diyAudio (
-   Instruments and Amps (
-   -   same transformer, different voltages? (

calx44 25th September 2012 07:07 PM

same transformer, different voltages?
I had a post on here not so long ago about making a guitar amp. I have a preamp schematic that runs off 15 volts and a power amp chip that works best off about 25V. Can i use the same transformer/power supply? If so how?
Really basic question i know...

Thanks in advance

sreten 25th September 2012 07:38 PM


You tap off and regulate the high current 25V rails down to 15V
for the low current supplies for the preamp, leaving the 25V rails
directly connected to the power amplifier.

rgds, sreten.

Assuming you don't use a multitapped transformer ...

calx44 27th September 2012 06:11 AM

OK, thaks for that. Makes sense really when I think about it.

calx44 1st October 2012 06:49 PM

I should have asked this before really, but how can i do this? with a voltage divider?

sreten 1st October 2012 07:44 PM

1 Attachment(s)

Zener diodes or regulators, you can't use a voltage divider for power
supplies. Look up some schematics of amplifiers to see how its done.

rgds, sreten.

calx44 2nd October 2012 04:38 PM

Thanks. I have never really done anything with power supplies before, but I thought a divider wouldnt really work.

Minion 7th October 2012 04:49 PM

Depending on yer preamp you might be able to run it off of 25v.
If it is an opamp preamp and runs off a single supply you can most likely run it off of 25v , most opamps can run off of 30v or more and you will get increased headroom useing a higher voltage supply.


Maybe post a schematic of your preamp design.

All times are GMT. The time now is 07:20 PM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 18.75%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio