"Equal Opportunity" MM Pre

[jackinnj]

The Idss of the 2N5460 is about equal to that of the DN2540 current source -- 3.8mA. I recognize that it isn't optimal. The Idss of the J74BL's is 8.3ma and the bogus parts 17.4mA.

The bona fide J74s came to me in a sealed lot of 200 (of which I had several boxes) -- most went to folks making F5 amplifiers.

I have some surface mount 5460's -- will have to check them out for noise at some point.

 

[billshurv]

I may regret finding this thread...

 

[Ardahan]

I sometimes regret finding diyaudio... ehh never...
Like HMN, it is balanced, right? with/without transformers.

 

[Brinkman]

I've been doing some comparative measurements of TEO with an input transformer vs. His Master's Noise for MC use. The TEO plus transformer is better. I'll see if I can dig out some of the spectra when I get back home- TEO has significantly lower HF intermod (though this is a bit of numbers-chasing, HMN is already way lower than any audible threshold).

Can the Sowter 8055 be used with TEO or are you using some other input transformer?

 

[SY]

It can be for MC (and I think it would work very well), but the intention was to provide a transformerless balanced input for MM with extremely low baseline input capacitance.

 

[Joel Wesseling]

Wow, this looks Delicious..

 

[billshurv]

well pay day, so that is €46 I won't be spending on beer this month!

 

[SY]

Jan has more info up on his website (layouts, schematics, Gerber files...). See the Linear Audio thread.

 

[2wice]

Jan has more info up on his website (layouts, schematics, Gerber files...). See the Linear Audio thread.

Hi SY

for this pre or something else? Don't see it on his site.

Regards

 

[billshurv]

I would feel a bit bad not supporting the publication tho. Everyone puts a lot of work into LA and it is only right I put some of my hard earned back. A few more days and I can start planning the gutting of my SA-1000 to put something better inside. Nice case, carp preamp!

BTW I thought I had odd sleep patterns...

 

[jan.didden]

Online Articles

 

[billshurv]

Downloaded

 

[2wice]

Good lord! what an awesome share!

 

[Ardahan]

Thank you very much Jan and Stuart.
Even though I am novice in electronics I'm looking forward to buy the volumes in the future (soon I hope).
Best regards,
Arda

 

[jackinnj]

If anyone was wondering why Mr. Yaniger uses a cascode ccs -- here's why:

 

[billshurv]

he explains that choice in the HMN article very well. But there are some other choices that I do not yet understand but are well worth the cost of the magazines to find out.

Shame he chose a boring tube tho. He's losing his sense of fun.

 

[jackinnj]

Online Articles

The schematic in the link doesn't reflect the changes SY made in Volume 8.

 

[SY]

It reflects what's on the PCB. The idea was to be able to use the same board for the first and second stages, but removing or jumpering components to reflect the slightly different topologies. One could design a single board that holds both stages, but I was trying for some universality and application of this gain block outside of this specific project.

Blame me, not Jan. He was just following orders.

 

[billshurv]

Well that certainly explains one thing that was confusing me!

 

[kevinkr]

Interesting design SY..