[Harp-L] Bassman pre-amp tubes vrs mic output

[Steven Rousseau <Steven_Rousseau@xxxxxxxxxxxx>]

Hi, 
	Just thought I'd throw my 2 cents in...
 
I've just completed a week of vacation building 
bullet mics.  I picked up 6 Harley Davidson turn signals and 
converted them into really nice bullet mics,  some with 
Shure crystal elements, some with Shure CM and some with Astatic MC-151.

During the testing phase, I played each mic cartridge through a 
100K ohm resistor (simulates an amp) and then read the voltage output on 
a volt meter.  

I was surprised at how hot a bullet mic can be. 

A guitar with hot humbucker pickups will send about 
200 milli volts (0.2 volts AC) to an amp's input when you bang 
away loudly. 

An Astatic MC-151 crystal will put out 4.0 to 6.5 Volts AC!

A Shure CM element will put out over 14 Volts AC !!!  
Thats 70 times more output then a guitar with hot pickups!

This is why harp players do not really need high gain pre-amp tubes
like a guitarist would need.

Even with a couple of 12AU7 tubes in your pre-amp section,  a bassman 
that is driven by a hot bullet mic will get as much sound pressure as 
a guitarist using all 12AX7.  Lower gain pre-amp tubes makes it easier 
to avoid feed-back with a mic. 

P.S.  My main amp is a Sonny 4x10 and I highly recomend it.  With all 
the testing that Sonny has done, this amp sounds great right out of the 
box and the construction is top quality.  Definitly worth the money!
I record with a 1958 Fender Harvard.  Those of you who have one 
know how great this amp is for harp.  If you don't think so then I'd 
be happy to buy it off you (-:

Regards.. Steven Rousseau 
SmokinGroove,  Montreal