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Neurochrome Modulus-286: 65W (8Ω); 125W (4Ω) @ <-120dB THD Composite Amplifier Module

Yep. I use a small socket set and various screwdriver bits all the time. The 1/4" drivers can be turned with a nut driver or small wrench, thereby making it possible to get into tight places.
You can also get quite far with an SAE set of Allen/hex keys when it comes to Torx.

There are two places where you'll need to work in tight quarters: Front panel screws (#2 Philips) and mounting screws for the amp modules (2.5 mm hex). I find it easiest to attach the heat sinks to the front panel then attach the amp modules, but some reverse the order. It depends a bit on which tools you have available. If you have a long-shaft #2 Philips screwdriver, attaching the amp modules first might be easier.

So far, the only Torx bit that trips people up is the T-8 (or TorxPlus IP-8). That's for the screws on the bottom of the chassis and the screws that hold the connectors to the rear panel. Nothing special is needed here.

Tom
 
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I was one of the lucky ones to get the kit at the lowest price offered. I have it working, and it's just what I hoped it would be. Dead quiet, plenty of headroom, and neutral tone. I do wish that Tom had designed a larger enclosure; the design is highly space efficient, but not for the fat-fingered builder. Still, I'm happy with the little beast, and recommend it highly.
 
Jack, I’d concur in hindsight that a chassis even only 20mm wider would have made for an easier assembly job for those of us less nimble that we used to be - it no doubt Tom had his reasons . I assembled literally hundreds of Hafler pre and power amp kits back in the day, and more recently the ACA mono and stereo chassis units, and numerous others along the way, and this build reminded me of how much fun it can be to contort trying to fit into some of those tight spots - I think of it as yoga for the hands.
Performance-wise, this thing is a gem.
 
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Yeah. It is a compact amp. I went with the compact chassis for two reasons:
  1. I really wanted to. I loved the technical challenge of it and could not get the idea out of my head.
  2. Cost. A smaller chassis means less aluminum and lower shipping costs.
My original goal was to arrive at a cost that would allow me to sell the kits at $999. Unfortunately, that price is not sustainable with the current cost of parts. Going with a larger chassis would have put me even further away from that goal.

I really like how the amp turned out, though I do agree that it is a compact build and that those with larger fingers might be challenged.

Tom
 
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Yeah. There is a 50 mm wider option as I recall. That gets you into the "why not just another 50 mm wider, so the power supply can go on the bottom and you can save the cost of the mezzanine plate" territory pretty quickly. Then if you're going to the 330 mm wide chassis to fit the power supply on the bottom, why not go to the 250 or 300 mm depth version as the 200x330 size is a sorta odd stubby form factor.

I'll take Scope Creep for $400, Alex... :)

That said, I do value your input. Should I make another kit available (and that is by no means a 'for sure' thing), I will go for something a bit more modest in size.

Tom
 
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Quite aware of that - I was contemplating using a spare Meanwell 24 supply unused from an earlier project, but the particular one didn’t quite fit the ACA chassis, and I only had one, plus the build for Dave was a pair to be used in bridged mono- block mode.
Back to the Mod286 - power difference aside, other than a fairly similar form factor to the ACAs, Tom’s amps are quite a different beast.
 
The ACA was indeed a source of inspiration in my design. I love the form factor, but despise the power brick. I prefer stereo equipment to be self-contained and not require "lumps" between the power outlet and the chassis.

I did toy with the idea of converting +24 V (or +48 V) from a power brick to ±36 V for the Modulus-286, but decided against it due to development time and cost.

I do agree that the Modulus-286 Kit is a tight squeeze. I'm happy with its size, but an extra 10 mm on all dimensions would have been nice. I'm rather impressed with its performance, though. It packs a punch (both on power and on distortion/IMD/etc.)

Tom
 
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Since my comments started this discussion of the amp’s form factor, I’d like to emphasize how happy I am with the 286 amp. It sounds wonderful, runs at a reasonable temperature, has no noticeable noise, and has plenty of power for my needs. My comments spoke more to my shortcomings as a builder than to any shortcoming in Tom’s design.
 
No worries.

BTW: If any of you are interested in buying #1 of 28 of the Modulus-286 Kit (Limited Edition) - the one tested by Amir at Audio Science Review - toss me a PM or email (add @neurochrome.com to my user ID here).

The amp is currently with Amir (so in the outskirts of Seattle), which makes shipping to the US quite affordable and painless.

I figure $1499 including shipping within the US for this fully assembled amp. It's a demo model after all... :)

You can see Amir's review and measurements here: Review and Measurements of Neurochrome Modulus-286 Amp | Audio Science Review (ASR) Forum

Tom
 
Thought I'd point out this quite nicely built Modulus-286 amp that popped up in the Chipamp image thread: Chip Amp Photo Gallery

I love it when chassis repurposing works out as well as it did here.

A couple of teaser images (there are more in the photo gallery thread):
755826d1557556110-chip-amp-photo-gallery-photo-download-5-8-2019-hifi-amp-builds-058-jpg

755828d1557556136-chip-amp-photo-gallery-photo-download-5-8-2019-hifi-amp-builds-057-jpg


Tom
 
I've decided to focus Neurochrome more strongly on affordable DIY products. I could also use a little seed money for my next venture. Thus, I've decided to put the Modulus-286 Kit (Limited Edition) on sale for $999/each.

There were only 28 of these made. I have 17 left. Last I offered the Modulus-286 Kit at this price, I sold the four I had available at that price within 15 minutes, so I expect them to go pretty quick.

You can check the current stock levels on my website. If it says "In Stock" for the option you've chosen, that option is in stock. The actual stock level ("Only 5 left in stock") will be shown once there are five or fewer left.

You can find the Modulus-286 Kit (LE) here: Modulus-286 Kit Limited Edition | Neurochrome :: Audio

Tom
 
Tom,

That's a nice offer and good see the units already moving! (not surprised :))

Your efforts and investments into kits and parts that make life easier for the potential builder deserves praise. The kits, the mounting brackets, semi and fully-assembled modules - all make it easier and faster for folks to integrate their amps and get to making music.

I am nearing 4 years of my Modulus-86 and THAT Driver preamp build. I use the amplifier on a regular basis and am very happy with it. Moreover Tom's documentation is very thorough, and customer service is top notch.

- Zia
 
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I'm still holding out for an affordable DIY balanced preamp to partner my Mod 686 Tom ;)

If you're expecting a full preamp, you'll have to hold out for a long, long time.

That said, a couple of Universal Buffers (coming by December) and a volume control would make a nice preamp.

That's a nice offer and good see the units already moving! (not surprised :))

Yeah. It's nice to turn stuff in my basement into money in the bank. It's too large of an investment to just have sitting around.

Your efforts and investments into kits and parts that make life easier for the potential builder deserves praise. The kits, the mounting brackets, semi and fully-assembled modules - all make it easier and faster for folks to integrate their amps and get to making music.

I am nearing 4 years of my Modulus-86 and THAT Driver preamp build. I use the amplifier on a regular basis and am very happy with it. Moreover Tom's documentation is very thorough, and customer service is top notch.

Thank you for your kind comments. I really appreciate it. I'm glad your builds of my circuits have gone well.

Tom