0
\$\begingroup\$

I pulled the preamp out of a broken guitar combo amp. The preamp has positive, negative, and ground leads for powering it at +/-25V. I would like to power the preamp with a dual channel benchtop power supply to see if it works. Is there any grounding or safety issue with plugging the DC-powered preamp into a power amp that is powered from an AC outlet?

With nothing connected to any power source, I verified that there is continuity from the preamp chassis all the way to the ground pin of the power amp's plug, so I think everything should be grounded safely. I also verified that the power supply's DC terminals are isolated. So everything seems correct, but I am still learning, so I wanted to double check before proceeding.

\$\endgroup\$
2
  • \$\begingroup\$ What's the benchtop power supply's make and model? \$\endgroup\$
    – BobT
    Commented Feb 7, 2020 at 4:29
  • \$\begingroup\$ It's a Topward 6603D. \$\endgroup\$
    – meanerelk
    Commented Feb 7, 2020 at 5:15

1 Answer 1

Reset to default
1
\$\begingroup\$

It should be fine. Just make sure that:

  1. You select a sensible current limit at the power supply based on the maximum current expected to be drawn by your preamp

  2. You connect one the terminal of each output channel together: -25 GND---GND +25. In a benchtop power supply each output channel is isolated from the others.

  3. Make sure not no mix up +25V and -25V :)

\$\endgroup\$
4
  • \$\begingroup\$ Thanks for letting me know! I feel much better about attempting this now. The power supply has a serial tracking mode that shorts the - master terminal to the + slave terminal, so I shouldn't have to worry about manually connecting them. \$\endgroup\$
    – meanerelk
    Commented Feb 7, 2020 at 14:35
  • \$\begingroup\$ I'm glad that I could be of assistance, please mark the answer as "accepted" if you found the info useful :) \$\endgroup\$
    – Ken Grimes
    Commented Feb 7, 2020 at 15:52
  • \$\begingroup\$ Test successful! Now I need to build an appropriate power supply. \$\endgroup\$
    – meanerelk
    Commented Feb 8, 2020 at 5:02
  • \$\begingroup\$ Happy to hear that :). Have fun! \$\endgroup\$
    – Ken Grimes
    Commented Feb 8, 2020 at 11:49

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.