XA252 SET is being prepared for a 1970’s Bose 1801 chassis. I will go for stacked dual donuts / dual mono into CRCRC power supplies. When the amp is working I will turn my attention to making the meters and LED dance on the front panel.
Attachments
First channel power up 🙂 1.2 A bias pucks at 52 degC.
I measure T1 and T5 at 64-65 degC, is that an expected temperature? (27 degC RT)
I measure T1 and T5 at 64-65 degC, is that an expected temperature? (27 degC RT)
T1, T5
I=0V65/120~5.5mA
heat=5.5mA*rail=190mW
for BC639, 0.83W part, nothing to write home about
I=0V65/120~5.5mA
heat=5.5mA*rail=190mW
for BC639, 0.83W part, nothing to write home about
What capacitors did you use in power supply? Scouring digikey and mouser aren't turning up any 50 volt 33k caps. Or not kept in stock, long leed time. Since Panasonic stopped making my favorites, and the stash is dry short of cannibalizing existing power supply.
Russellc
I'll be using Antek 600VA 28+28 volt trans, figuring 34-35 volt rails. Now that Panasonic not making them what next! Saw some CDE, but not available with digikey or mouser. I will check Newark.
Russellc
Russellc
Randy has a bunch of Cornell dublier caps listed in his build guides. I suspect that's probably what he used.
Digikey Part number 338-3814-ND
I bought these months ago. Mike is right, I do tend to go for CDE.
75 currently in stock at DK
What is everyone using for output device thermal pad? I assume sheets of keratherm and cut own? What type of keratherm ? (Mosfet version)
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no need for any pad, just thermal paste
metal base isn't electrically connected to mosfet itself
metal base isn't electrically connected to mosfet itself
Sweet. I was hoping that, not seeing any mention during everyone's build. Time to restock hook up wire.
This stuff works good and is convinient:
https://www.amazon.com/gp/product/B01M7NWX7A/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
https://www.amazon.com/gp/product/B01M7NWX7A/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1