Hybrid Aleph- anyone buit this??

[nate]

I read an article about this design in AudioXpress a few years back and I have been itching ever since to build it. This will be my first amp project and I was wondering if anyone has built this or something like it?? I post this here as it is based on NP's aleph circuitry.

http://digilander.libero.it/essentia...id_circuit.htm

The other project that I'm considering is an Aleph 30
Either of these will be run with a Rogue Audio 66 tube pre or a BZLS that is nearing completion.

Any input appreciated!

Nate

[GRollins]

The idea of a tube front end for the Alephs comes up two or three times a year. It's been about three or four months now, so I guess it's time again.
To begin with, I should note that the schematic you linked to is not an Aleph. Second, I'd suggest that 35V (note that the majority of the negative rail is taken up by the CCS) is a bit low for linear operation of a tube. Third, given that tubes can go through some gyrations as they wake up, I'd like to see some sort of protection for the Gates of the output MOSFETs. Fourth...oh, never mind...a friend of mine has an expression that covers circumstances such as this, but crucial portions of his saying would be rendered as asterisks and the flavor of the thing would be lost.
Suffice it to say that it can be done, but to be done well you're going to need to use a more robust front end, DC blocking caps, and a method of handling the output stage bias. Assuming that you're wanting an Aleph amp, you'll need to redesign the output anyway, so you're looking at a whole new project no matter what.

Grey

[h_a]

Grey, is there an area of amp knowledge where you don't have deep expertise?

Read my lips: you are frightening!

Just joking! Just wanted to say that your support and knowledge is amazingly great!

Cheers, Hannes

[Babowana]

For your info, my tube-SRPP/Zen V2 (Aleph CCS) combo makes very very good sound from the terrible speakers made in USA(Phase tek . . . ? I have to go back home and read the name correctly). Really warm and sweet . . .

[GRollins]

Originally posted by h_a

Read my lips: you are frightening!

Comes in handy at Halloween.
(Reminder: It's time to plant your pumpkins, folks.)
I make no claims to deep understanding of anything. I've used the analogy of a child building sandcastles in the past; all I do is play.

Grey

[nate]

Grey,
Thanks for your input. I've read the various threads and I wanted to know what the results were. It seemed like a very simple design.... its just missing a few parts and concepts.

Hope your sprign is going well!

Nate

[Nelson Pass]

I think it's a good design. You should give it a try.

[Zen Mod]

Originally posted by nate
I read an article about this design in AudioXpress a few years back and I have been itching ever since to build it. This will be my first amp project and I was wondering if anyone has built this or something like it?? I post this here as it is based on NP's aleph circuitry.

http://digilander.libero.it/essentia...id_circuit.htm

The other project that I'm considering is an Aleph 30
Either of these will be run with a Rogue Audio 66 tube pre or a BZLS that is nearing completion.

Any input appreciated!

Nate

besides all answer you're already given, its worth to mention that at broskie's site you'll find some (if I remember well - good ones) musings about this schmtc

[Kashmire]

You should spend a couple weeks reading Tube Cad Journal.

John Broskie has many hybrid amp designs, many of them excellent. He also deconstructs many published designs, such as this article that shows an Italian DIY design:

http://www.tubecad.com/march2001/ (look under the "email" section in this particular article)

Some other good ideas, which I have built and tried, are:

http://www.tubecad.com/2006/04/blog0058.htm

Here are some thoughts on the Zen.

http://www.tubecad.com/2007/03/blog0099.htm

[nate]

Thanks Kashmire,

There is quite a bit of info on the tubecad pages.....
Broskie's comments on the Italian hybrid design are pretty interesting. His explanations and modifications seem to be based on some serious knowledge.

The tube cad version of this circuit seems to be a little more based on common practices (higher voltage on the tube side and better safety on the mosfet side). I like this and I think that I have a busy summer ahead of me..... though I may need some help along the way.

Does anyone have any input on the advantages of the BUZ900db/905db versus the IRF9540/540? I think that my current speakers could use the extra power, but I can always build different speakers....

I welcome any comments or suggestion on the tube cad design that I've attached.

thanks
nate