I put an entry in the sheet for you - see line 42 in the group buy sheet. I'll PM to confirm the details.Hi Randy,
this one looks great!
Altough many projects in the pipe, I would really love to build a 60w Aleph
As I would build two monos - what should I write into the Google-sheet?
Many thanks!
I was reading through the build notes and noticed that the recommended transformer (per mono block) is 300VA 25+25. I happen to have a couple of 200VA 28+28 transformers lying around but am guessing they're a little light on power and a little high on voltage?
Aleph 30 in a 3U Mini Dissipante chassis? Hmm, I may get yelled at for this.. 😉
Since I have a 3U x 300mm Mini Dissipante bought during last year's sale, I got curious to see if Randy's UMS amp boards would physically fit on the 300mm heat sinks. They would appear to, even though these heat sinks aren't available from Modushop with UMS drilling. The smaller 33-200/250/300 base plate doesn't have room for much more than the PSU board (244mm wide x 170mm long), but with the 70mm longer plate (240mm), there might be enough room for both the PSU board and a toroid, if the toroid as an estimate were less than 120mm high and less than 60mm thick and likely mounted vertically. Rectifier boards might have to mount on the inside of the face plate, which would need drilling and tapping like the heat sinks do.
What about heat dissipation? The standard 4U/300 heat sinks, which are 300mm long x 40mm thick x 165mm tall, are rated 0.31C/W; these 3U/300 sinks are 300 long x 40 thick x 120 tall and rated 0.40C/W.
24V 2.2A bias/ch = 53W/ch = ~22C above ambient with the 3U sinks, vs. ~16.5C above ambient with the 4U sinks. Well, one thing I've learned from the ACA and the MoFo is the IRFP240s can both make and some heat, and I like smol cases, so maybe.. 😈
Since I have a 3U x 300mm Mini Dissipante bought during last year's sale, I got curious to see if Randy's UMS amp boards would physically fit on the 300mm heat sinks. They would appear to, even though these heat sinks aren't available from Modushop with UMS drilling. The smaller 33-200/250/300 base plate doesn't have room for much more than the PSU board (244mm wide x 170mm long), but with the 70mm longer plate (240mm), there might be enough room for both the PSU board and a toroid, if the toroid as an estimate were less than 120mm high and less than 60mm thick and likely mounted vertically. Rectifier boards might have to mount on the inside of the face plate, which would need drilling and tapping like the heat sinks do.
What about heat dissipation? The standard 4U/300 heat sinks, which are 300mm long x 40mm thick x 165mm tall, are rated 0.31C/W; these 3U/300 sinks are 300 long x 40 thick x 120 tall and rated 0.40C/W.
24V 2.2A bias/ch = 53W/ch = ~22C above ambient with the 3U sinks, vs. ~16.5C above ambient with the 4U sinks. Well, one thing I've learned from the ACA and the MoFo is the IRFP240s can both make and some heat, and I like smol cases, so maybe.. 😈
Attachments
ranshdow,
Don’t neglect that there are 2 rails @ 2.2A. Assuming the +/- 24V rail and 2.2A recommendations are correct (I haven’t looked at the Aleph 30 build doc)…
That’s +/- 24-25V @ 2.2A, or 106W/ch. Not 53W/ch.
Best,
Anand.
Don’t neglect that there are 2 rails @ 2.2A. Assuming the +/- 24V rail and 2.2A recommendations are correct (I haven’t looked at the Aleph 30 build doc)…
That’s +/- 24-25V @ 2.2A, or 106W/ch. Not 53W/ch.
Best,
Anand.
Ah. I missed that. That's a lot of heat even for the 4U sinks, 33C above ambient?
Also the Antek toroid AS-3218 is 5" wide, which won't fit vertically in a 3U chassis.
Aleph run hot. This is a good excuse to get a bigger chassis and set it up to be able to swap various amps. 
I was planning to use such chassis for an Aleph Mini... then these new PCBs came along and I started dreaming big... like 5U / 400 big. 🙂
BTW, my PCBs are currently in transit to Europe.
The 5U is quite a bit bigger than the 4U. I am building a Aleph 30 stereo, and seems like the best chassis would be something in between. Any recommendations on which one to favor for this beginner?
4U Deluxe will do the trick.
If you want monos, here's a brand new offering
https://www.diyaudio.com/community/threads/new-monoblock-chassis-sets-from-modushop.381702/page-9
https://modushop.biz/site/index.php?route=product/category&path=324
If you want monos, here's a brand new offering
https://www.diyaudio.com/community/threads/new-monoblock-chassis-sets-from-modushop.381702/page-9
https://modushop.biz/site/index.php?route=product/category&path=324
Did anyone mention the desirability of the Harris IRF9610 or 9510's over the IR branded parts? Rochester has them, but the minimum purchase encourages a group buy.
Minimum order = 874 for SFP9610. That’s a lot!Did anyone mention the desirability of the Harris IRF9610 or 9510's over the IR branded parts? Rochester has them, but the minimum purchase encourages a group buy.
What’s your experience with FQP3P20 compared to IR or Harris 9610?
Allow me to hijack this.... but IMHO all such amplifiers need to have big, round, old fashioned bakelite like 3" VU meters in the front panel.
Gianluca should offer such an option on his front panels.
Make sure they appear in the options before the Turbo V3s get built. ;-)
BTW- my PHEV uses a bunch of power. It may come down this summer, if I do go to work physical more often, I may have to choose between running the AC, the amps or charging the car. If I stay under 1200 KwH per month, my cost is a mere 0.22 per KwH. <:-0
