[Harp-L] getting high gain... no feedback

[Michael Easton <diachrome@xxxxxxxxxxx>]

I C/P'd  the message below from one I sent to the local harp players I  
network with.
I played at our local blues jam last night using the house Deluxe  
Reverb bought for harp use. (still set up with 12ax7's)  The amp is  
set on top of the house Leslie speaker at ear level.
Read on.

"I tried something different with the Deluxe Reverb last night.  I  
don't know if it will work for the rest of you because of the polar  
pattern of your mics. Maybe with Bill's 545 and Daine's  Sennheiser.   
I used the Heumann volume pot on my SM57 and a line transformer on the  
xlr cable.  I plugged into the 2nd input on the reverb channel and  
cranked the volume to 6. This drives the amp output to play hotter.  
The 2nd input has a lower gain, so while the amp was outputting hot  
the input was lowered so as not to force the signal through the amp.

 In other words I let the amp output control the volume rather then  
the strong mic input which could pick up the sound from the amp and  
cause feedback.

 I then fine tuned my vol. level from the mic vol. pot.  While I  
couldn't crank the mic pot as high as I normally do, and didn't need  
to do,  the setting provided for  a  strong output signal and I didn't  
need to stand in the "hot" spot of the amp to hear myself. I could  
have played louder but didn't need to. I had a decent amount of  
headroom to play with.  No feedback at all because the mic wasn't  
boosted to drive in  more signal.  The amp was boosted to provide more  
output.  And that is the secret to getting higher gain before feedback  
using hot mics.  Reduce the signal in, let the amp drive the signal out.

If you deal with the situation I use to have, hot mics causing you to  
keep your amp around 2 or 3, it might work better if you plug into the  
lower gain input on your amp, crank it up to around 5 or 6 and control  
everything from the mic volume pot if you have one.  I'm not sure how  
well this technique would work with wide pattern mics  but at least it  
works for narrow pattern wand mics.

Since I own a SJ amp now I don't need to deal with that problem but  
it's good to know how to tweak the high output Fender amps if the  
situation arises. :-)

Michael Easton
www.harmonicarepair.com