Balanced input all DC coupled RIAA preamp

[FdW]

After building lots of prototypes, first unbalanced and later with balanced inputs, I settled at the configuration show in this post. The posted configuration was considered the best sounding one that I have build and presented to my listening panel (actually 4 people, all used to listen to life music and owning high end audio systems).

I’m sure that posting these schematics is not going to make me famous, and I am aware of the fact that critiques here may make me look a bit silly. But I need to know, what do you diy people here, whose messages I am reading for years on end, think about the thing I concocted .

Let me know what you think of it…

Regards,
Frans de Wit

[FdW]

There is also a MCHead

Regards,
Frans de Wit.

[FdW]

And the PCB's

Regards,
Frans de Wit.

[FdW]

Finaly, more pictures can be seen at RIAA Preamplifier - a set on Flickr

Regards,
Frans de Wit.

[Joachim Gerhard]

Very nicely build ! I like the chambers. The LME49710 is a bit noisy for MC work, so are the 51 Ohm resistors. Topology is fine but i whould use the new LME4990, reduce the 51 Ohm to 10 Ohm and take 1.2kOhm feedback resistors. I really like the simplicity of your design and you did a major efford in the PSU so why waisting SN in the input stage ?
I do not know if that new OPamp is freely awaillable I got mine as free samples.
You could also try the AD797, LT1115, LT1020, OPA211, OPA1611 and there is a new low noise chip from Analog Devices.

[Joachim Gerhard]

Sorry, not LT1020 but LT1028. What are the black resistors ? Welvyn ?

[merlin el mago]

Originally Posted by Joachim Gerhard

Sorry, not LT1020 but LT1028. What are the black resistors ? Welvyn ?

If not are Welvyn will be Holco.....

[FdW]

Originally Posted by Joachim Gerhard

Sorry, not LT1020 but LT1028. What are the black resistors ? Welvyn ?

The risistors are 1/4watt IRC metal film types
RC55LF-D-100K-B-B IRC Metal Film Resistors

[FdW]

Originally Posted by Joachim Gerhard

Very nicely build ! I like the chambers. The LME49710 is a bit noisy for MC work, so are the 51 Ohm resistors. Topology is fine but i whould use the new LME4990, reduce the 51 Ohm to 10 Ohm and take 1.2kOhm feedback resistors. I really like the simplicity of your design and you did a major efford in the PSU so why waisting SN in the input stage ?
I do not know if that new OPamp is freely awaillable I got mine as free samples.
You could also try the AD797, LT1115, LT1020, OPA211, OPA1611 and there is a new low noise chip from Analog Devices.

When possible I will do a test with the proposed components, as I do not own a MC cartridge and my TD160b with SME3009 is not suitable, I need to arrange to use my friends player (and he lives Paris [I am in Holland]).

There is an audio sample available that was recorded using a Koetsu Rosewood Signature on a SME Series 20/2 record player. (For me it sounds like virtually noise free).
Diy ADC's

Regards,
Frans de Wit.

[FdW]

Originally Posted by Joachim Gerhard

The LME49710 is a bit noisy for MC work... i whould use the new LME4990...

Is this the one you are recommending
http://www.national.com/ds/LM/LME49990.pdf