CDP - running only one channel, can this damage?


I have a Wadia CDP driving my amps directly. One of my mono's is temporarily out of service. I want to get some music, would it hurt my Wadia to run just the left or right XLR to the one amp, and leave the other side disconnected?

Jim
128x128jim63
Personally, i wouldn't do this. If you want to do this and keep both me and your gear happy, i would suggest using a "dummy load" or "resistive shunt" on the unused channel. If your Wadia has RCA outputs as well as XLR's, the simplest way to do this would be to place a resistor across a cheap RCA and be done with it. So long as you use something over 10,000 ohms, you should be fine. The parts will cost you less than $5 at Radio Shack.

As a side note, one can "break in" line level gear like this too. By using "dummy loads", you can put in a disc and let it play on repeat for as long as you like. No harm to the gear and no noise in the background while you enjoy your main components. Sean
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PS... DO NOT try this with power amp outputs unless you are certain that you have resistors that are MORE than capable of handling both the power and heat dissipation.
Sean, I would like to hear your reasoning on this. What harm can possibly come from running a line level device unterminated?
Thanks for your replies. I need to run out for the day, but will check back in later. Thanks, Jim
Signal is still being passed and amplified without the proper load terminations. The amplitude of signals is reduced due to the lack of current flow, but that doesn't mean that the devices aren't sustaining some type of wear and or damage.

Try taking an amplifier and running it with no load with rated input. Theoretically, there is no voltage or current flow due to the infinitely high impedance it sees as a load, so there should be no problems. Wait a while and see what happens. While you might say that this is not a fair comparison, it is. It's just that the results that occur are far more visible / easier to measure with the amplifier. The same results / circuit degradation is taking place in the line level gear, it just isn't as evident or abrupt. Kind of like a slow and punishing life rather than a more timely death. Sean
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Sean, while I usually find your responses to be well reasoned, I find nothing in this one to support your position. Just what do you mean by " circuit degradation?" You state that it occurs, but offer no explanation of how it occurs or what form it takes.

What characteristic of any component will change? I can see the argument for power amps if the speaker is part of the feedback circuitry (very unusual), or in the case of inductive kickback from unloaded output transformers in tube amps, but for line level devices there is nothing I can see that is affected. Too low of an impedance can cause degredation of components due to heat, what can too high do? I say nothing.

The overwhelming majority of line level pieces use an emitter follower output stage. That puts the input impedance of the following stage in parallel with the emitter resistor. Without the load, it is driving current through a 600 ohm or so emitter resistor. With the load, add the input impedance of > 10k ohms in parallel, which is insignificant. Other circuit topologies can be analyzed in similar fashion.