Ultrapath

[dcoyle]

I saw this article

https://web.archive.org/web/20131122.../VTV/VTV10.pdf (Page11)

and tried it in a SE 6V6 amp, and it is cleaner, not sure if it is what I want. Its on a switch now, I will have to try it more, but definitely interesting.

Any one else try it?

Dan

[Leo_Gnardo]

Did you use electrolytic caps in the power supply and cathode circuit?

[nickb]

<Start Rant>
That has to be the worst article I have ever (partially) read. Is Jack Elliano deliberately being obscure? It's almost like he is making fun of the reader by pretending that there is some thing very special about this mundane design.

Read this


Is this guy serious? What he is saying, I think, in the most obtuse way is the the cap isn't leaky. It gets worse...



What he should have said is that electrolytics produce intermodulation distortion. Either this guy cannot write or is being deliberately confusing. One thing is certain. An article whose only claim to fame was the use of good quality capacitors by a guy who cannot communicate should have made it straight to the Editor's trash can.
</Rant>

Gee, I'm sorry dcoyle. That probably wasn't what you were looking for. I just couldn't help myself...

[Jazz P Bass]

"Zingy"?

That's s new one.

[loudthud]

I got bored waiting for it to download.

[g1]

<Start Rant>
That has to be the worst article I have ever (partially) read. Is Jack Elliano deliberately being obscure? It's almost like he is making fun of the reader by pretending that there is some thing very special about this mundane design.

I think you'll like this one much more :
Ultrapath = Ultra Simple...Except that it's not

[Leo_Gnardo]

I got bored waiting for it to download.

Sent the whole magazine. If I knew what issue, could have picked it off the shelf in 1/50 the time.

[nickb]

I got bored waiting for it to download.

Don't you miss out on this now Here is just that article.

[Mike Sulzer]

Most design for power supply rejection. This circuit embraces power supply acceptance.

[J M Fahey]

Why not add some carefully tuned spark gap from +B to cathode, so we also add some tasty buzz to the signal?

[nickb]

Why not add some carefully tuned spark gap from +B to cathode, so we also add some tasty buzz to the signal?

That's just flashy...

[martin manning]

That's just flashy...

If I recall correctly, Steve Connor succeeded in modulating a Tesla coil with a bass. Now, that's flashy!

[dcoyle]

I used a Solen 30ufd film cap to jump between normal and ultrapath, and the other caps in the power supply are Sprauge Atoms.

Yeah, the article by Eliano is not very well written, I cited it cause the idea is attributed to him. A better explanation is in an article by Lynn Olsen, here

https://web.archive.org/web/20131122.../VTV/VTV16.pdf

page 4.

I have great respect for Broskie and tube cad journal, and gratitude that he has shared so much knowledge, but I have to say he's a little sour grapes on his eval of Ultrapath, IMO. He sorta acknowledges his attitude in his article where he jokes about finding anything good to say about ultrapath. He points out that he came up with a very similar idea that didn't get the recognition, for what ever reason.

While not questioning the validity of his noise point, in my experience it is moot. Any one who dismisses or mocks the idea based on his noise objection is welcome to their opinion, but I haven't found it to be a problem.

My experience has been that what I thought was power supply noise was often grounding problems. My SE 6V6 amp uses the grounding technique suggested by Randall Aiken, where the local PS cap is next to each stage, and the neg lead of the PS cap is used as the local ground point for that stage, and then the local grounds star into the chassis ground. There is a inductor (5H?) before the plate supply cap. With this SE amp there is no noise on a Jensen r.i. alnico 10, which has pretty decent efficiency. I literally can not tell if the amp is on with out looking at the light. When I switch in the ultrapath, there is no perceptible increase in noise, to my ear.

My observation is there is enough tasty tube distortion in this amp, without the slight increase in, for lack of a better word, mechanical distortion, by the non ultrapath setup to make a jazz player very happy. If it makes me happy for what I play, I can't tell until I play with someone else. (Almost everything sounds "interesting" to me when I am noodling by myself.) YMMV.

Dan

[Dave H]

I must be being extra thick today (or it's the effect of my New Year hangover) but I don't understand what this circuit is supposed to achieve. The cathode resistor is bypassed not to ground but to B+ What's the difference? B+ is ground to AC. Why risk introducing noise?

[dcoyle]

I could answer what the difference is, by quoting the Olsen article, but really I can't say he's attributing the reason for change correctly. I can say there is a difference and it is less distorted.

I didn't find noise to be a problem, at all.

For the trouble of a temporary spst switch and a 30ufd cap hanging outside the chassis I was able to try it, and find out for myself. It was noticeable enough to me to think it might be of interest to others. If you have a Champ type amp check it out, otherwise one is just speculating. The Olsen article also shows how to implement it on cathode biased push pull, but I haven't tried it.

Mike S. and JMF, I have tremendous respect for you, based on your posts, but I would say that those who dismiss an idea ahead of time, based on one objection, don't really get a chance to see if there was something else going on that was interesting. If you think you are saving your self or others time by not checking out something, fine, but you don't really know, do you?

I could give a rip if any one thinks well or poorly of ultrapath, I am just reporting what I heard.

Cheers.

Dan