I will definitely order more chassis. In fact, I just heard back from the manufacturer that they'll provide a quote for the design I submitted on Saturday night. The new revision will have mounting holes for the Guardian-86 Rev. 2.0 and will also have holes in the bottom panel for the Connex SMPS300REh. Those changes aside, it'll be identical to the one currently shown on my website: https://neurochrome.com/collections/connectors-parts/products/modulus-chassis It'll be available in both black and "silver" (i.e., clear anodized aluminum).
The Modulus Chassis supports a stereo build of the Modulus-86, 186, or 286 powered by a Power-86, Power-686, or Connex SMPS300REh with (optional) speaker protection by the Guardian-86 Rev. 2.0 and the mains power controlled by an Intelligent Soft Start. Unfortunately the heat sinks are not efficient enough for the Modulus-686.
The only unknowns regarding the chassis at this point are the price and the delivery date. I expect to have those within the next few days and will update my website with this information. You're more than welcome to place a backorder before then. I'll honour the old pricing until I know the new price (which given what's going on in the world will likely be higher). My best guess is that I'll be able to ship the chassis in early/mid December, so if you want one in time for the holidays I suggest choosing FedEx or UPS for the shipping option.
The lack of chassis weren't so much due to the supply chain issues. It was more due to higher than expected interest and also the fact that I've been buried in a home renovation project this summer that just consumed me (and my time). Around this time last year my landlord announced that they were going to sell, so I scrambled and found a place to buy. Because I'm self-employed this was the first year since 2015 where I qualified for a mortgage, so I could finally buy something. It wasn't easy, but I managed to find a house in "inner city" Calgary that I could afford and that didn't require too much work. Still, it's remarkable how much work this "move-in ready" house required to become the way I wanted it. Over the summer I got pretty good at popcorn ceiling texture removal, drywall mudding, and painting. My existing skillset came in handy for installing recessed lighting, pulling ethernet cable, and fixing various electrical gremlins in the house.
Anyway. If it seems like I've been a bit absent or stressed out the past few months, that's why. I'm now 99% back in business. I need to rework a few things in the lab (to take advantage of the separate two-phase, 20 A circuit I pulled) and also to set up my listening space(!) I still have boxes to unpack and pictures to hang. But all that can wait. Neurochrome is once again my main focus. Yay!
Tom
The Modulus Chassis supports a stereo build of the Modulus-86, 186, or 286 powered by a Power-86, Power-686, or Connex SMPS300REh with (optional) speaker protection by the Guardian-86 Rev. 2.0 and the mains power controlled by an Intelligent Soft Start. Unfortunately the heat sinks are not efficient enough for the Modulus-686.
The only unknowns regarding the chassis at this point are the price and the delivery date. I expect to have those within the next few days and will update my website with this information. You're more than welcome to place a backorder before then. I'll honour the old pricing until I know the new price (which given what's going on in the world will likely be higher). My best guess is that I'll be able to ship the chassis in early/mid December, so if you want one in time for the holidays I suggest choosing FedEx or UPS for the shipping option.
The lack of chassis weren't so much due to the supply chain issues. It was more due to higher than expected interest and also the fact that I've been buried in a home renovation project this summer that just consumed me (and my time). Around this time last year my landlord announced that they were going to sell, so I scrambled and found a place to buy. Because I'm self-employed this was the first year since 2015 where I qualified for a mortgage, so I could finally buy something. It wasn't easy, but I managed to find a house in "inner city" Calgary that I could afford and that didn't require too much work. Still, it's remarkable how much work this "move-in ready" house required to become the way I wanted it. Over the summer I got pretty good at popcorn ceiling texture removal, drywall mudding, and painting. My existing skillset came in handy for installing recessed lighting, pulling ethernet cable, and fixing various electrical gremlins in the house.
Anyway. If it seems like I've been a bit absent or stressed out the past few months, that's why. I'm now 99% back in business. I need to rework a few things in the lab (to take advantage of the separate two-phase, 20 A circuit I pulled) and also to set up my listening space(!) I still have boxes to unpack and pictures to hang. But all that can wait. Neurochrome is once again my main focus. Yay!
Tom
These Takachi enclosures are so f* gorgeous.
Do you still recommend the Connex PSUs? I thought at some point there were some noise problems? I have one of your SMPS-86 PCB but haven't bought the BOM yet (intended these Xmas), so I might simply go for the Connex SMPS300REh at audiophonics. The extra power might come in handy as well, and is smaller.
Do you still recommend the Connex PSUs? I thought at some point there were some noise problems? I have one of your SMPS-86 PCB but haven't bought the BOM yet (intended these Xmas), so I might simply go for the Connex SMPS300REh at audiophonics. The extra power might come in handy as well, and is smaller.
The Takachi chassis are indeed super nice and the company is good to deal with as well. The chassis are certainly a bit on the pricey side, but not outrageously so considering the customizations and quality of work.
I'm not aware of any noise issues specific to the Connex SMPS300REh. Just keep the corner where the mains enter the SMPS300 away from the input to the amp. There's no reason to go crazy here. 40-50 mm of separation is plenty. That's no different than any other rectifier. The issue you remember is probably from the Modulus-286 Kit where I had the SMPS sitting on a mezzanine plate over the amp modules. That's rather different than the current chassis.
I go back/forth on exactly how strongly I'll recommend the SMPS300REh. The power supply performs well - better than its predecessor (SMPS300RE). I measure stellar performance of the Modulus amps both with the Connex and with the Power-86/686 and mains transformer. But Connex seems to cut the component leads flush with the PCB before the board goes through wave soldering, so the spade connectors for the output don't always get soldered reliably. I've had cases where the spade wasn't connected to the rest of the board and other cases where the spade would pull out of the board if I tugged on the wires. So I've taken to re-solder the spades.
So I guess the bottom line is that I'll recommend the SMPS300REh for DIYers who are willing to do a little touch-up soldering, but I would not recommend it for mass production. I decided to include mounting holes for the SMPS300REh because many here use them.
I'm not sure what "extra power" you're referring to. The SMPS300REh is rated for "300 W" but that's music power and assumes a crest factor of 10 dB. The supply can deliver about 125 W continuously. That's no different than any other audio SMPS on the market by the way. That's fine for a stereo amp based on the Modulus-86/186/286 intended for music reproduction into 4 Ω.
Tom
I'm not aware of any noise issues specific to the Connex SMPS300REh. Just keep the corner where the mains enter the SMPS300 away from the input to the amp. There's no reason to go crazy here. 40-50 mm of separation is plenty. That's no different than any other rectifier. The issue you remember is probably from the Modulus-286 Kit where I had the SMPS sitting on a mezzanine plate over the amp modules. That's rather different than the current chassis.
I go back/forth on exactly how strongly I'll recommend the SMPS300REh. The power supply performs well - better than its predecessor (SMPS300RE). I measure stellar performance of the Modulus amps both with the Connex and with the Power-86/686 and mains transformer. But Connex seems to cut the component leads flush with the PCB before the board goes through wave soldering, so the spade connectors for the output don't always get soldered reliably. I've had cases where the spade wasn't connected to the rest of the board and other cases where the spade would pull out of the board if I tugged on the wires. So I've taken to re-solder the spades.
So I guess the bottom line is that I'll recommend the SMPS300REh for DIYers who are willing to do a little touch-up soldering, but I would not recommend it for mass production. I decided to include mounting holes for the SMPS300REh because many here use them.
I'm not sure what "extra power" you're referring to. The SMPS300REh is rated for "300 W" but that's music power and assumes a crest factor of 10 dB. The supply can deliver about 125 W continuously. That's no different than any other audio SMPS on the market by the way. That's fine for a stereo amp based on the Modulus-86/186/286 intended for music reproduction into 4 Ω.
Tom
mmm if that is the case, it doesn't look too professional from their side, tbh.
I said power and should've said voltage. The SMPS-86 that I bought from you is ±24 (if I'm not mistaken) vs the ±30 of the Connex. Also, that would also force the use of 8Ω speakers if I'm not mistaken (maybe that's why I decided for the SMPS-86, so I have the choice to also opt in for 4Ω speakers if I wish). Are my assumptions correct?
Thanks. It is certainly a big relief to be done with the main living spaces. Now I can finally get out of camping mode.
