It seems like a good place to mount the Vfets.
I can't imagine them being made any differently in the future.
I believe that the TO-220 MOSFETs in the Supplemental Kit have exposed metal tabs which need to be insulated with a tiny sleeved plastic washer, an insulator between the back of the MOSFET and the heatsinks, and grease on both sides of the insulators for many insulators. Fortunately the Supplemental Kits DO include the tiny plastic sleeves, mica insulators, and there is plenty of grease in the Essentials Kit where you got your VFETS and brackets, etc.
6L6:
I changed the text about the TO-220 MOSFETs in your preliminary Build Guide in this thread to avoid confusion, of course feel free to edit the wording.
Variac
6L6:
I changed the text about the TO-220 MOSFETs in your preliminary Build Guide in this thread to avoid confusion, of course feel free to edit the wording.
Variac
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Hmm...was it so that the insulators/spacers were as big as the holes.
I had missed that.
Then I sort of understand why the holes are so big.
But I do not agree that it would be a particularly good place to mount the V-FETs.
After all I would think the area that heats up the most is the triangle inside Gate, Source and the further away screw hole.
Between that area and the bracket there is quite little aluminum.
Keeping in mind that even these bigger V-FETs are rated below 100W at some temperature (probably RT, I do not have the curve) and are derated by increasing temperature.
Just my opinion of course
I had missed that.
Then I sort of understand why the holes are so big.
But I do not agree that it would be a particularly good place to mount the V-FETs.
After all I would think the area that heats up the most is the triangle inside Gate, Source and the further away screw hole.
Between that area and the bracket there is quite little aluminum.
Keeping in mind that even these bigger V-FETs are rated below 100W at some temperature (probably RT, I do not have the curve) and are derated by increasing temperature.
Just my opinion of course
It seems like a good place to mount the Vfets.
I can't imagine them being made any differently in the future.
Nelson designed the bracket. Yes the holes are to accommodate the plastic tube insulators. I suppose they could be made smaller but those dimensions have been used for many years I believe. No, they won't change. It's not that hard to make your own version of the brackets though, it's really not very many holes....
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Where will you put them?
Remember that the bracket does 3 things - interface the UMS hole pattern on the HiFi2000 heatsinks, hold the PCB, and make a place to mount the TO-3 Vfets.
Your comment about heat would probably be true if we were running the Vfet at 100W dissipation, but in practice, the Vfet cases don't get much past 40C.
The capacitors, of course! That is the best method for reducing a 50 volt capacitor to a 35, right? Cut the unneeded portion off?
JK
I use the flat jigsaw blades to leave a gap beneath the resistors and the board. They're smooth enough that they slide right out when done, without damaging anything.
JK
I use the flat jigsaw blades to leave a gap beneath the resistors and the board. They're smooth enough that they slide right out when done, without damaging anything.
Well, it's not like you are planning to market and sell your own line of amps under the Sony label. And the amp does have Sony VFETS in it, so I think you are okay.
But definitely proofread for typos before sending the plate out for printing!
Great idea! Nicely done.
+1 with this technique we always see resistor reference on the pcb.
Yes very nice done
+1 with this technique we always see resistor reference on the pcb.
Yes very nice done
Exaccccctttlyyy. And it let's a little air flow under them too.
Thank you guys!
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Hi 6L6 these are what I'm including. What do you think?
Remember everyone, I'm happy to have questions and comments about the parts list as they are in the final stages and we don't want problems!
FQP3N30 Fairchild Semiconductor | Discrete Semiconductor Products | DigiKey
FQP3P20 Fairchild Semiconductor | Discrete Semiconductor Products | DigiKey
Remember everyone, I'm happy to have questions and comments about the parts list as they are in the final stages and we don't want problems!
FQP3N30 Fairchild Semiconductor | Discrete Semiconductor Products | DigiKey
FQP3P20 Fairchild Semiconductor | Discrete Semiconductor Products | DigiKey
Ok, no worries.
What parts are you supplying in the kits?
+1 with this technique we always see resistor reference on the pcb.
Yes very nice done
Above all, you can see the reference after the resistor has overheated.
This does not apply to 1Mohm resistors in solidstate amps, but it does apply to all resistors that can overheat. Good idea!
Where will you put them?
Remember that the bracket does 3 things - interface the UMS hole pattern on the HiFi2000 heatsinks, hold the PCB, and make a place to mount the TO-3 Vfets.
Your comment about heat would probably be true if we were running the Vfet at 100W dissipation, but in practice, the Vfet cases don't get much past 40C.
You are right, the bracket has the great feature of fitting the UMS, if I get such heat sinks. I know many here will use them.
They are running at about 25W dissipation was it?
100W with those devices is not even possible, but you are right, they could probably handle 50W with this setup.
I will think about making my own, but I will not likely do a better job.
Made a lateral fet class-AB amp for a couple of years ago. 8pcs of TO-3 devices with sockets.
It was enough work to make me tired and result was far from perfect
Hi,
I have listen my kit ! it's very good.
It sound soft and natural, like a 300b.
The sound is more precise and the bass are better than l'amp.
L'amp have a natural sound, a good "presence", I like it too.
The VFET part2 have a better definition, even with the compressions chambers.
So I will built a second kit, one for the medium and an other for the compressions chambers...
I thank everybody for the forum.
regards
I have listen my kit ! it's very good.
It sound soft and natural, like a 300b.
The sound is more precise and the bass are better than l'amp.
L'amp have a natural sound, a good "presence", I like it too.
The VFET part2 have a better definition, even with the compressions chambers.
So I will built a second kit, one for the medium and an other for the compressions chambers...
I thank everybody for the forum.
regards