Amp ouput

footwedge

I recently added a used B&K 200.2 to my line up and noticed this past Friday the right channel is not as loud as the left channel. I have yet to recalibrated the system after adding the amp but this noticeable sound difference just recently occurred. Last night I replaced the LSI7's with the LSIM 703 and the volume difference is still present.

I plan to recalibrate tomorrow and if the volume difference is still noticeable, I plan to bypass the amp and connect the left and right channels to the SC27. If the volume difference disappears then I would have to think the right channel is going bad.

Questions:
1. Is it possible for an amp channel to gradually go bad?

2. I assume an electronic repair shop, who is an authorized pioneer repair center, could easily check the output of each channel and repair if needed?

3. I guess there could be an issue with the right channel pre-out on the SC27 or a bad ic?

4. is there anything else that could cause this issue?

jeremymarcinko

Maybe it's your ears...not kidding, I have better hearing in my left. After I calibrate I bump the right channel up one db and I sit about a foot off center to the right....then it's all good....headphones aggravate me though

tonyb

Manually set speaker levels both to 0. Make sure your listening position is of equal distance too. It is possible the amp may need some updating. Play something in stereo mode. Also make sure one side isn't over dampened by curtains or some other obstruction. You can always adjust the gain in the receiver to compensate, but that won't solve the issue if the amp needs some repairs.

Also swap speakers to make sure it isn't the speaker and double check the connections.

footwedge

jeremymarcinko wrote: »

Maybe it's your ears...not kidding, I have better hearing in my left. After I calibrate I bump the right channel up one db and I sit about a foot off center to the right....then it's all good....headphones aggravate me though

It must be the DW ears also because when she walked in the room she put her ear to the right channel to see if it was outputting any sound.

EndersShadow

Also check if you hit the balanced connector on back the B&K which would drop the output considerably...

My tech did that initially on my 5 channel and was VERY confused lol

tonyb

What Dan means is....check all the dumb arse mistakes one can make first, because we've all done it at one time or another.

footwedge

tonyb wrote: »

What Dan means is....check all the dumb arse mistakes one can make first, because we've all done it at one time or another.

I will but before I changed the speakers everything was fine until last Friday when I noticed the volume difference. Never came close to touching anything on the back of the amp nor avr.

I failed to mention in my op that when I first noticed this no volume was coming out of the right channel. I then shut everything down and restarted. Then I had volume out of the right channel just a lot lower than the left channel. You have to get close to hear the sound

voltz

If it was a tube amp I'd say re bias it, I had the same problem with my Mc100b tube amp and I checked the bias and 2 power tubes where way low and when set correctly the sound was back to normal. but your B&K is SS.

jeremymarcinko

footwedge wrote: »

I failed to mention in my op that when I first noticed this no volume was coming out of the right channel. I then shut everything down and restarted. Then I had volume out of the right channel just a lot lower than the left channel. You have to get close to hear the sound

Seems to me you have some bad equipment then.

footwedge

Recalibration has resolved the issue and did find that I had the ic's crossed.

BlueFox

Along this line, does anyone know of a CD that will generate equal strength signals from each channel, but separately? I have yet to find a test CD that will do that simple task. I want to use the SPL meter and see if the setup is balanced. Since my left speaker is three feet from the wall, while the right opens into the dining room, I expect the left to sound louder, but it does seem balanced now. However, I would like some data to verify that.

BlueFox

Yes, but I'm not that curious.

If there is any difference it is only a DB or so, but it would be nice to know, and tweak the appropriate channel gain.

Easy Runnin

Along this line, does anyone know of a CD that will generate equal strength signals from each channel, but separately?

Would the static between radio stations and your balance control do the trick?

cfrizz

footwedge wrote: »

Recalibration has resolved the issue and did find that I had the ic's crossed.

LOL! This is why we tell everyone to double check everything before panicking! Glad you found and solved the problem.

footwedge

Yes. But it's getting more and more difficult due to recent additions to move this cabinet away from the wall to access the rear panels. New I should've put this cabinet on wheels. Getting old beats the alternative.

footwedge

Spoke to soon.

To clarify my statement about crossed ic's, I should have stated that avr pre-out R >amp channel 1 > left speaker and avr pre-out L > amp channel 2 > right speaker. In this scenario the left speaker produced much volume than the right to the point when seated at the listening position a mono sound was heard even though there was some volume from the right speaker that could only be heard from 2-3' feet away.

