[Patrick Turner]

Bret Ludwig wrote:

On Feb 26, 8:07 pm, Patrick Turner wrote:
ec wrote:

Hi
where can i find quality tube phono preamp schematics?


Preamps are not too challenging to build. If you want one with lots
of rotary switch selectable features such as the classic commercial
ones that are convenient and spouse-friendly the issue becomes getting
the switches. Rotary switches are more or less modular and you build
them up or specify what you want but it can get expensive and time
consuming.

Many many many people have built Marantz 7 clones. Variations include
using octal or other miniature tubes or even FETs in places, getting
rid of the tape sections, transformer coupled outputs (the ollies have
developed a taste for the WE transformers for this even though they
aren't that great) etc, etc. The first and most famous M7 clone is the
factory Mc C-22. They are as identical as twin sisters with a Horns of
Venus.

In my opinion the best of the tube phono sections is that shown in
the German language book, "Audio-und-Gitatrrenschaltungen mit Rohren".
Pat Turner has a copy. I know he does. It's a two stage design.

Yeeeeaaaah, and I do have paper copies of something in German that
someone so kindly sent me.
But when I saw the schematics with 12AX7s I wasn't so awfully keen to
chuck out
what I have for 12AX7s.


I don't have an electronic copy I can send along to anyone who wants
one.

But....if you are not primarily using vinyl as a source....your
efforts are best directed to not having any preamp at all. You want a
CD or universal player with a output section that will provide 0 dB
into a relatively low impedance load. It's doable with tubes or
discrete or op amp solid state.


True, cd source just needs a 20k pot straight into the power amp.
The opamps in the cd player have very low Rout, and usually a buffering
resistor.

Patrick Turner.