Can I run 2 signals into one pair of speakers safely?

[finallygotmyheresies]

Up until now I've had a pair of Heresys on top of Cornwalls. The Cornwalls are connected to a tube amp/CD player and the Heresys are connected to my Yamaha DSP-A1/TV. I'd like to bring the Heresys down as well as get rid of the bulky DSP-A1 from my entertainment stand. I bought a little 10watt t-amp and I'd like to use it for tv sound through the Cornwalls while keeping the tube/cd going to the Cornwalls as well.

I installed banana plug binding posts into the Cornwalls so it would be easy to have 2 sets of speaker cable running into them. One being a banana plug and the other being bare wire(from t-amp). Of course I would only run one source through them at any time.

Anyone know if this is acceptable or is it a big no-no?

[tube fanatic]

If I understand you correctly, you want to have 2 amps simultaneously connected to the Cornwalls, although only one would be in use at any given time. You don't want to do that!!! The output stages of the 2 amps will interact causing impedance mismatches, among other things. The best way to do it is to build a little switchbox which allows you to connect either amp to the speakers, but will prevent simultaneous connection. All you need is a dpdt (double pole double throw) switch installed in a minibox with the necessary jacks and you'll have a nice, clean arrangement (you need one for each channel, or you can install 2 switches in the same box for convenience).

[captmobley]

Try this---

http://www.nilesaudio.com/product.php?prodID=DPS-1&recordID=Source%20Switching%20Systems&categoryID=Switching%20Systems&catcdID=10&prdcdID=FG00003

I found one on ebay for $30.00 shipped but haven't been home long enough to hook it up. Another forum member said it would work.

You always have to have a clear path to speakers from a tube amp-make sure the switch is open to your speakers before you fire up your tube amp.

[tube fanatic]

Great idea captain! Forgot about Niles for switchboxes (senility, you know). It's a bit costly if bought new, but will absolutely do the trick here based on the info sheet:

http://www.nilesaudio.com/images/PDF/DPS-1_Cutsheet.pdf

[fini]

Here's one on eBay.

[gartenman]

just an idea

http://www.overstock.com/Electronics/Sima-Multi-zone-Volume-Control-Speaker-Selector/3382757/product.html

you can connect 2 amps, 4 sets of speakers and the unit provides impedance protection so if you upgrade and had 4 sets of speakers and wanted to use them all at once the Sima protects your amp such that even when running 4 pairs of speakers, your amp works as if it has 1 pair connected at 8 ohms...

[gmc]

I recently bought a used Niles DPS-1. I got it to switch between my Scott 299-B and an old Marantz receiver, with a single pair of Cornwalls, and it's worked great so far.

[finallygotmyheresies]

Thank you for the warnings and suggestions. I am eager to get my new setup set up.

[Don Richard]

You always have to have a clear path to speakers from a tube amp-make sure the switch is open to your speakers before you fire up your tube amp.

You must mean switch closed - tube power amplifiers must have a load connected while being played.

Solid state amps can be run open circuited... unless that manufacturer says differently.

[Mallette]

I've had a Niles for years and it works nicely and silently. I just wish they'd use something other than those itty bitty lead holes with itty bitty screws.

Dave

[jheis]

If you're REALLY carefull the Niles will accept 12 guage wire, but it is a pain....