As should be clear from my previous post, my foray into DIY was super successful. Any bias that people have is definitely misplaced. I replaced a $4000 300b SET for $1200 and got better sound. I would have bought an F4, but couldn't find one used. So happy that I didn't.
Dreaming of a DIY 8W Class A amp designed by Nelson Pass?
I've never built one, or heard them but this kit looks fun as hell, and includes everything you need:
https://diyaudiostore.com/collections/frontpage/products/amp-camp-amp-kit?variant=7072933085218
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uhm, just a comment here. I haven't felt any of Erik's posts are offensive or "stirring the pot", including this thread. He brought up a topic of discussion, and even if he can't participate in the actual building of this kit, I don't think any of his comments are bringing down the spirit of what this topic was meant to do. |
Has anyone moved from a single stereo model to a dual mono set? Comments on sound and performance? I’m seriously considering building a set of ACA dual monos. I had a lot of fun with the stereo build and it sounds amazing with some wide band speakers I’ve designed. I have another set of speakers that I think would be great for a dual mono set. The ACA Kit reminds me a lot of the interest and excitement around the 47 Labs (ChipAmp) designs that came along 20 years ago. |
https://www.ebay.com/itm/150VA-DC24V-5A-Low-Noise-LPS-HI-END-Linear-Power-Supply-for-Audio-PSU/11299... @auxinput Have you tried that particular lps? |
@lewinskih01 - nope, I have not. It was just one of the few linear power supplies on ebay that did 24V at 5A (which is what the Amp Camp power switching supply is). I have tried a few different Teradak power supplies. I generally try to get a PS that has many smaller capacitors in the power supply to reduce ESR and provide a faster response to voltage draws. These have been for transports and HDMI video processing devices (such as Lumagen Radiance and a HDMI KVM switcher). The Teradak have done an excellent job at this. I suppose for the Class A Amp Camp kit, two large caps in that power supply would be just fine. |
@lewinskih01 dual mono is really the way to go if you can. Each channel/board performs so much better when it's got it's own power supply. In my chassis I've got an f4 board on one side and a sissy sit (diy sit3) on the other. Left them both powered and just shorted the input on one side to do evaluation. The SIT amp got so much better when I finally unpowered the F4. Shocking really how much just having an amp pulling unchanging idle current off the shared power supply could impact the sound. |
Again, the sound improved when I went back down to a single board with it's own power supply. Didn't need the extra power at all. Which is Pass' whole point, simpler is better. An approach others have taken one way or another. CJ with their PV preamps for instance, and single driver speaker designs. |
@lewinskih01 - that's not really the best power supply here on ebay. You should search through all the Zerozone power supplies. I think those are usually the better ones for an audio device such as DAC or preamp because they usually have better capacitors (such as Nichicon Gold Tune or Nichicon Fine Gold FG). Such as this one: https://www.ebay.com/itm/Zerozone-Finshed-S130-Ultra-Low-Noise-DC-Linear-Power-supply-2-way-LPS-12V-... If you are looking to power an Audio PC, look at one of these (because they support all the voltages 3.3V, 5V, 12V): https://www.ebay.com/itm/ZEROZONE-4-Way-Low-Noise-Hifi-Linear-Power-Supply-DC3-3V-5V-12V-12V-L9-30/1... https://www.ebay.com/itm/TeraDak-high-power-850W-PC-ATX-Computer-linear-power-supply-output-3-3V-5V-... The TeraDak is for a full blown tower with a very high 850W capacity and full ATC motherboard connector and power cable chassis, but it is very expensive. |
Over the last year I also built the Amp Camp Amp kit. It's fun-value and performance were so good I immediately moved on and built the B1 Korg preamp kit. That was before they had a full kit available for the B1K, but they now have a complete kit similar ACA kit. I also added an internal LPS to the B1K along with improved Caps and other components. I then took the next step and built an F5 amp using the Pass Linear PS boards and the PCB and parts kits available for the build from DIYAudio. I am extremely impressed with the performance of these relatively simple amp designs. And the cost/performance factor is unequaled IMHO. It ain't like falling off a long to do this, especially the F5 build, but that's the challenging fun part. I highly recommend this experience. |
