COMPARISON TEST: Nelson Pass Amp Camp Amp (kit), Schiit Aegir, First Watt J2 and...

Steve reviews the DIYaudio Amp Camp Amp kit (version 1.8), watch the build in last week's video, • Robert built the Nelso... The amp was designed by Nelson Pass from Pass Labs and First Watt.
DIYaudio is where you can buy the Amp Camp Amp kit, diyaudiostore.com/products/am... I checked with ACA just before posting, and they said they will have 100 kits on Sept 20. They sell out quickly, after they sell, there won't be more until December.
TECHNICAL SPECIFICATIONS
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
Max Gain 14dB (stereo) 20 dB (Mono)
Damping factor 10
Output noise 100 uV
Power supply input Universal 86-264VAC 47-63HZ
Power supply output 24V 5A
Heat dissipation 20 Watts per Channel
Amp Camp Amp upgrading parts forum, www.diyaudio.com/forums/pass-...
------------SUPPORT--------------
Thanks for watching, this channel can be supported through Patreon
/ audiophiliac
---SUBSCRIBE-----------------
/ @steveguttenbergaudiop...
Audiophiliac T-Shirts and Mugs! teespring.com/stores/audiophi...
Twitter: @AudiophiliacMan
Instagram: Steve.Guttenberg
#Schiit #DIY #DIYaudio

[@freiheit6398]

Nelson Pass is awesome for supporting the DIY community. A firstwatt + klipsch cornwall is my dream system. Keep the videos coming! Thank you, Steve.

[@mitchsefton9402]

Just love your enthusiasm, your never ending optimism and of course knowledge. " i love my job " sums it up perfectly.

[@murraywebster1228]

A Gentleman and a scholar, always a pleasure to watch.

[@Carl-bd1rf]

One of your best reviews if not your best Steve!

[@luctardif8444]

Wow, great review of different price tag amplifier. Steve you’re one of the best!

[@williamsharp5973]

One of your best and most informative episodes ever. :)

[@Diatonic5th]

Excellent review! Your enthusiasm always makes it a pleasure to watch your videos.

[@sparkplugspark5987]

Thanks Steve, your best review yet, im buying a mono pair ACA on foot of this review, gonna pair them with the Klipsch RP600

[@joeycastillo1496]

Thanks Steve, I was very interested in this review!!

[@ericwilliams2173]

Thanks, Steve, for the comparisons. I built my own system with two Camp Amps in bridging mono mode driving a pair of KEF LS50's. I went to bridging mostly because a single stereo amp just didn't have the gain to drive the speakers to the levels I needed, especially with some lower level sound sources. The speakers (and their amps) sit on pedestals essentially in the middle of the room, about 8ft from the listener, and the accuracy and imaging is amazing, certainly the best sounding setup I've ever put together. (Which is why hearing your comparisons was nice.) The amps are driven by a Elekit TU-8500DX tube preamp (also a kit), and I later added a Klipsch R-112SW powered sub-woofer to fill in the low end, which adds a lot of fun to the listening experience.

[@Leicaphile27]

Settled in with my morning cup of coffee and another great episode...

[@carlitomelon4610]

Fun while my system warms up and the Tetley British blend tea brews;-) Now for an hour of baroque to start my day...

[@cablebrain9691]

Haha.....exactly what I had done. 😋

[@bombslab]

LCD 3, HE 1000 V2s and Susvaras - Oh my! Also, I've been waiting to pull the trigger on a pair of ACAs...I'm an EE student and Nelson's interviews are how I found this channel in the first place. Awesome channel BTW!

[@20thcenturyboy85]

LOVE your content, Steve! Thanks for all your videos.

[@hubreyireeuw6507]

Steve, I always like your podcast about audio. You have the gift of telling a story. Love it, keep going.

