Looking for the best SQ Phono LCR schematic

[waltube]

Try the best pentode circuit for first stage, you can get 200-400X gain before the step down IT.

I think no.
The besrt way to hve a LCR with two stage onlly ( incuded 600:15k interstage) is EC8020 or PCC900 ( parallel) considering the gain, Gm and Rp
They are quite tube.
And PCC900 costs around 1-4 euros each!!!!!!!!
I used E280F , E810F and others but with lower results of course coupled with a trafo as anode load.
I the last LCR I get around ( and more) 80 dB if s/n with 32-34 dB of gain that I consider the minimul legal value for MM.
This my point of view comes out after dozen of lab tests and listen test
And, as I know, I never seen a complete test around this type of circuit.

Walter

 

[waltube]

walt/jev
Are there actual schematic for these? I don't get audio review here and I am not good at turning words into schematics.

please look at the last link I sent

Walter

 

[2A3SET]

LCR benefits from strong input signal, you can either get from a high ratio SUT, an active pre-pre, or high gain best-pentode.
Best pentode (16d from linear audio article by Frank Blöhbaum) sounds more similar to triode than regular pentode, personally I prefer it (6j9p, 6j49p) over lots of single triode/strapped like e810f, d3a and ec8010.

 

[waltube]

LCR benefits from strong input signal, you can either get from a high ratio SUT, an active pre-pre, or high gain best-pentode.

Which are the Zout of the use of pentode or best pentode config?
You have to drive a relative low Zin
Them why to mix sand with vacuum?


Walter

 

[2A3SET]

I used LL1660 4.5:1 to LCR, so around 12K equivalent load.
Best pentode has 10-20% higher gain than classic pentode (gmXRa).
So overall gain is 3-4X than triode mode, saved the step up IT after LCR.

 

[waltube]

I re-form the question
Whic is the Rp of the pentode or best pentode you use ?
If the load will be 12 kohm it must be 1/4 (minimum) for a good response at low frequencies idf you use trafo as anode load

Walter

 

[grataku]

2A3SET, what is the current rating on your LL1660? I have a 1660/18mA I don't know what to do with. This may be a good application for it.

 

[2A3SET]

Same 18ma version.

 

[2A3SET]

I re-form the question
Whic is the Rp of the pentode or best pentode you use ?
If the load will be 12 kohm it must be 1/4 (minimum) for a good response at low frequencies idf you use trafo as anode load

Walter

Ideally pentode has infinite Rp as it works as a constant current device.