This is the sink:
(Alta potencia) 200x99x45mm de aluminio puro extrudado dissipador de calor refrigerador radiador para chip led eletronico refrigeracao diy|heat sink radiator|extruded heatsinkheat sink - AliExpress
The idle current is at 0.89A. And I'm still using a trimpot to control that current. She is at a minimum.
(Alta potencia) 200x99x45mm de aluminio puro extrudado dissipador de calor refrigerador radiador para chip led eletronico refrigeracao diy|heat sink radiator|extruded heatsinkheat sink - AliExpress
The idle current is at 0.89A. And I'm still using a trimpot to control that current. She is at a minimum.
I use quiet Noctua fans on similar heatsinks; mine are Wakefield and fit the fan size perfectly (120mm); the amp was used for aleph30 at 25V rails before it was converted into one of my BA-3b mono blocks.
https://www.diyaudio.com/forums/pass-labs/201281-burning-amp-ba-3b-balanced-57.html#post4794952
With digital fan control I have a much shorter wait time for amp to reach its optimal temp and max performance
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Btw: how much power are you guys planning on getting from Aleph Mini with 12Vac PS secondaries i.e. rails at ~+/-15V? I have a couple of those Xformers. I am considering bulding either a 4-channel F3 or MiniA for a multi-amped system. Currently using ACAs and they are really really good for that but I thought of maybe trying something mellower for the mid/highs.
https://www.diyaudio.com/forums/pass-labs/201281-burning-amp-ba-3b-balanced-57.html#post4794952
With digital fan control I have a much shorter wait time for amp to reach its optimal temp and max performance
.Btw: how much power are you guys planning on getting from Aleph Mini with 12Vac PS secondaries i.e. rails at ~+/-15V? I have a couple of those Xformers. I am considering bulding either a 4-channel F3 or MiniA for a multi-amped system. Currently using ACAs and they are really really good for that but I thought of maybe trying something mellower for the mid/highs.
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Here's the usual messy test rig photo. I had to improv with some old PC coolers while running it. Those ones here can run it without fans on. I suppose I could pull off 1 channel per cooler without fans, but they wouldn't be at comfortable temperature for sure
The mini clamps are awesome for testing stuff, no need to drill anything.
The mini clamps are awesome for testing stuff, no need to drill anything.
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I guess then the miniA at +/-15Vdc rails should be comparable to ACA at +24V as far as power delivery goes? The key difference being balanced input which would leave me with digital master volume control at miniDSP 4x10Hd while for the unbalanced (like ACA or F3) I also have a 6-channel bf862 preamp. Still undecided.
I guess I could use one 225Va 2x12Vac transformer for 4 minis plus some large caps. Not sure how much R in CRC I could afford with no voltage available to lose.
I remember my Aleph30: just great midrange; the twinkle in the treble not quite there. Not sure how F3 compares though Papa said that one had "a sweet top".
I guess I could use one 225Va 2x12Vac transformer for 4 minis plus some large caps. Not sure how much R in CRC I could afford with no voltage available to lose.
I remember my Aleph30: just great midrange; the twinkle in the treble not quite there. Not sure how F3 compares though Papa said that one had "a sweet top".
Finally fire it up after 10 years (just power supply) and I'm getting +/-18Vdc unloaded.
Got my order from Farnell/cpc and they screw it up again (just can't get a break)...
I may connect one channel tomorrow to see how much "sag" I will get from the power supply because I'm not happy with the 18Vdc output.
Got my order from Farnell/cpc and they screw it up again (just can't get a break)...
I may connect one channel tomorrow to see how much "sag" I will get from the power supply because I'm not happy with the 18Vdc output.
Really. After all the changes I made and the temperature doesn’t change, I’ve already come to the conclusion that all that remains is to change the heatsink.
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Here is a pic of my boards, a mini aleph with doubled outputs, it's a cheap build made of leftovers from other stuff, aleph green edition waiting for irf9610, but shipping theese days are a drag.
Really excited to get some power on.
I installed bc550c how high can I run rails, without compromising SOA
waiting for irf9610, but shipping theese days are a drag.Really excited to get some power on.
I installed bc550c how high can I run rails, without compromising SOA
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I see a few things you can improve
"L" profile not properly bolted to the main heatsink
"L" profile to wide and thin - get mosfets closer to the main heatsink or on the it (remove ""L" profile
Place the heatsink vertically to help heat evacuation (improve air flow)
And you are measuring the temp on the body of the mosfet and that will give you higher readings
Not been critical just a few things that can help with your issue.