[@pukebjorn]

I just want to say thank you so much for this review. I already owned an amp camp amp, but after viewing this video, I built another one. Wow! The difference when running them as mono blocks. I was stunned and you were absolutely right in your review. I am using a Musical Fidelity X.Can 8 as a pre-amp which produces enough gain to drive them (almost too much), coupled directly to a Moon Dac. The Amp Camps drive my Dali Helicon 800 without any problems. Only trouble is that I may have to build a B1 buffer too....:-)

[@morespinach9832]

Cool video and insightful as always. Schitt Aegir is a gorgeous sounding thing.

[@dansav4519]

This is just the video I've Been asking for thankyou Steve!

[@nabdrumworks4719]

Great review and detailed feedback, I thank you for your appreciation of music and electronics!

[@qqube4762]

I built a pair of Nelson Pass son of zen amps at 5 watts from the ground up. That allowed me much flexibility. Still have these amps after 20 years. This is my go-to amp when listening to headphones. Old and new headphones including stax headphones.Thanks for the video. Videos like this gives me new ideals

[@steveluck9541]

Big shout out to the DIY Audiostore boys for the care taken to gather all the parts and cut the different coloured wires to a generous length. Thanks for sourcing a good quality power supply. Thanks for the great photos and easy build instructions. Thanks to Modushop for the high quality case machined painted and printed beautifully so that it all goes together with no problems and looks great when finished. The postage getting the parts to your house would cost more than some people are claiming they could build one for. Cobblers to that.

[@richarddortch6122]

Thank You! It takes quite a bit of work to plan and put these kits together. I'm glad to see you like what we do. We are just a small group of enthusiasts that believe in the value that exists in DIY.

[@davidatrakchi2707]

Hi Steve, your review made me check my Nelson pass ACA as mono powering one speaker only. I liked the results so I ordered the second amp and I’m really amazed by the results I’m using 90dB per w Bronze 2 by Monitor Audio speakers and I’m very pleased getting such nice sound at a very modest investment Thanks

[@mdr4670]

Great comparison review Steve! I'm saving up for the Pass Labs Int 60 and Cornwall 4.

[@OldTooly]

I enjoyed this review. I am 2 years(of about 57 years in audio) into experimenting with near field low power sound. I have been running massively powered AND efficient speakers for decades so this was quite a switch and your statement about the sound field, detail and disappearing speakers was so spot on. Listening to a pair of 20 year old Celestion Model A compacts, being driven by a Wavebourn Edelweiss 3 amp (KT77 tubes 6wpc) directly off a PSAudio DAC created the most perfect sound I had yet to hear in my life. I was up late into the night for months every night playing every kind of music as well as rediscovering my classical and jazz roots. This is also a great system to check audio components since every detail is revealed, short of thundering bass and massive dynamics. It was nice to see something I had stumbled upon myself had also been experienced by a seasoned expert.

[@Canadian_Eh_I]

Good for you! I've found the benefits of high efficiency to be enormous. It turns out that you can get much higher quality watts for your dollar when you go low power. The problems start when you need more than 100watts for your speakers. I currently use a pair of Earl Geddes Abbey's which are 95db speakers and the imaging and directivity is phenominal and all they need is a few watts !

[@mmdusa]

I both sing your praises and curse you Steve. You are one of the main reasons I went with a Pass Labs amp when I decided to step up to the big leagues. I absolutely LOVE it. I can't believe how good it sounds. Yes, there may be better amps out there. I'm sure there are. But I have truly loved this amp. Now, I'm getting ready to buy a Pass Labs preamp. Again, partly because of you. You are costing me a lot of money. But I also have to thank you for introducing me to the wonder and genius of Nelson Pass and Wayne Colburn. For the quality and build, they are kind of a bargain. Don't tell them. I don't make much money. But I know I won't regret selling that kidney to get my preamp. ; - )

[@carlosroig5315]

This is a great review and comparison, thank you Steve!

[@AdrianIII]

Enjoyed especially the comparisons! Thank you!

