I needed help with a set of speakers, rightly blending them as best as possible. I saw this opportunity and knew that it gave me the best chance of doing so. The build was simpler than I imagined, so that is good, but there is a lot to know beyond the build and I am finding that even though I can do some of this by ear, I will need equipment to make it sure. At the moment the unit is in mule stage, but will be easy to mount it all in a chassis and make pretty. This choice of bi-amping is the best results that I have had so far with speaker building. FWIW, I did a sort of comparison as to the drivers that I might use, and ended up with a set of AMT4 ribbons that I can't tear away from.
Pretty easy build. Sounds great. Flexible.
It would be very difficult to dial this in by ear in my opinion. I used REW, and it took several hours of measuring and listening to get the crossover points, and levels dialed in. Also, as others have mentioned, the pots are very sensitive to adjustment, especially for level matching.
It is very quiet. I'm using it with a compression driver with a sensitivity of 113db, and I can't hear any audible hiss from the system unless I stick my ear in the horn.
I built two: paralleled the inputs and driving each section of a set of Klipsch RP-8000’s crossover inputs (2 way) with each output section. Biased at .400 with no problem!
I’ll steal a line that you have to make it to the build guide to read:
“This amplifier sounds fantastic, if you have any interest at all, you really should build one. :)”
Highly recommended!
This was my fist experience building anything electronic. The build was pretty easy and the sound is really impressive. I made a little base out of a wood box from the craft store. I am using it with some old KLH Model 33 speakers and it has plenty of power to drive them in a small room. I also got great customer service from the store. Thanks!
This kit contains everything you didn't get in the Balanced Essentials kit to complete stuffing the PCBs (you still need a power transformer and volume pot). It's worth it. I had a few of the parts laying around but trying to source the rest from Mouser and Digikey was tedious. I gave up and ordered this kit because I wasn't going to save any money anyway. All the parts are high quality.
This is not a beginner project. You need to be able to read a schematic. Follow the excellent 6L6 build guide for the SE version and you are 99% there. Pay particular attention to the test point values on initial setup.
Don't skimp on the volume pot. It is critical. I used a Goldpoint V24-4 ($300). I understand that you are already into this for $400 plus power transformers, connectors and a case, but the reward is a stunning soundstage - wide, detailed and lively. Skimp on these and you will negate your investment.
Yet another outstanding, high-value piece of kit from the Store. Extremely rewarding, wonderful-sounding, and I simply can't fault it. Following the B1K thread, I swapped out the coupling caps for Jantzen Standard PP, and tried some potentiometer upgrades, settling on a Tocos Cosmos (what an amazing bargain itself). Good luck finding the log taper version - I got a 50k linear and added 5k log-faking resistors.
The end result is part of my best-sounding system ever.
The Zenductor II BAF Edition kit is a straightforward build, with nothing trickier than lining up the 8 small JFETs so they look neat. It is an easier build than the ACA Mini due to more room on the PCB. I deviated from a standard build only in foregoing the on-board banana connectors, instead directly soldering banana pigtails to the speaker-out pads.
Biasing the Zenductor is particularly easy with only one pot per channel to adjust, a much much simpler procedure than biasing the ACA Mini or F5m. The heatsinks do run quite hot (mine are running 53-54°C above ambient, with a bias of 1.34A), but my limited experience so far indicates that bias is not as sensitive to ambient T changes as other Pass small DIY amps. The sound of the Zenductor is to die for (read the comments over on DIYAudio). I have no problem driving ca. 89dB speakers in smaller rooms (12’x14’). Just keep in mind that due to its limited gain, it will likely require more crank on the volume control of your source than most other amps. For that reason, pairing it with a passive preamp would benefit from higher sensitivity speakers.
After the left channel of my iBasso Amp9 card died (due to a fused filament wire on the original Korg Nutube) I set out to find a new / second-hand Amp9 for my iBasso DX220, however none could be found online, eBay or even AliExpress. So I opted for the DIY route and couldn’t be happier. For around 50% of the original Amp9 price (due to shipping and NZ$ conversion rates), I’m enjoying my music better than ever. This little tube is amazing, saving for a Cuyin RU9 as it uses the same tube and means I’ll be able to self repair in the future if required.
