I have either a 12 volt 40 amp supply or a 16 volt 10 amp supply .
not nearly enough to test the amp fully
not nearly enough to test the amp fully
Have you considered buying several server power supplies and at least one high-current battery?
Testing on the bench, even if it's not to absolute full power, makes it easier to find problems before the amp fails.
Do you have a flir thermal imager?
Testing on the bench, even if it's not to absolute full power, makes it easier to find problems before the amp fails.
Do you have a flir thermal imager?
A battery alone doesn't do much. After a minute or so, the parallel power supply will be at a steady full current output.
Server supplies are cheap. Look into buying several. Start a new thread to discuss them, if interested.
The flir thermal imagers (not IR spot thermometers) are somewhat expensive but allow you to see if all parallel components are operating at the same temperature. This is important, especially for large amps.
Server supplies are cheap. Look into buying several. Start a new thread to discuss them, if interested.
The flir thermal imagers (not IR spot thermometers) are somewhat expensive but allow you to see if all parallel components are operating at the same temperature. This is important, especially for large amps.
Installed the rectifiers and let the amp idle for 15 mins didn’t see anything heating up everything appears good .
The rail voltage is 144.3 and -142.6 at idle .
Is the rail voltage ok as it is with the 2 different readings?
The rail voltage is 144.3 and -142.6 at idle .
Is the rail voltage ok as it is with the 2 different readings?
Now I’m working on the output board of this amp . There are 2 10 ohm resistors R40,41 They are 2 watt resistors .
I ordered resistors without checking the package size and they sent me 10 ohm 2 watt resistors but a smaller package size resistor . Would these resistors still work ?
I ordered resistors without checking the package size and they sent me 10 ohm 2 watt resistors but a smaller package size resistor . Would these resistors still work ?
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Are they designated as miniaturized?
The diagram shows them as 15 ohm 1w.
If you're 100% sure that they're 2w, they should work but will likely run hotter than the originals. I'd install them slightly off of the board (1/4" or so) to prevent them from excessively heating the board.
The diagram shows them as 15 ohm 1w.
If you're 100% sure that they're 2w, they should work but will likely run hotter than the originals. I'd install them slightly off of the board (1/4" or so) to prevent them from excessively heating the board.
Sorry the originals were 1 watt the ones I ordered are 2 watt . The diagram shows 15 ohm resistors but when I got the amp used and blown there were 10 ohm resistors in it . Would you use the 10 ohm or the 15 ohm resistors ? Or doesn’t it make a difference
When you get the amp powered up, confirm that the input to the regulators is well below their maximum rated input voltage.
This may make the regulators run hotter than with 15 ohm resistors but if they're clamped to the heatsink, heating shouldn't be an issue.
This may make the regulators run hotter than with 15 ohm resistors but if they're clamped to the heatsink, heating shouldn't be an issue.
2 last questions on this amp .
the original thermistors on the output board had broken leads at the body of them .TH1,TH2 I forgot to order them so I’m gonna see if I can pull some off a junk board . Do I measure the resistance at room temp for the correct value ?
And I replaced pretty much everything on the output board even the audio driverboard is brand new .
Im kinda scared to power the amp up since if I overlooked something I can blow outputs almost instantly.
Is there anything I can do to prevent this from happening if I have an issues somewhere
the original thermistors on the output board had broken leads at the body of them .TH1,TH2 I forgot to order them so I’m gonna see if I can pull some off a junk board . Do I measure the resistance at room temp for the correct value ?
And I replaced pretty much everything on the output board even the audio driverboard is brand new .
Im kinda scared to power the amp up since if I overlooked something I can blow outputs almost instantly.
Is there anything I can do to prevent this from happening if I have an issues somewhere
Yes. Don't touch the body of the thermistor while measuring the value.
Yes. Have you followed the threads on using a low voltage supply produced by a few turns of wire around one of the transformers?
https://www.diyaudio.com/community/threads/4000-1.319174/page-4#post-5493113
https://www.diyaudio.com/community/...th-or-without-load.326262/page-2#post-5519590
Do you have a split power supply that will produce about ±15v?
Yes. Have you followed the threads on using a low voltage supply produced by a few turns of wire around one of the transformers?
https://www.diyaudio.com/community/threads/4000-1.319174/page-4#post-5493113
https://www.diyaudio.com/community/...th-or-without-load.326262/page-2#post-5519590
Do you have a split power supply that will produce about ±15v?
Read the relevant parts of those two threads. This will give you a virtually foolproof (nothing is perfect) way to reduce the risk to the output transistors since you'll have a fraction of the energy stored in the rail caps.
If you do this, you should also make sure that the mute/delay circuit is working before using full rail voltage.
If you do this, you should also make sure that the mute/delay circuit is working before using full rail voltage.
Unless I’m over looking them in the diagram . Do you happen to know the value of TH1,TH2 the thermistors that sit between the outputs
Is this the thermistors I need ?
https://www.mouser.com/ProductDetail/Littelfuse/KC203J2K?qs=gGwQ3tp6HcTZgXEQfxTgtA==
https://www.mouser.com/ProductDetail/Littelfuse/KC203J2K?qs=gGwQ3tp6HcTZgXEQfxTgtA==
Back to this amp . Not sure if it’s a fluke or what .
There are 2 separate boards in this amp. Power supply board and output board .
When the 2 boards are not connected together the power supply board will power up and idle perfectly. When I put the 2 boards together the amp shows no signs of life .
I added the Thermistors to the output board and the amp shows no signs of life after this . A
Any ideas what might cause this ?
There are 2 separate boards in this amp. Power supply board and output board .
When the 2 boards are not connected together the power supply board will power up and idle perfectly. When I put the 2 boards together the amp shows no signs of life .
I added the Thermistors to the output board and the amp shows no signs of life after this . A
Any ideas what might cause this ?