[@jeffkalina7727]

The only thing that beats DIY is buying them already assembled by a competent party as I did last November. Two Pass ACA mono blocks for $350 + $140 in upgrades to a better 24V wall warts and improved resistors. Sold my Cary 120S MK2 amp. The little guys brought out hidden detail and a clarity that made me say "More". Purchased a 9 month old XA25 for $3k. Now I am in heaven! Kept the little guys too.

[@DaveSchulze]

Where did you find the guy to assemble and upgrade?

[@jeffkalina7727]

@@DaveSchulze They were built when I purchased them.

[@DaveSchulze]

@@jeffkalina7727 Assuming then you didn’t by from the Amp Camp site? I didn’t see that option.

[@scottyo64]

I love the fact that you agree it's what each person likes. People have such different tastes. When I go to my step daughters and her and her daughters are jamming out to an Alexa Dot, I almost get jealous. They have fun dancing and singing along. I can't fault them but I can't do that myself.

[@stephensmith3111]

Kind of like the old days of listening to 45 r.p.m. singles on a portable record player with a piezo-crystal 'cartridge', cheap transistor radio class electronics (or basic tube circuit if you're even older) and a single paper cone speaker (maybe with a whizzer). Think of the scene from The Blues Brothers when Jake and Elwood were back in the basement of the orphanage listening to blues records with their mentor Curtis.

[@lynnpoole7830]

Steve, thank you so much for the review of the ACA! I love mine. I am super impressed that they compared as well as they did with the other amps. Hey, Steve likes my amp, how cool is that? LOL

[@pnojazz]

Steve, thank you for doing a review on these amplifiers! I recently purchased a pair already built from a previous owner. Unfortunately my small watt horn speakers are long gone to a new home. All I currently have are Martin Logan Electrostats (Spires) that have a sensitivity rating of 91 dB. I’m not a loud listener by any means. So, when the amps arrived I wasn’t expecting much. Connected in xlr bridge mode, I said to myself, here goes nothing. The amp’s truly began to open, and heat up after an hour. Having owned Pass Aleph series amps, the 3,5,O’s, some 25 years ago, these amps were almost a trip down memory lane. They were pleasurable to listen to. I was floored they drove ML’s to the levels I needed without a hint of fatigue or strain. Thank you for another honest and accurate review!

[@yourchildrensghost9736]

This was Awesome, Thank you Steve. It is Appreciated.

[@kozmiczian]

great work, Steve. I have set up quite a good 'nearfield' system, using my Android phone as source and streaming Qobuz. Audioquest interconnected to an Emotiva Basx-100 amp . . . driving two 80watt powered subs, connected to a pair of Klipsch B-200s on sand-filled stands. Small room 9x12. Thanks for the nearfield confidence booster. I was hearing a 24x192 recording, other nite, blew me away.

[@jessemalsbury9008]

Thanks for the review - I bought 2 ACA kits as a result of it.

[@nathanas64]

I was on the fence whether to build the Amp Camp but Steve certainly motivated me to do so and I ordered the kit!

[@lextr3110]

so do you like it, i ordered two for a 3 way crossover (mid-high)

[@nathanas64]

@@lextr3110 definitely like it. I paired mine with a Fosi tube preamp and with Klipsch RP600m speakers. It actually sounds pretty good. I also think you will enjoy building it

[@CobraChamp]

Nice review. I’ve been wondering about the ACA for some time....

[@christianjforbes]

2023 … I still run two ACA amps, love them as much now as ever.

[@user-od9iz9cv1w]

Great review. Really brought these amps to life by comparing to the other noteworthy amps. I am a DIY enthusiast. You briefly mentioned the upgrade forums. The ability to search for ideas to upgrade and then trying different components really makes a DIY project special. Not only does the sound improve, but that pride of ownership. I think the amp camp kit is an amazing value.

[@tejas.darwin]

I would love to see a great phono Pre kit. Great episode!

