RudeWolf

Just go for tube ubal/bal->bal and 4xCFA2's like a real man.

Well, I'm no EE, but generally feedback is what lets amps oscillate. Hence why KG said he doesn't know how to make a ZF amp do it. What makes you think that the amp is oscillating?

Super-Symmetry and Zero-Feedback. The input section of this board can do both topologies.

I think so. It's one of the reasons I don't like them.

Neumann NDH 20 when stationary and Sony WH1000-XM3 when commuting.

This stuff happened in my hometown, Riga! The depths of hell opened up to swallow a bimmer.

The soldering IS the fuse!

I adjusted the trimpot to nullify DC on input board outputs, before the servo opamps got installed. For the ceramic cap I used this - https://eu.mouser.com/ProductDetail/81-RDEC71E476MWK1H3B

Hunting for power switches is a nightmare, unless you're willing to go with a bulgin vandal-proof type of thing. I'm mounting my power switch on the bottom plate near the faceplate, so you can reach under the amp and easily push the toggler switch. This is also pretty okay - https://eu.mouser.com/ProductDetail/Amphenol-Audio/ACJM-MHOP?qs=t8VhaDIDl4uYvnn1Z02tXA%3D%3D But generally the choice isn't too big.

It lives! One of the better solid state amps I've heard. Now to drill some panels!

My Hera with about a year in between. From: To: She likes well biased amps!

I'd say that affordable delta-sigma DACs have become way less annoying. And the advent of R2R for less-than-MSB prices at least for me make hunting for rare old multibit chips largely redundant.

ATC is pretty cool, if a little overpriced. I consider a used SCM40 to be the best deal, as it's the easiest way to enjoy their dome mid. Probably the SCM20 will also cut the proverbial mustard, but I'd try to get the active version as it's extra special. For less cashmonies Neumann KH310 is also quite delectable.

I'll probably try to buy some from the local GB participants.

Second channel came up without a fault. For a 2U heatsink 200mA seems to be the highest what's thermally viable, the hottest transistors were above 70C. Once the spare THAT340 arrives, I'll try to do a listening test.

Looks great! One thing, when I was searching for parts, the 600pf ceramic cap seemed to be problematic. Mouser only had one part and the lead spacing was more similar to what's for the 47uF cap.

Got the channel to work. Turns out the culprit was a faulty THAT chip.

So, one channel of the CFA3 is assembled. As expected, it's acting funny! On the amp board only that LED stays lit. The four LEDs near the input stage only briefly light up when I'm powering on. The fifth outermost LED is dark no matter what. I have no problem biasing the output stages to 180mA, but have no idea how to do it for the input stage.

Might be the fumes talking, but don't try to solder a CFA3 in one sitting.

I've owned the Mini Griptillian which I lost during an airsoft battle and now daily carry a 940. I agree that they aren't a super great value, compared to say Kershaw, but I like the axis lock too much to complain. Generally I find the 940 to be the smallest big knife out there. It's super thin and the S30V steel holds a great edge, but sharpening them is a challenge.

Shit, I'm seeing birds everywhere. Gotto lay off the PRS.

What kind of a guitar is she playing? Bird inlays on the fretboard and a Fender headstock?

Both are shit, HD660S less so. Get the HD6XX or HD650 instead.

What? This guy has two Phonitor 2 amps!

The PCB shop could only do 5 as a minimum, so yeah, have 3 spares.