Amp Camp Amp
This is everything you need to build a working stero amplifier. The parts kit, power supply and chassis are also available for purchase independently. EU residents please click here.
After a long wait, the new and improved version of the ACA, the ACA V1.8, is now in stock.
Stuff you'll want to know about:
- V1.8 wiring diagram
- V1.8 build guide (currently under construction see note below)
- V1.8 parts kit contains a new rear mode selector switch allowing you to use regular stereo single ended RCA, or switch between
- Balanced Mono
- Parallel Mono
- Bridged Mono
- V1.8 chassis has two new features
- Rear panel V1.8 connection diagram to match the V1.8 wiring diagram clearly showing how to select all 4 modes (1 stereo, 3 mono) and how to wire inputs and outputs
- Improved more secure cover mounting system using weld nuts and hex head screws
Please note: The official V1.8 build guide has not yet been released. Please wire your ACA according to the V1.8 wiring diagram. There are some minor but important wiring changes compared to V1.6. These changes are shown clearly on the V1.8 build guide temporary page. We are slowly updating the site and build guides with V1.8 information. The official V1.8 build guide with new photos, will be released in the coming weeks.
A Beautiful "Class A" Amplifier Kit
Stereo chassis or monoblocks. Easy to Build. Everything included.
Parts Kit $129 - Power Supply $49 - Chassis $159
Watt's new in the Amp Camp Amp V1.6?
We're excited to announce the latest revision of our most popular and in demand kit of all time, the Amp Camp Amp. Use our ACA options wizard to help you pick the right options for you.
Improvements since V1.5:
- We have a new "ACA Information Directory" that gives you links to everything you need
- V1.6 features new and upgraded connectors and switches, including a Neutrik XLR input so you can build balanced monoblocks with twice the power!
- It's got a new high quality 24V 5A power supply, increasing power from the previous version's 5W up to 8W
- Comprehensive step-by-step ACA V1.6 build guide hosted at guides.diyaudio.com
- Just solder a few more wires to turn it into a single-ended or fully balanced monoblock with twice the power of the standard ACA!
- A front power switch
- Black or silver front panels, and both blue or red LEDs
What Exactly is an Amp Camp Amp Anyway?
The Amp Camp Amp was created by Nelson Pass for a special event called "Amp Camp" in which 20 people built their very first amplifier from start to finish in one afternoon. The event was held outdoors on a lovely sunny day in California and all attendees walked away with a fully functioning amplifier and a smile on their dials.
Naturally, other people wanted share that same amazing experience of successfully building their first amplifier so diyAudio has created the three essential ingredients you need for that same journey - the parts, the instructions, and the community.
Read more in the Amp Camp Amp article hosted on diyAudio.
How does it sound?
Once you build the Amp Camp Amp you'll never look at power and distortion figures the same way again.
Each channel is just 8 watts, but they're very good watts. In fact Nelson's DIY endeavors are called "First Watt" because in his own words "The first watt is the most important watt". The amp has enough power for medium to high efficiency speakers at normal listening levels. They sound even better bi-amped with an active crossover.
- "Insane amount of detail, deep bass and crystal highs" - Starbender
- "Great power, bass and massive detail" - Waam68
- "Highly detailed, yet smooth and sweet" - Mitchba
- "I am amazed at the sound quality" - Neoinc
It's not just a kit, it's an education - here's why everyone is falling in love with the Amp Camp Amp:
It can take days of searching and ordering from multiple suppliers to obtain all these parts. We've done that for you. Everything you need is included, other than basic tools.
Detailed Build Guide
We've put together an all new detailed build guide for the new ACA complete with step by step photos and instructions so you're never lost. Plus, our friends at TekThing recorded a beautiful 30 minute build-video of how to put together the previous version!
Quick and Easy to Build
Even a kid can build it and many have! All you need it one afternoon and you'll have finished and be listening to a beautiful class A stereo amplifier!
The Amp Camp Amp Kit makes a stereo amplifier that sounds great - here's why
Designed by an Audio Legend - Nelson Pass
Nelson's company Pass Labs makes some of the finest (and most expensive) amplifiers in the world. This amplifier has its roots in decades of award winning amplifier design experience.
Minimalist Amplifier Topology
Less is more. Nelson is famous for his "Zen" approach to design and this amp is no exception - it's a minimalist circuit that delivers purity through simplicity.
A Pure "Class A" Design
Most amplifier designs switch transistors on and off causing noise. Class A amplifiers are always operating in their sweet spot, which is why people say they sound "silky smooth".