After correcting the cabling (avr pre-out R >amp channel 1 >right speaker and avr pre-out L > amp channel 2 > left speaker) and recalibrating, now the right speaker has much more volume than the left speaker, mono sound, but sound is emitting from the left speaker. Calibration shows L & R channel at +2.5db and +3.5db respectfully. Which seems to make sense since my seated position is 2.5' left of center.

With the current wire configuration, I activated and deactivated the xlr connection alternating between the left and right channels. When channel 2 xlr was activated I could barely tell a difference in the total sound output; however, when I activated channel 1 xlr the total sound output was noticeably reduced. So it's obvious that amp channel 2 is producing much less volume than channel 1.

The question is why or is this possible?

Can an amp channel gradually weaken or is it all or nothing?

I have quadruple checked all connections, cabling and the amp does not have gain control.

I plan to bypass the amp tomorrow connecting the L and R speakers directly to the avr speaker terminals to see if I get this same volume differential.

Not sure there's anything else I can check.

cfrizz

Make sure that nothing is sitting on or pressing on your speaker wire. I thought one of my speakers was going bad because it was a lot quieter than the other. Then after checking all connections I noticed that my speaker wire was trapped under the base of it's speaker stand, I moved it out from under and tada! I had full sound again.

footwedge

After connecting directly to the avr, the volume is corrected.

Before this issue began, my normal listening volume for music was between -25 - 20db. During this issue, I could go as low as -15-10db and the volume would not be unbearable when before it would've been.

footwedge

cfrizz wrote: »

Make sure that nothing is sitting on or pressing on your speaker wire. I thought one of my speakers was going bad because it was a lot quieter than the other. Then after checking all connections I noticed that my speaker wire was trapped under the base of it's speaker stand, I moved it out from under and tada! I had full sound again.

Cfrizz,
All connections have been checked.

Unless I missed something, all things point to channel 2 on the amp. I assume any qualified electronic shop should be able to confirm and repair this amp. There's very few to choose from locally. The one I plan to take it to is actually a certified pioneer repair center that recently fixed my sc 27 after being hit by lighting. I plan to contact ATI tomorrow for the schematic.

footwedge

Been rethinking this deduction and think I need to eliminate any issues with the ic's because they have been reconnected.

footwedge

About to give up.

So today when I get home I put the amp back in service and believe it or not the volume is balanced. I grin thinking maybe it was a cabling error and because my sound is back. Then 9.5 songs into the "Alison Krauss + Union Station Live" cd, the left speaker (amp channel 2) disappears not completely but would estimate the output was reduced by 70%. The output lowered to a point were I had to get up I put my ear to the speaker to make sure it was outputting sound.

Any more ideas or suggestions on what could be the problem will be very much appreciated.

Easy Runnin

Did you try different ICs? Did you try switching the ICs on the pre and amp?

footwedge

I only have one set of ic's. I had planned on switching the L&R ic's to see if the volume differential would show up in the right speaker but once I brought the amp back into the mix and I was getting balanced volume from the speakers, I thought all was good. And, it was for 9.5 songs. I was too pi$$ed to try anything else.

tonyb

Get another set of IC's before taking the amp in for repairs. You have to know if it's a cable problem first.

footwedge

tonyb wrote: »

Get another set of IC's before taking the amp in for repairs. You have to know if it's a cable problem first.

Since the left channel seems to be the problem, if I switch my current ic's and the issue is still with channel 2 (LT), then would this not eliminate an ic issue? But possibly point at the amp or even the preout jack?

dkfreebird

I had the same problem with a belles amp I had,it would play perfect for about 10 minutes then the right channel would drop.It ended up being the preamp output causing the isssue.

footwedge

I've had issues with my sub dropping on occasions and would have to wiggle the cable at the preout jack to get it to come back. I've even turned the sub cable around and the issue still exists. So either the sub cable is bad at both ends or it's the sub preout jack.

I have no clue what it looks like on the inside or how the preout panel is designed but the sub preout is adjacent to the front l&r preouts! Could this be a clue?

dkfreebird

On my preamp it was the right channel throughout the whole pre,aux,cd etc.They all did the exact same thing.

footwedge

my only other device is my oppo connected via HDMI.

hochpt21

Sorry, just saw this thread.

Damn, footwedge I had absolutely zero issues with this amp.

Do you have any other pre's that you can try it with?

vcwatkins

Try direct from Oppo. Variable volume set to lowest before powering up amp.