[@awdadwadwad1723]

I have First Watt J2 (got it second time already) and Pass INT 25 and I had INT 30 and in my option Nelson amps are one of the most pleasant sounding on the planet. I had top A class from Accuphase, Luxman, also AB Yamahas, Cambridge plus much more. Nothing comes close to musicality and pleasurement of listening of Pass amplifiers. So I'm pretty sure those 300 dollars mono puppies are a real steal!! PS. they all running HOT ;)

[@juliaset751]

I am using 120 mm computer case fans sitting on my shelf blowing on the heat sinks of my J2. Fans are DC so you can choose a wall wart with the voltage you want for the speed, I’m using 8V. Heat sinks are now warm not hot. They are silent.

[@jlmain5777]

Great review. I’m digging out my soldering iron, work light, and visor.

[@gustercc]

I would like to undertake a project like this, but I’m afraid I’ll electrocuted myself. Ha ha

[@FOH3663]

@@gustercc The beauty of this kit is it's all low voltage. The power supply is already built, you simply plug it in to the rear of the amp chassis.

[@gustercc]

@@FOH3663 thanks for the info!

[@davidrusso4750]

Good review - meaningful and insightful.

[@TheRedspaniard1]

Great vid 👌 . Always inspiring

[@alfagerup]

Thanks a LOT for this good and entertaining informations Steve !! 👍 🤗

[@brianhansen7274]

I hope that you consider doing reviews of DIY audio. I have always been intrigued with them. Speakers and Amps both.

[@patrickmcguigan5939]

I've been tempted to add a pair of power amps to my system for a while..... Now I'm REALLY tempted!

[@homeaudio-ny7cv]

It's really a good episode and I was tempted to browse the webpage for placing order. Just about the final click, I started to see more detail circuitry on this amp kit...then I dropped. It's really a good kit but in old term, it called "OTL" amp circuitry, i.e. with a series connected capacitor for blocking DC to output (the speaker). I could understand that it is much easier for building a kit with single end power supply (i.e. 24V and GND) especially for beginner. The circuit design is very good indeed anyway with MOSFET and simple biasing, more direct and less electronics. The chassis design and high quality jack, binding post...it's really a piece of art after finished.

[@jamesmachado9366]

Amp camp monoblocks with Merlin VSM speakers. They rock!

[@kencohagen4967]

I like the new music in your opening!

[@mitchparker7652]

Thanks for review. I’d like to try to build one. Book on shelf, “The Rest is Noise”, I just looked up. I will eBay it. Seems to be a must read.

[@sirDanBaker]

‘A warm hug’ hahaha exactly how I would describe my ACA. Brilliant little amp, had good fun building it and listening to it. It does run really hot indeed, it uses about 120 watts (230v) to produce the 2*6 watt. My Bryston 4B Cubed does outplay it in all aspects though but it is approximately 24 times as expensive. I’d go for a larger actual Pass amp if not for the immense amounts of heat and energy usage, they’re just not practical for everyday use with a touch of HT use in the mix.

[@bartvanransbeeck1341]

Great experience dear, i remember the class a from matti ottala electrocompaniet, it was the best amp when hot, cold it distorted, with the ionovacs ionisator tweeter amazing, only 2x12 watt but what an unveiled sound ,aswell on klipshhorns

[@PanAmStyle]

Two things: 1- I am tempted ... my first amplifier was a Dynakit SCA-80Q, which is a really nice amp if done correctly. In fact, I’m running an SCA-80Q (factory built) for my back porch system and combined with the Dayton B652-Air speakers for the fronts, it’s really wonderful. In fact, I’m considering getting some of the upgrade kits for the Dyna. So building another kit amp 50 some years later? Oh yeah, that would be fun! 2 - All hail Steve Deckert! All hail the Zen amp! I have been tube rolling mine, including rectifiers(!), and it is SO SO sweet! It drives Large Advents - admittedly in a small room, but even in a larger room it would be very satisfying. As Steve (Deckert) says - if the first watt sucks, why continue?

