sov,
That's quite the tight layout in the small chassis. That in itself is not an issue. However perhaps the placement of the mosfets at the back end of the chassis/heatsink may be an issue with heat dissipation. I think the heatsinks at the front of the chassis will probably not see much of the heat, with the heatsinks at the back taking the brunt of the heat.
I suppose the distribution of heat will show itself once you start applying power and ramping up the current.
If heat dissipation becomes an issue, I suggest rearranging the capacitors and choke so that the mosfets can be moved to a central location to take advantage of the front heatsinks. A piece of aluminum may be needed on each side to help distribute the heat to the front and back heatsinks.
That's quite the tight layout in the small chassis. That in itself is not an issue. However perhaps the placement of the mosfets at the back end of the chassis/heatsink may be an issue with heat dissipation. I think the heatsinks at the front of the chassis will probably not see much of the heat, with the heatsinks at the back taking the brunt of the heat.
I suppose the distribution of heat will show itself once you start applying power and ramping up the current.
If heat dissipation becomes an issue, I suggest rearranging the capacitors and choke so that the mosfets can be moved to a central location to take advantage of the front heatsinks. A piece of aluminum may be needed on each side to help distribute the heat to the front and back heatsinks.
Attachments
Thank you for the concern. I have 10mm plate to help with heat dispersion. When I first started it up at 2A the heat felt evenly over hole side. If a thick aluminum bar from side to side do wonders I will consider it.
I have to take it apart for change of resistor MU-R1 anyway.
I’m a bit curious how you did it. Do you have any illustrations?
edit: sorry, I didn’t see your suggestion at first.
I have to take it apart for change of resistor MU-R1 anyway.
I’m a bit curious how you did it. Do you have any illustrations?edit: sorry, I didn’t see your suggestion at first.
Attachments
Last edited:
I did not realize that you have a 10mm plate. That would definite help, but I would expect the part of the heatsink at the back of the chassis would still get hotter than the part of the heatsink at the front of the chassis. That can be tested by running the amp for long enough to see if heat equilibrium is reached and no part of the heatsink is too hot.
After recovering from a minor cerebral prolapse I added pair of resistors and changed MU-R1 and MU-R2 to original values. Upper, puck side, 0R3 and lower 0R2.
Regarding bias I dare not explain it in other way than:
“this part is biased to Iq of 2A9 with Iq setting of Mu Follower, while output node is biased to half rail value with setting of P1”
I thought l’ll go with 2A9 and check long term heat. When I thought F4 was the end game for me, the Lazy Singing Bush open up new music dimensions with rock solid control. I love it! Turtle Iron Pumpkin in front is set on 4dB gain.
Regarding bias I dare not explain it in other way than:
“this part is biased to Iq of 2A9 with Iq setting of Mu Follower, while output node is biased to half rail value with setting of P1”
I thought l’ll go with 2A9 and check long term heat. When I thought F4 was the end game for me, the Lazy Singing Bush open up new music dimensions with rock solid control. I love it! Turtle Iron Pumpkin in front is set on 4dB gain.
Attachments
