Balanced input all DC coupled RIAA preamp
 

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

Balanced input all DC coupled RIAA preamp
 

There is also a MCHead

Regards,
Frans de Wit.

Balanced input all DC coupled RIAA preamp
 

And the PCB's

Regards,
Frans de Wit.

Balanced input all DC coupled RIAA preamp
 

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

Regards,
Frans de Wit.

http://farm3.static.flickr.com/2576/...6e85e668_b.jpg

http://farm5.static.flickr.com/4044/...01540271_b.jpg

http://farm3.static.flickr.com/2598/...96c9e584_b.jpg

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.

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

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

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

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).
http://www.diyaudio.com/forums/digit...ml#post2015941

Regards,
Frans de Wit.

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