[@logotrikes]

I love the flea-watt amps. Just built a couple of spud amps based on a Fred Nachbauer design on a dissimilar pre and power triode tv tube. One watt from one tube, with zero NFB... The only extravagance was custom wound output transformers. I used Hammond for the power transformers, 2 per side. A lot of money for 1 watt per channel but I saw it as a learning curve first attempt at a tube amp. It sounds nice enough to me but of course there's a lot of confirmation bias. I enjoyed the build as much as listening to them, and that was the real purpose, to enjoy and learn from the build itself. Always fancied the Decware amp. Maybe that'll be next, or an Amp Camp...

[@OrganNLou]

Steve, you inspired me to get into the low power, class a amp designs. I ended up with the pass F5 clone, and have been in heaven.

[@ethiesm1]

great comparison and content- Thank you

[@chrisbarnhart7944]

good video steve.. i have wanted to build the amp camp and this was great ...

[@nospoon17]

Love you Steve ! I couldn’t “pass” this up either. I never really pictured myself doing DIY audio amp builds but here I am with the pass kit in front of me. Here we go…wish me luck

[@jessemalsbury9008]

Yep - I bought 2 as a result of this review - dual mono hooked to K Horns. Can't wait!

[@carlosbauza1139]

Dynakits and Hafler kits were glorious!

[@stimpy1226]

I built the Hafler pre amp. David Hafler was another design genius. A leader in the audio industry.

[@BrianNavalinsky]

My first DIY, 1972 in my dorm room, Dynaco SCA 35. Thanks to Paul Wilde, my project ee, wherever you are.

[@nacarp2000]

Steve, the ACA have 3 modes. The two that you tested, the Stereo mode with RCA with the high level of 2nd harmonic and the Balanced Mono mode where the 2nd harmonic is cancelled out. The 3 option is the Parallel Mono on RCA, where the channels are added together in phase, that way the 2nd harmonic is not cancelled it. It should just be like the Stereo mode but with more Watts. I'm thinking since you said you might just keep one of them (for the harmonics I guess), that maybe you want to try them this way and see what you think. I'm sure other people other than myself will be interested in your observations too. I am currently in the process of building a pair too. Thanks.

[@BicycleJoeTomasello]

did you build the Mono pair? I'd like to hear your thoughts?

[@jessemalsbury9008]

Thanks for sharing this. I'll give it a try as well. I Initially bought a pair of them to run in dual balanced mono.

[@vincedebart]

great video always enjoy your passion ...

[@mrboat580]

I have 2nd version of the Amp Camp made into 8 watt mono blocks much like the original prototypes. I am powering a pair of diysoundgroup Fusion-12 speakers with them and it is a wonderful thing. Half power will run you out of the house with sensitive speakers. I listen near field at around 87db as my sweet spot so this amp kit is more than adequate. The kits were out of stock but the boards were available so I basically sourced the BOM separately myself. I have since bought the latest, stereo version when it became available, just because I was so satisfied with the sound, and the crude simplicity of the circuit. This tells us perhaps, how much, too much, we spend for audio.

[@stephenhylander9395]

Another Great video, Steve! Thank You for ALL of your hard work, and expertise! Have A Happy Labor Day Weekend! Cheers!

[@yannick930]

With a linear power supply and a bigger power supply this amp will be a beast.

[@steenhansen8]

Have an older Aleph 3 and will never let it go. Pass makes great amps.

[@rickg8015]

Recap those. Lytics break down in time especially at Class A. Ask Pass about an input board mod. Get an experienced tech for the job..

[@steenhansen8]

Rick G :Thanks Rick, didn’t know a mod existed

[@rw3915]

The Aleph amps are not tolerant of average or even good preamps. I went from an Aleph 5 to the Aleph 0 to finally the Aleph 1.2s which belt out 200w/channel into 8 ohms. I used an Adcom, Sonic Frontiers 2 box set up, with a myriad of tubes from Upscale Audio, and then the magic really happened with a Pass Preamp X02, the 3 box set up. Ohhhhh man!, The magic really happened with the 1.2s and X02 preamp. Those made my Von Schweikert VR6s sing like nothing else I’ve ever heard. Just glorious and an ethereal experience. So Aleph 3/5/0/1.2s yes, but using a really good preamp really takes the game from semi pro, to pro. Anyways...

