Line out to guitar pedal.

[served]

Hi.

Looking for a simple solution to send unbalanced Line signal to Valvecaster 12AU7 based pedal.
The main consern is that its not performing that well with Line signal.

Solution can be a simple potentiometer.
But I would like to buffer it. So that I have a buffer to match the Impedance also.
Saw this one here
http://audiodomain.blogspot.com/2012/11/reamp-design.html

But its a balanced one and I think if I connect the low pin to ground then this will not work.
A transformer based thing would be overkill in this case though I might consider it if its the only good way.

Please share your ideas and experience.


The box that I need is probably a reamp box, but maybe a simple opamp stage would do the trick.

[Johan]

Line level from where? . Easiest would probably be to replace the v.c. input grid resistor with a pot of the same value (1M?)

[Hatredman]

I guess it WILL work as expected if you short -in to ground. Why not breadboard it and try?

[served]

Good ideas.

The signal is Line Out from my mixer.
If I feed 0db line signal to the pedal.. well it just farts.
Tried a regular potentiometer but you need to turn it way down and there is a huge frequenzy loss.

[Johan]

Your frequency loss is more than likely your v.c high impedance output hitting the mixers low impedance input. Try a buffered pedal such as any boss or ibanez between v.c and mixer

[Hatredman]

Your frequency loss is more than likely your v.c high impedance output hitting the mixers low impedance input. Try a buffered pedal such as any boss or ibanez between v.c and mixer

Any buffer will do the trick, methinks.

But Johan`s idea is a good starting point: put a buffered pedal between your mixer and the Valve Caster. The pedal should be powered but can stay disengaded, the buffer will be there in the signal path anyway. If it works, just build a little buffer like the AMZ  and you are good to go.

http://www.muzique.com/lab/buffers.htm

[JFace]

Use the last buffer example from the muzique buffers page. It is an inverting buffer. The reason I suggest this is that your pedal is very likely to invert your phase, so you can use the inverting buffer to keep everything the same phase. It also allows you to vary your attenuation by replacing R2 with a potentiometer. I suggest making R1 100k, and making R2 a 50k potentiometer. At full resistance, the output is half, or -6dB. Decreasing the resistance attenuates even further. You may need to apply a fixed resistor in series with R2 so that the signal has a min and max setting. The signal will be buffered and will not change the frequency response due to loading.

[Hatredman]

Oh, another thing: you`ll have to be careful with your mixer faders.

[served]

Hi.

Great!
A good simple solution. Boss guitar pedal buffer.
Problem solved!
Thank you all for your input!

I will also build that AMZ buffer because of the phase shift.
I should probably buffer the input also. At the moment this is not that important as it sounds just like it should!

Thanks again!