vacuum tube active stepup for moving coils revisited

[Doc B]

You might ask Greg Orton if he would make a 1/4 track head. He has made them for me in the past. You might be able to specify the inductance. The 2 track head is 200mH IIRC. More inductance usually means more turns and thus higher output.

 

[johnsonad]

Thanks Dan. I'll shoot him an email.

 

[Doc B]

Today PB has duplicated the existing stepup, with the single change being the use of triode wired 7788s instead of 6C45Pis. We will compare the two tubes and see which makes the most sense sonically. It should be possible to set the kit up so it's reasonably easy to change from one to the other with a little bit of socket rewiring.

 

[ironbut]

Hey Aaron,

IIRC, in the early days (months?) of the Tape Project forum, Mike Paschetto (Mikey on this forum) had JFR switch out the heads of his Technics to some 400mH Tascam heads which he found to be more "tube friendly".
When you contact John French, you might ask about that. I would guess that if he was able to get those heads into the Technics headblock, getting one into an Otari with and outboard tube pre should work (maybe John is assuming you're using the stock playback electronics?).

Just went back and took a gander at the post I was referring to and I was wrong-wrong-wrong!
Here's what he actually got,..

1/4 track playback head, Panasonic RPB-065 (560mHy, 400 ohm DCR)

 

[johnsonad]

Hi Steve, thank you very much for that! I'll shoot John an email tomorrow. That must be the head Dan had mentioned to me in the past.

 

[Mikey]

IIRC, in the early days (months?) of the Tape Project forum, Mike Paschetto (Mikey on this forum) had JFR switch out the heads of his Technics to some 400mH Tascam heads which he found to be more "tube friendly".
When you contact John French, you might ask about that. I would guess that if he was able to get those heads into the Technics headblock, getting one into an Otari with and outboard tube pre should work (maybe John is assuming you're using the stock playback electronics?).

Hi Gang,

Here's the link to that archived post from the old Bottlehead forum:

http://db.audioasylum.com/mhtml/m.html?forum=bottlehead&n=111455

 

[ironbut]

Hey Mikey!
I was hoping this thread would flush you out of the bushes.
Man,..2006! So that was before the Tape Project forum.
Kinda scary!

 

[johnsonad]

John says they haven't been available in a long time. Thank you all for the help!

 

[Doc B]

OK, to get this back on track, PJ, PB and I spent yesterday afternoon working on the noise floor. It's very low, but we want to get it just a bit lower so it can work with really low output MC carts that are down below .3mV. We came up with a scheme that brought the noise down 3dB and have another one planned that we hope will give us another 1.4 dB of noise reduction. Bit by bit.

It sounds really good.

 

[denti alligator]

Shee-hut, even if you don't get it that far down it's pretty impressive. Looking forward to this.