DIY progress report

[Nelson Pass]

Well, it's not like I don't have one...

😎

 

[flg]

Seems to me to be a logical step to fold half of an F5 into a circlotron and replace the output fets with Jfets.

🙂

I had some thoughts like that when I saw The Amazing FET Circlotron

 

[flg]

Cool 😎
What exactly connects to "Ref1", "Ref2" and "Bias"?
What devices would this be for?

 

[Melon Head]

Thanks Nelson

 

[Zen Mod]

that's most likely just one plane of pcb

Papa is teasing us , as usual

 

[Nelson Pass]

Papa is teasing us , as usual

I wouldn't want you to think there's nothing behind the
curtain...

😎

 

[flg]

No, the copper we see makes Circlotron sense. There is some skinny traces going off to the left that would only be an LED thingy. And, no big holes for pwr supply connections or speaker outputs... But, the "Ref1", "Ref2" and "Bias" is an important area I have not suceeded in developing enough stability in output offset. I think that is the biggest area to conquer. But, Biasing the 2 halfs into a semetrical complamentary/balanced behaviour is also important.
I wonder though? Is it posible to apply susy to these things???

 

[Zen Mod]

I wouldn't want you to think there's nothing behind the
curtain...

😎

I wouldn't want you to think that I ever think that .....

 

[Nelson Pass]

Is it possible to apply susy to these things?

Yes, it's not very difficult.

Perhaps we should call it a Susytron.

😎

 

[Blues]

Something to drool over...

Home Page | Stereophile.com scroll down...

Still under development Mr. Pass or will it make it to production soon? With PapaFETs?

 

[Melon Head]

I wouldn't want you to think there's nothing behind the
curtain...

😎

I will take a guess and say, this is the output stage.
What about the input stage?

 

[flg]

Yes, it's not very difficult.

Perhaps we should call it a Susytron.

😎

"No more training do you require. Already know you that which you need."
―Yoda

 

[Melon Head]

Since you're so enthusiastic, here's a copy of the kind of circuit that
I used in the curves seen in "Feastrex Fun"

Will this work with the seas prestige full range?

 

[jacco vermeulen]

YouTube - Van Halen - Jump (HQ music video)

 

[c2cthomas]

I always thought that this guy wuz go'n fer da VH big hair "look" 😱

 

[troystg]

Is that "Silence of the lambs?" 🙂

 

[lhquam]

Well, it's not like I don't have one...

😎

It also simulates very well without any feedback. (This is with IRFP240s rather than the Semisouth devices we all know you are likely using.)

 

[Melon Head]

Here is the performance of my top secret circlotron circuit.
This is just the output stage.
I am still working on the front end.

 

[Melon Head]

Some minor tweaking and some more results.
The first is 1W average into 8Ohms, and the second is 10W average into 8Ohms.

 

[Manu]

Recently, a member of an another forum (froggy) ebayed some mosfets (IRf 240 and 9240) in order to build an UGS UP (Cheff de Gaar).
According to the seller they were matched Vth and Ids at this point (around 1 - 2mA for the most), with a so called Fet analyzer ...
Anyway, surprisingly it appeared that the fets offer not a bad match also at 100mA bias (measured in situ) .
Is it just chance? or is there a correlation between those Vth numbers and matching at any bias current ...

Manu