Irf610 is too weak for ACA. I wonder why did you choose it?
Ok, so that's why it's getting so hot. Makes sense.
I've used IRF610 because I read somewhere that it can be used instead of the IRFP240, but now I see it's only for low current use like headphone amps.
Thanks for pointing that out. I'll get the proper component!
You can test IRFP240’s that come in for Vgs. The lowest Vgs ones will give lowest drop. You can always add DC step up boost after 19v smps to diall in any voltage you want (they step ups are available
Thank you for the Vgs info, X. Is it realistic to expect about 4V drop with IRFP240?
And now that you mention a DC boost converter. It was on my list of ideas. I'll keep that as a last resort.
Yes it is.
Thanks Juma
I can get IPFP250 quite easily and cheaply here. IRFP240 is more expensive (different supplier).
I have the boards and they look great but missing IRFP9240 at the moment. Will need to order some. It may be the perfect solution that could replace the typical qnty 8 x 33mF 25V caps in a Class A CRC supply. That's about $35 savings for least expensive CDE brand.
ok great x, all the best for your build!
regards
Pasi
A noob question. I would like to use the basic core cap Mx to feed ACAs running at 24V. I cannot seem to find a BOM. There are 3 resistors (10K, 220 and 1.5 Ohm). What should their safe Watt ratings be?
All 1/4W would be safe. On my PCB, you could fit 1/2W or Vishay RN60D resistors.
Hi prasi,
are there any hints to run this board with +/- 45 V DC?
Ok, the values of the caps have to be adapated. Here actually from 4700µF down to 1800µF/63V and 220µF down to 150µF/63V due to mechanical limitations in size. The whole board is feed by a 2x 30000µF 63V capacitor bank.
are there any hints to run this board with +/- 45 V DC?
Ok, the values of the caps have to be adapated. Here actually from 4700µF down to 1800µF/63V and 220µF down to 150µF/63V due to mechanical limitations in size. The whole board is feed by a 2x 30000µF 63V capacitor bank.
I’m wondering if this cap Mx might be the solution to an amplifier hum?
I have a Forte Model 6 amp that I decided to re-cap because of its age and a slight power supply hum. While I had it apart, I figured this was the perfect time to rewire the transformer to convert my Model 6 (class ab) to a Model 4 (class a) and adjust bias.
When put back together and fired up, the same hum was still present!
I also noticed the transformer itself emitted a mechanical hum/buzz. I disconnected the original trafo from the bridge rectifiers and wired up a different transformer outside of the original chassis to bypass the original trafo. This time, when turned on the hum was gone! So, my plan was to remove the trafo from the enclosure and make a separate power supply chassis. At that point I kind of lost interest and put the project on hold.
Back to Juma’s Easy Peasy, now I’m thinking I could remove the huge capacitors, install this cap Mx and a new trafo all in the original enclosure and keep it as a single enclosure unit instead of having a separate enclosure for the power supply.
I have a Forte Model 6 amp that I decided to re-cap because of its age and a slight power supply hum. While I had it apart, I figured this was the perfect time to rewire the transformer to convert my Model 6 (class ab) to a Model 4 (class a) and adjust bias.
When put back together and fired up, the same hum was still present!
I also noticed the transformer itself emitted a mechanical hum/buzz. I disconnected the original trafo from the bridge rectifiers and wired up a different transformer outside of the original chassis to bypass the original trafo. This time, when turned on the hum was gone! So, my plan was to remove the trafo from the enclosure and make a separate power supply chassis. At that point I kind of lost interest and put the project on hold.
Back to Juma’s Easy Peasy, now I’m thinking I could remove the huge capacitors, install this cap Mx and a new trafo all in the original enclosure and keep it as a single enclosure unit instead of having a separate enclosure for the power supply.
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