Save Time and Money
You could spend days or weeks trying to find the right parts, then paying over and over for shipping from multiple suppliers. Or you could buy the Amp Camp Amp kit!
So Simple You'll (Actually) Finish ItWe've got you covered with easy to follow step-by-step visual Amp Camp Amp Build Guide. There's also an amazing build-video of an earlier ACA version from TekThing showing construction from start to finish!
Benefit From New SkillsDon't sit on the sidelines - get building today! You'll learn new skills you can apply to other projects, refine your ear and duly feel pride in your accomplishment.
Enjoy Quality SoundIf you want to hear the sound of one transistor clapping this is the ticket. Dead silent, pure and luxurious. Reviews speak for themselves: "Insane detail", "deep bass", "crystal highs", "great power", "fluid", "sharp", "smooth", "sweet".
Relax Knowing This Is a Great ChoiceThe Amp Camp Amp Kit sounds like a much more expensive amplifier, is quick and easy to build, simple to understand, includes all the parts, comes with instructions, and has a wealth of support if you need it. You can't go wrong with this tried and tested project.
Meet Other Audiophile MakersAs you breathe life into these amps, they'll literally breathe it back to you! Be a part of the super friendly Amp Camp Amp maker community on diyAudio and meet other makers that share your obsession with quality sound.
A step-by-step build guide and pit crew standing by
We've just launched "diyAudio Guides" (beta), a brand new place to find and share knowledge about audio DIY. The Amp Camp Amp Build Guide is now more accessible than ever. Follow step-by-step on your phone or tablet while you're actually building the amp or printed the guide as a PDF - it's never been easier to complete your Amp Camp Amp in one sitting!
If you need more help, there's hundreds of diyAudio members who consider it their mission to help any ACA builder get their first amplifier build completed. No question is a stupid question in the ACA thread, so join in the discussion and meet other first time and veteran builders in the Amp Camp Amp discussion thread.
Watch TekThing build the ACA
What's In The Complete Kit?
1. The Parts Kit
- High quality genuine parts purchased directly from "Tier 1" US distributors such as Mouser and Digikey
- Printed circuit boards (Revision 1.6)
- Transistors including Linear Systems LSK170 JFETs and IRC MOSFETs
- Switches, LEDs, capacitors, resistors, we include everything
- The same parts quality that Nelson Pass uses in his own amplifiers
- Components purchased either from "Tier 1" distributors or do-it-yourself audio favorites like Parts Express
- Keratherm® MOSFET insulators - very efficient and no grease required
- M3 board mounting standoffs, w/ stainless steel bolts and washers
- Stainless steel mounting bolts and washers for MOSFETs
- Gold plated speaker terminals and RCA Jacks
- Power connector jack
- Copper hookup wire in assorted colors
- Cover plate for XLR hole (for advanced users, the XLR hole gives the possibility to create monoblocks with 15 watts per channel)
2. The Power Supply
- From Meanwell, the best known producer of high quality SMPS in the world
- The power supply is universal and operates from 86-264VAC and 47-63HZ
- It comes from a best-of-breed manufacturer, has less noise, more power and weighs more than twice as much as the previous power supply
- You can read more about it on the Meanwell 24V 5A power supply page
- This new power supply is also a suitable upgrade for all previous Amp Camp Amps, just plug and play (see notes here)
- This power supply is Nelson's lab tested recommendation, but to save money you can BYO 19V or 24V 5A laptop style power supply. YMMV!
- It has a generic 3 prong IEC 60320/C13 power cord inlet suitable for use with a "kettle cord"
- We ship it with a Linvox 3271V86 6 foot cord that has a US 3 prong plug. If that plug doesn't work for you, you can use a plug adapter, or "borrow" an IEC cord from your least favorite piece of equipment.
3. The Chassis
- From the Italian chassis artisans at Hi-Fi 2000
- Custom design for the ACA / ACA parts kit
- Ships direct to you from Italy with FedEx International
- All the work done is for you - just screw it together!
- 10mm aluminum front panels drilled (dual LED holes), anodized and silkscreened with hole for a front power switch
- 3mm aluminum rear panels drilled (power jack, RCA input, speaker output, power switch and XLR expansion module hole) and anodized
- 40mm aluminum heatsinks pre-drilled and pre-tapped with M3 threads for easy mounting of circuit boards
This project requires some tools.
