BossAreaForum

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I've now done the mod to my spare Caline CP205. For this one I've used a 1N4148 diode to "jack up" the output voltage to 9.6V on 5 of the 8 outputs. See here for how the 9.6V output is done: http://www.bossareaforum.com/Forum/viewtopic.php?f=13&t=10&p=8508&hilit=7809#p8508 . CP205_96c.jpg . CP205_96...

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I've solved the overheating problem permanently.

I de-soldered the 7809 regulators, ran 2 inch wires from the PCB to the regulator, and bolted the regulators to the power supply lid. The lid is 1.2mm Aluminium so is an adequate heatsink.

So far, so good.

They are very nice amps.

Nice! Thanks for the update.

Today I finally finished the repair of my friend's Roland JX-3P (needed a new power cord and a new backup battery, as well as intensive cleaning) and the KORG Poly-800 (backup memory modification, corroded battery spring replaced plus lots of cleaning and filter calibration). Both units are working...

Zerksies wrote: ↑

Wed May 15, 2024 2:53 pm

Are the preamps tubes under that silver plate? I'm only seeing one but the schematic is showing five

Yep.

Bottom line - at 300mA the 7809 regulator is dissipating 1.5W which is enough to cause a temperature rise that pushes the 7809 into thermal shut-down. With high draw pedals (e.g. my Strymons) I am experiencing random drop-outs due to over-temperature cut-out of the regulators. Running pedals with m...

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