[@steenhansen8]

My words exactly. My “3” is fed by an Aleph L. Pure magic.

[@tomd5678]

Just finished building mine today. In my system the treble is sweat and lively. The midrange is musical. The base is very strong but a little muddy- that's probably my room. It's plenty loud. It gets quite warm/hot. I found it easy to build and the online instructions are good. Take your time. Get the right equipment. Organise your workspace. Watch a "how to solder" video

[@MrSouzy]

I actually use a hood 1969 class amp which I soldered together myself. That has 15 Watts and actually has enough power to drive a set of kef LS80s (whereby I normally use a set of quad 12l2s which are more sensitive). It's hard to describe the sound but it is very transparent and has a weightly low end. Designwise it is very simple. Subjectively it puts out about the same power as my NAD integrated. But boy does it run hot.

[@trevorhammons1930]

Steve - Id love an in depth comparison of all the first watt amps you’ve used with your klipsch speakers. I have the SIT 3 and would love to hear you articulate the differences with the other amps. Like you did here

[@ikymagoo]

Great review!

[@Larstig81]

I finished the amp camp amp yesterday and playing with it right now. I connected it with the Cambridge Audio CXA81, my main amp, it sounds really good. Don't know which better, but the soundstage is maybe better. I need more time, because I use temporary Audioengine P4 speakers and waiting the ProAc Tablette 10 Signature to arrive.

[@yannick930]

Nice little project. I think I'm gonna do something similar soon.

[@superdougie10]

"Roll Your Own - kinda sound" gotta love that expression Steve....funny.

[@ste1040bill]

I did build the ACA back when the project came out - just few days later it was ready in 2012 and still have it . Yes this amps hugs you in stereo . That's correct :-) with a good speaker it just does wonders :-) And I also like , the mid level of amplificatiion wich is 14 db , that is about my taste . Also some First Watt are like that :-) Many many amplifiers , amplify too much to be wasted then into the negative feedback . ACA , has only 9 db of negative feedback , and that is also one of the reasons why it plays music so well . Thank you

[@sarahX..]

would ACA suit a 115db midrange compression horn ?

[@riccitone]

I would love a big hug from theses amps. Especially such an affordable hug. May need to save some shekels.

[@patkoss1945]

Just a follow-up. I have two running as balanced monoblocks paired with Zu Audio Dirty Weekend Omens in my office. Loving it with ALL types of music.

[@DaveSchulze]

I just got my Zu Omen DW and I'm looking to run Aegir or dual Amp Camp. Sounds like you found a winner. What is your preamp?

[@patkoss1945]

@@DaveSchulze Yes this is a winner. I run dual Amp Camp still after 1 year. The pre is a ProJect Pre Box RS Stereo.

[@petersouthernboy6327]

Two mono blocks for me ❤️

[@kloss213]

Well done interesting Luv Nelsons kit own much First Watt as well as SET PP tube also class D-T. But will mention for 2 watts best to run full horns then they have really no SPL limitations its worth pursuing why many love the 45 2a3 300b and others SETs. I can generate over 110db SPL levels with such crazy more than a home needs.

[@No_Limits_411]

Good one, Steve 🙂

[@joelrunyan1608]

I can attest to the kit amps ran xlr mono.. they are amazing...

[@epi2045]

SG the OG of audiophiles! Great video. I’m fine with 8 wpc BUT it seems small for Class A. Will it last?

[@dulanthasampath3117]

Beautiful sound machine

[@brandonburr4900]

These kits were already selling like hotcakes at diy audio. Now with Steve's blessing I forsee they will go out of stock again😀 can't wait to build my dual mono diy audio aleph j and f6😀

[@michelcouture7026]

I just finish the build of the ACA, Still have to do the first test and gain adjustment. Looking foreward to put it to the test with DW6.

