Hi all,
Longtime lurker, first-time builder. I’m starting the planning phase of a dedicated solid-state amp build, and I’d love input from the minds here.
Goals:
Options I’m considering:
I’m not new to gear, but this would be my first full DIY build from power supply up.
Would love feedback on:
Thanks in advance. I’ve spent a million years thinking about this amp, and will likely spend a million more—but today felt like a good day to start.
Longtime lurker, first-time builder. I’m starting the planning phase of a dedicated solid-state amp build, and I’d love input from the minds here.
Goals:
- Drive my 87dB 4Ω 3-way custom speakers (“Butch Towers”) with grace and authority
- Honor a diverse music library: ambient, hip-hop, noise, jazz, classical
- Use what I already have: a CXN100 for volume control, and a 3kW SMPS with ±50V rails
- House everything in a piMetal enclosure that I can heat with guilt and good grounding
Options I’m considering:
- Honey Badger (Class AB, fully discrete)
- Neurochrome (LM3886-based, low noise, warmish neutral)
- Hypex NC252MP or Purifi if stock ever reappears
- Or something else you recommend?
I’m not new to gear, but this would be my first full DIY build from power supply up.
Would love feedback on:
- Which amp modules to prioritize (sound-wise)
- Thermal management tips for big metal cases
- Whether I’m insane for wanting this to be “the last amp I ever need (for now)”
- How to even go about sourcing stuff
Thanks in advance. I’ve spent a million years thinking about this amp, and will likely spend a million more—but today felt like a good day to start.
Here’s a better sketch of what I'm working with!
Speakers:
Custom-built floorstanders with a fairly complex driver blend:
The listening space is a medium-sized second-floor bedroom in a 100-year-old house—plaster walls, hardwood floors, and a heavy door. Not treated in any technical sense, but the old construction lends a natural weight and damping to the sound. Speakers are in a quasi-nearfield triangle with listening distance in the ballpark of 7–8 feet.
The Project:
We're building a power amplifier—Class D preferred, but not religious about it—around a beefy SMPS3k supply and a large, fanless pimetal chassis. Source and volume duties are handled upstream by a Cambridge CXN100, so this amp will be pure muscle. No preamp, no switching, no frills.
The goal is a build that can keep up with a very diverse, texture-heavy library—ambient, tape decay, avant-garde jazz, fragile electronic artifacts. Basically, not just slam and clarity. We want something that renders nuance and decay as well as it handles dynamic shifts. No sterile sound.
Would love any thoughts on:
Speakers:
Custom-built floorstanders with a fairly complex driver blend:
- Scan-Speak Illuminator tweeters
- HiBy midrange units
- Scan-Speak Classic woofers
- Front-ported, housed in Honduran mahogany
- Sensitivity is around 87dB, 4-ohm nominal
The listening space is a medium-sized second-floor bedroom in a 100-year-old house—plaster walls, hardwood floors, and a heavy door. Not treated in any technical sense, but the old construction lends a natural weight and damping to the sound. Speakers are in a quasi-nearfield triangle with listening distance in the ballpark of 7–8 feet.
The Project:
We're building a power amplifier—Class D preferred, but not religious about it—around a beefy SMPS3k supply and a large, fanless pimetal chassis. Source and volume duties are handled upstream by a Cambridge CXN100, so this amp will be pure muscle. No preamp, no switching, no frills.
The goal is a build that can keep up with a very diverse, texture-heavy library—ambient, tape decay, avant-garde jazz, fragile electronic artifacts. Basically, not just slam and clarity. We want something that renders nuance and decay as well as it handles dynamic shifts. No sterile sound.
Would love any thoughts on:
- Ideal module choice for this kind of speaker/load combo
- Pairing well with the SMPS3k without introducing grounding weirdness
- Whether it's worth pursuing exotic input buffers (e.g., opamp swaps, tube stages)
- Philosophical or technical strategies for making Class D sing emotionally
Bold plan. 😱
I'll just make a comment about the proposed 3kW SMPS. My understanding is that:
* for best results, an SMPS should be designed to suit the specs of the amplifier it's powering - so an off-the-shelf SMPS may not suit.
