Did adding a speaker selector screw up my system?

Hey, isn't your NAD an integrated amp? And is your Exposure the power-amp version, or the integrated. You may want to look at how you've connecting your stuff. Let's see some pictures of your connections on the back of both.
 
BMWCCA said:
Hey, isn't your NAD an integrated amp? And is your Exposure the power-amp version, or the integrated. You may want to look at how you've connecting your stuff. Let's see some pictures of your connections on the back of both.
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Yes! I just had that same thought in the post immediately preceding. The 3020 is an integrated amp, which I'm currently using as a premap; the Exposure is the power-amp version. (The Exposure has two rows of inputs per channel, but my understanding is that that's for bi-amping only).

Looking at the manual for the 3020, it looks like I can run a y-connector from the "pre-amp out", with one going to the "normal in" and the other going to the power amp; is that right? Is there another/better way? Also, we got the power amp mostly to run the OLAs, which sound better with more juice; I'm not sure if the EPIs are equally thirsty?
 

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Looking at the manual for the 3020, it looks like I can run a y-connector from the "pre-amp out", with one going to the "normal in" and the other going to the power amp; is that right? Is there another/better way? Also, we got the power amp mostly to run the OLAs, which sound better with more juice; I'm not sure if the EPIs are equally thirsty?
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I think this is your best option. My guess is the EPI's will be fine with the NAD amp. You might find the SPL difference between the 2 speakers has changed however because the power amps may have a different gain level.
 
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charles 1973 said:
I think this is your best option. My guess is the EPI's will be fine with the NAD amp. You might find the SPL difference between the 2 speakers has changed however because the power amps may have a different gain level.
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Success! (more or less...). I now have the EPIs hooked up to the NAD, and the OLAs hooked up to the power amp. It sounds good, though on some records the OLAs are especially boomy in this setup (is that what you mean by the SPL difference?), which probably isn't helped by the fact that they are currently resting directly on a hardwood floor (Kate Bush's "Hounds of Love" was extra heavy on the low end, but Donald Fagan's "The Nightfly" sounds much more balanced). I'm getting some risers made for the OLAs which hopefully will disperse some of that boominess...
 
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Probably for another thread, but set up as it is now, the balance on the 3020 works when I'm using it alone with the EPIs, but once I engage the power amp to run the OLAs the balance knob disengages. Is that supposed to happen?
 
econeditor said:
Probably for another thread, but set up as it is now, the balance on the 3020 works when I'm using it alone with the EPIs, but once I engage the power amp to run the OLAs the balance knob disengages. Is that supposed to happen?
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First, double check all speaker cable connections for proper phasing (+ on +, - on -) and clean tight connections. and double check your rca connections.

If all is well, perhaps the rca cable grounds are the problem. Try different rca cables, preferably some with an open ground. They often have small arrows on them. You might have some on other gear like that.
 
I have used an Adcom GFS-3 speaker selector for almost 30 years. Never had a problem with it. I never used the speaker protection either. I think if you can find a GFS-4 , it comes without a speaker protection button.
 
I think, if it were my setup, I would have tried swapping the L-R inputs for the hell of it. It would have maybe made clear if the input source might have been the culprit. I'm glad you were able to settle the issue. Now enjoy.
 
If all sounds good, before moving on as though nothing happened, I would check offset and bias. If that checks out good, then I would move on.
 
econeditor said:
Thanks! Stupid question: how do I do that?
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For bias, it’s different amp to amp. One would have to check a service manual. But if you know how warm it ran before and it still runs at that temp, likely nothing changed. An increase or decrease in bias will have a corresponding increase or decrease in operating temps. If you detect that the amp runs warmer or cooler than before, then something went wrong. Time to check bias properly. Or you can check bias anyways.

Offset is a little easier as it is mostly the same amp to amp. Take a voltmeter, set it to dc volts, put the probes where you normally put the speaker wire. One probe to + and the other to -. Does not matter which probe goes where. Do this with the amp on and the selector switch if you have one, set the the jacks you are probing. Since it is set to volts dc, hopefully you don’t get much of a reading. If you do get 1 volt or more, you have problems. But if you don’t, time to switch from volts dc to millivolts dc. Now you should definitely get a reading. You will have something higher than 1 millivolt and less than 1 volt. The closer to 1 mv dc the better. Generally, anything less than 30mv dc I call good. Anything up into the hundreds of mv dc is bad. Less than 100mv dc but more than 30mv dc is….ok but not ideal. Measure left and right channels. Warning…don’t short the leads. Anything goes wrong, not my fault. This is info only to give you an idea. Study up a little, watch videos, look at service manual….
 
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