[@mr.george7687]

Roll your own, Yes!

[@roberthart9886]

Nice report

[@juliaset751]

Steve, the next time you interview Nelson Pass, ask him if he can explain the difference between current and voltage amplification. I was going back over some of your more recent interviews and Nelson said that he was experimenting more with current amplification lately.

[@williampearson4968]

Steve, your enthusiasm and passion for value in Hi-Fi is infectious! What a value --- Turn back the clock 50 years to 1970 and the cost is only $47 per the U.S. CPI (Consumer Price Index). How would your First Watt Sit-3 instead of the J2 compare with ACA Kit? They are of the same Nelson Pass design pedigree.

[@leekumiega9268]

Back then they had the Dynakit 70 , a 35 watt per channel stereo tube amp kit designed by David Hafler , it sold for $99.95 .They were so popular (nearly a half million sold) that you can still find any part you need on line to keep it going.

[@miquifaye]

I see the Jolida lurking behind you !

[@gorkushka]

Thank you for covering these 8W and 20W Class A amplifiers. I was wondering if you could do an episode precisely on speaker choices for low power amplifier power apartment dwellers like me - many of us have 300B and 2A3 Bottlehead kits, and more. What speakers are out there that are efficient enough to be enjoyable with 8W Power (300B/Amp Camp) and further what about speakers that pair well with 2W Power (2A3 Bottlehead, Decware Zen and others) ?

[@rjpwp001]

I now have a fully Audiophiliac approved system. I just started running a stereo ACA with my Zu Omen DWs and I’ve been staying up way too late listening to a bunch of favorite recordings. The sound is rich and smooth but with crisp highs. Listening to the snap of drums in good jazz recordings is almost shocking in its realism. And vocals. Wow. I put on PJ Harvey’s To Bring You My Love album and it’s like she’s in the room. It plays pretty friggin loud with 97db speakers. My Outlaw 2160 may be sitting idle for a while.

[@lynnpoole7830]

I like Polly Jean too.

[@vivianvaldi7871]

Seems great but what source format ? CD's ? If u can appreciate CD's with them, then what about DSD's ! You should call the doctor before the uppercut in the face.

[@rjpwp001]

Update. I’m now running two ACA’s in stereo monoblock via XLR. The improvement is tremendous. The sound is smooth yet very detailed and punchy at the same time. Source is Amazon HD. I’m using an SME ADI-2 as my DAC/preamp. I’ve never heard an actual First Watt amp. I’d love to hear how the monoblock ACA compares to the “real” thing.

[@DaveSchulze]

I just got some Omen DW Mk2 and I'm dying to build two ACA to listen!

[@rjpwp001]

@@DaveSchulze I will say this. I loved the sound of the ACA monoblocks with my DWs but after swapping them out for something a bit more powerful, an Iotavx PA3, it was clear they were not doing the DWs justice. The Iota had so much more control over the speakers and took music to places the ACAs could not go. This was unsurprisingly apparent at louder listening levels. I have since pulled the trigger on a used Pass INT25 to get back to that Pass sound. It did a number on my bank account but I’ll be keeping this one for a long time.

[@bnkk1]

I bought a kit with the intention of building it with my Daughter and introduce her to HiFi. Life happened and we were not able to get together as planned last year so I built it. Wow I fell in love. I bought a second kit to build with her. I couldn’t wait so I built it. Running the pair in mono really got my attention. I ran the pair with a DIY Pass B1 zero gain preamp. Wow! Now my Daughter now has the pair. She loves them, and I need to build another PASS DIY amp(s). Maybe an F6?

[@rbhis000]

I highly recommend the F6.

[@ChaiBearProductions]

A pair of these in mono drive my 91db Chora 826 towers to ear splitting levels while maintaining composure. As I push my DACS volume they just come alive with these amps.