It's possible that things have improved, but what I wrote was my experience with their products ordered 1-2 years ago. That said, they have made improvements, for example in the packaging of their products. That may seem like a small thing, but it is important that products arrive without shipping damage.
Or ±36 V for the Connex. Correct. You can explore the tradeoffs and power supply options here: https://neurochrome.com/pages/output-power
I generally recommend ±28-30 V for the Modulus-86 and -186. ±35-36 V for the Modulus-286. That's based on music reproduction into a 4 Ω load.
The main limitation of the SMPS-86 (which I discontinued a few years back) is the 2.5 A (DC) current limit of the IRM-60-24 switching modules. If you power a Modulus-86 with that, you'll get 28 W into 8 Ω (voltage limited) and 28 W into 4 Ω (current limited). You can run a stereo amp off of one SMPS-86 and get 2x28 W into 8 Ω, assuming music reproduction. I wouldn't count on more than 2x14 W into 4 Ω due to the 2.5 A current limit.
The SMPS modules will shut off if you exceed the current limit. They'll turn back on after 2-3 seconds of recovery. So the supplies, hence the amp, will operate in hiccup mode until you turn the volume down. I found 2x28 W to be plenty loud with inefficient bookshelf speakers (8 Ω, 85ish dB/1W@1m, Dali 3A) but some were rather dismayed that they couldn't rock their house off the foundation with 4 Ω speakers.
That's in part why I discontinued the SMPS-86. You really want the RPS-200-24 if you want the full power from the Modulus-86. The SMPS-86 is fine for a li'l desktop amp, which was my intent with the circuit.
Tom
OK I might have a look at other PSUs then, since I still didn't get the BOM.
OK when I bought the SMPS-86 I had an idea in mind, but now I think I will want a little more extra juice, in case I finally get a pair of low-ish SPL 4 Ω speakers. So maybe the Connex are a good option.
I had a look at the Meanwell RPS-200-24, and I think I am missing something here. Sorry
Without fan it delivers 5.9A which is double the IRM-60-24. BUT, is the RPS-200-24 the equivalent to the RM-60-24? I mean, did you suggest it to use them in your SMPS-86 board? Otherwise I don't think these Meanwell open frame PSUs are intended for ±24 or ±30, the max negative rail they have is -15VDC. As I said I might be missing something.
Do you mean that you haven't bought the parts yet or that you don't have the BOM?
If you have not yet bought parts, you could consider the IRM-90-24. According to its data sheet it should drop straight into the SMPS-86 circuit board. It delivers 4.13 A (10 second duration) so it'll certainly power a stereo Modulus-86 for 8 Ω operation and possibly also 4 Ω operation. If you run the two Modulus-86 in a stereo amp in opposite phase (so reverse XLR pins 2,3 and the two output pins on one of the MOD86) it'll work well for 4 Ω loads as well, assuming music reproduction.
Only the IRM-60 and IRM-90 will work with the SMPS-86. If you go for the RPS-200-24 you'll need to mount two of them in the chassis and connect them in series on the output to from ±24 V.I had a look at the Meanwell RPS-200-24, and I think I am missing something here. Sorry
I'm not aware of a dual-output Mean Well that delivers a symmetric output voltage AND also a symmetric output current.
Tom
The parts, excuse my english. EXACTLY what I needed then, didn’t know about the 90-24, thanks. I understand the rest of the BOM remains the same, or should I change something else? Thank you as always
From the last page of the RPS-200 data sheet:
And for those who use the RPS-400-27(-C), here are the connectors:
If I recall correctly, the Hirose DF11 works for the 4-pin connectors as well.
Digikey carries the JST connectors. There's an equivalent by TE that's available at Mouser. Both Mouser and Digikey carry the Hirose connectors, though I seem to recall that they're being obsoleted.
Tom
And for those who use the RPS-400-27(-C), here are the connectors:
If I recall correctly, the Hirose DF11 works for the 4-pin connectors as well.
Digikey carries the JST connectors. There's an equivalent by TE that's available at Mouser. Both Mouser and Digikey carry the Hirose connectors, though I seem to recall that they're being obsoleted.
