I am trying to take the output from my Sumiko Pearl MM phono cartridge, to a a MiniDSP 2x4 HD (apply the RIAA equalization here), then to my amp, and eventually my speakers.
Any suggestions on how to take the signal from 4.0 mV output voltage from the Sumiko to the 4v required by the MiniDSP?
The RJM Audio B-board looks to be a contender but I'm open to suggestions.
Any suggestions on how to take the signal from 4.0 mV output voltage from the Sumiko to the 4v required by the MiniDSP?
The RJM Audio B-board looks to be a contender but I'm open to suggestions.
The board you linked is a unity gain buffer, the output voltage will match the input voltage.
What you need is a flat voltage gain stage of 50dB or thereabouts (more if your cart is MC type)
What you need is a flat voltage gain stage of 50dB or thereabouts (more if your cart is MC type)
I'm busy doing something similar, see this thread:
Overload margin in Phono pre-amp
I'm using Analog Devices inamp evaluation boards to provide the required gain (AD8421 looks like the best inamp from AD for this application).
Overload margin in Phono pre-amp
I'm using Analog Devices inamp evaluation boards to provide the required gain (AD8421 looks like the best inamp from AD for this application).
Last edited:
Yup RJM emailed me back with a few suggestions. I guess the MiniDSP isn't really suited for this project as it'll still need a EQ adjusting circuit prior.
Whoa very cool. Going to follow this thread. Would be happy to beta test this if you need.
I used a Schitt Mani Phono Preamp between my turntable and my miniDSP DDRC-24
(The miniDSP DDRC-24 is the same hardware as the miniDSP 2x4 HD).
I also jumped the miniDSP for 2v input since that's what most devices output.
(CD Players, DAC, Bluetooth receivers etc).
(The miniDSP DDRC-24 is the same hardware as the miniDSP 2x4 HD).
I also jumped the miniDSP for 2v input since that's what most devices output.
(CD Players, DAC, Bluetooth receivers etc).
Last edited:
The miniDSP can do the RIAA correction and a rumble filter, no problem. It can also do some cart EQ. Really the only thing you need before the miniDSP is a gain block.
Now this sounds easy, and in principle it is, but I have experienced you really do need to pay carefull attention to the power supply and wire routing. It's really easy to get noise and hum problems.
It will be a one of just for my personal use, no plans for anything commercial. But the complete design is in the thread. I have some way to go, but you can of course copy (parts) of it in your project.
I imagine that you could also take something like Elliott's Project-06 phono preamp (Hi-Fi RIAA Phono Preamp) and simply rework the circuit to turn it into a 2-stage low-noise amplifier. Essentially you would bypass most of the caps and rework the resistor values to give you the appropriate gain at each stage.
I imagine you could do the above with almost any phono preamp board. I actually have one of RJM's old VSPS boards (circa 2008) which I think would do the trick. It's bare - I got it as a spare when I built first VSPS. PM me if you are interested.
-b
I imagine you could do the above with almost any phono preamp board. I actually have one of RJM's old VSPS boards (circa 2008) which I think would do the trick. It's bare - I got it as a spare when I built first VSPS. PM me if you are interested.
-b
That's a general challenge related to the approach of pre-amplifying the phono signal with a flat gain, rather than any limitation of the specific DSP device. Anyway I don't think it's insurmountable.