Best Pass LAB Power AMP - Opinion

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Dear All,

I am still newbee in this arena, so pls forgive me if I started fire ...

I am done with all my tube Sound System and looking more hybrid

What is the best Amp for Pass Lab to built in term of

1. Value (cost)
2. Sound (I knew this may be depend on room/speaker etc, but just say in general)

I dunno where to start. Maybe for me

This is to power Jim Holtz statement Speaker

But maybe in the future to drive other different speaker

In broad terms I think it's safe to say (Broad terms!) it's a toss up between the AlephJ and the F5. With the Aleph J being likened to. "Tube sound"

I have the F5 and it's an awesome Amp, the best I've ever owned.

I plan to build the Aleph sometime soonish also, why not :)

Before then, very soonish, I will be putting together the Juma pre amp design. Just a heads up If your wondering about the sensitivity of your speakers or you have a need to rattle windows sometimes, it is said to be a fantastic marriage.
If you have built a single FW-amp then to redesign it into another one is very cheap since the major costs are the enclosure with heat sinks and the PSU.

There is a big camp that likes the softer sound of 2nd order harmonics amps like the Alephs, F2.

There are some who like 3rd dominant amps like the F5.

Some want something in between where they can change the character like the PLH or the F6.

All types have several versions, Nelson has a nice table on FIRST WATT PRODUCTS where he states if they are single ended, balanced, push-pull and what is special about each amp.
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This is to power Jim Holtz statement Speaker

This is mid 80's effeciency? 85-87db?

F6 is 30w Class A. (Requires a power Jfet that's hard to get today.)
F5T v2 is 50w Class A
F5T v3 is 100w Class A

You can tune the harmonic distortion in these amps to suite your taste.
They are tuned best with a spectrum analyzer (SA). There are simple plans for a SA, search the net or these forums. Just need a PC and a ASIO capable sound card and a few components.

If these intererst you, you have some reading to do.
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For the low impedance, moderately low efficiency statements, consider either a F5X or a pair of F4 monoblocks using a pumpkin preamp to create a balanced amp for each speaker. There are other front end options for the F4, you need something that can swing pretty substantial voltage. An X-BA3 front end would be interesting, too.

An A75 or would be decent options as well. I think you'll find most people seem to prefer the more recent jfet front end designs, though.
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