Help with a power amp stage for a Guitar

[PD186]

Hi

I have a design for a pre amp that I want to build but I am after a solid state power amp stage to go with it.

The pre amp will run 18 to 30 v

I have a design for an amp but it is 60v

Can I power both from a single transformer?

Or better still a 30v power amp design would be a great help

I have found some but not sure if they are suitable?


Your help will be much appreciated

Thanks

Phil

 

[Nigel Goodwin]

The output power of an amplifier depends on the supply voltage, you need the 60V to get the power from it.

There are various ways of feeding the preamp, but a separate PSU is probably the easiest.

 

[PD186]

Thanks

Thanks for the reply

If the power is needed for the output would running it at a lower power only reduce the output or would it have other effects.

I see the output varies as to the resistance of the speaker attached and as I haven't got the speaker yet I could go for a lower resistance to increase output.

Also I don't really need a big output anyway.

The design I found had the power supply preamp and power stage separate which made it easy to change the design and put in a different preamp.

Apart from the different voltage.

 

[Nigel Goodwin]

Thanks for the reply

If the power is needed for the output would running it at a lower power only reduce the output or would it have other effects.

It reduces the output (a LOT!), but may also require the power amplifier redesigning to take account of it.

I see the output varies as to the resistance of the speaker attached and as I haven't got the speaker yet I could go for a lower resistance to increase output.

You couldn't reduce it enough to compensate, and again the amplifier might need redesigning to do that.

Also I don't really need a big output anyway.

The design I found had the power supply preamp and power stage separate which made it easy to change the design and put in a different preamp.

Apart from the different voltage.

Usually the preamp is fed from the main supply via big resistors and a pair of zener diodes (crude regulators), but these also isolate the preamp supply from the power amp supply - which is also important.