6moons
Have you seen the latest article on First watt. Interesting to see pictures of members and the listening area. Neat method to swap out full range drivers. Pleased to see the modest 15 in eminence woofer. Got my first F5 monoblock PD boards up and running just the last couple of days. Printed out this particular forum when it was over 750 pages. Great reading thanks to all of you.
Have you seen the latest article on First watt. Interesting to see pictures of members and the listening area. Neat method to swap out full range drivers. Pleased to see the modest 15 in eminence woofer. Got my first F5 monoblock PD boards up and running just the last couple of days. Printed out this particular forum when it was over 750 pages. Great reading thanks to all of you.
Hi,
Do you think these heatsinks will cut it for the F5 (I plan on two per channel, one for each transistor). I can't find any specs but they are pretty cheap, ~4 dollars each.
They are 12" x 3.5" x 1" fins, and the mounting surface is ~2.8mm thick. They run very cool with the ~30 watts dissipation of a pair of LM3886 chipamps. I thought they would work for the heatload of one transistor, do you think they'll cut it?
Do you think these heatsinks will cut it for the F5 (I plan on two per channel, one for each transistor). I can't find any specs but they are pretty cheap, ~4 dollars each.
They are 12" x 3.5" x 1" fins, and the mounting surface is ~2.8mm thick. They run very cool with the ~30 watts dissipation of a pair of LM3886 chipamps. I thought they would work for the heatload of one transistor, do you think they'll cut it?
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Not enough, eh? Not even for 31 watts of a single transistor? I'll probably have to back off the bias then. Thanks for the input...
Hi,
note how thin the back plate of those sinks are.
They are designed to take multiple output devices.
An F5 will cook it's pair of output devices on this sink.
note how thin the back plate of those sinks are.
They are designed to take multiple output devices.
An F5 will cook it's pair of output devices on this sink.
Power supply in separate case
If going with the power supply in it's own separate case, would any issues be created since the Filter caps would all be in the power supply case -- far from the amp itsel?
Is it more ideal to have at least the last bank of filter caps inside the amplifier case?
Thanks,
Steve
If going with the power supply in it's own separate case, would any issues be created since the Filter caps would all be in the power supply case -- far from the amp itsel?
Is it more ideal to have at least the last bank of filter caps inside the amplifier case?
Thanks,
Steve
I would always recommend that the first stage of smoothing caps be kept very close to the rectifier and that in turn must be kept very close to the transformer. Even doing this is not sufficient, the loop area of the transformer to rectifier cables must be minimised and the loop area of the rectifier to smoothing cables must be minimised.
If one adopts a CRC or CLC PSU then the second stage of smoothing can be separated from the first stage.
The inherent resistance of low area copper in the umbilical cord can be used as the R between the two banks of smoothing caps. This may just be sufficient to avoid adding adding resistors into the CRC.
So to answer the question: splitting the C into one bank very close to the transformer and the second bank very close to the amplifier makes very good sense.
On a final note, the amplifier bank of caps has a much higher impact on the amplifier sound. The first bank has very little influence of the final sound of the amplifier. This may help to determine how you allocate budget to the two halves of the CRC.
If one adopts a CRC or CLC PSU then the second stage of smoothing can be separated from the first stage.
The inherent resistance of low area copper in the umbilical cord can be used as the R between the two banks of smoothing caps. This may just be sufficient to avoid adding adding resistors into the CRC.
So to answer the question: splitting the C into one bank very close to the transformer and the second bank very close to the amplifier makes very good sense.
On a final note, the amplifier bank of caps has a much higher impact on the amplifier sound. The first bank has very little influence of the final sound of the amplifier. This may help to determine how you allocate budget to the two halves of the CRC.
the comment on "designed for multiple devices" to each sink still applies.
One device on each sink will cook the device if asked to dissipate high power. Exactly what an F5 will do to it's pair of output devices.
A four pair with four devices each dissipating ~5W would make much more sense for these sinks.
One device dissipating ~30W on one sink is a nonsense for reliability.
One device on each sink will cook the device if asked to dissipate high power. Exactly what an F5 will do to it's pair of output devices.
A four pair with four devices each dissipating ~5W would make much more sense for these sinks.
One device dissipating ~30W on one sink is a nonsense for reliability.
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Separate power supply
Hi Andrew,
If going with that scenario - separate case for power supply with first bank of caps close to rectifiers in the power supply case and second set of caps in amplifier case - where would the optimum location of the inductors be - if using CLC - by the first bank of caps wiht the poers upply case or the second set of caps in the amp case?
Thanks,
steve
Hi Andrew,
If going with that scenario - separate case for power supply with first bank of caps close to rectifiers in the power supply case and second set of caps in amplifier case - where would the optimum location of the inductors be - if using CLC - by the first bank of caps wiht the poers upply case or the second set of caps in the amp case?
Thanks,
steve
@Andrew: Thanks 🙂 Would adding a 1/3 inch copper heatspreader (say 3x4") under the transistor help, in that case? I could couple the transistor directly to the copper and use an insulator between the copper and the sink...
I could also look at getting sinks meant for industrial IGBTs, but mounting the F5 on those is going to be a challenge.
I could also look at getting sinks meant for industrial IGBTs, but mounting the F5 on those is going to be a challenge.
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Power Supply
Hey Andrew,
One other thing I did not quite understand -- in your above quote, what do you mean by "loop area"?
Thanks,
Steve
Hey Andrew,
One other thing I did not quite understand -- in your above quote, what do you mean by "loop area"?
Thanks,
Steve
Hi Sekess
I am doing the exact same thing with all of my amps.
I put a bank of capacitors in the power supply case and then another bank of capacitors in the amplifier case.
It would be best to put the inductors well away from the amplifier because of the magnetic field generated by the inductors. So I would put them in the power supply case.
I am doing the exact same thing with all of my amps.
I put a bank of capacitors in the power supply case and then another bank of capacitors in the amplifier case.
It would be best to put the inductors well away from the amplifier because of the magnetic field generated by the inductors. So I would put them in the power supply case.
Power Supply
Hi Thanh,
Yea, that was the way I was leaning.
I figured it was a good idea to keep the inductors away from the amps. But at the same time I wasn't sure if the umbilical would be picking up noise and that the inductors would have been better placed after the umbilical (in the amplifier case).
Thanks,
Steve
Hi Thanh,
Yea, that was the way I was leaning.
I figured it was a good idea to keep the inductors away from the amps. But at the same time I wasn't sure if the umbilical would be picking up noise and that the inductors would have been better placed after the umbilical (in the amplifier case).
Thanks,
Steve