"L" profile not properly bolted to the main heatsink
"L" profile to wide and thin - get mosfets closer to the main heatsink or on the it (remove ""L" profile
Place the heatsink vertically to help heat evacuation (improve air flow)
And you are measuring the temp on the body of the mosfet and that will give you higher readings
Not been critical just a few things that can help with your issue.
In addition to my previous post here is the schematic, only difference is is my ballast resistors are 0r9 , I have four talema toroids, which loaded deliver 26.5 volts, that's 37 volts ,can this aleph handle that?, I plan to use crc psu so the real voltage will probably be 35 volts loaded
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pardon my ignorance, but what's "MINI" about that ?
even if just pcb, when going for elevated dissipation, it's wise to get those mosfets spread on heatsink, not keeping them tightly packed in so small area
"mini" should be strictly contained inside +/-15Vdc rail bracket
everything above that, that's regular Aleph territory , where usual relations regarding rails, dissipation, heatsinking, number of outputs are effective
even if just pcb, when going for elevated dissipation, it's wise to get those mosfets spread on heatsink, not keeping them tightly packed in so small area
"mini" should be strictly contained inside +/-15Vdc rail bracket
everything above that, that's regular Aleph territory , where usual relations regarding rails, dissipation, heatsinking, number of outputs are effective
say that with regular CRC filtering , you'll have your DC voltage in range of x1.25 to x1.3 of your AC voltage
so, with 24-25-ish secondaries, there will be 31-32Vdc rail
you don't want that current capability of OS lags behind voltage capability and most easy and certain way of deducing relations is just to searc through various original PL Aleph iterations, find one with same rails and see what's done with OS
so, Aleph 5 is most comparable ( you'll find schematic and even SM easy here)
60W of output power, calling for minimum 300VA Donut per channel, no less than 30mF caps invested in each rail, no lesser case than 5U/400 Modushop for stereo amp (being at slightly above 100W of heat per channel)
original Aleph 5 having 3+3 mosfets , sum Iq around 1A5
if you want to keep 2+2 mosfets (as your pcbs are allowing) , use IRFP150 (stick of 25pcs will give you plenty pairs to choose from), changing source resistors from (Aleph 5) original 1R to, say, 0R68
if you can deal with all that, go for it
if not, scale down, chosen case dissipation ability being most limiting factor
......easypeasyshort&sweet......
so, with 24-25-ish secondaries, there will be 31-32Vdc rail
you don't want that current capability of OS lags behind voltage capability and most easy and certain way of deducing relations is just to searc through various original PL Aleph iterations, find one with same rails and see what's done with OS
so, Aleph 5 is most comparable ( you'll find schematic and even SM easy here)
60W of output power, calling for minimum 300VA Donut per channel, no less than 30mF caps invested in each rail, no lesser case than 5U/400 Modushop for stereo amp (being at slightly above 100W of heat per channel)
original Aleph 5 having 3+3 mosfets , sum Iq around 1A5
if you want to keep 2+2 mosfets (as your pcbs are allowing) , use IRFP150 (stick of 25pcs will give you plenty pairs to choose from), changing source resistors from (Aleph 5) original 1R to, say, 0R68
if you can deal with all that, go for it
if not, scale down, chosen case dissipation ability being most limiting factor
......easypeasyshort&sweet......
pcb itself would serve as base for any size Aleph - it's all matter of changing few resistor values here and there, and using brain how to accomodate different number of outputs
so, regarding pcb, you're good
again, as I said - you are one to decide how big shoes you wanna fill there, so with that short summary I hope I did some helping
most important thing, regarding Alephs, we got in years from Pa - Aleph is an Aleph is an Aleph - understand it, scale it for your own needs
so, regarding pcb, you're good
again, as I said - you are one to decide how big shoes you wanna fill there, so with that short summary I hope I did some helping
most important thing, regarding Alephs, we got in years from Pa - Aleph is an Aleph is an Aleph - understand it, scale it for your own needs
I had a look around and found the seller for that kit (assembled) and wish you good luck with it they are a hit and miss jobby.
Do you have the schematic for it ?
How does it compare with the original schematic posted here by Grey Rollings ?
I already made the heatsink change. I put twice as much aluminum. Each weighing more than 1kg. Unfortunately I did not find these sinks available at the store where I bought them here in Brazil and I will have to wait to arrive to buy another pair. I believe that this time it is not possible for the temperature to rise.
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