| dkimble |
I am finally building a Pearl. (Got the parts almost 2 years ago. I am using the power supply schematic in the instructions. Transformers are Digikey TE70053, each with two 15VAC .5A secondaries in series. The trouble is that the supplies put out about 53 VDC unloaded, and exactly 50 VDC with a 1K ohm load (50 ma). Will this be too high for the regulators on the Pearl pcbs? Or will the load of the Pearls drag down the voltage further? Should I drop the voltage down further before the Pearl boards?
I will post pictures when this is finished.
Thanks in advance for any help!
Dave Kimble
dave.kimble@gte.net |
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| Nelson Pass |
| Wayne says no. |
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| dkimble |
Thanks!
I am super cautious when it comes to the initial powering up of a project. I've failed numerous "smoke tests" in my life!
Dave Kimble |
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| Nelson Pass |
Amplifier builders and vampire hunters have two traits in
common: Patience and Fearlessness .
:vampire3: |
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| Panelhead |
| quote: | Originally posted by dkimble
I am finally building a Pearl. (Got the parts almost 2 years ago. I am using the power supply schematic in the instructions. Transformers are Digikey TE70053, each with two 15VAC .5A secondaries in series. The trouble is that the supplies put out about 53 VDC unloaded, and exactly 50 VDC with a 1K ohm load (50 ma). Will this be too high for the regulators on the Pearl pcbs? Or will the load of the Pearls drag down the voltage further? Should I drop the voltage down further before the Pearl boards?
I will post pictures when this is finished.
Thanks in advance for any help!
Dave Kimble
dave.kimble@gte.net |
No sweat on this! I used a 50 watt dual thirty volt transformer. Under operating conditions it runs right at 50volts into the circuit board. Running those 10,000K caps at 50 volts places a lot of stored energy on the regulator.
The series regulator can handle a bunch more disapation than this. Mine barely heats up the sink.
I think the sonics are improved when running the input voltage up on a regulator like the one in the Pearl. The stored energy increases with the square of the voltage differential. A cap at 20 volts above the regulator stores 4 times the energy of one running at 10 volts above.
George |
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| moe29 |
| just be sure to use silver solder too :vampire: |
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| dkimble |
Yep! Silver solder was my first choice!
I am also using Arctic Silver II thermal compound on the regulator heatsinks, although it sounds like they don't really need it. I have used it on CPU heatsinks, noticeably increasing the heat conductance, but I have never heard of it used in audio. I imagine it would work well in power amps.
Dave Kimble |
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