Re: Rod Piazza mod

[Grbullets2@xxxxxxx]

In a message dated 3/20/2003 4:48:12 PM Eastern Standard Time, Markburness 
writes:


> 
> 
> Even a 5 meg pot in an Astatic mic will not allow the mic to "deliver what 
> it is capable of" unless that mic in turn is plugged into a significantly 
> higher load. There was some discussion on the list in which became apparent 
> that 5Meg was the largest value pot that could realistically be installed 
> into a JT30 shell (if anyone knows better please say so, retail source & 
> part no. would be nice). The 5Meg pot is used to reduce the effect of the 
> pot loading down the impedence of the input circuit.
> 
> Pot size when considering CR/CM/Hi-Z dynamics would appear to be less of an 
> issue as these mics typically have elements with much lower resistances.
> 
> Personally I prefer an on/off switch on crystal/ceramic mics and blow more 
> gently when I want to be quieter :-)
> 
> Regards, Mar

       If you could find a 10 meg pot,I'd say use that.The problem is the 
impedance mismatch when you use a pot of a low value.You will loose alot of 
the low freq. response with a low value like the 500K's that Astatic put's in 
them.Ever try to measure the impedance of a crystal element?Chances are you 
couldn't unless you have a very good VOM meter that will go that high.That's 
all.Impedance mismatch.It's hard enough finding a good quality 5 meg pot let 
alone anything higher,although you can get them if you know where to 
look.Just about any guitar amp will have a high enough load resistance to 
accomidate a crystal element and have it sound good........Dave