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.



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[nigelwright7557]

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]

...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]

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]

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]

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]

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]

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]

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?"

 

[mjf]

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?

hello.
you can add another two diodes to the existing ones , so you will have three diodes in series on each half side...........
if the output is too low again go up to four diodes per side.
greetings..........

 

[shaan]

All done... after placing a gain-of-2 buffer yesterday I ran it and it's fine. The soft clipping is quite cool! Sounds almost like the "FL Slayer"'s default power chords or Inferno of the Sytrus synth of FL Studio.

Great preamp! 9/10