His Master's Noise: A Thoroughly Modern Tube Phono Preamp - Page 13

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 2011

On Hiatus

For boards, contact Jack at www.tech-diy.com . I'm rebuilding the project on one of the boards he designed and I suspect it will look a lot better than my current point-to-point version. (Disclaimer: no commercial interest in board sales, but I did get a free board)

I'm finishing up an article on a tone control line amp- once that's done, I'll write up my MM amp. Until then, you can turn this into a very good MM preamp if your cartridge is tolerant of capacitance (e.g., Grado): just eliminate the input transformer and change the first stage grid resistor from 6k8 to 47k. If your cartridge needs a low input C (e.g., the Audio-Technica 150MLX that I use), my upcoming MM-only design will take care of that.

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

23rd October 2011

Carlp

diyAudio Member

Note I don't think the tech-diy site has the boards listed, but you can contact them via their sales email address and inquire about them. I think they are still available.

24th October 2011

jackinnj

diyAudio Member

I've got to figger out the cost of the HMN boards -- then I'll put them on the site. I don't know why I forgot to do that -- it's just cost plus shipping and the PP fees. I have one for my own purpose and make 49 more at cost! Tech DIY Company Store

26th October 2011

jackinnj

diyAudio Member

OK, the boards are on the Tech-DIY website at cost -- shipping in the US and overseas is via Priority Mail and is added when they are ordered. Tech DIY Company Store

Because I've been tending to a sick relative there might be a delay in shipping.

21st August 2012

PET240

diyAudio Member

Hey Sy,

Entertaining read that. Have you any closer to the MM version. If I get the HMN PCB kit, can it be added to this?

Thanks muchly for the efforts! More maths than I'm used to!

Cheers,

Drew.

21st August 2012

On Hiatus

Thanks. Drew. No, the MM version will look quite a bit different. I made the mistake of changing jobs and moving to Chicago, so that delayed things a bit. I managed, though, to get some of the basic topology worked out and breadboarded before I relocated, so once my lab is unpacked and set up, things should move pretty quickly (famous last words).

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

22nd August 2012

PET240

diyAudio Member

Hey Sy,

I know how that feels, I moved 3 years ago and still trying to sort a listening post!

This is the cart I'm using, the music maker Classic LE:
Variable-reluctance stereo phono cartridge with line-contact stylus and silver coils.
Output: 4.0 mV output
Loading: 47K ohms (not capacitance sensitive.)
Tracking Force: 1.6 grams.
VTA/SRA Alignment: Front face of cartridge perpendicular to record surface (viewed from the side).

Any thoughts?

Thanks,

Drew.

22nd August 2012

On Hiatus

If it really isn't capacitance sensitive (I have a hard time believing that!), then you can use the HMV without the stepup transformer, though you lose the advantages of balanced inputs. You'll get superb noise performance.

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

22nd August 2012

PET240

diyAudio Member

Hey Sy,

Having an idea to double the stages and run it balanced then perhaps into a circlotron 6SN7 stage and not need the output cap.

Capacitance of course it is irrelevant, it won't do anything to phase......not. Not that I completely understand all this yet but I'm sure it come to me.

Thanks Sy.

22nd August 2012

PET240

diyAudio Member

Hey Sy,

Another question....what do you use for schematic drawing?

Somewhat OT but yerknow?

Thanks,

Drew.