Ultrasimple mm/mc RIAA preamp 2

[tschrama]

Originally posted by GlidingDutchman


<< RANT >> HAVE ANYBODY EVEN READ MY POST???

D

My friend, what characteristics?

Noise: will go down with the square root of parrallel devices, but idle current for be proportional increased, and you need to degrease the load resistor to keep the same idle drain voltage.

Linearity: does not nessecerely improve, but you might end up with less low order, and more high order distortion.

input capacitance: will also go up, and likely bandwidth will go down.

[GlidingDutchman]

Originally posted by tschrama



My friend, what characteristics?

Noise: will go down with the square root of parrallel devices, but idle current for be proportional increased, and you need to degrease the load resistor to keep the same idle drain voltage.

Linearity: does not nessecerely improve, but you might end up with less low order, and more high order distortion.

input capacitance: will also go up, and likely bandwidth will go down.

Thank you - that is all I wanted to know.

D

[GlidingDutchman]

Originally posted by Mad_K
This crude little riaa pre is too good to be true.

Indeed it is!! Whoa - I am gobsmacked. Just now listening to Brothers in Arms using an Ortofon Salsa MC cartridge (0.3mV out)

This phonostage is a diamond in the rough!

Cheers Mad K!!

D

[johnm]

Hi Gliding Dutchman!

Would you mind sharing your layout? I happen to have exactly the same strip board lying around and I'd love to build this to try out on my Denon 103R and Garrard 401.

Many thanks

- John

[GlidingDutchman]

Originally posted by johnm
Hi Gliding Dutchman!

Would you mind sharing your layout? I happen to have exactly the same strip board lying around and I'd love to build this to try out on my Denon 103R and Garrard 401.

Many thanks

- John

John

I just soldered the parts onto the tag strip in a "random" fashion with no "propper" layout (ofcoarse according to the design!).

A friend of mine and I am working on a higher gain stage in a similar fashion to MAD K's - I'll send you the details of that circuit as I believe it would be a better match for your Denon 103R.

The above circuit works well with low output MC cartridges but higher gain would be a benifit.

Also checking out the circuit to run from 12vdc (incl IC regulators etc).

Cheers
Dewald the GD

[johnm]

Many thanks Dewald - look forward to seeing the revised design

- John

[Zigis]

Hi GlidingDutchman,
nice building, I am on half way building this too.
What kind PS you use, battery or regulated?
Thees violet el caps are on output?

Zigis.

[GlidingDutchman]

Originally posted by Zigis
Hi GlidingDutchman,
nice building, I am on half way building this too.
What kind PS you use, battery or regulated?
Thees violet el caps are on output?

Zigis.

Hi Zigis - currently I am running it from a Pb Acid battery (2x 12vdc) but I am looking into doing a IC regulated PSU.

The violet caps are the outputs yes - will be replaced by some plastic film types in due course.

D

[GlidingDutchman]

Originally posted by johnm
Many thanks Dewald - look forward to seeing the revised design

- John

John - I'll post the new schematic for discussion. I am having trouble getting the thing to work. Actually back to the original design as per Mads K.

In comparson with the EAR 834P it can most certainly do with a touch more bass or will that be treble attenuation?

D

[tschrama]

I had the same feeling... it was a bit bass-light... I cured it by making a proper inverse-RIAA, and adjusting the filter section untill it was within 0.5dB...