His Master's Noise: A Thoroughly Modern Tube Phono Preamp - Page 16

21st April 2010, 12:00 PM
SY On Hiatus Join Date: Oct 2002 Location: Chicagoland	His Master's Noise: A Thoroughly Modern Tube Phono Preamp After more than 25 years of faithful service, it seemed that it might be time to redo my phono system. After all, I like to think that I've picked up a few tricks in the intervening years... The old system consisted of a VPI HW17-II, a Linn Ittok LVII tonearm, and a Troika cartridge. The Troika was... Click here to read the entire article Last edited by Variac; 2nd April 2011 at 12:17 AM.

7th April 2013

SMOTH

diyAudio Member

Thank you! I'm not terribly concerned with the balanced input since my interconnects are very short and of good quality. However I did not take into account the difference of capacitance... Am I correct in thinking that a mismatch might compromise the tone? To solve this, is it safe to assume I would have to find a different tube with the right input capacitance for a mm? If I left the circuit as is, would a mm in conjunction with the SUTs overdrive the first input stage? I'm beginning to think I ought to just buy a mc!

7th April 2013

On Hiatus

The problem will remain for just about any high mu triode because of the Miller Effect. If you want to experiment, you could play around with conversion of the first stage to pentode (the noise goes up but for a D3a, it's still pretty low), but that's getting into advanced territory.

"You tell me whar a man gits his corn pone, en I'll tell you what his 'pinions is."

12th April 2013

McLanz

diyAudio Member

Hi there, as so much attention has been drawn to this (very nice) article I 'd like to ask simple question:

Anyone owns Nelson's Xono and His master noise and has compared the sound?

Xono is a hugh step to any pre I had especially in terms of dynamic its like comparing an "cassette player dynamic to CD".

How is this pre sounding?

I'm interested as I built Xono for my friend and I'm so blown away about the musical improvement that I thought about building one for myself. But maybe this pre is interesting too!

Thanks Jochen

I listen with vintage Fullrange drivers, a EL34 PP Amp, built many NOS DACs called "Monica", enjoying the good old vinyl with my full DIY turntable, Schroeder arm clone and phono pre. ...Located in South/West of Germany.

14th April 2013

luvdunhill

diyAudio Member

I can make that comparison probably at the end of the summer for you

For Sale: Yet-Another-FirstWatt-PSU | "CSX1/2" "Buffered F6" FE

19th April 2013

Kmh3212

diyAudio Member

Very, very nice article. It in now In my lists of plan to build one day soon.
Thanks to the author!

23rd April 2013

SMOTH

diyAudio Member

Hello SY, last question on this: would a high output mc rather than a mm solve any of the problems you mentioned with bypassing the sut's?
Thanks.

29th October 2013

Brinkman

diyAudio Member

Hello SY,

First, a small correction of sorts:

Quote:

secondary resistance plus grid stopper is 1k5 + 100R + 100R = 65R = 1R765

should read:

Quote:

secondary resistance plus grid stopper is 1k5 + 100R + 100R + 65R = 1k765

Code:

"With," not "instead of." I'd put it between the raw supply and the regs.

I was wondering if you had advantageous reasons for placing the common mode choke here, as it seems elsewhere that common mode chokes are being used between the regulators and load.

Thanks for the great article, I look forward to building one!

Best regards.

30th October 2013

On Hiatus

Putting the choke after the regulators increases the supply source impedance. That doesn't strike me as a good thing!

Thanks for spotting the typo. I've been finding a few here and there and editing them out, missed that one completely.

"You tell me whar a man gits his corn pone, en I'll tell you what his 'pinions is."

3rd November 2013

giuliaudio1

diyAudio Member

A masterpiece amplifier and article!! Thank you! I learned a lot and will build something similar with 6N17-B, just for fun. Will 7806 regulators for heaters be a problem for noise? Regards, JJ

3rd November 2013

On Hiatus

Shouldn't be a problem, but make sure to use complementary regs as shown here for common mode noise reduction.

"You tell me whar a man gits his corn pone, en I'll tell you what his 'pinions is."