O.K. I think we've all seen the Depletion Mode MOSFET Zen Lite variant displayed by N.P. at BA'09. Personally, I did not know that part existed? But, it appears to have some quite conveniant qualities:
Suitable Voltage rating, Current rating, self biasing like the LU1014D, "Idss" of about 2.5A, Rthjc .31 C/W, plenty of S.O.A., fairly linear C in our typical operating range, and by all accounts so far, fairly linear and good sounding. Oh yea, affordable price in small enough orders. Did I miss something?
I'm not so interested in another Zen Lite but as I've seen recently, I'm not the only one interested in creating a monster B1 circuit. I was thinking of paralelled LU1014Ds with car battery rails. This device can take that idea further and easier as Paul Hynes did a few years ago (someone posted an AudioCircle link around here somewhere). I've also played with the Circlotron circuit quite a bit and it's very nice but, with self biasing and ground refrenced input as Paul Hynes has already done also wow 🙂
Personally, I can't wait to play with this part. There is a GB thread started to research the interest in obtaining some.
So, I thought I'ld get us all started on a discussion for everyone's benifit. Oh, yea, another great quality, N.P. seems to like this part too...
Any other comments? questions? previous experiance? Ideas?
Suitable Voltage rating, Current rating, self biasing like the LU1014D, "Idss" of about 2.5A, Rthjc .31 C/W, plenty of S.O.A., fairly linear C in our typical operating range, and by all accounts so far, fairly linear and good sounding. Oh yea, affordable price in small enough orders. Did I miss something?
I'm not so interested in another Zen Lite but as I've seen recently, I'm not the only one interested in creating a monster B1 circuit. I was thinking of paralelled LU1014Ds with car battery rails. This device can take that idea further and easier as Paul Hynes did a few years ago (someone posted an AudioCircle link around here somewhere). I've also played with the Circlotron circuit quite a bit and it's very nice but, with self biasing and ground refrenced input as Paul Hynes has already done also wow 🙂
Personally, I can't wait to play with this part. There is a GB thread started to research the interest in obtaining some.
So, I thought I'ld get us all started on a discussion for everyone's benifit. Oh, yea, another great quality, N.P. seems to like this part too...
Any other comments? questions? previous experiance? Ideas?
Just a few examples of simplied circuits that could use these devices... I'm sure you recognize them 🙂
And the interesting thread regarding these parts by Paul Hynes from another forum 😱
Two simple Current Amplifiers for low impedance loads
And the interesting thread regarding these parts by Paul Hynes from another forum 😱
Two simple Current Amplifiers for low impedance loads
Attachments
The part I used on the BAF example was the IXYS
IXTH20N50D which has about 1.25A current with a 0
Gate voltage.
😎
IXTH20N50D which has about 1.25A current with a 0
Gate voltage.
😎
I don't mean to misslead anyone or anyhing but first I must say this: I've done some data sheet tests myself, mostly because my Boss always responds to my reasoning gathered from datasheets with "Data Sheets Lie".
Having said that, I realized recently that I have 2 copies of the datasheet for this device. One of them from 2006??? And the other is current on the IXYS website(2009). I may not have been thoughtfull enough with looking at them? or posting accurately.
I have one other peice of info I was going by. The Link I posted refrencing Paul Hynes work states that in his application, at his temps etc. he see's about 2.5A.
All in all, I think it's a very interesting part and I would not even know about it's existance without The One And Only sharing with us. Thanks Nelson.
Having said that, I realized recently that I have 2 copies of the datasheet for this device. One of them from 2006??? And the other is current on the IXYS website(2009). I may not have been thoughtfull enough with looking at them? or posting accurately.
I have one other peice of info I was going by. The Link I posted refrencing Paul Hynes work states that in his application, at his temps etc. he see's about 2.5A.
All in all, I think it's a very interesting part and I would not even know about it's existance without The One And Only sharing with us. Thanks Nelson.
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"I ran across it somewhere in this site, so of course I just
bought some."
I asked about them 5 May 2006 here (#16):
http://www.diyaudio.com/forums/pass-labs/78734-new-tron-2.html
bought some."
I asked about them 5 May 2006 here (#16):
http://www.diyaudio.com/forums/pass-labs/78734-new-tron-2.html
My intentions for this or a similar depletion MOSFET will be tubish, involving a transformer, 250V, and some JFET accomplices. Unlike tubes, a big, fat heat sink gets tossed in...
Isn't there a somewhat popular, classic maybe, Zen-like amp that uses an output transformer and a MOSFET? I don't recall the name obviously but it has somewhat of a reputation?
Let us know when you figure out the name... The use of a depletion mode FET simplifies the design and makes it more tube-like in concept, if not in sound. I prefer to view the Ixys depletion mode fets as pentodes without heaters and extra annoying pins. Treating them as such may prove to be interesting.
I nosed around a bit in the forums devoted to Hiraga's works, and haven't seen mention of a transformer coupled amp yet (not that that means a whole lot). The concept is so obvious, I can't believe no one's done it before. The addition of a deplection mode output device adds a touch of innovation, but not a whole lot, Anyway, it's an excuse to dust off the pair of One Electron UBT-1s that have been gathering dust, because this application is made to order for them.
I suppose the lowish idle current you would want for the typical transformer might contradict the highish idle current you would want for the MOSFET to be in a linear area? Unless maybe a para-feed type topology were used😕
Hiraga Amp
Hiraga's SE Mosfet amp (called the Nemisis) from memory used a Hitachi lateral mosfet (2SK135) and an output transformer (64 ohm primary winding). The mosfet had 1A of current running through it. So I think the UBT-1 would be well cooked, even fried. Also if you check Bonavolt's website you should find a circuit of the Nemisis there. Hope this helps.
Regards
Ejam
Hiraga's SE Mosfet amp (called the Nemisis) from memory used a Hitachi lateral mosfet (2SK135) and an output transformer (64 ohm primary winding). The mosfet had 1A of current running through it. So I think the UBT-1 would be well cooked, even fried. Also if you check Bonavolt's website you should find a circuit of the Nemisis there. Hope this helps.
Regards
Ejam
Wrong Spelling
Sorry, got the spelling wrong, it should be "Nemesis". Jan Didden at Linear Audio has a few words about rebuilding one of these amps. Try http://www.linearaudio.nl/nemesis-1.htm
Sorry, got the spelling wrong, it should be "Nemesis". Jan Didden at Linear Audio has a few words about rebuilding one of these amps. Try http://www.linearaudio.nl/nemesis-1.htm
The original output transformer is no longer available, but I have a prototype from another manufacturer on order. As soon as I get it, I will test it in the original Nemesis and with one of these depletion mode MOSFETs. I'll keep you guys posted.
I am currently using the ECF10N16 from Exicon, but the new device should make the circuit even simpler. Maybe even beat Nelson at his own game 😉
jd
janneman - have you any info about these xformers ?
winding ratio etc ?
edit : I forgot that in original schematic is written 64:8 ohms
any other info , besides that ?
winding ratio etc ?
edit : I forgot that in original schematic is written 64:8 ohms
any other info , besides that ?
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This one perhaps...
" Schematic by Jean Hiraga published in "L'Audiophile" named Némésis. "
2SK135 SE Amp
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