I managed to place two Mod686, two Power686, two Guardian686, one ISS and two 500VA transformers in one chassis. And i am not using the vertical connectors. I am however using an aluminum plate above my two transformers to house the ISS and Power686 modules.
I’ll see if I can find some time today to make a few pictures.
I’ll see if I can find some time today to make a few pictures.
I'm pretty sure wcwc is planning to put a MOD686 and a MOD186/286 into a Mini Dissipante, though. Putting those bits into a regular 430 mm wide Dissipante is no big deal. Squeezing them into a Mini Dissipante will require some work.
If you haven't posted them already, I'd certainly welcome your build pictures. It's always fun to see people's builds.
Tom
If you haven't posted them already, I'd certainly welcome your build pictures. It's always fun to see people's builds.
Tom
Here are my new addition to the family - two new Mod686s. Finally ready and making some wonderful music. I have built two monoblocks, each using a 800VA, 2x25VAC Amplimo toroid, a Neurochrome ISS softstart to get the beast going and a Power686 (2x36VDC)linear power supply. All that tamed inside a Modushop 4U Dissipante housing. The 6DMF powerswitch awakens the whole thing from its standby mode, while switching the LED ring from red to green. Alternatively the backside contains a 3.5mm phono plug for the 12V remote start trigger signal. See pics below. Each Mod686 operates in the 20dB gain setting with the lower noise floor and is being fed by the Auralic Altair providing up to 4Vrms via balanced XLRs. This gets me a maximum of 200Wrms into 8ohms - plentiful I would say for the KEF R700s speakers (to be replaced by the Reference 5 soon - which was the motivation for the additional power and current capability of the Mod686 vs the existing Mod286s). .
If you like, I’d be happy to share first (subjective) listening impressions in comparison to my two Mod286 monoblocks (also 20dB gain) once I had some time listening more intensely.
If you like, I’d be happy to share first (subjective) listening impressions in comparison to my two Mod286 monoblocks (also 20dB gain) once I had some time listening more intensely.
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That is a super nice build you have there! Congratulations on a job well done. I especially like how you have all exposed connections (input connector, AC mains inlet, etc.) covered in heat shrink. It also looks like you've minimized the routing and loop areas of the various connections. Excellent!
The low-mounted, off-centre power switch is a nice aesthetic touch.
That'd be cool. If you've had a chance to compare the Modulus-286 and/or Modulus-686 against other amps, I'm curious for your insight there as well.
Thanks,
Tom
Questions and Advice for a first timer.
Read every page in this thread and really enjoyed it. Tom, I poked all through your website and read your resume, extremely impressive.
Currently I have the Doug Self Preamp on my plate as my first PCB build and soldering project. I have built many computers, pi's and soldered many speaker crossovers. That being said, I am not in the realm of any of you when it comes to electronics knowledge or skill. I'm a hobbyist and love to tinker, but I'm a software guy and not hardware.
I had planned to buy the Benchmark AHB2 because of the low distortion, s/n ratio and reviews, but finding this project has me thinking otherwise as this amp has more power and great numbers from what I've read. That being said I have serious concerns if I'm biting off more than I can chew. I'm certain if I buy everything assembled I wont have too much trouble putting the amp together, but there's a huge savings and satisfaction of soldering the components (though I was going to fork over $3000 for the AHB2 and maybe 2 of them). I will say my soldering skills are more entry level than expert and the Preamp project will be my first real challenge. That being said, I know there's a limited amount of boards left before there's a price jump so the frugality in me is calling.
The SMPS version was my initial go to, but I think I want to be greedy and go for power(though shipping to NZ will make me cry). So I plan on the 4U chassis; just wish I could take advantage of Tom's chassis template.
I'll be using it to power a pair of Statement II's that my wife wanted me to build. I have lots of different speakers to test from high sensitivity like the SEOS12/TD12M's to low sensitivity power hungry.
Any advice from those with less and more experience on which direction I should go?