* and an SMPS performs best when it's delivering 80-90% of its rated output.
Your spkrs are 4ohm which suggests the amp needs to be able to deliver lots of current. How much power you need will depend on the room size, as Ray has stated - also how loud you like to listen.
My thoughts are as follows (please feel free to correct any wrong assumptions / arithmetic!):
- if the SMPS was outputting 2500w, it would be operating at an ideal state.
- 2500w with +/-50v rails means a potential 25a current delivery.
- say, +/-45v peak, at clipping.
- this is 32v rms.
- power output at clipping is Vrms^2 / spkr impedance - which is 32^2 / 4 = 256w.
Which of the amp modules you listed are rated at 250w into 4 ohms?
Honestly, I think you’re right—it doesn’t make sense to force a build around the SMPS just because it’s on hand. I’m leaning toward putting the 3kW 63V supply up on Swap Meet and starting fresh from the actual needs of the speakers and room.
So, if we throw out the power supply constraint entirely—what’s a good foundation for a first serious build?
I’ve looked into a few options—Purifi 1ET400A, Hypex NC502MP, ICEpower 700AS2, even the Alpha Nirvana route—but availability, pricing, or sourcing from sketchy channels has made most of them tricky. I’m open to something more approachable if it’ll still deliver on sound and keep the build meaningful. Any direction or known-good paths would be hugely appreciated.
So, if we throw out the power supply constraint entirely—what’s a good foundation for a first serious build?
I’ve looked into a few options—Purifi 1ET400A, Hypex NC502MP, ICEpower 700AS2, even the Alpha Nirvana route—but availability, pricing, or sourcing from sketchy channels has made most of them tricky. I’m open to something more approachable if it’ll still deliver on sound and keep the build meaningful. Any direction or known-good paths would be hugely appreciated.
If your SMPS can actually deliver 30 amps of current (3kW, 100v) without going into a hiccup mode that’s 90% of the battle. If your Scans are anything like mine, minimum impedance gets down to 2.8 ohms for the system. So you have to consider potential loading in the neighborhood of 30-35A, for 10 to 50 milliseconds at a time, repetitively, depending on how much BASS you typically add. Stuff they put in consumer goods generally doesn’t take too kindly to that kind of treatment. Any quality amplifier that can deliver those currents with reasonably low distortion and no blow ups will serve you well. You will probably want three pairs of MJL3281/1302 - and lose your fear of triple emitter followers.
I think that's a sensible approach. 👍
Given this:
... and this comment:
I can definitely say - although they would sound fabulous, in terms of your requirement for "nuance and decay as well as it handles dynamic shifts. No sterile sound." ... you need to cross the Class A Alpha Nirvana off your list. 🙁
I built two of the 4R version, for my 4ohm active spkrs. 40w into 4 ohms is fine for my spkrs ... but that's because:
* I hand over bass to my subs at 110Hz - so the ANs aren't subject to the heavy load imposed by loud, low bass, and
* my drivers are pretty close to 4 ohms all their range; they don't drop to 2.8R!
You need a high-current amp. From reading the specs of the March Audio P502, whatever Class D modules they use ... would be entirely suitable. Or buy the finished amp - given Oz products only have a 10% import duty! 🙂
Thanks—that’s a solid lead. I’ll dig deeper into the P502’s implementation and PSU topology, but on paper it looks like it checks most of the right boxes for what I’m chasing. Appreciate the point about current delivery; that 2.8Ω floor really does narrow the field fast.
And no worries—I’m doing most of my tech deep dives off-thread. Just wanted to sanity-check a few assumptions before I commit to a topology. You’ve already helped more than you know!
And no worries—I’m doing most of my tech deep dives off-thread. Just wanted to sanity-check a few assumptions before I commit to a topology. You’ve already helped more than you know!
I’d recommend the Wolverine project over the Honey Badger if you choose to go that route. It’s a more refined design and can be build with 4 output pairs for low driving difficult loads.
It’s a advanced design for a first build, but it is well documented with an active support thread.
It’s a advanced design for a first build, but it is well documented with an active support thread.