Solid State Class A Amplifier

[alexs2]

Having owned solid state Class A amps for several yrs,I'd be interested in building one,if only to see exactly what goes into one,and I'd love to try something along the lines of a PassLabs Zen or Aleph,having looked at Pass's site so many times over the years,and seen some of the amazing things that some people have cooked up(have any of you seen the lightbulb Zen?)

A really good SS Class A amp has it's good and bad points,but will always sound very different from a tubed amp,but the power can be very useful at times,and 100W+ of Class A is lovely.

[dan_s]

IMO a reasonably priced SS amp will not sound better than any of the wad kits. a very very good ss amp will probably not be better than the 300B kits, so what i'd really want is a high output (200-400W) ss amp for driving subwoofers/bass-section-in-a-bi-amped-system like a class T amp or an AB class likes the Haflers.

[alnewall]

Originally Posted by dan_s

IMO a reasonably priced SS amp will not sound better than any of the wad kits. a very very good ss amp will probably not be better than the 300B kits, so what i'd really want is a high output (200-400W) ss amp for driving subwoofers/bass-section-in-a-bi-amped-system like a class T amp or an AB class likes the Haflers.

I don't think SS amps will ever sound better overall than a good tube amp, but they will sound different and can be very good. However, some people might like to have the choice and indulge in a little alternative listening from time to time..

[Max N]

I'd be interested in a Class A ss amp, if only because it would be toddler friendly (assuming the heatsinks were conservatively specced...)

[vitalstates]

I for one would love to see somebody(knowledgable) in the uk post some info on Nelson Pass designs(aleph). It is written that they are 'to die for' but its tricky sourcing or getting parts info here in the uk(particularly monster heat sinks).

Regards

Ed

[Scottmoose]

I built the V6 Son of Zen. Impressive stuff, though it has rather different priorities to most other amps and sucks power like nothing else I know. Matched my horns well before I sold them on.

[Black Stuart]

I have to agree with Al,
about really detailed instructions and posted on another thread some time ago that SME in the very early 70's showed the way with lots of photos.

I don't like PCB based amps maybe because they are cheapskate productions - why not 'proper eyelets solder points' as most builders will experiment with different comps. The WAD ones are bad, how bad I don't know because I have never built others. The tracks will lift if you just look at them - simply not good enough.

I would have much preferred to start with tag boards or point to point - all it needs are properly explained procedures (thanks Al) and photos - a picture is worth a thousand words and in the age of very cheap photo copiers - there is simply no excuse.

Black Stuart

[leo:)]

I'd say classD will eventually replace solid state but not yet for a while, you'd be struggling to build any classD amp from scratch to be honest, have a look at the circuits, the better ones are all surface mount too, some are even quad layered pcbs you also need a really good quality power supply , these things are much more picky than a solid state amp even though they are claimed to be alot more efficient.

I've built more than a few different amps, WAD kit88, solid state,chip based ,classD and T etc but the only solid state classA design I tried was Pavel Macura's Mosfet power follower with DoZ pre-amp which I hard wired to a pair of huge heatsinks

[Greg.]

And, Leo, what did it sound like? Is it worth doing?

Best wishes,

Greg

[John Caswell]

Hi all,
The one thing most people seem to forget about class D amps is that they are a switching type device a la Switch Mode Power Supplies (SMPS), and can be the very devil to get rid of RF type interference. As Guido Tent of Philips said "I spent years trying to build a quiet SMPS, but gave up in the end". Of the 3 I have had a look at, 2 put out so much residual RF interference that a CD player adjacent was blanketed out. Had similar problems with CD players and AM and FM radios.
As Leo says they can and will be very difficult, if not impossible, to build from scratch, and I guess that most people will use a readily available base modules from companies like Tripath, which takes the whole fun out of it.
Not for me thank you!

John aka Dr john