ESP Guitar Preamp Output Swing

[shaan]

The page says that for the diodes the power amplifier must have a sensitivity of 750mV for full power. I plan to run it with my 20Watt SE Class-A amp which has a sensitivity of 1.5V for full power.

Is there any way to increase the preamp's output voltage swing while keeping the soft clipping behavior intact?
Are there ways to make the preamp soft-clip by means other than using those diodes at the output?

http://sound.westhost.com/project27.htm

Thanks in advance.



.

[nigelwright7557]

Originally Posted by shaan

The page says that for the diodes the power amplifier must have a sensitivity of 750mV for full power. I plan to run it with my 20Watt SE Class-A amp which has a sensitivity of 1.5V for full power.

Is there any way to increase the preamp's output voltage swing while keeping the soft clipping behavior intact?
Are there ways to make the preamp soft-clip by means other than using those diodes at the output?

http://sound.westhost.com/project27.htm

Thanks in advance.



.

Outputs are usually 0dB so perhaps the two values are RMS and peak ?

[juma]

Originally Posted by shaan

...Is there any way to increase the preamp's output voltage swing while keeping the soft clipping behavior intact?...

Yes, add another gain stage (another OpAmp, for example) with a gain of 2 (or more) on preamp's output (before the power amp).

[nigelwright7557]

Originally Posted by juma

Yes, add another gain stage (another OpAmp, for example) with a gain of 2 (or more) on preamp's output (before the power amp).

Or alter your amp to have twice as much gain.
Its probably one resistor change to double the gain.

[juma]

Originally Posted by nigelwright7557

Or alter your amp to have twice as much gain.
Its probably one resistor change to double the gain.

It might not work if the amp doesn't use a lot of GNFB.
BTW, what power amp are we talking about?

[nigelwright7557]

Originally Posted by juma

It might not work if the amp doesn't use a lot of GNFB.
BTW, what power amp are we talking about?

The 20 watt amp he mentions in the first post.

[juma]

Originally Posted by nigelwright7557

The 20 watt amp he mentions in the first post.

Ha, ha, great answer - that much I've read myself.
I suppose the original poster should answer that question...

[shaan]

Originally Posted by juma

Yes, add another gain stage (another OpAmp, for example) with a gain of 2 (or more) on preamp's output (before the power amp).

Thanks for the suggestion. On my way.

[shaan]

Originally Posted by juma

It might not work if the amp doesn't use a lot of GNFB.
BTW, what power amp are we talking about?

It's a common drain MOSFET power follower driven by DoZ preamp, modified with the maximum suggested gain in the article.

http://sound.westhost.com/project83.htm

[shaan]

Plus, I was wondering whether any kind soul would answer my second question or not?
"Are there ways to make the preamp soft-clip by means other than using those diodes at the output?"