Frank's Ultimate Tube Preamp.

[grataku]

Originally posted by Jay
Frank: "Well, I don't want to blow my own horn here but in the words of countless people who've actually listened to it (well in my system that is) : very transparent, dynamic, it just doesn't get in the way of the music."
======================

Sorry with the question, Frank. But, what does it mean with not getting in the way of the music?

It's just your stereophile boiler plate sentence. Never search for meaning in such things. It kind of disappointed me as well.

Frank do we REALLY need 4 enclosures for this thing? Could we condense while keeping separate gnds?

[Peter Daniel]

I think he simply meant that:

Originally posted by fdegrove
if I find myself not tapping my foot to the rythm of the music on the appropriate material the whole amp is not worth a dime to me.

[fdegrove]

Hi,

Frank do we REALLY need 4 enclosures for this thing? Could we condense while keeping separate gnds?

Sorry if I misled you here.
I actually built it in two cases, one for the PSU and another for the preamp proper.
Dimensions: 16" * 11" * 3"
( Just to give you an idea about what you need if you'd add the phono stage as well.If you don't need that half the width should do.)

Starground is for anything PSU related is inside the PSU chassis, everything signal related is starground inside preamp chassis.

Grataku,

Since you prefer measurements:

Specifications Line preamp:

Powerconsumption: 40W.
Weight 2 Kgs. preamp and 3.5 kgs for the PSU.

Sensitivity (IHF 0.5V)

Line: 525mV into 100K.

THD Typically better than 0.05%.

Frequency Response: 10Hz - 200KHz. +/- 0.2dB.

Noise: better than -90dB.

Input overload: Infinite.

Maximum Output level: 45V

Output Impedance: 47 Ohm.

Stereo Separation: better than 100dB at 1KHz.

Feeling better now ?

Peter,

I knew you'd bring that up.

Cheers,

[Peter Daniel]

[fdegrove]

Hi,

This uses yet another PSU, both are identical to the line peamp though.

Cheers,

P.S. Dave, redraw to your hearts content...

[fdegrove]

Hi,

This circuit mates to the previously posted phono stage:

This stage is a candidate for improvement, any suggestions welcomed:

[planet10]

Originally posted by fdegrove
This uses yet another PSU, both are identical to the line peamp though.

P.S. Dave, redraw to your hearts content...

These ones are pretty good, but if you'd like a set with matching "feel" i'll get at it sooner or later.

I note this uses an ECC83 class tube. I wonder how close it is to the RCA one?

dave

[planet10]

Originally posted by planet10
I note this uses an ECC83 class tube. I wonder how close it is to the RCA one?

Found what i believe to be the RCA one -- looks like there are some significant differences.

dave

[analog_sa]

Hi Frank

Interesting phono. One of the few (i only know of the 834) where all the gain comes from the first stage and all the correction - from the second. How would you describe its sound compared to more traditional topologies like fully passive or 2 stage with an overall feedback. Not that i've tried many, but to me the split passive RIAA has always ruled in both vacuum and sand implemetation. I should try something different though
Your pre-pre can certainly benefit from battery plate supply and something better at the heaters too.


cheers

peter

[fdegrove]

Hi,

These ones are pretty good, but if you'd like a set with matching "feel" i'll get at it sooner or later.

It would be great or I could have a stab at it myself...I've no idea what font you used for it though.
Anyway, I was just teasing you a little.


The RCA diagram you posted should sound very good too, it reminds me of the first phono preamp Jadis made.

Any idea what the number of the RCA manual is? I've two different ones and none sport the cct you posted.

Cheers,