Moskido - Hybrid Aikido/MOSFET amplifier

[lineup]

Originally posted by beau2317
And here is the PSU

FRED bridge rectifiers, Jensen 4 pole caps, Tube transformer from PartsConnexion

MOSFET transformer from RS Components, 500VA

Common mode filter made from some ferrite RF chokes and 0.1uF

beau2317

I am of the opinion ( I have expressed this in other contexts at our board, too )
that
There are too few designs done to explore Combination of Different Semiconductors.
MOS JFET BJT VALVES
Let each type do what does best and take care of this, in Amplifier.

I have started quite a number of such topics, over the years at www.diyaudio.com
Why so relatively little interest?

I have tried to explain such:
diyAudio builders are divided into camps, you 'belong' to one sort of builders
- a gang for mutual encouragement and exchange of applauds
We have:
1. The MOSFET maffia. FETdaMOSalists.
2. Solid State BJT Super Group. They do not make much Noise in circuits, but ...
3. Chim Amps Gain Crown rulers.
4. The only, The real AudioPhile Understanders: VALVES Lovers!

And we have not so many doing HyBride explorations.
And if they do, they do not get attention.
They do not Belong to 'Da Group of COOL People'
...as seen from view of 'those gangs'
====================

About your attached circuit here:
http://www.diyaudio.com/forums/attac...amp=1180583678
It is a no global feedback amplifier, right?
Have you simulated it?
How low a level of distortion? Your Acceptable target value?


Regards
lineup

[beau2317]

Can you fill in the value for the mystery resistor from the Hybrid SE schematic?
http://www.tubecad.com/2006/04/blog0058.htm
The only difference for my case will be Buz900 rather than Buz901.
Thank you. - Jeffrey Hill (marsupialx)

Sorry I used the push pull circuit. Not sure what that R value is. Email john and he might be able to tell you.

[beau2317]

About your attached circuit here:
http://www.diyaudio.com/forums/attac...amp=1180583678
It is a no global feedback amplifier, right?
Have you simulated it?
How low a level of distortion? Your Acceptable target value?

[/B]

Hi

I know what you mean about camps. I have built amps of all kinds.

For instance when I built a Peter Daniels gainclone using his kit and following the instructions to the letter, I was not very impressed with the sound quality. When I had the temerity to post this opinion in the chip amps forum, let's say it was not well received.

As far as the hybrid goes, no I have not measured the distortion. People have measured the distortion of the aikido part and found it to be very low (see Broskie's blog). But I don't know about the whole thing. I suspect it's pretty low.

What I do know is that it's the best sounding amp I have ever heard. I think it's down to the horses-for-courses idea that you suggest. That's another reason I like JB's writing. Love the way he throws in. for example, solid state CCS along with snarky comments

[tubee]

Originally posted by JoshK
One could also try the pentode aikido, where a pentode is used for the first position (EF86, 6AU6, 12HG7, etc) and the Aikido followere thereafter. Its a less used but proven design. I'd like to try this one in a 813 SET design with the 12HG7 or something like that.

I have a box full of EF86's not knowing what to do with them.... maybe sometime?

[tubee]

Originally posted by beau2317
And here is the PSU

FRED bridge rectifiers, Jensen 4 pole caps, Tube transformer from PartsConnexion

MOSFET transformer from RS Components, 500VA

Common mode filter made from some ferrite RF chokes and 0.1uF

Wich hexfred diode or bridge did you use beau2317?

I made a bridge of HFA08TB60's to upgrade my hybrid (SRPP E88CC/j50/k135) Transformers: two mono 120VA toroids. Now the bridge can have 15A, HFA only 8

[beau2317]

Originally posted by tubee


Wich hexfred diode or bridge did you use beau2317?

I made a bridge of HFA08TB60's to upgrade my hybrid (SRPP E88CC/j50/k135) Transformers: two mono 120VA toroids. Now the bridge can have 15A, HFA only 8

I used the 22A 600V IXYS FRED Bridge rectifier http://www.partsconnexion.com/catalo...onductors.html

But if your transformers are 120VA, and A = 15 then V is only 8 volts??

Or am I missing something...

[tubee]

Originally posted by beau2317



I used the 22A 600V IXYS FRED Bridge rectifier http://www.partsconnexion.com/catalo...onductors.html

But if your transformers are 120VA, and A = 15 then V is only 8 volts??

Or am I missing something...

Hi beau2317. Thanks for reply.

My post was not very clear.
I had 6 HFA08 hexfreds lying around here, ordered two extra to create 2 mono diodebridges and replace the standard 15Amp diodebridge. I replaced 1N4007 in HT PS too before for BYV's with great result (deeper soundstage)

Each mono transformer used is 120VA, 2 X 22V/2.7A toroid. For cap i use a pair of 10000uF/50V panasonics each channel.

The HFA08 can have 8 ampere, and 60 ampere for a short moment (start-up) so i think this is sufficient. My powerstage is running on a lowish 600mA just in class A. (but i can switch it into B) I can solder the hexfred's in, maybe tomorrow. Want to build a DC blocker for the toroid's also, they buzz sometimes. (bridge in mains line decoupled with big lytics)
I am curious what this HFA mod will do to the sound.

Btw large resistors you used in the PS, more then 1 ohm? I used 0.1 or 0.2 ohm in to AC line. Have some 0.12 Ohm extra to put in the DC line after hexfred.

http://img102.imageshack.us/my.php?image=hybridnw3.jpg

[marsupialx]

beau2317,
Have you met John Broskie? You write with a sense of 'knowing him?'
I get the feeling I'm the guy... well, the guy that can't see how to begin to determine the value of that mystery resistor, and as such, of very limited 'use' to John. I guess on some small level, I'm a paying customer. Perhaps I should get some emulation software so I can use his software on my Mac. Anyway, I guess I'm just delaying emailing him.
Thanks, I feel much better now. - Jeffrey Hill marsupialx

[billr]

Originally posted by marsupialx
Beau2317,
Can you fill in the value for the mystery resistor from the Hybrid SE schematic?
http://www.tubecad.com/2006/04/blog0058.htm
The only difference for my case will be Buz900 rather than Buz901.
Thank you. - Jeffrey Hill (marsupialx)

Hi

If you look at the next diagram in the blog, it shows that 5v is required on the gate,

I am guessing that it is the same for this diagram too.

therefore the resitor should be the ratio giving 5 volts, with the 100k other resistor so X/100 time 40 = 5

got to rush.

bill

[beau2317]

Originally posted by marsupialx
beau2317,
Have you met John Broskie? You write with a sense of 'knowing him?'
I get the feeling I'm the guy... well, the guy that can't see how to begin to determine the value of that mystery resistor, and as such, of very limited 'use' to John. I guess on some small level, I'm a paying customer. Perhaps I should get some emulation software so I can use his software on my Mac. Anyway, I guess I'm just delaying emailing him.

No I have not met him, but I have talked via email several times, especially regarding the moskido hybrid. And end up talking about all sorts of things. I would love to meet him and buy him a beer.

Note that if you email him, he gets an awful lot of email, so he usually only manages to reply something like 20% of the time (then is apologetic when he does find time to reply.) So if you don't get a reply, wait a week or so and write again. Also be sure to put "Tube Aikido" in the subject line or it is likely to be spam-binned.