adn6244,
The GB is going on currently for the 20W version. Here you go with the link with info:
http://www.diyaudio.com/forums/soli...rid-aleph-alpha-amplifier-13.html#post5327744
The GB is going on currently for the 20W version. Here you go with the link with info:
http://www.diyaudio.com/forums/soli...rid-aleph-alpha-amplifier-13.html#post5327744
Due to space limitations, I was considering a 2U HIFI2000 dissipante (300mm deep) for 2-channel 20W Alpha.
Is there enough heatsink?
HIFI 2000 Heatsink Case 2U 300mm - Front 4mm Silver - Audiophonics
Is there enough heatsink?
HIFI 2000 Heatsink Case 2U 300mm - Front 4mm Silver - Audiophonics
jacques,
X is running his ALPHA 20W with a 4U chassis - my understanding from the post linked below is that is the bare minimum if you are using passive heat-sinks (no fans):
http://www.diyaudio.com/forums/soli...rid-aleph-alpha-amplifier-28.html#post5337182
With fans you can go smaller.
X is running his ALPHA 20W with a 4U chassis - my understanding from the post linked below is that is the bare minimum if you are using passive heat-sinks (no fans):
http://www.diyaudio.com/forums/soli...rid-aleph-alpha-amplifier-28.html#post5337182
With fans you can go smaller.
You might consider using small quiet fans if space it tight. Look how small laptop computers are - made possible with heatpipes and fans.
I'm using passive ones I have in my "Guardian" (theres temporary dartzeel inside, link in my signature). They are about 10kg each, should be enough. It takes some work though to get grounding properly done in that case. I would like to make monoblocks with separate psu, but I seem always have grounding issues with monos!
Ground loops are a real pain. They still get me from time to time. I have indeed found that earth grounded monoblock amps are more susceptible. The Aksa Lender Preamp PCB is not a monoblock and is absolutely dead quiet and feee of ground loops as it was meticulously designed by JPS64 with proper ground planes and Star point at main connection point where signal enters the PCB. As JPS64 said to me, “You must think like an electron when designing the layout!”
Sure seems to work.
I know
they get me always at first fire up.. It seems I can't think like an electron . So no monoblocks this time might be the answer.What do you think, could it possible be enough cooling with normal bias if I mount both channels on one huge heatsink? They measure w345mm * h390mm * d70mm and 10kg each?
X for the 20W type what would be the proper Voltage rating
I do have some 20-0-20V 500VA and one 625VA Plitron transformers
Or I have one with higher voltage 24-0-24V total 9.79A
The 625VA was used at the Aleph 30 which gave 30W per channel. Only got a bit warm under the 2 channel load. You know the Aleph 30 was also single ended but a bit different concept.
The reason I ask I see you get only 14W or so with the AJ transformer. Usually, that uses 20-0-20V type. This amplifier named Alpha20 because of produces 20W if I am right.
I do have some 20-0-20V 500VA and one 625VA Plitron transformers
Or I have one with higher voltage 24-0-24V total 9.79A
The 625VA was used at the Aleph 30 which gave 30W per channel. Only got a bit warm under the 2 channel load. You know the Aleph 30 was also single ended but a bit different concept.
The reason I ask I see you get only 14W or so with the AJ transformer. Usually, that uses 20-0-20V type. This amplifier named Alpha20 because of produces 20W if I am right.
Gaborbela; yes, this is 20w amp
I was thinking some casework again. Something "small" and simple, maybe like this? If I place only toroid and bridge rectifiers in remote location, how do I have to wire groundings? Idea is that I could use same trafos for many amplifier projects, there would probably be 3 toroids in the same case. CRC supply, cap mx and stuff would still be in the amplifiers case. Dead idea?
I was thinking some casework again. Something "small" and simple, maybe like this? If I place only toroid and bridge rectifiers in remote location, how do I have to wire groundings? Idea is that I could use same trafos for many amplifier projects, there would probably be 3 toroids in the same case. CRC supply, cap mx and stuff would still be in the amplifiers case. Dead idea?
Attachments
The 20v-0-20v is good as it gives 28vdc rails which can work at lower 1.3amp bias as is, or use the Prasi/Juma cap Mx board in between to drop it to 24v rails. That is the ideal solution as ripple will be non-existant.
Great idea. As a DIYA amp enthusiast, we build many amps for fun. The joy is the building and comparing so nothing is static, "this is the case and this is the amp forever."
That's why all my trafos are terminated with round loop crimp connectors. I have a screw terminal panel in the case and the CRC's are all terminated with spades as is the amp. So switching trafos, CRC's, amps (especially if they are UMS compliant) is not too much trouble.
The idea of a separate case for the trafos and CRC with a thick PSU cable is just not so practical. It could be done but you would need vertical rack to effectively do it to keep cables short. Then you may have to deal with some ground loops.
Wise words!
I've tried this once actually, with class-a mono's. Power cables was quite long too.
What I learned from there is you can add couple of caps in trafos case, but your actual CRC supply should position in amplifiers case. Grounding was a problem then (suprise
). I was just wondering would it be easier with one trafo stereo build to handle ground loops?Havent done anything UMS compliant, I have some kinda love/hate relationship with case building without proper tools