If I'm going to the trouble of laying out a board and the expense of getting them made( I know cost isn't much these days with all the Chinese board houses), then I'm going to use the best quality transistors and ICs that I can find even though I know that there's no guarantee that they will "sound" better.
I think fake transistors may "work" in a lot of circuits, but may not measure as well as originals. The differences may be too small to be audible...I don't know as I've never done a transistor comparison before.
I buy more op-amps than I do transistors.
The Chinese are masters at "relabeling" a cheap op-amp to make it look like the real thing.
So I don't trust most Asian sellers when it comes to solid state devices.🙂
Good points Jay. I agree that if I had a critical application where I HAD to have high reliability or ultimate performance - I would buy from Digikey/Mouser/Newark where they certify source is genuine. It's not worth it to take a chance if critical. From standpoint of having fun making DIY amps that like designs here - and Apex churns out a new one every few weeks - using low cost parts is part of the fun for me. There is something satisfying about listening to an amp that sounds great and that costs a total in parts (not including PSU or heatsink) of under $8. For the hobbyist - spending $3 on a bag of 50 TO92's is not big deal if they don't turn out to be as good as the real ones.
I think there is a place for low cost parts. Just as there is a place for high quality genuine parts.
I still buy my IRFP240/9240 from Digikey - because they are well priced and convenient. The conformance certificate says IRFP240 is made in China. 🙂
I think there is a place for low cost parts. Just as there is a place for high quality genuine parts.
I still buy my IRFP240/9240 from Digikey - because they are well priced and convenient. The conformance certificate says IRFP240 is made in China. 🙂
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I was looking for the LEDs but I guess this version is the first version which doesn't have LED's as gate voltage reference. Could you please update the layout to the latest version?
Thanks
Damn that was fast! Mr. Mile has a good eye for layout mistakes. Perhaps he will chime in.
One suggestion...I would increase the hole size of the zener pads. Zener leads are quite a bit larger in diameter than regular diodes.
No, not yet. Not for lack of trying though. I just can't fire it up without a real heatsink. Mine are all 150mm wide and this one needs to be 180mm at least. They are on order and will be here in a few days. In the meantime I am building a 300va 49v PSU. Running some sims for a CRCLC filter with 4700uF banks. Rolled some 0.5mH toroid chokes with 18ga magnet wire. So it's making progress.
Dear olaf,
Please be kind enough to post the schematic also alongside, every time you post a PCB layout. Saves a lot of posts later.
--gannaji
I've never heard of the MPQ6700. After doing a little research, the Fairchild version appears to be 4 transistors in a 16 pin SOIC package.
Maybe one of the Sprint experts here can incorporate it into one of their layouts.
Yes, heatsinksusa.com sells them by the inch. The 7.28in wide one I am getting is $2.63/in.
7.280" Wide Extruded Aluminum Heatsink - HeatsinkUSA
Thank you for the link. So you're getting the 7.28" x 7" heatsink?
I would like to get 2 good-sized sinks and use them for different boards.
I would like to get 2 good-sized sinks and use them for different boards.
7.28in wide x 4.0in tall is enough sink for my application.
I got this tip from Jwilhelm who sold me the VHex boards. I think a lot of folks know about it.
I got this tip from Jwilhelm who sold me the VHex boards. I think a lot of folks know about it.