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Jfet + Mosfet SE Headphone amp + Jade circuit (updated)

post #1 of 14
Thread Starter 
This Circuit is design by ASL Joseph Lau. It topology is simuliar to Jade but use Jfet + Mosfet. It is simple and easy but good sound. It is patented in China. It output can get from D or S or get both to become balance output.
post #2 of 14
¬ _¬

wut?
post #3 of 14
Do you have an actual pic or link to schematic? All we see is a logo. I would be interested in hearing a hybrid design especially from antique sound labs.
post #4 of 14
Thread Starter 



Audiotailor Jade circuit. Can output from Plate & Cathode.
post #5 of 14
Such an amp can be improved a great deal by doing it with CFP and/or cascoded input stage. A single SK170 used in this manner will sound grainy IMO.
post #6 of 14
Thread Starter 
Quote:
Originally Posted by NelsonVandal View Post
Such an amp can be improved a great deal by doing it with CFP and/or cascoded input stage. A single SK170 used in this manner will sound grainy IMO.
Why Need a CFP ? Distortion is not very low but sound not bad. Why Need Cascode on 2SK170 if no need very high gain ? 2SK610 on this topology has very high input impedance. It can easily drive by a 2SK170 without any side effect. It high frequency can up to 500Khz -1db with 3~6db nfb only. I had test this circuit in China Audiophile. It accept by most of them. Ofcourse not 100%.
post #7 of 14
A cascode only uses a few more parts. Also you cancel some Miller Capacitance with the use of cascodes, which is evidently better for JFETs especially since the have quite the nasty input capacitance.
post #8 of 14
Thread Starter 
Quote:
Originally Posted by TzeYang View Post
A cascode only uses a few more parts. Also you cancel some Miller Capacitance with the use of cascodes, which is evidently better for JFETs especially since the have quite the nasty input capacitance.
Thank ! I know eliminated the Miller effect can widen bandwidth but If It don't has problem on extend high. Do you feel it need Cascode ?
post #9 of 14
Quote:
Originally Posted by Hz_joe View Post



Audiotailor Jade circuit. Can output from Plate & Cathode.
I know this is probably obvious to people familiar with tube circuits, but
where do the two transformers connect? Also, where is circuit power (+V) applied? Thanks!
post #10 of 14
Quote:
Originally Posted by SmellyGas View Post


Quote:



Originally Posted by Hz_joe View Post






Audiotailor Jade circuit. Can output from Plate & Cathode.



I know this is probably obvious to people familiar with tube circuits, but

where do the two transformers connect? Also, where is circuit power (+V) applied? Thanks!


I'm sure some tube expert can answer these questions.
post #11 of 14
Quote:
Originally Posted by MDR30 View Post


I'm sure some tube expert can answer these questions.

 

If you can't figure that out, you seriously should rethink what you're doing.

post #12 of 14

Wow... 4 year old thread... biggrin.gif

post #13 of 14
Quote:
Originally Posted by holland View Post

 

If you can't figure that out, you seriously should rethink what you're doing.

 

If you saw Joe's other designs you'd know this is not as simple as it seems. The design of the output transformers (ratios), and the impedance line converters, have not been discussed in detail. Not to speak of his combined OTL amps, my dear Mr. Holland.

post #14 of 14
Quote:
Originally Posted by MDR30 View Post

 

If you saw Joe's other designs you'd know this is not as simple as it seems. The design of the output transformers (ratios), and the impedance line converters, have not been discussed in detail. Not to speak of his combined OTL amps, my dear Mr. Holland.

 

You're an idiot.  Who cares about his other designs.  You asked about the schematic he posted.  If you know so much, why'd you ask such basic questions?  Because you didn't know and now you're trying to pull of some one-up BS.

 

The statement still stands.  If you need to ask, don't mess with the circuit.

 

Edit: That was too harsh.  I'll answer the questions, but you should not mess with it as it's most likely high voltage and you'll likely kill yourself as it's clear you've never done any electronics work.  First, you don't plug in an AC transformer.  The AC transformer goes to a rectification stage to convert it to DC and to smooth it.  It then plugs into the top side of C9.  How much voltage was not specified, but you can work it out based on the values of the sheet, and take a guess at an operating point.  There's also the matter of the heater.  All of this is more or less implied, and not essential to the circuit, but yet mandatory.

 

As for this circuit, it's an OTL circuit, there is no output transformer.  The jargon you threw out, it's basically nonsense as it pertains to this.

 

Edit: looking at some of the cap values, you're looking at around 300+ volts, but less than 400V, for B+


Edited by holland - 7/5/13 at 1:43pm
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