I would like to buiild a Phono Preamp for my vintage TT with Ceramic Cartridge. Output from this phono would be fed to Onkyo HT-R380 AVR.
Below are some schematics. Let me know the best one or any other alternative.
Below are some schematics. Let me know the best one or any other alternative.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
What do you mean by "best"? We can't tell you which preamp you might prefer, any more than we can tell you which type of music you should play. Why not build the simplest one, and see if it is good enough?
Figure 2, 8, 9 look as if they have the RIAA roll off, and 2n3904 are easy to come by. The op amp one looks as if it is missing the RIAA rolloff. If you can find an opamp mag phone schematic, you can adapt for ceramic input by decreasing the gain by decreasing the feedback resistor. See the mag phono input at the end of this thread http://www.diyaudio.com/forums/anal...improving-disco-mixer-mid-fi-performance.html The feedback resistor is the 1.5 megohm one from point to minus input, try 150k at first. I'm using ST33078 op amps. They don't latch up if the input hits the rail like TL07x ones do.
IMHO ceramic cartridges don't really do hi-fi so an ultimate low noise gain stage is probably a waste of time. 1-10 uf capacitors are as easily film dielectric now as electrolytic, and you don't have to worry about the polarity.
IMHO ceramic cartridges don't really do hi-fi so an ultimate low noise gain stage is probably a waste of time. 1-10 uf capacitors are as easily film dielectric now as electrolytic, and you don't have to worry about the polarity.
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Going from memory back in the old days of discos in the 60's and 70's, there wre two options when using ceramic carteidges, when the cheapo's were Sonotone 9TAHC's, or if you went posh you'd use Decca Derams.
You could either high impedance load them and the natural response of the ceramics was a close approximation to the RIAA curve, or you could 'velocity' load with a lower impedance and use RIAA equalisation which again was the preferred approach.
Us with velocity loaded Derams could sneer at lesser types with Hi z 9TAHC's. A bit sad really......
You could either high impedance load them and the natural response of the ceramics was a close approximation to the RIAA curve, or you could 'velocity' load with a lower impedance and use RIAA equalisation which again was the preferred approach.
Us with velocity loaded Derams could sneer at lesser types with Hi z 9TAHC's. A bit sad really......
Assuming that your AVR has a phono input (not automatically true these days...) the best solution is to load each channel with a coupla-K ohm resistor and feed it into the phono input. In this case the exact value of load resistor doesn't change frequency response, but does change level.
All good fortune,
Chris
All good fortune,
Chris
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