Yes it will do the job but technically you only need a DPST. I have this one in my cart that seem just perfect : https://www.mouser.ca/ProductDetail/CW-Industries/GRS-4021-0022?qs=qit5zruqE%252B%2FQTDoTW5oGZg%3D%3D
Of course I have to wait till the boards are available, to try, but, well . . I can't stop thinking.
The VFET pt2 is for the N-Channel in common source, with the 2SK82. 'It is planned that there will also be kits for those who already have the 2SK82 or 2SJ28'
What about the 2SK180/K182? The biasing in the schematic should work for those devices too starting from a V+ of around 40V, and if you want the DC at about again to be equal to around 1.5A, that can be arranged too with the bias of the IRF250 adjusting R3 probably. There is just a big off-board component.
And probably 'the end performance of the 2SK180 N channel amplifier in common source is virtually identical to that with the 2SK82'.
- Or will there be a common drain version SIT for the 2SK180 family of devices, being more appropriate?
The VFET pt2 is for the N-Channel in common source, with the 2SK82. 'It is planned that there will also be kits for those who already have the 2SK82 or 2SJ28'
What about the 2SK180/K182? The biasing in the schematic should work for those devices too starting from a V+ of around 40V, and if you want the DC at about again to be equal to around 1.5A, that can be arranged too with the bias of the IRF250 adjusting R3 probably. There is just a big off-board component.
And probably 'the end performance of the 2SK180 N channel amplifier in common source is virtually identical to that with the 2SK82'.
- Or will there be a common drain version SIT for the 2SK180 family of devices, being more appropriate?
Pretty sure I read about someone, at least talking about it, but damned if I remember where...
JT
This is about V1, but here ya go. EDIT:Article - Sony VFETs part 1
JT
This is about V1, but here ya go. EDIT:Article - Sony VFETs part 1
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I want to repeat all he appreciation we all have for the hard work and generosity that made this kit possible. If you have not ordered a DPST rocker switch yet, I suggest you opt for one that has a DC rating. Digikey has in stock GRSV-4021-006, and Mouser has GRS-4021-0004. They may give a slightly longer life. However, if you already have another DPST switch, go ahead and use it and do not worry about it.
The switch that was supplied with the kit, a SPST, will still work if you do not have a turn-on/off thump problem. I remember a similar situation with the SMPS on the ACA, but the thump was so small on my speakers that it was far from objectionable. Maybe high-efficient speakers have more thump. Anyway, disconnecting the AC side (unplug the AC cord, or switch off the AC) greatly reduced whatever thump there is. 6L6 once suggested an AC power cord that had a switch built in, but I cannot find it.
If you do not think you have much of a thump problem, you can also try the amp without the thump-suppression section connected. Find the two 18G RED wires from the O+ pads on the PS board and disconnect them from the speaker posts, and tape the ends, or do not install these two red wires. You may be just fine with the small thump.
However, you do need to do something if you are using the supplied SPST switch, because the NC contacts on the relay will continue to short the speaker outputs S to G until the relay is energized (from a second pole on a DPST switch) or the O+ wires are disconnected.
The switch that was supplied with the kit, a SPST, will still work if you do not have a turn-on/off thump problem. I remember a similar situation with the SMPS on the ACA, but the thump was so small on my speakers that it was far from objectionable. Maybe high-efficient speakers have more thump. Anyway, disconnecting the AC side (unplug the AC cord, or switch off the AC) greatly reduced whatever thump there is. 6L6 once suggested an AC power cord that had a switch built in, but I cannot find it.
If you do not think you have much of a thump problem, you can also try the amp without the thump-suppression section connected. Find the two 18G RED wires from the O+ pads on the PS board and disconnect them from the speaker posts, and tape the ends, or do not install these two red wires. You may be just fine with the small thump.
However, you do need to do something if you are using the supplied SPST switch, because the NC contacts on the relay will continue to short the speaker outputs S to G until the relay is energized (from a second pole on a DPST switch) or the O+ wires are disconnected.
That is next in line after a couple other alternate front ends. I'll be writing it up in the earlier VFET builders thread.
The trick to 'rolling' the signal transformer is to get the right amount of gain. I have already found that I like a couple more dB in the front end after experimenting with the Dreadnought front end. Even so, there aren't any other readily available signal transformers that offer the 1:5 gain of the Edcor.
Currently on deck is the Bulwark front end, which should be making music later today, with the standard Edcor. Since I happened to get four PCBs with my order from Digikey, the second pair of boards will get stuffed with a pair of Jensens. Since these can only be configured for 1:1 or 1:2, I will need to use the Bulwark amplifier's ability to get better than unity gain. Then there is the matter of building a mezzanine board to translate the Edcor pinout to the Jensen..