I went looking through my cap drawer and found a quad of these, so I have some 15,000uF on hand. Not sure how much I trust the 18,000 hour rating lol.
15000 be more than sufficient, or should I try to add some capacitance?
Dan
15000 be more than sufficient, or should I try to add some capacitance?
Dan
They do run somewhat warm. The board is pretty crowded with traces there, but I’ll see what I can do.
Dan
Another way is to cut some of the fins, so there is a gap between board and part of the heat sink. Some air flow will be achieved.
That is less risky for tracks.
The heat sink will need removal and machining, a file or small grinder, away from the work place, will do fine.
A 3 mm or so gap, about 15 mm long, should do.
That is less risky for tracks.
The heat sink will need removal and machining, a file or small grinder, away from the work place, will do fine.
A 3 mm or so gap, about 15 mm long, should do.
While I have been guilty of over-over-over-sizing caps(*), IMHO 15000 is way more than ample. Certainly in a Global Shortage. Any place but here, I would not be ashamed at 3,300uF*2. The difference in PEAK power is about a dB, and the waveform is a bit prettier (ramps instead of spikes).
(*) I remember a 2-6L6 20uFd amp hot-rodded to 470uFd, and a series of 300W 8417 amps with 8X the factory uFds. These may have been improvements but not 8X or 20X better.
Even 10,000 should be fine, unless you run very loud music at full volume all the time.
Use whatever you have at hand.
Oh, and more thing, check if the original location make them run hot for whatever reason.
If yes, think of shifting them to another location with extended wires like I said earlier.
Use whatever you have at hand.
Oh, and more thing, check if the original location make them run hot for whatever reason.
If yes, think of shifting them to another location with extended wires like I said earlier.
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20,000 uF per rail is what it takes for an an amplifier to produce full power (relative to mid band) at 20 Hz into 4 ohms. 10,000 uF is sufficient for full power at 8 ohms, or 40 Hz at 4 ohms. The only reason to insist on the full 20,000 uF is when high levels of low frequency are expected. For full range use, the 10,000 is plenty - and for infra sub use 20,000 may not be enough.
It is the same filtering action as if the amp was capacitively coupled, except that it is inside the feedback loop and only shows up at clipping. At sufficiently low frequency, dependent on the speaker impedance, the voltage on the supply falls between charging pulses and you get the early clipping which limits the undistorted low frequency power.
A badly worn bulging 20,000 uF cap can easily be outperformed by a brand new 10,000. If the 15,000’s fit I say use ‘em. Full power to 30 Hz at 4 ohms. Good enough for me and I’m a bass head who pushes amps to obvious clipping.
It is the same filtering action as if the amp was capacitively coupled, except that it is inside the feedback loop and only shows up at clipping. At sufficiently low frequency, dependent on the speaker impedance, the voltage on the supply falls between charging pulses and you get the early clipping which limits the undistorted low frequency power.
A badly worn bulging 20,000 uF cap can easily be outperformed by a brand new 10,000. If the 15,000’s fit I say use ‘em. Full power to 30 Hz at 4 ohms. Good enough for me and I’m a bass head who pushes amps to obvious clipping.
Btw I remenber a time where NAD putted Elna in some of their amps, as usual the purchasing dpt went there and the techs have nothing to say....
For information what are the former pitch between the cap legs of this huge 4 cm width 20 000 uF cap ?
All I see for now smells good : good Panasonic FC, some Nichicon that are good too. You can put KZ high v 100 V in small value near power transistor but their size and pitch are never near from the others brand.. Put some Rubycon and Elna in the mix to smooth out the sound as the FC are crystal clear for balancing the sound... too much of a same lythic may sound weird according the shematic. The big you chose are Cornell Dublier rigth ? Panasonic have big cap with long life here, Rubycon good too here, not limited list.
For information what are the former pitch between the cap legs of this huge 4 cm width 20 000 uF cap ?
All I see for now smells good : good Panasonic FC, some Nichicon that are good too. You can put KZ high v 100 V in small value near power transistor but their size and pitch are never near from the others brand.. Put some Rubycon and Elna in the mix to smooth out the sound as the FC are crystal clear for balancing the sound... too much of a same lythic may sound weird according the shematic. The big you chose are Cornell Dublier rigth ? Panasonic have big cap with long life here, Rubycon good too here, not limited list.