interconnects cause hum?

[hammerin]

I have a pair of SILVERLINE,and a pair of ALPHA-CORE micropurls that cause my st-70 to generate a loud hum when i turn the preamp off first.but when i have a pair of MONSTER CABLE ic's in use there is no hum when i turn off the pre first?????[:|]

[Mighty Favog]

It almost sounds like the ground on the IC's is not well connected somewhere internally.[^o)]

[CaptnBob]

Short answer - yeah. Actually, to be more precise, they allow it.

"It's generally considered a bad idea to turn the preamp off before the power amp" says Bob "Inverted woofer cone" A.

Any pops, thumps or other anti social behavior by the units upstream can cause really bad results when they get to the power amps. You want to turn things on in order from the source to the speaker and turn them off from the speaker back.

[joshnich]

I am assuming that you are speaking of the ICs between the Dynaco and the preamp. If so I had the same thing happen when I inserted a pair of Grover Huffman ICs between my peach and power amp. When the amps turned on there was a loud hum until the peach went from standby to on. Mark Deneen explained to my why that happened but I really didnt understand it. It was not a fault of the ICs. He said that a slight modification on the wiring of the peach would solve it. I ended up just putting the old ICs in that position and used the Grovers elsewhere.

Josh