Nelson Pass and the folks at DiyAudioStore have hit their biggest home run yet in the pair of mono-block amplifiers. The Zenductor 2.2 is bar far the best DIY project I have embarked on. The build instructions, while slightly carried from the kit I purchased, were by far the most comprehensive yet. Between the guide and the forum I was able to find and parse all of the information needed. I was able to come home from work, find these in a box in my porch and go from there to warming the heat syncs in one evening with a perfect build the first try. Oh, and did I mention, they sound amazing! Truly the best sounding amps I have owned and very nearly the least expensive. Now if I could just get someone to develop a chassis these could drop into that looks like the Aleph 0, I would be all in. These amps would certainly benefit from the additional aluminum. I would also jump at the opportunity to buy one more mono-block kit, to have one powering my center fill. Absolutely astounding work from these designated hitters. A+
Really love these amps with the naked look, the ease of build, and the balanced sound.
These are very musical amps that run my 6 ohm 97 db Volti speakers with ease. I also built a pair for a friend and he loves them on his Zu Omen speakers.
The build is the easiest I’ve encountered only taking an hour and a half.
I initially bought a used Whammy from eBay that a seller had built using odd spare parts. It didn't sound terrible but not what I was expecting. So I set about modifying it. It soon became clear that I wanted to change everything so I bought a new PCB and started from scratch, re-using just the case and the heatsinks.
The parts I used that are non-standard are Sparkos discrete voltage regulators, PRP PR9372 non-magnetic 1% resisters, Nichicon FW power supply capacitors and Audio Note Kaisei capacitors and Audio Note silver plated RCA connectors. A Saligny Universal discrete synchronous rectifier instead of diodes from https://evotronix.eu/product/saligny-universal/ Transformer from Digikey and other components from Farnell. I tried various op amps from Digikey and Farnell.
Screened input cable is BICC silver, single core screened, in pink because I bought it on World Trans visibility day and my cousin is a Trans woman, the output cable is DueLund copper in cotton and oil insulation - because why not ? DIY Audio is about making interesting decisions and trying something new like oderous cable and the Salingy rectifier :)
I tried various op amps from the venerable 5532, OPA2134, OPA2132... 134, 1611 LF353... lots of OPA op amps and also a Muses02. The best reasonably priced chip was the OPA2134 which did everything really well, but it was beaten quite clearly by the Burson V7 vivid which is what's in it now. It does run warm so I added some ventilation to the case but even without that I think it would be fine.
The built process was very easy once all the parts had arrived. Planning the build is important as putting large items in first makes adding resistors and smaller parts more difficult later on. There's plenty of space for most things if you use the recommended values, but if you want to increase or change to different types or values, double check the space available. Make sure you can clean the board using a proper solvent mix, especially around the op amp.
The community on DIYAudio is fantastic with a number of people offering great help and support. I'm a latecomer to the project so there are already lots of questions answered which make for interesting reading.
How does it sound ? It's brilliant ! It copes with my 300 ohm Sennheisers very easily, the bass is deep and strong without being overpowering. (Fit the MUSES02 op amp if you want emphasised bass response) It's easily the equal of most commercial headphone amplifiers.
The PCB quality is very good, double sided and if you find you need to de-solder a part, the pad doesn't automatically lift, as happens with even good commercial products. Being black it looks great with contrasting components, hence the red resistors.
I'd really recommend this project to anybody, forget the fact it's relatively easy to build, what you end up with is a great headphone amplifier which you can modify and test ideas on for years to come.
Many thanks to Wayne Colburn of Pass Labs for the design, you know a Pass Labs design is going to sound great !
The chassis has a lot going for it. Most of all, I like the thick front plate. It is what separates the chassis other offers out there. Then of course is the fact that chassis is completely silk screened, holes drilled and even the inset for the volume control is a nice touch. I like the way that the chassis goes together, but also wish that the nuts didn't have to be kept in alignment while you are assembling the unit. What I did to compensate was to use a bit of putty on each side of the nut to keep it exactly where it needs to be when you are inserting the screw. It would be a good idea to have 6 of these screws instead of only 4 to hold the top and bottom plates down all the way across the side/top/bottom of the chassis. I used G6000 to keep these plates from rattling. Having that, I would readily buy another one of these for my next Whammy build, as you won't find a chassis better suited for this project.
This was a fun one to build. I used a fan to cool off some smaller heatsinks. Loving the sound so far!
