Which Pass Amp to build F5/F6/Or anything else?

I have been thinking about building one and only one Pass's Class-A amplifier. I always used BJT based Class-AB for serious builds and recently Chip-Amps and never built a Class-A.

What would be a good Pass Class-A that I should build to experience that? I was looking at F5 and F6, or are there any better ones with readily available components (from Mouser or Digikey)?


Thanks for your suggestions!
 
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If you want to play it safe build one of the designs that will perform well with more difficult speakers loads: F6, F5, M2, Push pull vfet if you're lucky enough to have the vfets.

+1.

Like others have said, your speaker sensitivity, seated listening position, size of room and listening habits, all play a part.

For example, the Aleph J is not bad, output Z is 0.4 ohms, 25 watts into 8 ohms but the amp only puts out about 13W into 4 ohms (since it is a SE output stage) which may not be enough for your listening habits. A benign impedance curve will help. That being said, Magnepans have “benign” impedance curves but they are 83-86 dB efficient with a nearly flat 4 ohm impedance. I don’t recall the phase angles being extreme either. But I would expect the Aleph J to run out of steam in that setup.

Can you link the measurements of the Solstice speaker you are considering?

Best,
Anand.
 
Anand,

The Parts-Express site lists the Solstice kit as 4 Ohms.

The Pass F6 manual mentions that the amplifier's rated output is 25 watts at 8 ohms and 50 watts at 4 ohms, so possibly more suitable from an output power perspective.

Agreed, although I was hoping for full impedance & phase measurements or an avid diy'er to have a built Solstice kit with a Parts Express DATS measurement done. I think every one of us should own this:

Dayton Audio DATS V3 Computer Based Speaker & Audio Component Test System

Dayton DATS v3 | An Absolute Must Have - YouTube

or equivalent (you can do it with REW too, but it takes some extra gear; the DATS is no fuss).

The DATS also has a precision LCR included.

Best,
Anand.
 
I sort of lurk here, I’m just starting to get back into this hobby after a bit of a hiatus. However, my 2-cents, the M2. I went from a chip amp (LM3886), to a JLH class-A, to a First Watt M2, and I haven’t been able to stop listening to the M2. There’s just something special and magical about that little amp. Here soon I’ll be playing with some VFETs so that may very well dethrone the M2, we’ll see.
Now, I’m currently running Klipsch KG5.5’s, so probably a little different from the Solstices
 

ra7

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Joined 2009
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I have an M2 and recently built the F4. Haven’t gone back to the M2. The F4 is so good. It will drive low impedances. Just needs a capable preamp.

Edit: this is not to downplay the M2, which is superb also. Really, you can’t go wrong with either, or the F5. Just depends on how much time you have.
 
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