Morgan Jones' E88CC Phono

[ECC33]

This phono appears in all of Morgan's books and utilises the E88CC.
Although his latest book substitutes the ECC82 with a 7N7.

I have searched extensively (honest!) and can find no mention of anyone having built one.
I was thinking of building one, but maybe using an E88CC per channel and maybe a D3A as an input valve. And subbing the 7N7 with another E88CC (or ECC88)

Why?
I've got D3As, E88CCs and ECC88s but no 7N7s.

Has anyone built one?
Thanks!

[GlidingDutchman]

My friend has built one... see here: http://vinylsa.co.za/forum/viewtopic.php?t=1116

D

[GlidingDutchman]

Also see here: http://vinylsa.co.za/forum/viewtopic.php?t=953

[SY]

That is pretty much how I have my phono stage set up. I've updated some things, used different operating points, and (I think) have the overall design pretty close to optimized. I'll have it up on my website in a few more weeks.

Here's a 1kHz spectrum, 3VRMS out:

[Eli Duttman]

I've got D3As, E88CCs and ECC88s but no 7N7s.

The 7N7 is electrically equivalent to the 6SN7. Do you have a 6SN7 or 6CG7/6FQ7? A 6GU7 might do too.

[SY]

I should mention that if your cartridge or transformer can bear the input capacitance, a triode-connected D3a is a superb input tube.

[Stephen R]

And if it can't take the capacitance, try it is a pentode, same load R. I think it's better like this.

cheers,

Stephen

[kevinkr]

Originally posted by SY
I should mention that if your cartridge or transformer can bear the input capacitance, a triode-connected D3a is a superb input tube.

I'll strongly second SY on that one, I use it triode connected too. I expect pentode connection would result in significant partition noise, this might or might not be an issue depending on the source - as a triode the D3A is almost impossible to beat for noise performance at reasonable cost. (It's about as noisy as a 68 ohm resistor.)

[Stephen R]

Noise with the D3a in pentode mode with same load as you would use in triode mode is no issue at all. I use to use it as a triode before going to pentode.

cheers,

Stephen

[ECC33]

GlidingDutchman, SY, Eli Duttman, Stephen R, kevinkr; thankyou all for your replies.

I wanted to stick to Noval based valves; hence not opting for a 6SN7 (ECC33)
I also wanted to keep the channels seperate, using seperate valves for left and right channels (well......if you can...you should)
I've got some D3As here so wanted to put them to good use. I was thinking of triode strapping them, naturally, but my also try them as pentodes. They didn't cost me much either.
SY, I look forward to reading your article.
Any more comments most welcome.

Thanks again.