Class A SS: Journey for a budget champion for LCD-X

I've seen that posted around here quite a bit, but have not heard it personally myself yet. The synergy I experienced between the LCD-X and this DIY ACP+ makes it hard to imagine it gets a whole lot better for <$1000...so much so that I sold off the Lyr 3 and officially bought the ACP+ from the original builder/owner yesterday! I could not put my headphones down last night - and was getting caught up in some music genres that I don't typically spend much time on...that simply did not happen with the Lyr 3. The engagement factor is just incredible with this amp.

 

You'd be surprised. I think part of the issue is that the Lyr 3 is maybe a bad match for the LCD-X so you're starting with bad synergy. I haven't heard the Lyr 3, but very few tube amps do Audezes' justice and from what you describe, it sounds like the issues I have heard before in tube amps with Audeze's. However, when a tube amp works with Audeze's it's REALLY good, but very few do.

The LGX is not only Class A, it was designed for Audeze's. worth hearing or buying cheap used if you get the chance.

 

Shit, dont' listen to me, just enjoy the new amp you just got and love! Forget the LGX.

 

Ha! I'm definitely open to hearing a LGX at some point, out of sheer curiosity at least. That said, I'm firmly keeping my wallet shut for a while (probably a couple years - hopefully) until I can really plunge into the upper tier stuff.

 

Update time (ACP+ DIY transfer to aluminum chassis)

Ok, so this took waaaaay longer than I expected it to - turns out holidays, 2 very young kids, work, and other life things can really slow a project down! But I have finally finished the transfer of the naked ACP+ to an aluminum chassis. I learned a ton, got plenty frustrated at times, made some dumb-f**k mistakes, but ultimately ended up with a finished product that I'm truly happy with.



I'd be happy to share a full BOM list if anyone is interested, but the bulk of this enclosure consists of a Modushop Galaxy 2U black anodized aluminum chassis (supplied by DIYAudioStore) - more on this later - internal wiring, switches and connectors from Digi-Key or Mouser, and a knurled aluminum volume knob from China. Brass 1" standoffs were used to raise the PCB to the height to center up the PCB-mounted components up front (input selector, volume pot, and HP jack). Items removed from the PCB and fly-wired were the LED, power switch, power connector, SMPS filter, and RCAs. All component holes were drilled by hand with a basic cordless hand drill.

I thought it would be pretty straight forward and easy, but boy did I underestimate the time and attention to detail it would take. The biggest time killer was painstakingly measuring, sizing, and planning the front faceplate holes for the PCB-mounted components. I ended up buying several purpose-specific tools/materials (like the drill bits) to precisely get things fitting correctly. I was fortunate to find a CAD template buried in the ACP+ thread on DIYAudio, but even that did not align perfectly and I had to improvise.



After a couple of months obsessing over every possible question about how to do this all the right way, I took the plunge and bought some accessories for my soldering iron and decided to give this all a go myself. Originally I planned to have the original owner take care of all the transfer work, as he had the tools and experience. However, I decided against it and wanted to challenge myself. Once I purchased the aluminum chassis, I got to work planning everything out and starting with hole drilling work. Enter master fuckup #1.

The back plate was a piece of cake, as 6 of the 8 holes were the same size and it was all a straight line. Where the challenge came in was the front faceplate. Originally, I thought I was smart and tried to apply the template to the back side of the front faceplate, so to help protect the front side from accidental scratches or marks. This was great in theory, but I made one critical error: I forgot to either invert the template image or flip it horizontally 180 degrees. Because when I went ahead and drilled the holes into the back of the faceplate, upon turning it over, the HP jack was on the upper hemisphere of center, rather than the PCB's lower hemisphere of center. F#$K!!!

So I had to end up buying a replacement faceplate from Modushop, which operates out of Italy, because DIYAudioStore does not sell replacement parts - only the complete kits. Costly mistake, but one that ended up having a silver lining: it enabled me to use the failed faceplate to trial other holes to perfect the drilling skills and get a perfect alignment for the final take. I just felt like a complete moron, that's all.



After all the holes were drilled in the plates, I did some sanding of chassis joint surfaces, and then moved onto the tricky part of de-soldering certain components and soldering fly wire leads for them. I think I watched a couple dozen different soldering videos on Youtube to understand PCB soldering, but more importantly, the art of de-soldering. Man, that shit sucks. It took a lot of trial and error to get all the various components removed from the PCB and holes perfectly cleaned out of the old solder. It all worked out and I was very proud of myself, but that was a bitch to work through.

From there, all I had to do was solder in the wiring, which was straightforward in of itself, except for the difficult nature of dealing with solid core wiring. I guess I didn't take to heart (or fully understand) what various forum posts said about them being much less flexible than stranded. I'm glad I used solid core, but I probably would have had a much easier time just using stranded all around (I did use stranded for the LED and power switches, though, figuring I needed some excess length) and ability to maneuver in their destinations.







All in all, this was a great experience and I'm truly glad I did it. I love the look and feel of this thing (adding some Dynamat Xtreme I had on hand helped add some heft and dampened the top and bottom covers). Now I have that little sense of pride looking at it each time I listen, and as I'm actually now experiencing in comparison to the Ferrum Orr/Hypsos stack (thanks Loaner tours!), this thing is as legit of a final product all-in around $350 as many production-grade solid state amps out there. I'm smitten with this thing!

 

Nicely done. Casework is the worst part of DIY for most people, so nice to pop that particular cherry.

 

For crying out loud...just realized that I misaligned the L/R channel RCA washer colors to the wrong channels on the PCB. So I was listening to a reversed image so far. UGH. Well, these things are all soldered in, so nothing's going to change any time soon - just something I have to keep in mind when plugging in my RCA cables. Seriously?

 

In case anyone is interested, it looks like the ACP+ is currently back in stock with the full kit (price increased from $200 to $240): https://diyaudiostore.com/collectio...s/acp-amp-camp-pre-amp?variant=40205532397641

Edit: I, for one, would love to see impressions on the ACP+ from other members here. Despite dozens of thread pages on DIYAudio, there’s barely a few sentences in total on the actual sound performance of this thing.