Help with SC-71 - Shutting Down Somewhat Randomly - AVS Forum
Receivers, Amps, and Processors > Help with SC-71 - Shutting Down Somewhat Randomly
ajorgensen 01:36 PM 11-19-2014

I recently purchased a Pioneer SC-71 along with a pair of B&W CM1's. I love the setup however the receiver shuts down at times and I don't what I'm doing wrong.

If I crank it up too far (at about 70%), it shuts down. But even at low volumes it shuts down. After shutting down, the iPod iPhone iPad light blinks while the receiver is off. In the Pioneer manual, it says "

I'm using Audioquest X2 speaker cable with Audioquest banana plugs. None of the banana plugs are touching. I'm also bi-amping the speakers. I have already 'told' the receiver to only have bi-amped stereo speakers connected to the receiver in the setup menu.

I have attached 3 pictures of the setup for reference.

Attached: 2014-11-19 14.19.01.jpg (75.8 KB)  2014-11-19 14.18.20-1.jpg (74.7 KB)  2014-11-17 23.22.09.jpg (153.2 KB) 

ajorgensen 01:41 PM 11-19-2014
Forgot to add in what the Pioneer manual said for this issue:

"Check that there are no loose strands of speaker wire touching the rear panel or another set of wires. If so, reattach the speaker wires, making sure there are no stray strands."

"The receiver may have a serious problem. Disconnect from power and Call a Pioneer authorized independent service company."

Ami I doing something wrong? This is my first receiver setup so I'm not sure if it's an easy fix or not.
kikkenit2's Avatar kikkenit2 09:41 PM 11-19-2014
When bi-amping remove the jumper plates between the two speaker binding posts.
Better to leave plates on and turn off bi-amping. It is a mostly useless feature.
Either way you have it wired very wrong right now.
RayDunzl's Avatar RayDunzl 11:56 PM 11-19-2014
Remove the jumpers if there are 4 amplifier channels involved in this setup of two speakers.

You are creating a short-circuit between channels on the amplifiers.
ss9001's Avatar ss9001 07:17 AM 11-20-2014
Agree with both posts. The jumpers HAVE to be removed for biamp connections. your CM-1 manual also says this on pg 7
Attached: 11-20-2014 9-10-18 AM.jpg (127.5 KB) 
FMW's Avatar FMW 09:08 AM 11-20-2014
Undo the passive biamplification. It doesn't do anything useful and can do bad things as you have discovered. Read more here.
ss9001's Avatar ss9001 02:39 PM 11-20-2014
Originally Posted by FMW View Post
Undo the passive biamplification. It doesn't do anything useful and can do bad things as you have discovered. Read more here.
I wasn't going to get into that in my reply but now that you did, I second your advice. only active bi-amping with ext crossovers accomplish anything meaningful. Passive biamping done in all receivers is practically useless.

I've done the math -- adding 2 amps of same power amounts to a mere 1.5 db volume and even that is at max power only. It makes a miniscule difference to perceived volume for vast majority of time when amps are running at 1 to several watts.

at max power, doubling the power is like increasing the vol knob 1.5 db.

and like you said, it complicates setups with no real benefit.
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