing.

Rush
 

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I have two transformers that I can use with the FSP.A Toroidy Toroid which gives 43vdc unloaded and a Selectronique R core which gives 48vdc again unloaded.Both have 15v secondaries connected in series the toroid giving 33v and the R core 38v unloaded.
Which would be the best to use bearing in mind that I have been using the FSP with the toroid with no problems.The heatsinks barely get warm.
 
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R Cruz,
If you believe in such things, the Siemens Sikorels are nice in the Prereg. May I ask what bypass caps you are using the PSU as well as coupling caps in the RIAA. I will be trying the Audyn copper next for output cap on RIAA. It will be in combinatin with Obbligato Gold interstage.

Hi Buzz

After many combinations I settled with Ft-3 interstage riaa cap.

The best output cap for the riaa is undoubtly the Clarity cap MR 600v..... Outstanding

For the bass cap in the riaa I use obbligato gold or copper (same thing ?)

For high freq cap in the riaa I usually use Relcap copper on polystyrene.

For bypass caps in the psu I use ussr K71 styros
 
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The Rcore is an Selectronique branded Schilcar(made in India) which despite being a 15v secondary reads nearer to 18v even when loaded.I also have a Chinese made R core also with 15v secondary which stays within a volt of that whether loaded or not.Which is the better toleranced?
Thanks for the replies.
 
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diyAudio Chief Moderator
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The Rcore is an Selectronique branded Schilcar(made in India) which despite being a 15v secondary reads nearer to 18v even when loaded.I also have a Chinese made R core also with 15v secondary which stays within a volt of that whether loaded or not.Which is the better toleranced?
Thanks for the replies.

I suspect they are calculated for 220VAC primary originally hence the "healthy" secondary output. That big Indian electrical components company was set up by the Japanese for their Rcore production department a long time ago so they could be following old 220VAC standard designs without risking to modify.