I have an old RCA 2X 6V6 15W PA head with a 500ohm tap on the OT that I have a couple of questions about.
First - Does anyone know the original intended use of this tap? It's common either as a 500 or 250ohm tap in nearly every RCA PA schematic I've seen. I've taken some rough measurements and I'm getting ~ +8 to +10dbm output into a 500ohm load with average input drive voltage. Perhaps they used it to feed a bigger dedicated distribution amp ? The particular one I have (no available model#) also has a dedicated 124ohm/70.7V distribution tap(assumedly providing full power output at that impedance) .
Second - My bigger concern was whether it was intended that the 500ohm tap be used as a line level feed in conjunction with standard speaker connection. In other words, is there risk in using just the 500ohm tap without having a speaker load simultaneously connected using one of the low taps?
The online catalog sheets don't mention any specific use of this tap.
This is not the exact amp I have, but is similar enough for a reference
http://www.theused.com/manuals/rca/rca_mi-12287_12295.pdf
First - Does anyone know the original intended use of this tap? It's common either as a 500 or 250ohm tap in nearly every RCA PA schematic I've seen. I've taken some rough measurements and I'm getting ~ +8 to +10dbm output into a 500ohm load with average input drive voltage. Perhaps they used it to feed a bigger dedicated distribution amp ? The particular one I have (no available model#) also has a dedicated 124ohm/70.7V distribution tap(assumedly providing full power output at that impedance) .
Second - My bigger concern was whether it was intended that the 500ohm tap be used as a line level feed in conjunction with standard speaker connection. In other words, is there risk in using just the 500ohm tap without having a speaker load simultaneously connected using one of the low taps?
The online catalog sheets don't mention any specific use of this tap.
This is not the exact amp I have, but is similar enough for a reference
http://www.theused.com/manuals/rca/rca_mi-12287_12295.pdf