1773C

[erichayes]

This is a test to see if I have Photobucket somewhat mastered. Thanks Ty.

This is a "conceptual prototype" of a 1773 on a polished 304 stainless chassis. It never got wired--we just wanted to get people's reaction. The transformer bells are 95% black instead of the 50% we used for the regular bells.

The chassis is now residing with Bud in Warren OH and the iron has been absorbed into the system.

[Ty_Bower]

Looks good to me. :) I've read multiple references to the 1773, but I don't think I've ever seen a photo. I always wondered what it looked like...

[TomMcNally]

Very cool chassis.

Maybe you could let us see some more of your work
when you have some time Eric.
I googled you and didn't find a web page or anything.

... tom

[Ty_Bower]

I don't want to ask you to give away all your secrets, but...

The output tubes are 6BQ5 (EL84/6p14p), of course. The splitters look like 12BH7 long tailed pairs? But what is the driver tube hiding under the RF shield?

[sorenj07]

Looks pretty cool except it's "backwards" - I always put my PSU on the left, and my output tubes on the right for some reason! Other than that, it looks cool. Wouldn't mind seeing a nice big choke on top, and the RCA jacks in the back, but hey. Good work :)

[erichayes]

The outputs are, indeed, EL84s--Sovtek non-military, to be exact. The PIs are 6GU7s, one per channel. The shielded tube is a 5751 first audio stage, one section per channel, directly coupled to the grids of the 6GU7s. The circuit is very similar to Shannon's Eiclone or the Eico HF87/89, just tweaked for operating at lower B+ voltages.

I'm in the process of wearing down my commercial photographer daughter to shoot some of the other stuff, but she hasn't quite relented yet. Soon, though.

The power supply is where it is to get it as far away from the input stage as possible (The choke and filter caps are under the chassis to raise the female acceptance factor). Likewise, the input jacks are mounted as close to the input tube as possible. These two ploys bought me an extra 20dB of noise floor. Measured hum and noise is -120dB referenced to 1 watt.

[sorenj07]

Them's are some pretty ridiculous numbers. If you weren't in Cally I'd want to give it a listen. How are you feeding the 6GU7's by the way, is it a CCS or a more traditional negative voltage fed tail?