I went to radio shack to pick up a solder, and asked a salesman (who said he knew what he was talking about in ref to amps) about the above quote who told me:
If i cut off the plug of a cable, twist the wires together, and plug the other end into my input, its still gonna blow if the channel vol. increases. He said just tape the volume down.
Could i please get some clarification on whats happening in the cable? How is no signal able to get into the input even with the plug cut off and wires twisted?
- im assuming you/yall know best but that guyhaving just said ill destroy my channel by doing the above has got me a bit scared.
thx for the!
Sorry I wasn't more clear about the construction of a shorted plug--when you cut off a plug from a bad cable, THAT's the plug you're going to use in the input, after you disassemble it and connect the two terminals together. Twisting the wires from the cable together and inserting the other end wouldn't work because the cable has a break in it somewhere, so the connection between the two terminals would not be complete.
Now for the theory about shorting the input. This is what a physicist friend wrote to me when I asked the same question you've asked. He isn't a tube guru and neither am I, so you have to take this information as something to consider and possibly do more research on:
"NO HARM can be done if there is NO A/C (audio) SIGNAL going to the transformer. Open, shorted, 8 ohms impedance matched, terribly mismatched, it makes no difference. There will be a nice big spike (harmless) when the tubes warm up, then it falls into quiescence to use the engineering term. Transformers can pass no DC, so you only have to be concerned with the impedance matching of an A/C load. No A/C, then no problem. The transient doesnt figure into the equation, as it is a one-shot event.
"If you keep the channel turned down, there is no problem.
"If you want to be really sure, then hook up a shorted-out input plug and insert it in the unused input jack. No signal including noise can come from the shorted connector; no matter what the volume setting, the amplifier will be amplifying silence. No A/C. No problem."
This theory makes sense to me, and the one time I tried it, my unused channel did not burn up its output transformer. But if some of the tube gurus here are more conservative or knowledgeable and shoot holes in this theory, I'm not going to defend it since it's "over my head." Peace, Bob