On the PC LPS, this is what I have and it is very impressive for that application. It’s been in service for more than a year and never gets turned off. It was a genuine improvement for my self-brewed music server PC. https://hdplex.com/hdplex-fanless-400w-atx-linear-power-supply-with-modular-atx-output.html I also use a couple of the Teradak products to power other components such as my SOTM USB card and a couple of other external digital components. https://www.ebay.com/itm/Teradak-DC9V-2-5A-SOTM-DX-USB-HD-special-linear-power-supply/254398773540?h... |
This thread is unreadable . The truly bored seem to be taking the bait from each other . Thanks Eric for passing on the info for Nelsons diy kit . I think it is great that nelson is a man of the people . I have forwarded the info to some of my less fortunate audiophile friends that took up a life in electronics. Should save time from building an amp with offshore design. |
Allane, I built the dual mono blocks and love them. I also own a retail Firstwatt J2 and M2, all having slightly different but highly enjoyable sound. You can set the monos up in either series or parallel, and honestly it depends on your speakers as to which will sound best to you. In my case it’s series (I have horns), parallel with my speakers is so hyper detailed, you get insane details while in the adjoining room! But I know others where parallel is best. The latest version of ACA in mono form can also be setup to ran balanced... so many options. They are rather remarkable for the price. |
Built one w my daughter last Christmas when she was home from college.Took us a couple of days, probably 14 hrs total, but I did a lot of talking. She had never soldered before. I've done some kits. Her gift was the finished amp. Mine was the time together. Sounds great for what it is. Had so much fun w the build, I got their "SS-2" pre/headohone amp. They work well together. I hope others check them out. Jay |
Is this DIY 8 watt amp a chip amp? What about the Nelson Pass First Watt amps, are they chip amps too? I'm looking for an inexpensive SS amp to go with my Museatex AVC-1 preamp. I have a PP EL84 amp already but don't want to run tubes all the time and would like to be able to have a relatively low powered SS amp to compliment this. The speakers are 90 db Castle Durham 900's that are rated for a 15-85 watt amp. I normally prefer a class a/b/ab Mosfet amp. Thanks in advance! |
@robeswi Thanks for the information! I’m going to build a dual mono set. The stereo version sounds great with a small wide band monitor I designed and built. I think a dual mono set driving a pair of 8” wide band speakers in a larger room will be awesome. The BK-20 Kit that @schwartz36 mentioned might be a solution. It would be wonderful if we could share photos of our ACA builds. I see some on the DIY site, but I’m sure there are more. |
they alll seem somewhat sterile and lifeless. IMHO, they all need a tube preamp to warm them up@lou_setriodes Nelson understands the importance of lower ordered harmonics since you can't eliminate distortion altogether (this is a lot bigger topic than there might be room for on this thread!). So his stuff doesn't have that dryness to which you allude above. But a good tube preamp shouldn't be particularly warm- just neutral :) |
I love building kits. This is a great sounding little amp. I’ve built 3 of these. First I built two to run as mono. But found that a single running in stereo was really enough and sounded just as good with an efficient set of speakers. So I sold one amp. Then after awhile, I wasn’t using the ACA amp and ended up selling that one too. But then I missed it, so I bought a third kit and built that one which gets switched into a second system. I pair it with a Schitt saga. I also have paired one with an Elekit 8500 preamp I built and have since sold. Ps. Elekit are great products, I’ve built four different amps from them. cheers k |
@dgarretson - you can test these Zerozone power supplies stock, but you can also upgrade the power cord and the fuse. In addition, I upgraded my DC output cables as well. I used a 5.5mm x 2.1mm DC plug from Digikey: https://www.digikey.com/product-detail/en/switchcraft-inc/767KS17/SC1389-ND/2238432 And 16awg UTP VH Audio cryo-treated OFC hookup cable w/ AirLok insulation below: https://www.vhaudio.com/wire.html#ofcairlok The results of the DC cable upgrade were significant. I kept the DC connector on the power supply side because it's hard to find the correct size replacement. I just de-soldered the existing cable and solder on my VH Audio wire. |
