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how much heatsink?

PostPosted: July 4th, 2019, 2:49 pm
by bk_856er
How much heatsink do I practically need on Q5/Q6 for preamp duty?

Built up a pair with big heatsinks, but also have some nice slender units that would afford a bit more space near the 4-pin connector. Not yet soldered, so I can swap.

BK

Image

Re: how much heatsink?

PostPosted: July 4th, 2019, 3:00 pm
by amb
The ones shown mounted are the ones I recommend. I use these on my own α20s.

Re: how much heatsink?

PostPosted: July 4th, 2019, 3:12 pm
by bk_856er
Thanks, amb. Big ones it is!

BK

Re: how much heatsink?

PostPosted: July 5th, 2019, 11:59 am
by vlad
Along the same lines - any thoughts on using a large aluminum monoblock heatsink for 4x or 6x alpha 20s?

Re: how much heatsink?

PostPosted: July 5th, 2019, 1:51 pm
by amb
vlad wrote:Along the same lines - any thoughts on using a large aluminum monoblock heatsink for 4x or 6x alpha 20s?

Yes, you could do that. The transistors won't get all that hot in normal use if you bias them to the recommended 30mA, but more heatsinking means more stable thermal behavior and avoids the possibility of thermal runaway.