Looking for true high-end Class A design

[DutchMark]

Hi,

I have recently purchased some Martin Logans Sequal series. I previously owned a 300B SE amp, which does not do the job as expected.

I now wish to build a nice stable really high-end Class-A amp using all FETs (not just the power stage). What is the best musical design class A you ever heard, and do you have the full schematic (or building instr. if possible)?

Thanks for helping,
Mark

[acenovelty]

Take a look at the Krell KSA 50 pcb thread. While not meeting your other ideas, it is one of the best musical design class A designs that will drive those window panes without effort.

[BobEllis]

Of course any of the Pass designs meet your criteria but the A75 may be better able to deal with the Martin Logans. See passdiy.com under legacy projects. I am very happy with my A75s.

[AndrewT]

Hi,
have a read of the Borbely site.

[traderbam]

Why do you want an "all FET" design?

[DutchMark]

Originally posted by acenovelty
Take a look at the Krell KSA 50 pcb thread. While not meeting your other ideas, it is one of the best musical design class A designs that will drive those window panes without effort.

Hi,

I have had a look at the schematic, and all transistor is not what I am after. Coming from a 300B amp, I intend to build something tubelike, hence the wish for a JFET design.

Thanks for your help,
Mark

[DutchMark]

Originally posted by BobEllis
Of course any of the Pass designs meet your criteria but the A75 may be better able to deal with the Martin Logans. See passdiy.com under legacy projects. I am very happy with my A75s.

Hi,

I like the A75 design a lot. It is exactly the kind of design I was looking for. There are a LOT of FETS in this design for just 75Watts of power. With more modern FETs I would expect that the amount could be reduced. Have you ever seen a variation to this design like that? Also I would like to avoid non-silent cooling methods.

I understand you built one (must be quite a job). Do you use active cooling? Did you go with the mechanical design as documented?

How would you rate this amps sonic qualities?

Nice to hear from you,
Mark

[lumanauw]

300B amp

How about use 96pcs (close to 100 pcs) of Western Electric 300B?
This pair of speaker (2pcs, left and right) is powered by 4 amp blocks.

[lumanauw]

Each amp block has this : 24 of Western Electric 300B's. That means total of 96 of 300B's powering a pair of speaker

[bigwill]