[sts9fan]

I finally did it and thought I would post some money shots.  It is a Zen Variations 9 which is very very similar to the FirstWatt F3.  It is a fully class A J-Fet power amp that uses the Lovoltech LU1014D power J-fet.  It puts out ~15 Watts/Ch into 8 ohms.  I have been loving this amp.  I do need to fix the grounding a bit as one channel is dead silent while the other has a bit of noise.




Testing on the "work bench"

[Folsom]

How much do the parts cost for those?

[TomS]

Nice job Kris!

Love the speakers too   Looks about like my benchtop specials from Koss.

[sts9fan]

I would say somewhere in the $550 range without the Cocobolo faceplate.  That board cost me $100 but there is lots left.

The speakers are TangBand 2" "fullrange" in media bottles tuned to 1/4 wave with cardboard tubes

[Folsom]

I would like to compare some of the First Watt style amplifiers (class A) to my GC. I can really notice between class A and not sometimes when A/Bing. Well some day... It would probably cost a lot more to build. I think a much better source is what I really need, well DAC anyways, which I have, but need to get volume control for it, and finish my pre-amp.

[sts9fan]

You know I went from Tripath and GC amps to the ClassA and there is a BIG difference.  Personally I perfered Tripath vs GC but the Pass designs( I have used F1, F4 and Zv9) all have a control and slam the others lacked.  For me with my druids it was all about control. 

[blizzard]

Hey sts9fan,

  Nice work.  Where did you source those nice heatsinks from?  Finding the right heat sinks always seems to make me hesitate taking on projects like this.

                Thanks,
                     Steve

[Folsom]

What was your GC like?

I have really high efficiency speakers (95db)(subwoofers are not but). Mine seems to have pretty good control, slam though I am not sure on. I suspect I would more so notice difference in finer instrument detail from a class A, making them shorter (less slur).

I am pretty naive when it comes to knowing the difference between all the Pass Labs modules (or where to get kits).

[TomS]

Hey sts9fan,

  Nice work.  Where did you source those nice heatsinks from?  Finding the right heat sinks always seems to make me hesitate taking on projects like this.

                Thanks,
                     Steve

I'm pretty sure those are the same as mine.  Conrad MF35-151.5 from www.conradheatsinks.com in Australia.  There was a group buy on DIYAudio.com though I bought mine direct from them.

[blizzard]

Thanks Tom,

  I thought those might be Conrad Heatsinks.  They must have killed you on shipping from Australia.

                         Thanks again,
                               Steve

[sts9fan]

They are in fact Conrad's large MF35-151.5.  I think they were $135 shipped to Boston, MA.  They will ship sea freight and say it will take a month but I had mine in under two weeks. 

DOS
These are not a kit.  They do board groupbuys on DIYaudio everything else is up to you.  peter Dainels is now doing one for F1, F3 and F5 boards.  I think I am gonna grab a F5 set.

kris

[blizzard]

Interesting.

  That's not that bad.
  No more F4's huh?  Those seem a bit more interesting because of their flexibility.

    Thanks for the info Tom,
          Steve

[sts9fan]

they are well worth the price for sure