[@barryb911]

Great review! A pair of the ACA's would probably do well with the Tekton speakers. Now to find a good balanced pre...

[@nacarp2000]

The ACA can also be run as strapped (parallel) monos using the RCA input. This will double the power, and retain the 2nd harmonics.

[@mikehydropneumatic2583]

Bought a used Synthesis Nimis (2x15W integrated class A) tube amp some years ago and still got it. Buena Vista Social Club and Frank Zappa sound great with that little amp.

[@euclidallglorytotheloglady5500]

I gotta say I'm really excited! I ordered 2 the other day and should be here today! I also have Cornwall IV's and can't wait to do some playing! FYI it only took 2 days for shipping!

[@b97209]

What preamp are you going to use? Do you mind writing back about what works for the preamp after you get some time with it. We have Cornwall IVs too.

[@euclidallglorytotheloglady5500]

@@b97209 Absolutely! I'll be using a Belles 21a tube preamp that I've changed out lifeless Dayton caps for Mundorf Mcap supreme silver gold oil.. It does have balanced outs. I did get the actual ACA's and power supplies today, it looks like the chassis are being shipped out the 7th. I was surprised seeing the delivery notification today, I just assumed everything was going to be shipped the 7th. Anyhow, in the mean time I'm going to get familiar with everything and see about changing up some things to squeeze as much as possible outta it.

[@b97209]

@@euclidallglorytotheloglady5500 sounds like a fun preamp. We got a Musical Paradise 301 integrated and love it. Good luck with your ACA and hope to hear how it goes. Thanks for sharing!

[@HareDeLune]

Steve: "How good can a kit amp sound?" Me: "Let's find out!" Excellent review, Steve! Much appreciated information. Thank you very much!

[@stimpy1226]

So I know now that I'm not crazy after hearing your review Steve. Well maybe I am crazy but after I completed the construction of the amp camp amp I was floored by the sound I heard coming out of the Klipsch RM- 600 P speakers that I purchased for voicing. I never expected to hear the quality of sound that this amplifier is capable of. Now I'm thinking of building another kit to send to my son who has the first unit if he agrees to buy the Tekton's.

[@sparkplugspark5987]

mono or stereo with the rp600s?

[@stimpy1226]

Sparkplug spark. Stereo. That's why I'm thinking of building a second

[@sparkplugspark5987]

@@stimpy1226 was worried the ACA wouldnt be enough power for the 88db RP600s, so you find them a good match?

[@thomasmleahy6218]

I think Danny Richie @ gr research has a mod for the rm600p.

[@stimpy1226]

@@thomasmleahy6218 I built the PASS kits and purchased the speakers for voicing. I sent everything to my son in California when I was satisfied that the amp and preamp sounded fine so I’m not doing any modifications since I don’t have the speakers anymore and my son is happy. It’s difficult to enjoy the small Klipsch speakers made in China when I own a high-end system with Magnaplanar 3.6R’s.

[@ERRORFACE1]

wow there is a lot of stuff around you Steve

[@seanlobdell502]

I wish you ran a pair of the Aegirs in mono mode. That is what I am running now and the sound is better than in stereo IMO.

[@pemmicanstash394]

I’m running a pair of Aegirs in mono, too, and I’m pretty satisfied with the sound; it’s a big step up from running one in stereo. However, my Elekit 8600 (another DIY) is significantly better with holographic soundstage and sweet midrange.

[@ahmadramjaun9542]

Everytime you say voila! THD 99%.NICE.wish i could get some soldering skills.

[@hugobloemers4425]

This is what I have been thinking about making good audio cheaper (apart from buying Shiit). Sell kits that people can either buy and build or tap in to a community of audio and electronics hobbyists who can compete to build it. More over the better your reviews the more you can ask. And everybody can benefit so in that case the Aca camp becomes accessible to people who want plug and play and some hobbyist can have fun and earn a bit on the side. One could call it UberAudio.