Not required. Upper device is FQA40N25 and lower is FQA36P15; complementary but not matched.
HD
I don't have a preference for any.I am only in the planning stages. That is why I am asking those who have more experience.
This is Class A and outputs are heavily loaded, to about 50W each.
A 240/9240 is rated to 150W each so running at one third their spec.
The FQA pair are rated at 280W and should last just a little longer particularly if passively cooled where junction temps could be a little higher. With electronic devices MTBF in hours halves with every increase of 11C (Arrhenius rule) so a lighter loading is preferred.
HD
A 240/9240 is rated to 150W each so running at one third their spec.
The FQA pair are rated at 280W and should last just a little longer particularly if passively cooled where junction temps could be a little higher. With electronic devices MTBF in hours halves with every increase of 11C (Arrhenius rule) so a lighter loading is preferred.
HD
Actually for 8ohm speaker, total Impedance is higher than 8 ohm then current can not get limited by Q4( R15,R16) meaning no have clipping even with 4 ohm speaker .
It appears that the question below was asked a few times before, but I didn't see any specific answers....
Can the C3503D be substituted with the 2SC3503E or KSC3503ESTU parts? I'm guessing the answer is "yes", but looking for confirmation. I'm guessing if so, I'm then the obtainable KEC part, KTC3503-Y would also be a good substitute.
Thank you in advance!
Can the C3503D be substituted with the 2SC3503E or KSC3503ESTU parts? I'm guessing the answer is "yes", but looking for confirmation. I'm guessing if so, I'm then the obtainable KEC part, KTC3503-Y would also be a good substitute.
Thank you in advance!
Excellent, thank you for the reply @AKSA !!!
KEC part is a TO-126 package. Luckily I have these on hand.
KEC part is a TO-126 package. Luckily I have these on hand.
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Hi Everyone
Another AN4R brought to life on the testbed.
Still have a few things to iron out, but they work and was playing music last night for about 45mins before I had to go to bed.
2x Antek AS-3220
2x SLB
2x AN4R running 0.12R at R141/R142
TTC004B at V113/V115 (I'm not sure why I chose TTC004B here, as I do have KSC3503DS on hand, got them from Digikey)
BD140 at V131
KSA992 at V111/V112
FQA40N25 for the N-Channel MOSFET
IXTQ36P15P for the P-Channel MOSFET (FQA36P15P not readily available at Mouser)
22R at R113 because I didn't read carefully, have -35mV at both speaker terminals which isn't too bad
I have about 125VAC at the wall outlet, AS-3220 22VAC unloaded, SLB's outputs are 27.5VDC unloaded, about 24.5VDC loaded. TP-Link multiplug power meter at the wall outlet measures 376W
For now, the heatsinks on top of the SLB are not a concern temp wise with the active cooling, need to see what it does without the active cooling. I'll likely have an a aluminum plate with standoffs to mount the heatsinks above the caps, not sure yet as I haven't decided on the chassis.
One thing I did notice though was that the right channel (38C) runs significantly cooler than the left (53C) channel. Not sure why, perhaps its the temp probes. Will swap the temp probes around tonight to check. My room is about 17C ambient currently, around 23C in summer.
Sounds good, have a bit of hum, but I need to sort out the grounding
In progress, SFPP v2.3 EZ
Still to connect, SSR v2.3
Having fun with this project
Another AN4R brought to life on the testbed.
Still have a few things to iron out, but they work and was playing music last night for about 45mins before I had to go to bed.
2x Antek AS-3220
2x SLB
2x AN4R running 0.12R at R141/R142
TTC004B at V113/V115 (I'm not sure why I chose TTC004B here, as I do have KSC3503DS on hand, got them from Digikey)
BD140 at V131
KSA992 at V111/V112
FQA40N25 for the N-Channel MOSFET
IXTQ36P15P for the P-Channel MOSFET (FQA36P15P not readily available at Mouser)
22R at R113 because I didn't read carefully, have -35mV at both speaker terminals which isn't too bad
I have about 125VAC at the wall outlet, AS-3220 22VAC unloaded, SLB's outputs are 27.5VDC unloaded, about 24.5VDC loaded. TP-Link multiplug power meter at the wall outlet measures 376W
For now, the heatsinks on top of the SLB are not a concern temp wise with the active cooling, need to see what it does without the active cooling. I'll likely have an a aluminum plate with standoffs to mount the heatsinks above the caps, not sure yet as I haven't decided on the chassis.
One thing I did notice though was that the right channel (38C) runs significantly cooler than the left (53C) channel. Not sure why, perhaps its the temp probes. Will swap the temp probes around tonight to check. My room is about 17C ambient currently, around 23C in summer.
Sounds good, have a bit of hum, but I need to sort out the grounding
In progress, SFPP v2.3 EZ
Still to connect, SSR v2.3
Having fun with this project
Attachments
Maybe they haven't pressed the mosfets properly, take a look there. I really like these heatsinks.
"""have a bit of hum"""
Try to route the mosfet wires away from the input capacitor.
Thanks Nikos. Will check it again later tonight. I've been lurking here for a while, really like your build. Where did you get those fan shrouds that you mounted on your rear panel?
Hi Nikos
Yes this is the one I’m currently using with the diamond shaped copper pad. There is a better one I believe, it has a larger rectangular copper plate, which may be better for heat dissipation. When searching for it, look for the part no. CN-0FD841-73304, Vunce mentioned it in post #682. I only realized after I bought them that there were two versions of the fd841
Yes this is the one I’m currently using with the diamond shaped copper pad. There is a better one I believe, it has a larger rectangular copper plate, which may be better for heat dissipation. When searching for it, look for the part no. CN-0FD841-73304, Vunce mentioned it in post #682. I only realized after I bought them that there were two versions of the fd841
I think there won't be a big difference in terms of temperature, it's just that this one with the square shape maybe takes three mosfets together.I recently bought my own diamond-shaped ones. Knowing their shape...Here in Greece, they are very difficult to find.