# transformerless guitar amp



## ezcomes (Jul 28, 2008)

i know some older style low wattage amps are built this way...does anyone have a schematic for one...i've been thinking about trying to build one...or...is it not possible/safe?

does anyone know?


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## greco (Jul 15, 2007)

I'm not 100% sure, but I think the only way to be certain that this type of amp is as safe as possible is to use a isolation transformer with it....so then you are back to having a transformer involved. 

Many of these amps have been used without isolation transformers through time (and still are) but there is a risk.

I'm sure others will comment.

Cheers

Dave


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## dtsaudio (Apr 15, 2009)

Do not attempt to build an amp without a power transformer. While the designs are simple, the lack of isolation from the power line is a serious danger. However these simple low wattage designs can be built. Use an isolation transformer (110V to 110V).


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## greco (Jul 15, 2007)

If you want to try something safe (in comparison), and with low(ish) voltages (around 40 -50 VDC) , why not build a low wattage (i.e., 10 watts) solid state amp? You will still need a small(ish) power transformer.

Just a thought.

Cheers

Dave


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## Wild Bill (May 3, 2006)

ezcomes said:


> i know some older style low wattage amps are built this way...does anyone have a schematic for one...i've been thinking about trying to build one...or...is it not possible/safe?
> 
> does anyone know?


Designs without a power transformer of necessity are in the 2-3 watt class! Ok for a practice amp but you'd need to mic it for any serious work.

Also, having no power transformer doesn't change the tone! Such an amp would sound the same whether or not you used a transformer.

So other than being cheap lofu why do you want to do this?

A good transformerless design can be perfectly safe. However, it's not likely to be so if it's built as your first project! You really should acquire some experience before tackling the dangerous stuff!

If you want some schematics you might go to schematicheaven.com and research some old Silvertone schematics. There are other brands from that era that are similar. Just look for the brand names that no one hears about today!

If you aren't comfortable reading a schematic then DON"T try to build a transformerless amp!

WB


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## LowWatt (Jun 27, 2007)

Wild Bill said:


> If you aren't comfortable reading a schematic then DON"T try to build a transformerless amp!
> 
> WB


What if I don't like living and I've always aspired to win a Darwin Award?


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## Wild Bill (May 3, 2006)

LowWatt said:


> What if I don't like living and I've always aspired to win a Darwin Award?


Then there is a position for you in the provincial government's cabinet!kkjuw

WB


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