Tom
I hesitate to post here because my relationship with DIY is more aspirational than yet actualized. But I recently acquired an already-built Modulus 86 with the latest 3.0 board revision, and I'm pretty floored. I thought I'd share my subjective impressions since my use case may be fairly atypical.
I listen primarily to vinyl, so the match between a high-distortion medium and an extremly low-distortion amplifier might seem an odd one - but I've found the combination to be fantastic. For a while, I thought single ended triodes were it, but I got sick of replacing unreliable tubes at ever-growing expense. So, I acquired a vintage Yamaha VFET amp trying to retain some of that sound signature. It turns out VFETs don't really sound like tubes, but I was impressed by the added grip on the music, and a certain je ne sais quoi that I attributed to the exotic transistors and glowing amber VU meters.
In the back of my mind, though, I was always worrying that the thing might break. I'd come across a forum post heaping effusive praise on, I think, the Modulus 686 and was intrigued by idea that an amplifier could, and should, sound like nothing, and that engineering could trump the esoteric, elusive, and expensive dragon I'd been chasing. Populating the circuit board of a Modulus 86 was out of the question for the time being, and testing the theory using a pre-assembled 186 and 286 seemed too costly (or so my thinking went; I now recognize them as bargains.) But a pre-built 86 finally popped up for an affordable price, and I decided to take the plunge. While I was waiting the amp to be shipped, I acquired a tube pre-amp, worrying that the Modulus 86 might sound boring and clinical using the passive attenuator I preferred to put in front of my Yamaha.
Well, I was wrong about that. I never suspected that distortion-free transparency could sound so natural and so refined, yet effortless. There's a relaxed and completely unfatiguing quality to the music that comes out of Modulus 86, and most impressively, that quality persists as the volume goes up. The harshness that before I attributed to my speakers - full range single drivers on open baffles - is now mostly gone. True, I haven't really been able to crank the volume yet. I quickly took the tube preamp out of the signal chain, preferring the passive unit, and my phono pre (the excellent Darlington MP-7) only provides so much voltage even going to my 97db/m sensitive speakers. So my first DIY endeavor will be to add a resistor for more gain at some point. But it goes plenty loud right now for my everyday listening.
In summary, I'd like to thank Tom for a fantastic amp. I've been wary of objectivism in audio, maybe due to the aggressive attempts of its most vocal proponents to deny subjective experience. But it's actually a relief to find that excellent measurements can correspond to an excellent listening experience. The curtain has been pulled back, so to speak, on the wizard and his myriad vacuum tubes and audiophile-grade capacitors. With that said, I'll continue to prefer vinyl to digital. I guess there's no accounting for taste after all.
I listen primarily to vinyl, so the match between a high-distortion medium and an extremly low-distortion amplifier might seem an odd one - but I've found the combination to be fantastic. For a while, I thought single ended triodes were it, but I got sick of replacing unreliable tubes at ever-growing expense. So, I acquired a vintage Yamaha VFET amp trying to retain some of that sound signature. It turns out VFETs don't really sound like tubes, but I was impressed by the added grip on the music, and a certain je ne sais quoi that I attributed to the exotic transistors and glowing amber VU meters.
In the back of my mind, though, I was always worrying that the thing might break. I'd come across a forum post heaping effusive praise on, I think, the Modulus 686 and was intrigued by idea that an amplifier could, and should, sound like nothing, and that engineering could trump the esoteric, elusive, and expensive dragon I'd been chasing. Populating the circuit board of a Modulus 86 was out of the question for the time being, and testing the theory using a pre-assembled 186 and 286 seemed too costly (or so my thinking went; I now recognize them as bargains.) But a pre-built 86 finally popped up for an affordable price, and I decided to take the plunge. While I was waiting the amp to be shipped, I acquired a tube pre-amp, worrying that the Modulus 86 might sound boring and clinical using the passive attenuator I preferred to put in front of my Yamaha.
Well, I was wrong about that. I never suspected that distortion-free transparency could sound so natural and so refined, yet effortless. There's a relaxed and completely unfatiguing quality to the music that comes out of Modulus 86, and most impressively, that quality persists as the volume goes up. The harshness that before I attributed to my speakers - full range single drivers on open baffles - is now mostly gone. True, I haven't really been able to crank the volume yet. I quickly took the tube preamp out of the signal chain, preferring the passive unit, and my phono pre (the excellent Darlington MP-7) only provides so much voltage even going to my 97db/m sensitive speakers. So my first DIY endeavor will be to add a resistor for more gain at some point. But it goes plenty loud right now for my everyday listening.
