Hello,
not quite satisfied with the sound of my Pro-Ject Phono Box SE preamp, I started to improve it and would like to have your opinion about what I have done and what can still be improved.
This preamp is dual mono with 3 op amps per channel. It works between a Pro-Ject 1-Xpression turntable (with 2M blue cartridge) and a Nad C326BEE amp.
I started by replacing some PSU capacitors.
Then I swaped the four NJM 4580 op amps for dual OPA 627, and the two TL071 for AD797 (replacing these two was a HUGE improvement).
I don't have the doc, so I tried to draw it but as I am not very experimented with electronics I coudn't quite understand the circuit. Here it is anyway, I'm very sorry if it is badly drawn and incomplet, this is all I managed to track with my eyes and my multimeter...
Power Supply stage :
RIAA Preamp stage :
Is there anything obvious you see could be done to improve it further?
Or is it a bad architecture and I should directly buy something more serious?
I'm thinking maybe going to a tube preamp like the Yaqin MS-23B or the Douk audio Little Bear.
Thanks anyway for your help.
not quite satisfied with the sound of my Pro-Ject Phono Box SE preamp, I started to improve it and would like to have your opinion about what I have done and what can still be improved.
This preamp is dual mono with 3 op amps per channel. It works between a Pro-Ject 1-Xpression turntable (with 2M blue cartridge) and a Nad C326BEE amp.
I started by replacing some PSU capacitors.
Then I swaped the four NJM 4580 op amps for dual OPA 627, and the two TL071 for AD797 (replacing these two was a HUGE improvement).
I don't have the doc, so I tried to draw it but as I am not very experimented with electronics I coudn't quite understand the circuit. Here it is anyway, I'm very sorry if it is badly drawn and incomplet, this is all I managed to track with my eyes and my multimeter...
Power Supply stage :
An externally hosted image should be here but it was not working when we last tested it.
RIAA Preamp stage :
An externally hosted image should be here but it was not working when we last tested it.
Is there anything obvious you see could be done to improve it further?
Or is it a bad architecture and I should directly buy something more serious?
I'm thinking maybe going to a tube preamp like the Yaqin MS-23B or the Douk audio Little Bear.
Thanks anyway for your help.