@dgarretson - What Furutech connectors did you use? I don't see any DC connectors made by Furutech. The best I have seen is the Oyaide ones below: https://www.vhaudio.com/connectors-rcaxlr.html#OyaideDC But they are gold-plated, which slows down and warms up the sound. I chose the switchcraft ones because of this. As far as wire, I prefer pure copper (my preference) because silver can be a little to fast/sterile for me. I can't imagine trying to solder 10-11awg wire to these tiny DC connectors! lol. |
@auxinput - Woops, the connectors are indeed Oyaide-- for the ACA, 2.5 ID x 5.5 OD (based on the Meanwell data sheet spec.) I do a custom build to 10-11awg with a twist of 20awg .999 dead soft silver strands from Rio Grande on-line. IME, with DC the higher the gauge and shorter the length the better. For terminations to small connector tabs, extend 2-3 strands out of the bundle to make the solder junction. |
I've been experimenting with a bunch of sources and preamps over the last few months. @jayh - I built these with my kids as well. Our second or third project. Even my 7 year old participated. System photo: https://drive.google.com/file/d/1RG7oFzBtF1pH-ViMwFv83GhkWPTNIU6-/view?usp=sharing |
Upon returning from the CAF audio show with good sounds freshly implanted in the memory bank, I was greeted by two Zerozone 24V/5A linear supplies from Hong Kong. Even without break-in they improve on the stock Meanwell SMPS. Increased dynamics. Weighty and extended LF. The slight opaqueness, politeness, and soft-focus of the stock unit is gone. Soundstage is larger and more dimensional. Resolution is increased across FR. Mids are supple and SET-like. There is a vivid tactile quality as heard with top echelon amps. Well worth the $450. |
@lou_setriodes Nelson understands the importance of lower ordered harmonics since you can't eliminate distortion altogether (this is a lot bigger topic than there might be room for on this thread!). So his stuff doesn't have that dryness to which you allude above. But a good tube preamp shouldn't be particularly warm- just neutral :) Perhaps using the word "warm" to describe tube sound isn't the right word. Sweet sounding might be better, at any rate, with tubes, there's a certain something there - warm, sweet, euphonic whatever it is that just sounds so right and is to me more appealing than listening to solid state. Maybe even order distortion is the term I'm looking for. |
Even without break-in they improve on the stock Meanwell SMPS. Increased dynamics. Weighty and extended LF. I have found that going from switching power supply to a linear with a very large capacitor bank will yield significant improvements in bass strength and body. Along with all the other improvements! lol |
Pass ACA measurements and review. https://www.audiosciencereview.com/forum/index.php?threads/pass-aca-class-a-power-amplifier-review.9... |
lak, I would not get too hung up on "upgrades" and start with a basic kit and just getting it to work, enjoy the sound, and learn as you will probably make mistakes. It is hard when you don’t have experience, as what appears as "experienced upgrades" are often just stuff thrown against the wall with hopes it sticks ..... and usually claiming that it does. There are DIY forums more appropriate to a beginner and people generally more experienced with electronics who can walk you through it if you go that route. lak3,702 posts10-20-2019 10:17amI’m in agreement, for someone that has not built electronic equipment before (myself included), the Kit looks like a lot of fun. |
lak, One thing I should have mentioned, is, if you plan to build a kit then learn to tweak it, then this is probably not the best kit to do that with. This is a very basic amplifier circuit. It has low distortion at very low power, but as soon as the power gets up to anywhere reasonable, like 1W, the distortion is very high. No matter what component tweaks you do, you can't make much difference in that, it needs a different circuit. |
Thank you Erik! Tomorrow I'll be receiving an inexpensive Amp Camp clone that appears to be very well made; however, it's only 5 wpc instead of 8. If it weren't for this thread, I would have probably never considered one of these. Many thanks! Looking forward to hearing it. https://www.usaudiomart.com/details/649568662-amp-camp-amp/images/2473892/ |
Erik, Sorry, I see I never responded, sobered goes, better late than never. I liked the Amp Camp Amp @ 5 wpc, but just didn’t have the right speakers for it at the time. I’d didn’t stay around that long because at the time I didn’t want to build a system around it. Later, I got a beautiful matching custom Fleawatt 20 wpc amp (3118dt chip) and tube-based passive line stage preamp that was truly gorgeous & outstanding matched with Omega Super 3XRSs |