In summary, I'd like to thank Tom for a fantastic amp. I've been wary of objectivism in audio, maybe due to the aggressive attempts of its most vocal proponents to deny subjective experience. But it's actually a relief to find that excellent measurements can correspond to an excellent listening experience. The curtain has been pulled back, so to speak, on the wizard and his myriad vacuum tubes and audiophile-grade capacitors. With that said, I'll continue to prefer vinyl to digital. I guess there's no accounting for taste after all.
And we promise not to pee in the pool...Welcome. Jump on in. The water is warm
You're quite welcome. Your feedback brings a big smile to my face. This is why I design circuits.
I can't blame you. The militarization of "science" (please note the quotation marks) and measurements (valid or not) is pretty high in some circles. "This product is $x for this many dB SINAD, that's this many dollars per dB SINAD, so product A has better cost/benefit that product B"
🤮. They seem to forget that we humans use the products for our enjoyment. Humans are not rational critters and our perceptions are derived from many inputs.Then again, others claim that measurements and the perceived experience are completely uncorrelated. That's certainly missing the point too.
I used to be pretty hardcore in the objectivist camp but have taken a more moderate approach in the past couple of years. I know too much psychology now.
Good measurements are an indicator of good engineering. And I remain unimpressed by products that don't even get the data sheet performance of the parts they're using. That's common for DACs for example.
Welcome aboard.
Like I said: Humans are not rational critters.
I think there's a lot to be learned from the resurgence of vinyl. There's a big difference between consuming music and enjoying music. Could you imagine listening to Pink Floyd, "The Wall" on shuffle? Or any classical album for that matter?Anyway. I'm glad you enjoy the Modulus-86. Thank you for sharing that.
Tom
The chassis went into production about 10 days ago, so I should have 20 chassis on my doorstep in about two weeks. I'll get 10 of each colour option. A few have sold already.
The chassis will come with all the mounting hardware needed to mount the circuits in the chassis. They do not come with the connectors, switches, etc. as those tend to be personalized. I will get a BOM together so that those who order the chassis can order the connectors and switches from Mouser/Digikey/et al.
I have received a few requests for a full chassis kit with connectors, etc. I may get a couple of kits together and see how it goes. The number of colour options on the power switch frightens me from an inventory management standpoint. At $20/each I can't afford to fill my basement with them.
Oh, and speaking of kits. I've started collecting parts for a Modulus-86 kit. I don't have a price quite yet, but I expect to have stereo kits available before Christmas (knock on wood!)
Tom
The chassis will come with all the mounting hardware needed to mount the circuits in the chassis. They do not come with the connectors, switches, etc. as those tend to be personalized. I will get a BOM together so that those who order the chassis can order the connectors and switches from Mouser/Digikey/et al.
I have received a few requests for a full chassis kit with connectors, etc. I may get a couple of kits together and see how it goes. The number of colour options on the power switch frightens me from an inventory management standpoint. At $20/each I can't afford to fill my basement with them.
Oh, and speaking of kits. I've started collecting parts for a Modulus-86 kit. I don't have a price quite yet, but I expect to have stereo kits available before Christmas (knock on wood!)
Tom
Attachments
I cannot hold my excitement, I just finished a DAC test between the Mola Mola Tambaqui vs the Resolution audio Cantata 3.0 on a pair of Joachim Gerhard's Surveyor(one of his best mini monitors ever). Cabling was S.I.N. Audio and Tara Labs. The Modulus 86 was the amp and I am shocked at how good it is!! It was warm and ocean wide with good recodings, it was cold and analytical with low quality recordings meaning that it just showed what is on the recording. Drove the speakers with ease, what a magnificent little amp! the Tambaqui is 13K, the Cantata is about the same and these are world class devices, the Surveyor is one of the best ever monitors as well, the Modulus 86 fit perfect in that company, cannot recommend it enough and I sincerely thank Tom for being so generous with us!