His Master's Noise: A Thoroughly Modern Tube Phono Preamp - Page 22

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.

22nd October 2015

On Hiatus

Yes, exactly.

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

22nd October 2015

TUBESMAN

diyAudio Member

One last (for now) question. The IR LED is 1.25V, I don't suppose a 1.5-1.6V LED would make a big difference. Yes? No? Thank you!

Dedicated to the proposition that man's innate thirst for knowledge will someday overwhelm his passionate lust for stupidity.

22nd October 2015

On Hiatus

It will likely require a higher B+, and increased dissipation in the first stage tube. IR LEDs are super cheap and easily available- for the initial prototype, I pulled a couple out of some old remote controls. For my nicer build,I bought them at Radio Shack.

Classy, that's me!

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

22nd October 2015

TUBESMAN

diyAudio Member

Yeah they are cheap but it seems they are specked at higher than 1.25V on voltage. I know you like the IR diode because of the low forward resistance. I just had an idea, how about two regular Si diodes in series to get the drop, and sets of them in parallel to get the resistance down, sort of like what you did in the RLD

Dedicated to the proposition that man's innate thirst for knowledge will someday overwhelm his passionate lust for stupidity.

22nd October 2015

On Hiatus

That won't get the resistance down because each diode will handle less current.

This one should work fine. 30 cents in onsie-twosies from Mouser.

https://www.mouser.com/ds/2/311/SFH%2...ant-532132.pdf

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

22nd October 2015

TUBESMAN

diyAudio Member

Ok, I will look into it. The data sheet looks good. Thanks!

Dedicated to the proposition that man's innate thirst for knowledge will someday overwhelm his passionate lust for stupidity.

11th November 2015

poli

diyAudio Member

Thanks a lot for this fine article, Stuart!

11th November 2015

On Hiatus

Appreciate the kind words. Update coming soon!

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

11th November 2015

luvdunhill

diyAudio Member

Quote:

Originally Posted by SY

Appreciate the kind words. Update coming soon!

Oh?

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

11th November 2015

On Hiatus

In light of Merlin Blencowe's excellent JAES paper on tube noise, I'll be lowering the plate currents of the first and second stages. It won't change the performance significantly, but it will reduce heat and probably extend tube life.

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