[NJARC] Help with AMP

[njarc@mailman.qth.net]

I have a Bogen Challenger Pa amp, I want to add a 1/4 inch MONO Phone Jack to 
the front panel allowing me to connect a guitar to it. Should I use an open 
or closed circuit connector? can I bridge the wires from the phone jack to 
the terminal strip connecting the MIC input, or is it better to disconnect 
the MIC wires? Should I use shielded wire connecting the Phone jack, or is 20 
gage stranded wire from Radio Shack?  Is it OK to replace the 6V4 full 
rectifier tube with 6CA4 full wave rectifier? The substitute book shows that 
you can replace it but the filaments must be parallel. The way the tubes are 
wired are 6V4 pin 5 "H" goes to pin 5 "H" of the 7868 pin 5 "H" of the 7868 
goes to pin 5 "H" of the 12AX7. Pin 4 "H" of the 6V4 goes to pin 4 "H"of the 
7868 pin 4 "H" of the 7868 goes to pin 9 "Hc" of the 12AX7. "H" being the 
heater pin. Is this a series circuit?  can I add a 47 6.3 bulb for a power on 
panel indicator by connecting it to pin 4 and 5 of the 6V4 to tube or will 
this cause a problem and just connect a NE-51 glow lamp to the A/C switch.
I picked the bogen up for a $1.00 at the Kutztown radio meet auction with no 
tubes, and replaced the electrolytics and any out of tolerance resistors, 
cleaned it up and seems to work nice. By the way anyone who did not attend 
the Kutztowmn meet missed a real good event. Good thing I brought the station 
wagon!