Read every page in this thread and really enjoyed it. Tom, I poked all through your website and read your resume, extremely impressive.
Currently I have the Doug Self Preamp on my plate as my first PCB build and soldering project. I have built many computers, pi's and soldered many speaker crossovers. That being said, I am not in the realm of any of you when it comes to electronics knowledge or skill. I'm a hobbyist and love to tinker, but I'm a software guy and not hardware.
I had planned to buy the Benchmark AHB2 because of the low distortion, s/n ratio and reviews, but finding this project has me thinking otherwise as this amp has more power and great numbers from what I've read. That being said I have serious concerns if I'm biting off more than I can chew. I'm certain if I buy everything assembled I wont have too much trouble putting the amp together, but there's a huge savings and satisfaction of soldering the components (though I was going to fork over $3000 for the AHB2 and maybe 2 of them). I will say my soldering skills are more entry level than expert and the Preamp project will be my first real challenge. That being said, I know there's a limited amount of boards left before there's a price jump so the frugality in me is calling.
The SMPS version was my initial go to, but I think I want to be greedy and go for power(though shipping to NZ will make me cry). So I plan on the 4U chassis; just wish I could take advantage of Tom's chassis template.
I'll be using it to power a pair of Statement II's that my wife wanted me to build. I have lots of different speakers to test from high sensitivity like the SEOS12/TD12M's to low sensitivity power hungry.
Any advice from those with less and more experience on which direction I should go?
It'd be nice to find an easy way to let the other heatsink participate, at least a little bit. (the one on the right side of photo3 post844).
On the theory that mass transfer is often more efficient than heat transfer, a copper slug on the left that transfers heat from the left heatsink to serpentine water tubes, which pump water to a copper slug on the right with its own serpentine water tubes. Hot water flows from left to right, heat gets transferred to right heatsink, cold(er) water flows from right to left.
Or else just a big aluminum bar straight across the chassis, bolted to both heatsinks.
On the theory that mass transfer is often more efficient than heat transfer, a copper slug on the left that transfers heat from the left heatsink to serpentine water tubes, which pump water to a copper slug on the right with its own serpentine water tubes. Hot water flows from left to right, heat gets transferred to right heatsink, cold(er) water flows from right to left.
Or else just a big aluminum bar straight across the chassis, bolted to both heatsinks.
Germane to this discussion is Harmonic THD’s anticipated new speaker, the KEF Reference 5 and Stereophile’s measurements:
KEF Reference 5 loudspeaker Measurements | Stereophile.com
We should also bear in mind that we can comfortably adopt a 14 dB crest factor since we are using Tom’s amps to listen to music and not sine waves! I am so thankful of that!
Best,
Anand.
KEF Reference 5 loudspeaker Measurements | Stereophile.com
We should also bear in mind that we can comfortably adopt a 14 dB crest factor since we are using Tom’s amps to listen to music and not sine waves! I am so thankful of that!
Best,
Anand.
True. Though, the 4U heat sink is sufficient for one channel of Modulus-686 on ±36 V, so I'm not overly concerned.
I must admit that I got a pretty good chuckle out of this. Now we just need an aquarium pump to circulate the water. It'll have to be an audiophile aquarium pump, of course ... with its own regulated power supply. Preferably also with a temperature dependent speed controller to avoid any noise.
On a more serious note: Water is certainly a good medium for heat transfer and one could likely borrow much of the pumps, tubing, and hardware from the water cooling of PCs. I'd personally hesitate to include water cooling unless it was absolutely necessary. I don't see any reason to include a corrosive liquid and another source of failure, but it can certainly be implemented.
An alternative would be to use heat pipes to connect the two heat sinks. They work by condensation and evaporation of a substance within the tubes themselves. You can buy them from Mouser/Digikey/et al. and they're actually not all that expensive. From what I understand, they can be a bit hard to work with (the copper tube is really thin-walled), so if going that route, I'd suggest approaching one of the many "pimp my PC" computer customization places and have them form the heat pipes. I'd also implement some sort of coupler that would allow from some slop in the heat sink to heat sink distance as the ModuShop chassis isn't exactly machined to the micron tolerance levels.
In reality, however, I generally find that there's quite a bit of thermal conduction through the front panel as well as top and bottom panels. Obviously, the heat sink with the amp on it will be warmer, but the other heat sink gets to participate a bit too - even without fancy coupling shenanigans.
Interesting thought, though.
If you wanted to make a complete mess, you could also seal all openings in the chassis and fill it with mineral oil... Yes. I have seen that done on some $50k amplifier. Just because! Just saying.
Tom
I don't see anything electrically wrong with that. I'd be a bit skeptical of the mechanical aspects, though. If you wanted two toroids in one enclosure, I'd put the toroids side-by-side with a mezzanine plate on top for circuits (like the rest of the power supply). Just be careful that you don't create a shorted turn through the mezzanine (so use standoffs to the chassis around the toroids rather than using their centre bolts for mounting the mezzanine).
Tom
>>>t'd be nice to find an easy way to let the other heatsink participate, at least a little bit.<<<
Although I am not planning on building the 686, I do plan to do mono builds of the 286, and plan to mount the toroid transformer vertically against the "unused" heatsink, with some kind of thermal transfer compound. That will keep the toroid cooler and reduce internal case temps. Not sure there is any significant benefit, but any economic (this is free) way to reduce temperatures for the transformer, caps and rectifiers should have some benefit and no performance downside.
Although I am not planning on building the 686, I do plan to do mono builds of the 286, and plan to mount the toroid transformer vertically against the "unused" heatsink, with some kind of thermal transfer compound. That will keep the toroid cooler and reduce internal case temps. Not sure there is any significant benefit, but any economic (this is free) way to reduce temperatures for the transformer, caps and rectifiers should have some benefit and no performance downside.
Thank you. I'm glad you enjoyed it.
The Doug Self Preamp should be a reasonable starting point for someone who's starting out in DIY electronics.
If you choose to take on the Modulus-686, I will recommend that you use my fully assembled modules. I think the risk involved in completing the assembly of the SMD pre-populated boards is higher than I'd recommend for a beginner to take on. I expect to have the fully built modules in stock by next week and they're currently on sale, so get 'em while you can. My website allows for backorders, so you can order the modules even though they're not in stock.
I could also create a 4U ModuShop Dissipante template for you in exchange for a case of beer or two.
I'm also happy to build a custom amp for you. To save on shipping, we could even agree on which power transformer to use and I could build the amp without the transformer. Once the chassis arrives, you just crack it open and mount the mains transformer. So all options are open.
If you'd like me to create a custom amp for you, just gimme a shout via email. Take my username here and add @neurochrome.com.
Thanks,
Tom
I will be in touch shortly. What kind of beer and how do I get good beer in to Canada?Thank you. I'm glad you enjoyed it.
The Doug Self Preamp should be a reasonable starting point for someone who's starting out in DIY electronics.
If you choose to take on the Modulus-686, I will recommend that you use my fully assembled modules. I think the risk involved in completing the assembly of the SMD pre-populated boards is higher than I'd recommend for a beginner to take on. I expect to have the fully built modules in stock by next week and they're currently on sale, so get 'em while you can. My website allows for backorders, so you can order the modules even though they're not in stock.
I could also create a 4U ModuShop Dissipante template for you in exchange for a case of beer or two.
I'm also happy to build a custom amp for you. To save on shipping, we could even agree on which power transformer to use and I could build the amp without the transformer. Once the chassis arrives, you just crack it open and mount the mains transformer. So all options are open.
If you'd like me to create a custom amp for you, just gimme a shout via email. Take my username here and add @neurochrome.com.
Thanks,
Tom
When you said that Pliny the Elder and Melvin 2x4 popped into my head, what I would do for for one of those.You could be like this:
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Thanks to all the well wishers.
