Anyone built this mosfet follower (or similar)?

[GregH2]

Hi All,

I'm thinking about building this circuit and using it with a valve preamp design I have sen that can supply a +/- 20v signal:

Project 83 - MOSFET Power Follower

Has anyone tried building one of these followers or something similar? Any comments on how it sounded? Any ideas, suggestions or improvements? I'd love to hear your thoughts.

Regards,

Greg.

[wahab]

distorsion is high with powermos without NFB, though this one is better
than Pass s ZEN...

regards,

[wahab]

forgot to add that if you stick to 36V, it s better to drive it with a
quality OPAMP, a NE5532 would be very fine and much better than the
discrete preamplifier provided you use it with no more than 20 db gain...

all da best,

[Circlomanen]

Taylor Source Follower

This is a good link about source-followers.
A Taylor source-follower can give twice the current to the speaker compared to Rod Elliots project 83.

[tiefbassuebertr]

Originally Posted by wahab

distorsion is high with powermos without NFB, though this one is better
than Pass s ZEN...
regards,

Source follower resp. power follower still have a large amount of serial NFB, therefore there are only a unity gain factor (actually a bit lower than "1")

[tiefbassuebertr]

Originally Posted by swordfishy

Hi All,

I'm thinking about building this circuit and using it with a valve preamp design I have sen that can supply a +/- 20v signal:

Project 83 - MOSFET Power Follower

Has anyone tried building one of these followers or something similar? Any comments on how it sounded? Any ideas, suggestions or improvements? I'd love to hear your thoughts.

Regards,

Greg.

I have build follow:
the project about
the Power Folllower
but modify to a unity gain preamp with 1A idle current and only 9V supply voltage (for undistorted +/-1,5Vss, for the user the best preamp on this planet)
and your suggested project, but with a sziklai modification of Parvel Macura for the upper MOSFET and 3,5A idle current by 22V supply voltage (sziklai means a current feedback pair = discrete IGBT, that content follow type: IRF510 and 2SA1216) ask Parvel Macura for schematic, because this isn't online currently.

[Bigun]

Originally Posted by swordfishy

Hi All,

I'm thinking about building this circuit and using it with a valve preamp design I have sen that can supply a +/- 20v signal:

Project 83 - MOSFET Power Follower

Has anyone tried building one of these followers or something similar? Any comments on how it sounded? Any ideas, suggestions or improvements? I'd love to hear your thoughts.

Regards,

Greg.

sorry - I can't comment on the sound. But I think your idea sounds good and worth building. I think it makes sense to do the experiment with the Power Follower.

[AKSA]

I did an amp several years ago using a 6SL7 as voltage amp and a very similar output stage to Pavel's follower. All distortion was low order, and the sound was indeed wonderful. If you have never heard one of these amps - or indeed the Pass Zen which was seminal too - do yourself a favour and knock one up from junk box parts.

They sound absolutely transcendental, particularly good on jazz and vocals. IMHO they tend to fall down a little with orchestral music.

Hugh

[PMA]

Well said, Hugh. Still more controlled than the ZEN topology.

[AKSA]

The Zen was my re-introduction to electronics after a 20 year lapse.

I would never criticise it - no one does more with less than Nelson Pass.

Hugh