- A good Soldering Iron and good Solder
- Digital Multi-Meter (DMM)
- Philips Screwdriver
- Needle-Nosed Pliers
- Diagonal Cutters
Nice to have
If you bought each part yourself
- Bolt Depot (Bolts) - $7.71
- Digikey (Small electronic components) - $42.43
- diyAudio Store (Keratherm, Transistors, PCBs) - $71.89
- Mouser (Power Supply and power cable) - $62.33
- Parts Express (Mounting hardware, wire, etc) - $57.18
- Customized chassis - over $200, more likely $300 including heatsink tapping
- Total: $441.54, plus a day hunting for parts and a day drilling your chassis and tapping your heatsinks
Save money, and time
To assemble this same kit yourself would cost over $440 including parts, hardware, sales tax and shipping. And you wouldn't get the tapped holes or front and rear panels drilled. And then there's your time in buying all the parts and working the chassis...
* All prices were calculated live on 11 June 2016 using real products and a shipping address of San Francisco, some prices updated May 4th 2018
|Frequency response||10 - 20 kHz +/- 0.1 dB|
|Power (stereo)||8W into 8 Ohms per channel|
|Power (monoblock)||15W into 8 Ohms per channel. See ACA operation modes for details on monoblock operation.|
|Power Measurement||Measured at clipping with 3% distortion|
|Distortion||0.7% at 1 Watt (primarily second order harmonic which being even-order is described as "sweet, tubey" and being low-order as "benign/inaudible")|
|Input impedance||10 Kohm|
|Output noise||100 uV|
|Power supply input||Universal 86-264VAC 47-63HZ|
|Power supply output||24V 5A|
|Heat dissipation||20 Watts per Channel|
More specifications found in the original ACA V1.0 article, and power and distortion graphs are here. See ACA operation modes for more details on monoblock operation.
The ACA is a minimalist, low power amp that's easy to build and the perfect choice for your first amp building project. It's the "fixie bike" of Class A amplifiers; no gears, no brakes; zen and the art of amplifier maintenance.
It likes efficient speakers that present an easy load to the amplifier. The right pairing will give you great sound full of audiophile buzz-words, and more than adequate volume for everyday listening or to annoy your neighbours (8W with 91db speakers gives 93db at the couch). Double the power per channel with monoblocks.
If you have a particular pair of speakers in mind, ask about them in the ACA discussion thread.
You're In Good Company
The Amp Camp Amp Kit has received coverage in these publications
The reviews speak for themselves
This is the Best "First" Amplifier Kit You Can Buy
A beautiful class A amplifier design from the master of the art with all the parts, instructions and help you need.
I bought this as a fun holiday project, and with appropriate reverence for the talents of Mr Pass, but with none for myself as I'd never soldered before. I kitted-up with a basic soldering iron and a decent multimeter and took a deep breath. Rest-assured, if you're a reasonably methodical person capable of following basic instructions, you'll be fine. Faults were easy to track down using the diagnostics supplied and first principles. Mistakes were easily remedied. Once I'd biased the channels (simple but finicky process) and checked for DC offset (almost negligible at about 3mV), I hooked the amp up to my usual Sugden IA4 running as a preamp. This being a low power amp, I was happy to be feeding it to very sensitive Klipsch Forte IIIs. I expected it to sound decent. It's way better than that, it blew me away. While it lacked the muscularity of a higher-powered amp, it had no problem driving the speakers to ear-splitting levels with real class. The midrange clarity and soundstage are lovely, really suiting quieter acoustic music. The biggest issue I noticed, is that during particularly busy sections, the amp couldn't deliver the clean and tight bass that the Sugden can - the ACA bottom-end reaches plenty-deep, but its presentation is more disorganised and smeared. Another thing to note: this amp runs hot. Very hot. It has that classic slightly warm class-A sound and the heat that comes with it. This is probably not an amp to leave on all the time.
So, is the Amp Camp Amp any good? Well, there is joy and pride to be found in building the amp yourself, but that only goes so far if it sounds bad or even just disapoointingly fine. Fear not, it's much better than that. I'm so impressed that I'm building a new desktop system around it for my workspace. I've selected Omega speakers for their ease with flea-watts... and I see those Zen Triode kits... However, ACA? I freaking love it!
I started this project being amazed by all the comments and fantastic feedback posted everywhere. I thought this is definitely something, well, I am a natural maker with very little electronics knowledge and an audiophile newby, so it could be an inexpensive way to begin this journey and it catches me deeply.
The sound signature is delicious, the only drawback is its small power, but found out thanks to James from TungstenAudio and his genius and generosity, that it is possible to hack the ACA and take it to a better level, I followed up his recommendations and wow, more power and even better sound, it reminds me the sound stage of a tube amp, very, very nice.
