Solid State Guitar Amp Forum | DIY Guitar Amplifiers

Solid State Amplifiers => Amplifier Discussion => Topic started by: NPreston on February 16, 2019, 09:26:46 AM

Title: Power transformer questions
Post by: NPreston on February 16, 2019, 09:26:46 AM
I'd like to build a power amp somewhere in the range of 30-100 Watts running an 8 ohm cab. When it comes to building a +/- dual rail power supply, I am thinking I will need a center tapped secondary on the transformer.. (or is dual secondary coils better?? if so why?)

Does this transformer seem adequate? Under powered? Overkill??
What would be the maximum wattage amp one could safely build using this transformer?
https://www.digikey.ca/products/en?keywords=166M72

What models of transformers are others using for their power supplies, and what sort of wattages are they achieving??

I havn't messed around with transformers at all since a few labs 15+ years ago in college..  Know enough to not get myself killed, but don't want to waste a ton of money on the wrong transformers either..
Title: Re: Power transformer questions
Post by: Loudthud on February 16, 2019, 03:53:31 PM
The 166M72 does have a center tap according to the data sheet. You'll need that to make +/- 50V or so rails. At 216VA it's a little oversized but it will run cool even at 50Hz. Could be used for roughly 200W @ 4 Ohms.
Title: Re: Power transformer questions
Post by: joecool85 on February 22, 2019, 02:09:23 PM
I'd like to build a power amp somewhere in the range of 30-100 Watts running an 8 ohm cab. When it comes to building a +/- dual rail power supply, I am thinking I will need a center tapped secondary on the transformer.. (or is dual secondary coils better?? if so why?)

Does this transformer seem adequate? Under powered? Overkill??
What would be the maximum wattage amp one could safely build using this transformer?
https://www.digikey.ca/products/en?keywords=166M72

What models of transformers are others using for their power supplies, and what sort of wattages are they achieving??

I havn't messed around with transformers at all since a few labs 15+ years ago in college..  Know enough to not get myself killed, but don't want to waste a ton of money on the wrong transformers either..

I like to have 2x the VA rating as compared to the wattage at RMS.  IE, for your situation you would need a 60-200VA transformer.  The one you linked should be fine.  In this case, other than size and price, there isn't a problem with going larger.