I like the Aquarium idea - put some tasty fish in it and when you’re hungry just crank up the volume to cook. ;-)
Why did I build monos? Just because. I guess I just liked the idea of having completely separated amps and short speaker cables and it looks cool doesn’t it ;-)
I like the Aquarium idea - put some tasty fish in it and when you’re hungry just crank up the volume to cook. ;-)
Why did I build monos? Just because. I guess I just liked the idea of having completely separated amps and short speaker cables and it looks cool doesn’t it ;-)
This is the BOM for one monoblock. Sorry I hope it formats ok as I tried to copy it over from xls which I couldn’t attach here.
Total cost for two monoblocks ca 2.000EUR, ca. 2.300USD just so new builders get an idea what to budget. However compare that to commercially available amps. Granted with commercial amps you cannot screw up during your build and you get warranty, but I guess as long as Tom is around that isn’t a real concern.
Mod686 Monoblock, 360W (4ohm) Currency Total ExChangeFactor
1 Mod686 Board, 20dB gain 1 249 USD 0,9 224,1 EUR
2 Mod686 Parts 1 56 USD 0,9 50,4 EUR
3 PowerSupply Board 686 1 59 USD 0,9 53,1 EUR
4 PowerSupply Parts 1 75 USD 0,9 67,5 EUR
ISS Softstart 1 50 USD 0,9 45 EUR
4 ISS Softstart Parts 1 44 USD 0,9 39,6 EUR
5 Amplimo Trafo 2 x 25V, 800VA 1 120 EUR 1 120 EUR
6 IEC Inlet Schurter EMC 1 24 EUR 1 24 EUR
7 IEC Mains Cable 1 4 EUR 1 4 EUR
8 CMC Speaker Posts gold 2 15 EUR 1 30 EUR
9 XLR Neutrik NC3FD-LX-B 1 4 EUR 1 4 EUR
10 Modushop Dissipante 4U/300 incl. feet, internal base plate, hole punch 1 260 EUR 1 260 EUR
11 Miscellenous (Cables, Solder ….) 1 20 EUR 1 20 EUR
12 Shipping Charges Total 1 25 EUR 1 25 EUR
Total cost for two monoblocks ca 2.000EUR, ca. 2.300USD just so new builders get an idea what to budget. However compare that to commercially available amps. Granted with commercial amps you cannot screw up during your build and you get warranty, but I guess as long as Tom is around that isn’t a real concern.
Mod686 Monoblock, 360W (4ohm) Currency Total ExChangeFactor
1 Mod686 Board, 20dB gain 1 249 USD 0,9 224,1 EUR
2 Mod686 Parts 1 56 USD 0,9 50,4 EUR
3 PowerSupply Board 686 1 59 USD 0,9 53,1 EUR
4 PowerSupply Parts 1 75 USD 0,9 67,5 EUR
ISS Softstart 1 50 USD 0,9 45 EUR
4 ISS Softstart Parts 1 44 USD 0,9 39,6 EUR
5 Amplimo Trafo 2 x 25V, 800VA 1 120 EUR 1 120 EUR
6 IEC Inlet Schurter EMC 1 24 EUR 1 24 EUR
7 IEC Mains Cable 1 4 EUR 1 4 EUR
8 CMC Speaker Posts gold 2 15 EUR 1 30 EUR
9 XLR Neutrik NC3FD-LX-B 1 4 EUR 1 4 EUR
10 Modushop Dissipante 4U/300 incl. feet, internal base plate, hole punch 1 260 EUR 1 260 EUR
11 Miscellenous (Cables, Solder ….) 1 20 EUR 1 20 EUR
12 Shipping Charges Total 1 25 EUR 1 25 EUR
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DoubleIPA - you might want to exchange some PMs with Tom re his thoughts on linear vs SMPS supplies for the 686. The unit I heard this summer was the exact same unit in his photos earlier in this thread, and it definitely had no issue with powering a pair of DIY multi-ways - albeit not as elaborate as the KEF Reference 5s. The Modulus686 is the little silver box on the floor with green power indicator.
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