Tube/MOSFET hybrid results/comments/suggestions?

lgo51

Member
2002-03-10 9:29 am
MileHigh
OK, i've been reading a lot and searched for *any* posts on hybrid amp actual results w/o much luck.

I've been looking at the Hybrid and Hybrid+ amps by Generoso Cozza described here in some detail. Sure does look enticing.

What i'd like to know is if anyone has experience, heck even hearsay would be nice, with this or any of the handful of other hybrid circuits floating about? My particular goal is to build a relatively low power amp for the top end of a tri-amp'd setup. [Yes, Nelson, i'm watch'n for your cross-over with great anticipation ;) ]. Did i mention that the middle tier is covered by an Aleph3 - from the master his good self.

Thanks all!
 
I've been using a hybrid for some years, and am very pleased. I build a few different amps a year, and always end up using this amp no matter how good I feel the other designs are. It simply sounds great. It's single-ended so rather low powered, but certainly powerfull enuff for me.
It's found here

http://home.c2i.net/semfielec/tubemos.htm

I've now built this amp into a single chassis, so it's neater looking and less cablings and boxes.

If you need more power, a PP output stage is more practical, and just as well done as a hybrid vs purebrid.

Personally I dont like the design you refer to since it has loop NFB.

Regards, Nick.
 
Some good hyrbids

http://www.uspto.gov/ and search patent #5,017,884

It'll also reference numerous past of-the-art designs you can view too. The company using that patent in production today is www.avahifi.com. There current amplifier models incorporating it are not low powered, quite the opposite, 160wpc to 250wpc. However, they seem to be very nice hybrids and better than most. Work what you can with the circuit. I own 'em.
 

lgo51

Member
2002-03-10 9:29 am
MileHigh
Re: Some good hyrbids

ezmeralda11 said:
http://www.uspto.gov/ and search patent #5,017,884

It'll also reference numerous past of-the-art designs you can view too. The company using that patent in production today is www.avahifi.com. <snip> Work what you can with the circuit. I own 'em.

Thanks for that great reference. Very interesting reading. As they say; 'the devil's in the details' so it would be very instructive to study some of the realized designs.

LarryO
 

lgo51

Member
2002-03-10 9:29 am
MileHigh
Thanks SemperFi

SemperFi said:
I've been using a hybrid for some years, and am very pleased. snip It's found here

http://home.c2i.net/semfielec/tubemos.htm

I've now built this amp into a single chassis, so it's neater looking and less cablings and boxes.

Hi Nick,
Interesting read. Would you have any pix/prints of yours that you'd like to share? Did you build it up as a balanced design?

Personally I dont like the design you refer to since it has loop NFB.

Hhmmm, that seems to be on the those 'political' topics. Liberal = 0dB NFB, Conservative = 18dB NFB, Moderate = 6dB NFB. :D

LarryO
 

Nelson Pass

The one and only
Paid Member
2001-03-29 12:38 am
100 dB would be radical conservative (Iverson)

50 dB would be reactionary conservative (D'Agostino)

20 dB would be center of the road moderate (Rowland)

10 dB would be moderate liberal (Curl)

0 dB is foaming-at-the-mouth, (rrrrrrrr!! Mad Dog!! rrrrrr!!)

:) :)
 
naming names and kicking feedback

Does it strike anyone as remarkable that Mr. Pass knows that much about how much feedback his comtemperaries use. Having poked around with a few designs from the list of usual suspects, I actually concur that he is accurate on these facts. I am casting my vote for "Amplifier Nerd of the Millenium" for Nelson Pass.

H.H.
 
Hi, guys.

here is my way to make a valve/mosfet "hibryd".
(actually it is not a hybrid, but as valves and fets, so...

My preamp is a Audionote Preamp kit - all valve kit, the input stage and the RIAA stage. it as a double output to bi-amp.

I have two amps, one for the low frequencies and another for the high frequencies.

I use a Audionote Kit One (single ended, no feedback, class A, DC heated triode (300B) and valve & choke & capacitor rectification for the high frequencies.

For the low frequencies, I use the Famous SOZ amp Designed by Nelson Pass(I think HE and IT doesn't need any presentation).

Obviously it is not an "Hybrid in a box" but I can say that my system has valves and amps... All in class A operation.

Hope it help someone,

Pedro ;)
 
This is a nice Kit Hybrid design, IMO

Take a look at the A50 from APN in the Netherlands.


Hawk Audio



[IMGDEAD]http://www.audio.nl/a50boven.JPG[/IMGDEAD]


This is a non loop feedback design. I have no direct experience of this unit, though I've built several of their MP-DAC's, another NLFB design, which sounds quite nice, and is something of a bargain.


Hmmm, is

0 dB is foaming-at-the-mouth, (rrrrrrrr!! Mad Dog!! rrrrrr!!)

really that far out? Didn't know I was that far gone. The more stuff I design, build, and evaluate (not just on the bench), the more I'm forced to conclude that NLFB is the way to go. Maybe just because it forces you to do everything as right as rain as you can at each stage.

Even my attempts to compare the same circuit, configured for FB, or without, always seem to point to "without" as the best sounding choice. Maybe it's just a personal preference. YMMV.

Regards,

Jon
 

lgo51

Member
2002-03-10 9:29 am
MileHigh
Re: Hawk Audio A50

The Hawk A50 was an interesting read. Sure looks to be solid. But why would i want that over an Aleph5? ;)

However, the Hawk Audio Hb30 that they discuss is a rather new an quite interesting design concept. I like the logic, using a tube as a voltage to current converter and a transistor as a current to voltage converter, but i'm not anywhere experienced enough to comment on the potential sonics. :confused:

Be well,
LarryO