I built a pair of the 1.8 version amps over the past year, along with an ACP+ preamp. I have previously built a few 500 series modules for music recording so I suppose I qualify as an intermediate builder. The only issue I encountered with the ACAs was a broken brass stand-off for one of the heat sinks from over tightening. I drilled it out and was able to friction fit a replacement without too much trouble. Everything worked perfectly after powering up. Drilling and wiring the ACP+ chassis was by far the most difficult part of the whole project, I’m using this set-up (bridged mono) with a Rasberry Pi music streamer and am so happy with the results that I will be replacing my tube integrated amplifier with the Amp Camp gear. With sensitive speakers (Zu Omen DW), this set-up is awesome for a home system and provides the extra satisfaction of DIY.
Sweet sound to embrace yourself within. Easy to build with excellent sound. Dressed with bricks for a neon personalized style. Love it!
Was not that difficult to weld despite the smd transistors, had it running for a few hours to burn in. Comparing it to my pro ject DS+ I could notice a better sound with lower noise floor. I'll be using the lower gain with my Lundhal sut's, noise floor is much lower this way.
My aluminum case from China is delayed for some reason, that's why it is presented this way.
The power supply is separate in another box
Thanks for this very nice ce project, in line with the F6 and korg B1
This was a fun build with some minor challenges for this newer DIYer with very limited EE knowledge. But with help from the community it all worked out.
The SE IronPre sounds lovely, even after just a few days of use. It replaced an Elekit TU-8500 (tubes) in my rig (with Elekit TU-8900 [2A3 tubes] and Zu DW6 spkrs). The IronPre presented clean open and perhaps more delicate (in a good way) sound, with stronger imaging. Still breaking in, but very satisfying so far.
The ACP+ goes together quickly and has to be the most bang for your buck in audio. While this would be a great first build it in no way is a "toy" project. It's right at home in between my Pearl 3 and Aleph JZM playing beautifully. Hats off to NP and the DIYaudio store crew for making these projects available. You folks are doing the good work of spreading the diy hifi gospel and it is greatly appreciated. Cheers!
The Kit went together well. The only issue that tripped me up was Neutrik headphone jack. I didn't realize it was different than what the schematic showed. Of course I ended up wiring the wrong side of the jack. Then it took time of chasing signals. It was only when I plugged in and unwired 3.5mm to 1/4in adaptor that I noticed contacts moving. My stupidity.. 😳
Other than that it all worked on the 1st shot, sounds fantastic and was a fun project. I'm embarrassed to mention my screw up... Oh well, live and learn.
The pick shows the mistake ...
I always felt that solid state amps lacked the soundstage, presence and timbre that you can get from a good tube amp. I was wrong. My Whammy is *almost* as good as my OTL tube amp, and I mean it's very close. Building it was a fun experience and not that hard, even for a novice like me.
A great performance from such a simple and reasonably priced project.The next chassis dual mono power supply and pair of boards built and ready to go but I need another pair of boards to try a balanced version as soon as available.
This was my first time building an amp. After some research and advice I settled upon the ACA Mini. The build process was straightforward and not difficult. I ended up making a custom case for this, as well and using different power switch and plugs. I think it came out pretty good. But man o man the sound…this little thing sounds incredible. It’s my new go to amp for my sensitive horns and coaxials. Highly recommend
This is my second (and third!) PSU kit. I built one for an F5m several months ago, and have just built a dual-mono supply for an Aleph Jzm. I really appreciate the recently-added power-entry hookup boards, which saves having to put together a termination block for the capacitor and thermistor connections.
Even though this PSU seems to be marketed for the F5m, I can confirm that it's a great choice for the Aleph Jzm, and I plan to use this dual-mono PSU chassis to try out other FW amps. See my build thread for more details at https://www.diyaudio.com/community/threads/dual-psu-build-in-mini-dissipante-3u-400mm-for-f5m-f4-m2x-aleph-jzm.420582/
Thank you so much for your service.I used two power supplies in a dual mono configuration and the results are audibly fabulous,its by far the best amplifier I own on an outright performance per $ spent ever.
I bought "Toshiba 2SK170/2SJ74 Octet IDSS 6-8mA" and used them to building up my latest Dead Bug Power Amplifier, 80 ~ 100(W) continuous rated power. (Dead Bug means Flying Wired without PCB artworks)
The FETs are so exactly matched that there is no struggle to adjust DC bias. At next chance, I will also use these FETs. Here after I attached several photos of my last project.
