The New-Tron

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coloradosound said:
This threads been dead awhile...

I'm a Circlotron type too. I'm so happy to see this thread revived :D :D :D
My prototype was IR MOSFET parts (no Lovoltechs) but, the properly assembled version I let sit for a while... And it's still not operating... DC stability could have been better... Needs a servo...

What's the link to this GR-25 you mention? ...

When I first heard, I searched. It's there...

Let's keep this thread going. UGS, GR-25, or any JC type comp front end would work great. I used a high voltage BOSOZ circuit for mine...

;)
 
It sounds interesting. I have some Acoustat 2+2's and
Carver B&G ribbons and want to build something interesting
to drive one or both. I ordered at least 30 of the LU1014D's
and had a guy from our machine shop make little mounts
from some thick copper stock I had laying around.
(has a machined surface carved in where the JFETs can lay down
inside, then I can solder them to the copper, then screw holes
out to the sides so I can attach them to real heatsinks)

I certainly believe an F3 would do nice for my Coral Beta 8's
(which I plan on doing two per enclosure with perhaps some
Heil AMT's sitting on top), but I do plan on consuming (and
hopefully not blowing up) some if not most of the LU1014D's.
Also just joined that GB for the LSK170's (100 B grades and
another 100 A grades)(No, not selling till I pick through!)
heeeeheee!

Certainly agree with keeping the thead going, flg, but don't
want to see it get as long as the ESS sabre threads
 
coloradosound said:
This threads been dead awhile.
So Grey,
What was your favorite JFET New-Tron config?
What's the link to this GR-25 you mention?

Anybody else build JFET New-Trons and impressions?

I'm still sitting on my Loveltechs that I bought from Grey
last year!


Favorite New-Tron...hmmm...probably tomorrow's...
I rarely, if ever, comment on sound quality of my fiddlings because no one knows my hearing and my system is not something someone could easily reproduce, even if they wanted to. There's also the fact that I'm never satisfied; always on the move (albeit slowly...think glacier, not hummingbird).
The GR-25:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=120673&highlight=
It's a 25W (heavily, heavily biased...keeps doubling in power down to around 2.5 Ohms), pure class A, all FET, zero feedback design. Note that the thread is quite short (not unlike this one), which indicates to me that though a lot of people say they're interested in zero feedback, it's only in a theoretical, arm's length sort of way; they only want to talk about the circuits, not build them.
That's okay, I've got mine, and ideas for another four or five variations on the basic theme. All I did was do a writeup for something I was already working on, anyway.


flg said:


I'm a Circlotron type too. I'm so happy to see this thread revived :D :D :D
My prototype was IR MOSFET parts (no Lovoltechs) but, the properly assembled version I let sit for a while... And it's still not operating... DC stability could have been better... Needs a servo...



When I first heard, I searched. It's there...

Let's keep this thread going. UGS, GR-25, or any JC type comp front end would work great. I used a high voltage BOSOZ circuit for mine...

;)


DC offset need not be a problem, and it need not require a servo. In most direct coupled amplifiers it's handled by the feedback loop. Assuming that you're using feedback (and most people do--the GR-25 is very much the exception, not the rule) then look to the feedback loop if you're having DC offset problems.
Note that a lot of DC offset problems can be managed simply by keeping the devices at a stable temperature.

Grey
 
yes i'm planning ss circlotron also. i may start just by using them in bottom half, with lovoltech up top, then move to all ss when i get some more. i have 4 x matched r550 here waiting for something to make them sing. so its either play with crosscoupled x'd type output stage using them on the panson lme49830 initial series driver board, or on patricks x'd lovoltech circlotron headphone/line amp
 
yeah thats the idea, but i actually already have IRF, TOSH, Lovoltech and R550 here 'lying around', because i'm going with patrick's 2 stage power jfet circlotron X'd, i'll probably start with lovoltech and 1529 as with his design and then drop in the R550 for the toshibas as a tweak to try them out. i think it would be a very good circuit to really get a feel for their sound. also building up the dao and daox and trying all these out when i have the time
 
why bad choice of article headline? its a circlotron, so those looking for a circlotron will find it, i think it will be more rare for someone that needs to search for circlotron designs to search for cross shunt push pull, as its only once you are more involved in the topology that you know they are the same thing.
 
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