[likewake]

I came across this "zeny" amplifier in audiodiy, why people here don't discuss this one much? how its sound quality compared to pimeta or ppa? It's only be mentioned once here:

http://www6.head-fi.org/forums/showt...highlight=zeny

 

[tomb]

Well, the Zen amp with the Nelson Pass circuit is being offered in a Group Buy by Digi over on Headwize. Headwize also has the original Library article about the Zen, too. As near as I can tell, the "Zeny" appears to be a single-channel modular board knock-off.

According to the article (grain-of-salt handy), the application of this amp tends more toward Grado's, with very low gains and high currents. If you're interested, I would check out Digi's Group Buy - it will close at the end of the month, he says.

 

[mb3k]

I remember there was a "Death of the Zen" amp (DoZ). I'll have to fish out the link somewhere deep in my bookmarks.

 

[wobberly1]

Quote:

Originally Posted by mb3k I remember there was a "Death of the Zen" amp (DoZ). I'll have to fish out the link somewhere deep in my bookmarks.

Did you mean Rod Elliot's DoZ at http://sound.westhost.com/project70.htm

 

[blip]

I've actually been thinking about Zen or DoZ a lot lately. I really want to build a no-holds barred (except for a vaguely moderate budget), amazingly inefficient, ultra-low distortion amplifier for my new desktop speakers.... something in the 10 watt range or so. There is something that just appeals to me about using raw power to beat distortion into the ground (a bad and innaccurate description... but viscerally appealing) I've got some wacky ideas about cooling them that I'd like to give a shot.

But on to the topic, I haven't heard either of the Zen designs but they both seem interesting. I'm a bit turned off by the output cap... not for any rational reason (well maybe cost) but I just hate having another component to get all "tweaky" with. However, if you want a simple class A, it seems to be par for the course.

Rod Elliott's critique of the Zen concept is rather damning. (http://sound.westhost.com/project36.htm) Basically, he really dislikes MOSFETs in the Zen configuration and conducts a test which shows that they have far higher levels of distortion than a cheap bipolar. It certainly is troubling if what you are interested in is super low distortion. On the other hand, his test is a bit ideosyncratic and may not be the best way of judging Zen.

That said, for the price ($50 + transformer +heatsink?) it could be a good alternative to a Dynalo and would probably make a very nice preamp/headamp.

Edit: Post 1776... Anyone have a flag I can wave?

 

[Uncle Erik]

blip, I built the Zen and found it a very rewarding project. Mr. Elliott may be correct (I'm no EE, just a hobbyist and a ham) but the Zen is *not* a bad sounding amp. Far from it. It's a relatively easy and inexpensive build, too. I have no regrets and fully expect to use this for many years. You might want to take a look at some of the Aleph clones over at Pass' site, as well.

 

[blip]

Quote:

Originally Posted by Uncle Erik blip, I built the Zen and found it a very rewarding project. Mr. Elliott may be correct (I'm no EE, just a hobbyist and a ham) but the Zen is *not* a bad sounding amp. Far from it. It's a relatively easy and inexpensive build, too. I have no regrets and fully expect to use this for many years. You might want to take a look at some of the Aleph clones over at Pass' site, as well.

That's sort of the problem with the critique... It has a lot of information but little real exploration of what that information will mean to the listener. Even the worst MOSFET doesn't provide horrible distortion (if I read his figures right) so in practice is it actually audible? Is the negative of the increased distortion outweighed by the superior clipping behavoir of the MOSFET? Is his test circuit really equivalent to a functioning Zen? What about the multitude of modifications to the circuit... would they change the results?

All hard things to answer certainly, but critical in deciding which amp to build. That's part of the reason why I go back and forth between Zen (which certainly has a chorus of respectable, even golden-eared supporters) and the spec-friendly Death of Zen.

 

[tomb]

As mentioned earlier, there is a Group Buy at Headwize for Digi's board implementation of Tortello's Zen:
Group order for Zen headamp V2.0.

However, for those interested in the basic concept of a zero-feedback amp, you might check out the Cavalli-Kumisa at Headwize:
New Cavalli Kumisa III plus Boards. The Cavalli-Kumisa is based on a bipolar output, and incorporates a DC servo and a star ground.

Amb is actually designing and producing the boards. There is a preliminary interest-check for a future Group Buy here:
Interest check: Cavalli Kumisa III PCBs.

 

[jarthel]

this is 1 thing I notice in head-fi/headwize

if the designer is not millett, amb, gilmore tangent or cavalli, it probably won't be "flavor of the month"

 

[mb3k]

Quote:

Originally Posted by wobberly1 Did you mean Rod Elliot's DoZ at http://sound.westhost.com/project70.htm

That's the one!

Quote:

Originally Posted by tomb As mentioned earlier, there is a Group Buy at Headwize for Digi's board implementation of Tortello's Zen: Group order for Zen headamp V2.0. However, for those interested in the basic concept of a zero-feedback amp, you might check out the Cavalli-Kumisa at Headwize: New Cavalli Kumisa III plus Boards. The Cavalli-Kumisa is based on a bipolar output, and incorporates a DC servo and a star ground. Amb is actually designing and producing the boards. There is a preliminary interest-check for a future Group Buy here: Interest check: Cavalli Kumisa III PCBs.

I'm investing in the Kumisa III and the Beta22... thats when I recover some money in the summer.

 

[dsavitsk]

Quote:

Originally Posted by jarthel this is 1 thing I notice in head-fi/headwize if the designer is not millett, amb, gilmore tangent or cavalli, it probably won't be "flavor of the month"

This is true, and I have certainly found it with my little project.

However, building these projects does cost real money, so people who are not designing their own from the ground up are right to be weary of new things. Further, all of those designers have demonstrated through past performance and forum contribution that their projects are the real deal, so they have earned the respect they enjoy.

 

[jarthel]

Quote:

Originally Posted by dsavitsk Further, all of those designers have demonstrated through past performance and forum contribution that their projects are the real deal, so they have earned the respect they enjoy.

There are many distinguished designers out there. IMHO more distinguished than gilmore or tangent or amb or cavalli (Nelson Pass would certainly qualify) and these designers share their knowledge in their own website/other forums.

maybe it's case of people now knowing there are other great designs out there. maybe people need to branch out of head-fi?