Thanks, I have a lot of time involved in machining and building the cabinets. I hope to be listening to them sometime this weekend.
Not anything particularly new, and some contributors own work on here is excellent, but here is my now rather aged Musical Fidelity P170.
Uprated RATA 15000uF PS caps
Metallised polypropylene Kimber Kaps
RATA Supersound capacitors
Philips axial electrolytics
Vishay resistors.
Ian
An externally hosted image should be here but it was not working when we last tested it.
Uprated RATA 15000uF PS caps
Metallised polypropylene Kimber Kaps
RATA Supersound capacitors
Philips axial electrolytics
Vishay resistors.
Ian
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Joined 2009
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Project started last year , but I will finish soon
Alex
I noticed something special, the insulators between power devices and heatsink. I think I know why you have them - can you say where / how you got them ?
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Joined 2009
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Do you know if these are made from Beryllia? If so, please be extremely careful if you use them since chipping or cracking one will produce a toxic dust.
I've always used SIL pads myself, mostly for the convenience, no paste required, but actually some types are very low thermal impedance.
I've always used SIL pads myself, mostly for the convenience, no paste required, but actually some types are very low thermal impedance.
From beryllium oxide to be exact. BeO dust dangerous but in such concentration as at plants. Best ceramics for transistors has a pink color maybe it Al2O3
You're joking, right ?
Beauty of a forum, the answer is never far away => www.diyaudio.com/forums/pass-labs/121228-f5-power-amplifier-281.html#post3908184
Mr. Borin's design uses 230W bipolar OnSemi devices in the output stage (4302/4281).
http://oi43.tinypic.com/104ffi0.jpg
Alex picked Sanken power transistors with higher fT (A1303/C3284 ?), but those are 125W Pd devices.
By using oversized Al2O3 substrate insulators and clamping the power devices at the die center-line, he can compensate some of the 0.456 C/W difference in thermal resistance.
http://oi43.tinypic.com/104ffi0.jpg
Alex picked Sanken power transistors with higher fT (A1303/C3284 ?), but those are 125W Pd devices.
By using oversized Al2O3 substrate insulators and clamping the power devices at the die center-line, he can compensate some of the 0.456 C/W difference in thermal resistance.
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Paid Member
It's worse than you thought - I have seen two commercial amplifiers where it was claimed that having large 'eddy current' conductors near the signal path was detrimental. The power amp had thick insulators like shown above, the other was a pre-amp and the casework was all perspex with no metal.