switching between a tube int. and SS

[Shiva]

Greetings all,

My tube integrated (ASL AQ1003 DT) and my Rotel rb991 power amp each have their own speaker wires. When the tube amp is turned off, how long should one wait if at all to unplug the speaker cables from my Epic CF3's so that I can hook the Rotel back in. I have read that it is a good idea to drain the amp for awhile before disconnecting it from the speakers.

Thanks,

[jheis]

Shiva:

I have a new "in the box" Niles DPS-1 for sale that will allow you to connect your two amps to a pair of speakers and switch back and forth. The Niles retails for about $90 - I'm asking $60 plus $10 UPS. email me if you're interested.

James

[Shiva]

Bump.

[garymd]

I use the Niles switchbox also. I've never had a problem switching between amps which means I never "drain" the tubes before disconnecting the speaker wires. If that's needed, nobody has ever mentioned it to me. I've been doing this for over 2 years now and never had any problems.

[Colin]

more like 20 years for me, the tubes hold a charge, but that should not matter unless you are messing with the circuitry inside

[cjgeraci]

Props here also on the Niles unit. Allows me to use two different preamps and amps for my RF-7s, depending on whether I want them to act as rear surrounds in one setup or...

to sing on their own in two-channel.

Device works as advertised.

Carl.

[Shiva]

Thanks for the responses and the nice offer as well. I will give the Niles some consideration, though I would rather not add another piece of equipment to the growing number of black boxes I already have.

Best Regards,

[WMcD]

Do I understand that you're just disconnecting the speakers and then connecting them to another amp? And there is suppose to be some residual d.c. at the amp output after it is powered down?

Not so.

In tube amp with an output transformer there is never any d.c. at the output. There can't be. The windings of the output transformer have very low resistance at d.c.

Even in s.s. amps without output transformers, I've never heard of a situation where there is any d.c. to be bleed off. There may be a small amount of d.c. offset during operation.

In this case we encounter it sometimes when we switch off the speakers to listen, only, to headphones. Jacking in the headphones we hear the click of the d.c. offset in the phones.

Further. If your amp has a switch to allow A or B or neither, you'll sometimes hear the effect of d.c. offset when you go from neither to A (or whatever it takes to connect your speakers to an otherwise unloaded amp). There may be a very slight click.

All of the above is in distinction to turn on thumps, when the amp is powered up.

Gil

Gil