Pass DIY Addict
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Thanks guys! You have helped me to be confident enough to order the parts for an Aleph A3 tomorrow. Will use a 18Vac x2@12A transformer, 4kg heatsink for each channel, 800mA quiecent current on each IRFP244, 40,000uF on each 25Vdc rail. Will add a speaker protector as well. Any further advise before I take the plunge ?
Last edited:
You can use IRFP240. Don't forget you need to match them if you are using them
in parallel.
Also check out this thread:
http://www.diyaudio.com/forums/pass-labs/267857-aleph-design-reloaded.html#post4184920
in parallel.
Also check out this thread:
http://www.diyaudio.com/forums/pass-labs/267857-aleph-design-reloaded.html#post4184920
Input capacitance is about 2x that of IRFP240 or IRFP244. On the other hand,
it is a bigger part...
Looks like you want to run 1.6A current, so about 40W dissipation. I think
ZenMod uses a single IRFP150 in his Babelfish-J (in the thread he linked above)
so you should be able to do the same for the Aleph-3.
If you're going to just use IRF9160, an alternative part to consider is FQP3P20.
it is a bigger part...
Looks like you want to run 1.6A current, so about 40W dissipation. I think
ZenMod uses a single IRFP150 in his Babelfish-J (in the thread he linked above)
so you should be able to do the same for the Aleph-3.
If you're going to just use IRF9160, an alternative part to consider is FQP3P20.
Pass DIY Addict
Joined 2000
Paid Member
Here are some notes that I recorded a few years ago. Some of the numbers might be a little off, but they provide a pretty good guideline.
Power transformer's VA rating needs to be 7.5x channel output power for each channel
per channel:
a40 24v 300va (~30v rails 40wpc output, 100w heat dissipation
Aleph 2 35v 750va (~45v rails) 100wpc output, 300w heat dissipation
Aleph 4 35v 625va (~48v rails) 100wpc output, 250w heat dissipation
Aleph 5 26v 300va (~34v rails) 60wpc output, 150w heat dissipation
Aleph 30 20v 250va (~25v rails) 30wpc output, 100w heat dissipation
Power transformer's VA rating needs to be 7.5x channel output power for each channel
per channel:
a40 24v 300va (~30v rails 40wpc output, 100w heat dissipation
Aleph 2 35v 750va (~45v rails) 100wpc output, 300w heat dissipation
Aleph 4 35v 625va (~48v rails) 100wpc output, 250w heat dissipation
Aleph 5 26v 300va (~34v rails) 60wpc output, 150w heat dissipation
Aleph 30 20v 250va (~25v rails) 30wpc output, 100w heat dissipation
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