30W mosfet Planteféve

30W Mos Fet Plantefeve

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Re: 30W Mos Fet Plantefeve

GEirin said:
Recently I found an old article of a power amplifier, 2x30W AB Mos Fet of J.M. Plantefeve.
Has anyone heard of this?

I know the website of Plantefeve from France.
There are some interesting amplifiers over there!
Very minimalistic Power Amplifiers.
:)

I do not know the details of this MOSFET you are asking about.
It uses 2SK1058 / 2SJ152 lateral MOSFETs.

Bias is set only with resistors.
This means you should have very large heatsinks to avoid problems with bias runaway.

Here is a link to original article, with a picture of this amplifier & schematic:
MOS-FET 2 x 30 W

Plantefeve Hompage:
Plantefeve ENGLISH version
 
GEirin said:
Ok.
R82 and R83 are trimmer pot for adjustament.
GEirin.

That's OK.
You can adjust both offset and bias with them.
Another thing: it has very high gain, are r74 anf r79 correct?
By contrast open loop gain is low, therefore low feedback.
You will have to bias mosfets heavily for low distortion and low output impedance.

regards
 
I ressussite this subject after 10 years of sleep to talk about this amp and other amp JM Plantefeve.
I built this amp at the very beginning of its history almost 20 years ago and it accompanies me today as well as others of his schemas. I highly recommend building it, it's one of the best A / B I've ever seen. I built many of his amps (zenotron, amperotron, zenquito) and now to celebrate the 20 years of this first success that is the 30w nrds, I attacked the construction of one of his first schemas, the zenith which can be declin in version A or A / B. Jean Marc is one of his people who share their knowledge with pleasure and who always answers the question put to him, it was time for me to pay him homage.
2A & DIY
 
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What other latfet amps have you built?

I used crescendo PCB (it's TO-3) to build the nrds but I thought the circuit sound didn't worth the expensive and rare TO-3 latfets. Currently the TO-3 latfets are powering my active 3-way speaker using the original Hitachi 1979 50W circuit.
 
What other latfet amps have you built?

I used crescendo PCB (it's TO-3) to build the nrds but I thought the circuit sound didn't worth the expensive and rare TO-3 latfets. Currently the TO-3 latfets are powering my active 3-way speaker using the original Hitachi 1979 50W circuit.
grand mos
zenotron
amperotron
mosquito
and no lateral fet
pass PLH
pass zen
pass f5
pass f5 turbo
ACA 5w
etc etc etc ...
for the j50 and k135,I buy power amp for parts (C-audio) for example
for j162 and k1058,i have a stock NOS hitachi
 
@johnego: Which speakers? Which circuit?

I started using latfet with Mini Crescendo and Crescendo. Never satisfied and tried many more amps up to Goldmund clones. Then I built my own amplifiers. Still, not fully satisfied. Been thinking to purchase those Toshiba FET for my best amplifier.

I built my own speakers long before I built my own amplifiers. Last speakers I used before my own were Pilotis (Vifa P17WJ and D21TG) and I forget the name, it was a bookshelf with Vifa PL14 and D26. I think both were from Speaker Builder magazines. Those are used with Mini Crescendo, Aleph-3, JLH69 and a vintage 18W tube amp (forgot the tube).