'Tis a 2U ModuShop Dissipante. Looks like a nicely executed build too. Reddo used the optional internal bottom plate.
Tom
Looks great, but I'm such an idiot, I ordered a case from modushop and i've ordered the mini by mistake.
It obviously wont all fit in the mini case.
It's probably not ideal to return the case from the UK to italy, I wonder if its worth buying some other small box for the transformer & power supply to give it that more "bespoke" look.
Or try to sell the mini case to someone on this forum in the UK and buy the correct siezed case from modushop?
Quick note of thanks to Tom for making such robust designs. I was doing some speaker swap experiments when my Mod86 went into protection. I initially thought it might be thermal, but I wasn't playing too loudly. A couple more cycles of protection even with reduced volume later, I finally clued in to the fact that one of the speaker cables was shorting out. I was fearing the worst, but it looks like no apparent damage done - still soldiering on and sounding great.
Oops... You can always stuff a preamp into it.
Yep. The 300x330 Mini Dissipante would be able to house a stereo MOD86 with a switching supply of some sort I'd think. The Mean Well RPS-200-24 would make a really nice supply for a Modulus amp. You'd "only" get about 30 W into 8 Ω (1.25 dB lower than the 40 W you'd get at ±30 V).
I was able to shoehorn a stereo Modulus-286 with power supply into a Mini Dissipante 2Ux200x230 mm. That was a significant challenge, but I succeeded in the end.
Awesome. Thanks for sharing. Yeah. The LM3886 is hard to kill. I ran the Modulus-686 with a 1 Ω load by accident once. It was delivering 150 W quite happily until the power supply reached its limit and turned off.
Tom
mine is 330 x 200 unfortunately, and the hammond tranny is very very big, so it wont a accommodate it with the power 86 and a pair of amp boards.
image for reference 20200110-181836 — imgbb.com
I've assembled the case, the anodised finish is very nice, I think I might just buy another one exactly the same and have the power in a separate box. it would look pretty nice, 2 unassuming matte black boxes.
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I’m pretty sure Tom has very good reasons against the umbilical approach, do a search on the forum xD
Thanks for the heads up.
Question for Tom, After doing some reading I can see why you advise against housing the power supply separately from the amp boards, due to the increased impedance caused by the additional cable length.
My question is, does this apply only to the cable after the power supply, or will it also be true for the cable from the trafo to the power supply.
My thinking is that, at a push I can get the power 86 and the pair of amps in the small enclosure, and put the trafo in a separate box.
If you still advise against this for reasons of performance then I'll just bite the bullet and buy the larger enclsure.
Thanks
Tom
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FWIW, I built the Modulus-86 with SMPS-86. This is housed in the smaller Mini-Dissipante chassis. The power boards sit about 1/8" away from the SMPS on either side. I run 104dB horns and also 97dB fullrangers. I can turn this all the way up with no noise. There is no reason for a separate power supply or large chassis.
That is the chassis I used! I was going to switch to the linear PS so I could turn it up more (the SMPS cycles when I crank up my Snell E's). I decided I did not want to drill and tap another hole in the heatsink to move the boards to clear the transformer, so I left it go since it already sounds so good.
That is the chassis I used! I was going to switch to the linear PS so I could turn it up more (the SMPS cycles when I crank up my Snell E's). I decided I did not want to drill and tap another hole in the heatsink to move the boards to clear the transformer, so I left it go since it already sounds so good.
Alright, i think i'll give it a go.
I'll wait for Tom to reply with a bit of advice about the best placement configuration.
R12 and R13 are the ones that matter for performance (both objective and subjective). If you're going to 'geek out' with fancy resistors, those are the ones I'd attack. R1 and R2 should be metal film as well, but they're inside the composite loop so their impact is reduced by several orders of magnitude thanks to the error correction.
That said, the performance I measured and posted on my website was achieved with the parts specified on the BOM - regular KOA Speer metal film resistors with ±1% tolerance. Nothing fancy, because fancy rarely results in better performance.
Tom
That said, the performance I measured and posted on my website was achieved with the parts specified on the BOM - regular KOA Speer metal film resistors with ±1% tolerance. Nothing fancy, because fancy rarely results in better performance.
Tom
What about putting the transformer towards the front plate away from rca/speaker posts?
open question, but would also love to hear Tom's wisdom on this.
So I've been researching Magnepan's, as a mid term future purchase I'm considering their new LRS (quasi ribbon) speakers.
While researching I've come across a lot of audiophile reviews (I normally avoid hyperbola) who say they really only sound their best with amps that can deliver a lot of current, so my questions are:
1: has anyone here tried the Modulus86 with the Magnepan LRS, or similar ribbon or planar-magnetic speakers, which are considered hard to drive or current hungry.
2: If no one has specifically tried it does anyone think the modulus86 would be suited to driving them.
3: Is there any truth / science to claims that these speakers can sound "better" when driven by amps which can supply more current. (Is current supply even a consideration, and is it as important as the wattage specification)
Or anything else thats relevant that I've not managed to ask here.
Thanks
Tom
So I've been researching Magnepan's, as a mid term future purchase I'm considering their new LRS (quasi ribbon) speakers.
While researching I've come across a lot of audiophile reviews (I normally avoid hyperbola) who say they really only sound their best with amps that can deliver a lot of current, so my questions are:
1: has anyone here tried the Modulus86 with the Magnepan LRS, or similar ribbon or planar-magnetic speakers, which are considered hard to drive or current hungry.
2: If no one has specifically tried it does anyone think the modulus86 would be suited to driving them.
3: Is there any truth / science to claims that these speakers can sound "better" when driven by amps which can supply more current. (Is current supply even a consideration, and is it as important as the wattage specification)
Or anything else thats relevant that I've not managed to ask here.
Thanks
Tom
Always an option, and if it is better to have the PSU nearer the I/O connectors rather than the trafo, then thats the route I'll go.
Always happy to hear people's wisdom on this build