KG CFA3 headphone amp

[dstarr3]

A CFA3 is going to be a BIG increase in difficulty coming up from the Crack. Selecting and sourcing parts, heatsinking, casework, doing the mains wiring and grounding yourself without instruction, and a far smaller community of builders for troubleshooting. Completely different league, with a very really chance of failure meaning your investment would be essentially unusable.

I'm not saying you can't/shouldn't do it. But ask yourself whether you are willing to spend all that time and money and potentially still not end up with a functional amp.

Well, I also have experience building mechanical keyboards, which involves ordering custom PCBs, choosing proper components and soldering them. Which, if I'm working with Gerber files that are already floating around out there, no problem. Heatsinking and casework, I'm a DIY'er/maker in general, I can handle that. Mains wiring/grounding would take some learning, and I'll need some guidance for sure, but I feel like it's something I can handle.

 

[Beefy]

Is there a more beginner friendly amp that you would recommend?

Back in my day, you'd go through any number of Cmoy, Pimeta, Dynalo, CKKIII, M3, Millett Hybrids, etc. to work your way up to a Dynahi or B22. They were all great amps that were better and cheaper than the commercial equivalents. You could easily on-sell them as you made your way up the chain.

Any of those are going to be good experience to work up to the complexity of a CFA3. But, the value proposition of these older amps is really quite poor now. Entry-level DIY makes less and less monetary sense, meaning there is no obvious gateway drug. So I'm hesitant to suggest any specific model, but anything from AMB is still attractive given boards, parts and documentation are still available.

Well, I also have experience building mechanical keyboards, which involves ordering custom PCBs, choosing proper components and soldering them. Which, if I'm working with Gerber files that are already floating around out there, no problem. Heatsinking and casework, I'm a DIY'er/maker in general, I can handle that. Mains wiring/grounding would take some learning, and I'll need some guidance for sure, but I feel like it's something I can handle.

That's less concerning than just coming from a Crack, but I do still feel that a high voltage/current amp is a different skillset to small-signal applications like keyboards. Just also consider that someone like Dukei or Kerry probably put about $2000 worth of labor into their builds, and they are well-practiced, well-trained experts. It's a big job, guidance isn't always available, and the best sources of information aren't necessarily newbie friendly.

 

[Ethereal Sound]

Well, I also have experience building mechanical keyboards, which involves ordering custom PCBs, choosing proper components and soldering them. Which, if I'm working with Gerber files that are already floating around out there, no problem. Heatsinking and casework, I'm a DIY'er/maker in general, I can handle that. Mains wiring/grounding would take some learning, and I'll need some guidance for sure, but I feel like it's something I can handle.

I've built tons of keyboards and agree with Beefy in that there is a pretty huge difference in difficulty between building a keyboard and something like the CFA3. Not saying you couldn't pull of a CFA3 build though, I'm rooting for ya.

 

[kevin gilmore]

Well i do know someone that built a T2 as his first amp ever. And he was successful. And then he built another just to be sure.
and has built many amps since. He does however seem to have some extra help from a deity. If you have the ability to drill and tap a
whole bunch of holes, then a cfa3 should be relatively easy. far less dangerous to build than a t2.

 

[dstarr3]

On the subject of parts, what volume knobs to people use? I'm going to make second version of my speaker-tap-to-4-pin-XLR adapter, and I'd like to include a volume knob so I can just put the adapter box on my desk and then hide the AVR itself underneath somewhere.

 

[rsbrsvp]

I wanted to update everyone on my CFA-3 journey.

I bought a dac from China called HIBIKI SDS signature DAC. The research I did seemed to indicate stunning detail retrieval and fantastic saturation.

I was looking for this kind of saturation to match the CFA-3. After around three weeks with the dac, I am extraordinarily pleased. IMHO it matches the CFA-3 perfectly and beautifies the sound in the most natural way while maintaining stunning speed, slam, and dynamics..... Tube saturation without veil, loss of speed or rounding.....

I'm extraordinarily pleased.....

 

[K3cT]

Congrats @rsbrsvp. I was looking at DAC too but didn't dare to blind buy because there are so few impressions around.

 

[bfin3]

I wanted to update everyone on my CFA-3 journey.

I bought a dac from China called HIBIKI SDS signature DAC. The research I did seemed to indicate stunning detail retrieval and fantastic saturation.

I was looking for this kind of saturation to match the CFA-3. After around three weeks with the dac, I am extraordinarily pleased. IMHO it matches the CFA-3 perfectly and beautifies the sound in the most natural way while maintaining stunning speed, slam, and dynamics..... Tube saturation without veil, loss of speed or rounding.....

I'm extraordinarily pleased.....

What did you have before?

 

[CopperFox]

Would the CFA3 be appropriate for low impedance planars, for example 18 or 16 ohm impedance and 90dB to 100dB / 1mW sensitivity?

 

[RudeWolf]

Would the CFA3 be appropriate for low impedance planars, for example 18 or 16 ohm impedance and 90dB to 100dB / 1mW sensitivity?

I don't see why not. The amp can be used for driving speakers, headphone sensitivity is much higher.

 

[CopperFox]

I don't see why not. The amp can be used for driving speakers, headphone sensitivity is much higher.

There was one comment earlier in the thread (search is broken ATM) saying it would "probably" be noisy with Focal Utopias. However it was more of a speculative comment and not first hand experience, also in the measurements it does not seem very noisy.

Most people seem to have used the amp with hard to drive phones so I'm wondering if someone has experience from low impedance planars.

 

[rsbrsvp]

I use my ES-R10 for my CFA-3. But I have a ultra-low gain option installed on my CFA-3. I do think my oor sounds better with the ES-R10; just a better natural partner even with the low gain setting on the CFA-3.

 

[all2ofme]

Have my own wee beauty on the way thanks to @Dukei.

I’ll echo what others have said here: a fantastic person to work with, and he was accommodating of not just my requests, but my horrendous Swedish. So much fun. Now hurry up, FedEx, I want to plug this in!

 

[Hiker816]

Have my own wee beauty on the way thanks to @Dukei.

I’ll echo what others have said here: a fantastic person to work with, and he was accommodating of not just my requests, but my horrendous Swedish. So much fun. Now hurry up, FedEx, I want to plug this in!

"Eleven". That could not be more brilliant.

 

[all2ofme]

Just another little post to say that I'm so, so happy with my @Dukei CFA3.

It's an incredible amplifier, and works so well with the dCS as a front-end.

(I've just listed my Enleum, which — while very, very good — I no longer need. Thanks for the encouragement, all! And a special nod to @paradoxper for the final push.)