You can find the suggested upgrade here https://www.diyaudio.com/community/threads/aca-amp-with-premium-parts.328357/post-5569767
I am running a pair of Elac's Debut 6.2 (87 dB sensitivity) and they sound great.
My next step is to try a 48V linear power supply and see how it performs, if it does't give more power I will purchase another one to build a mono block set.
Thank you to Nelson Pass for his creativity and generosity and to DIY audio to make it so easy and also thanks to James from Tungsten audio for the tweeks, he really took this mini amp to another level.
I finally purchased this DIY, my first one to build as a complete kit. I up the stakes by replacing all the caps with AudioNote (blackgate version) Caps and Mundorf for the coupling cap. i also used silver solder and silver wire for all. All I can say it is all the hype I've read. I paired it Klipsh Rp600M and sometimes switch it to my Maggie LRS just to listen how it sounds
well, compared to my reference system, it is holding up its claim to fame. i am amazed that this simple design, using upgrade caps and driven by a Tube amp, can sound that good. i suggest use better caps as you can
I had modest expectations for this little amp. I have had this kit sitting all summer waiting for a rainy day. Well, we got snowed in for 4 days so I took the opportunity to build this unit. I took my time. It’s been a while since my early Hafler kits in the mid ‘80’s.
The build guide is very helpful. Thanks 6L6 !
First tried the amp with an iPod and my spare ProAc Tablette’s. Not enough gain for daily use but promising enough…
Today, on a whim, I connected it to my Acoustat 1+1 electrostatics (Meridian G02 preamp with plenty of available gain)
I’m impressed! This shouldn’t be enough power but it works AND sounds quite good. Vocals are lovely.
Depth and soundstage : check. (pretty close to my Meridian G57 power amp, until it runs out of gas, of course.
Very tempted to build another to hear monoblocks. I may have to bring out my Klipsch Heresy III’s to see what happens on a high efficiency speaker.
Very rewarding to build this and discover it is better than expected! Well done, folks.
I ordered two ACA kits to make as mono blocks, ordered with black face plates. Received one of each. Not the end of the world, fun to build, and they still sound great!
Ran out of “free” time after the first one, and it sounded so amazing that I lost my sense of urgency for the second. But last night the wife went to bed too early. So I headed to my happy place and finished the second ACA. After setting the DC offset and running a couple of songs through it, I couldn’t resist sneaking quietly upstairs and removing the first one and bringing it downstairs. After hooking them up in monoblock configuration, I turned on some tunes to try them. They sounded amazing, and in my excitement managed to wake up the wife. It’s a good thing she has the patience of a saint. I can’t wait to try them together with my B1 nutube preamp. I’ll wait until she goes to work to put them through a proper workout. You guys are great, keep doing what you are doing, and I’ll keep enjoying my relatively new hobby.
What a great kit. Very doable for a first timer. Actually did 2 kits right away to have the mono blocks. Lots of fun and they sound amazing.
It was 6 years since I built my tube amp 8Wpc driving a pair of Klipsch Heresy IIIs. Then the DIY bug bit me a few months ago and started searching for my next kit. ACA was in my radar but was leaning towards something more powerful like F5. The total cost for F5 was too much since I have to import every nut and bolt, especially the pricing of the chassis for F5 was too much.
Ended up getting a pair of ACA to run in bridged mono and not at all disappointed. I took time to assemble them. My daughter who is a medical student helped me too and steadied her hands with soldering for the first time in her life.
The whole story is here https://www.hifivision.com/threads/another-aca-build-coming-up.88927/#post-999071
After powering up, my daughter who has astute ears to music said "Wow!!! what clarity these have". Truly, I seem to hear more with these amps. Very low noise floor. With a pair of 12 inch high efficiency full rangers simply on a 900mm folded open baffle, the sound is "baffling". Bass is limited by the open baffle design but vocals, mids and highs seem to be very clear for us.
I used thicker wires for the DC +ve and speaker outs. Salvaged from old speaker 16AWG I think.
For the LEDs I used a pair stripped from a ribbon cable.
DC IN and LEDs have Phoenix type screw terminals fitted for easier disassembly if needed.
For the common ground used a bit of silver plated 14AWG speaker wire stripped.
For back panel wiring followed my procedure to fix and wire the speaker terminals and DC that are at the bottom and then the upper RCAs, XLR, and finally switch.
For the wiring at the switch I used single length of wire stripped where required to connect the switch and finally the XLR.
All wires routed through the sides.
Fitted Blue LEDs to L channel and REDs to the R Channel to differentiate.
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