Is there a Tube Mc Riaa?

[analog_sa]

Best of both worlds, low noise firststage and high headroom secondstage.

This looks like a textbook opamp riaa + nice linestage. For some reason without a volume pot. Having two stages is an opportunity to split the riaa into active/passive or just go passive...

 

[Koifarm]

I also tested the passive option. So firststage opamp, then passive filter then secondstage tube. The one in the schematic i like most.
I also have phonodude, mini-me, just opamps, discrete fet phono preamps and project tube box se phono preamp.

 

[analog_sa]

The one in the schematic i like most.

Fair enough. Whether it qualifies as a "tube mc riaa" is open to interpretation.

Do you use an active pre? It seems tempting to incorporate a volume control preceding the tubes

And another question: did you try an srpp?

 

[Koifarm]

The last 50 years or so people have searched for MC tube preamp but the alternitives like transformer, fet, opamp, discreet as first stage were always a better choice. It can be done but always with great compremises.

Volume control you do by adding a resistor to pin 39 and ground.

MM tube amps with srpp first and second stages i have build before. For all tubes designs i like the phonodude.

 

[analog_sa]

MM tube amps with srpp first and second stages i have build before.

Sorry i wasn't clear: just wanted to know how do you subjectively rate srpp vs μ-follower.

 

[Koifarm]

I like the sound of srpp stages with ecc99 or 6n6p. I use them as outputbuffer for my cd player and dac. I also build preamps with 6n16 with srpp and cathode follower.
But for phono preamp you need a lot of gain, good psrr and driving all possible impedances at the output. Then the mu follower is a good choice.
Soundwise i did not hear a lot of differense between two setups with the same tubes.
Harmonics are a bit different between srpp and mu follower but if distorsion stays below 0,2% i can not here a difference.

 

[Koifarm]

So it is transforers then (SUT)...
What about this with a MM tube Riaa after https://boozhoundlabs.com/products/bhl-audio-jfet-moving-coil-pre-preamp-phono-kit-2sk170
not tubes,but it´s simple anyway..

The pacific pre pre is also a good MC preamp. A lot of people have switched the SUT for a pacific pre pre.

 

[Koifarm]

If someone wants to try a tube mc pre, see schematic below.
I build that with ecc86(6gm8) tubes. double parallel 1k2 resistors at anode and 12v batterysupply. Had a good noise floor( -67db).

 

[Ryssen]

If someone wants to try a tube mc pre, see schematic below.
I build that with ecc86(6gm8) tubes. double parallel 1k2 resistors at anode and 12v batterysupply. Had a good noise floor( -67db).

Interresting..

 

[Ryssen]

But quite expensive tube.

 

[6L6]

Funny how 6GM8 has gotten expensive, they were unknown 10 yr ago.

 

[Ryssen]

Then there´s the 6N27P just a little cheaper.

 

[Rodeodave]

While we're posting jfet designs in a tube thread, let's not forget the Salas MC pre-pre:

 

[Koifarm]

Then there´s the 6N27P just a little cheaper.

I still want to test the 6n28b-v for mc pre. Tube has very low microphonics. With the schematic i posted before and 48v of anode supply.

 

[Ryssen]

I still want to test the 6n28b-v for mc pre.

Yes they are even cheaper..

 

[Turbon]

Why not the first stage of Salas simplistic with sk369'ers followed by your favourite tubes?

Regards

 

[Koifarm]

Topic says tube mc riaa.

I have also tested 6n16b in srpp as mc pre with my mini me design.
Noisefloor was at -63db and part of that was from powersupply.
So better power supply can lower noise.

Oh, my MC cartridge is Denon DL103R.

 

[Turbon]

Jfets have been proposed so I just added a thought. Surely I will try an whole tube mc riaa if it seems doable within somewhat decent specs.

I have a few LOMC: Denon 103R, Stanton 981LHZ and VdH MC-10

Regards

 

[Ryssen]

Doesnt 6N28B-V have a little to high gain 16-28?
How long does this miniatyre tubes last?

 

[lcsaszar]

It was used in MIGs