I used IRF520/9520 for a short time in my prototype and didn't hear an appreciable difference once I swapped to IRFP140/9140, though I also wasn't listening for that and didn't do an A/B comparison. I think there is value there if you're interested in finding the subtle differences.
eBay is an excellent place to buy shoulder washers, silicone insulators, and bolt-nut-splitwasher-starwasher combinations. If you are willing to search and evaluate for yourself. If unwilling, Mouser has all of the requisite pieces but you still need to search for yourself.
Going by the listed specs, I only found a single insulating shoulder washer on DigiKey that will fit a TO-220. As Mark says, eBay and Ali are reasonable sources for that type of component, but you do have to check dimensions carefully. I've got more than one bag of shoulder washers for TO-220s where the length below the shoulder is greater than the typical thickness of the transistor tab, so they don't actually clamp the transistor to the heatsink.
There are a few different styles of clamping bars that bypass the need for shoulder washers by pressing on the body of the transistor. I've been meaning to buy a variety to try out, though maybe not on this particular amp / chassis.
There are a few different styles of clamping bars that bypass the need for shoulder washers by pressing on the body of the transistor. I've been meaning to buy a variety to try out, though maybe not on this particular amp / chassis.
My initial idea was to mount the psu inside the amp box. But after putting the box together with the amps in place, I realized that it will be to tight when i add in the preamp boards.
Soo out with the psu. I will make a small aluminium block-off plate where the iec 230 V connector / fuse block should have been mounted. I will then drill a hole in that plate to mount the psu connector.
Also have to make up a mount for my power switch, the hole in the front of the box is to large. Should be easy enough on the lathe.
Soo out with the psu. I will make a small aluminium block-off plate where the iec 230 V connector / fuse block should have been mounted. I will then drill a hole in that plate to mount the psu connector.
Also have to make up a mount for my power switch, the hole in the front of the box is to large. Should be easy enough on the lathe.
Thanks,but aluminum isnt that hard to machine.
BUT after thinking some more, i have a new plan.
Hopefully i will have this done this evening.
Holes (from the right) right hand led, preamp volume pot, 2-way input selector switch, power switch, 1/4" Jack socket and lastly left hand led.
I can then use the left hand large hole for the 1/4" Jack...
Ok, finished (for now) the case.
On the front panel, left to right:
Left channel led pilot light, empty hole for 1/4" headphones Jack, power switch, 2 channel input selector switch, empty hole for the volume pot knob, right channel led pilot light.
The led pilot holes are 2 mm, on the bakside they are countersunk with a 5mm drill bit. Then, the leds are glued in with some cyano glue with a little dash of cicker.
Backside are 4 red/black (right/left) channel rca connectors, then the 4 speaker terminals. In the middle, the psu connector and on top a switch for the linear / harmonic feature. There are 8 screws in the top cover, so I copied the original idea of an external switch...
Hopefully tomorrow some wiring...
On the front panel, left to right:
Left channel led pilot light, empty hole for 1/4" headphones Jack, power switch, 2 channel input selector switch, empty hole for the volume pot knob, right channel led pilot light.
The led pilot holes are 2 mm, on the bakside they are countersunk with a 5mm drill bit. Then, the leds are glued in with some cyano glue with a little dash of cicker.
Backside are 4 red/black (right/left) channel rca connectors, then the 4 speaker terminals. In the middle, the psu connector and on top a switch for the linear / harmonic feature. There are 8 screws in the top cover, so I copied the original idea of an external switch...
Hopefully tomorrow some wiring...
