Relay clicking in Rotel amp (1 Viewer)

[RichardHOS]

One of the Rotel amplifiers I recently purchased (a 991) seems to suffering from an overactive relay. This amplifier has a turn on delay relay to prevent turn on thump. There is a characteristic click when that relay (opens, closes ?) activates ~5 seconds after the amp is powered on.

I'm hearing that same distinct relay clicking sporadically during normal listening. It always seems to click at least once in the first half hour after being powered on, and after that it may click a couple of times in an evening, or I might not hear another peep out of it. The volume or material doesn't seem to correlate with the clicks, and their spacing doesn't seem to follow any repetitive pattern.

The amplifier, other than this somewhat annoying relay, seems to be functioning fine. I can't hear any differences between it and another identical 991 I have, whether at low or high power levels. I also can't hear any momentary interruption in the sound when the relay clicks, but seeing as how it is in a biamp setup driving the mid-bass end of L/R speakers, perhaps it is actually dropping out for a moment and it just isn't pronounced.

I have this plugged into a Rotel power strip, with the amp always on but unpowered until the strip sends AC power (hope that makes sense). Not sure if that makes a difference... haven't ever noticed anything like this in the other seven Rotel amps I have.

What are your thoughts on this? Is it likely to be the relay itself, or a cap or other component feeding the relay? It seems like it could be something that is DIY repairable, especially if it is just replacing a relay (assuming it isn't some hard to find bizarre relay). Any suggestions for where to begin the troubleshooting process?

 

[Claude M]

my guess would be the relay needs to be swapped

 

[Chu Gai]

That or some flaky wiring around there. Heck it's warranteed, why not let them repair or replace it?

 

[RichardHOS]

The amp was purchased used, and I'm not sure if Rotel has a transferrable warranty. I'll look into it.

Still, the cost of shipping the thing even if under warranty would likely be more than the cost of the part if I could locate and replace it. Being that it is a mechanical relay, I feel better about my chances of doing so... if there was some static or bad humming going on, I'd be mostly lost.

I'll take it apart and look at the relay. Perhaps I can just order a direct replacement for minimal cost. If so, I'll try that first.

 

[Chu Gai]

and knowing that you're a brave but careful soul you'd probably looking inside with the cover off. could be just a bad solder joint. think the user knew about it?

 

[Claude M]

take it to a local guy with a good solder station (or buy one if you don't already have one, the tip must be calibrated or you can over heat the board and screw it up)

http://www.action-electronics.com/wewes50.htm

 

[Andrew Pratt]

Rotel should look after you if you ask nicely. I can get you the contact names you can email if you like...an email to one of the tech's might help with a few suggestions or what it would take to replace etc.

 

[RichardHOS]

Andrew, that would be great. You can PM the contact info to me. I thought about just calling their general tech support, but... well, that just seemed like an odd thing to do - ask them to diagnose the component over the phone when they'd rather me ship it to them and pay to have it fixed.


Chu, I wouldn't doubt that the seller was aware of the clicking. It doesn't really upset me... I've made so many deals now for used equipment without one single problem that I feel I'm due for something like this. Besides, I got if for a really great price (possibly because of the problem), and if it's a cheap fix then I still come out way ahead. Crossing my fingers...

 

[Andrew Pratt]

I PM'd you.

 

[RichardHOS]

Thanks!

 

[RichardHOS]

Damn, now I'm confused. Well, not really... just surprised. I assumed that the relay clicking was coming from the new Rotel amp I added to the stack of equipment. I mean, I've never heard that sound in the previous several years I've owned all the other equipment in that particular rack (Rotel power strip, three other amps, and an AM/FM tuner) until I added the 991.

Well... as I sit here at the computer I've noticed the relay still clicking (coming from the other room - doors open). All the amplifiers are connected to a Rotel RLC-900 powerstrip/line-conditioner/turn on timer. Which means that with the system powered down (as it is now), the amplifiers are disconnected completely from AC (or should be at least). With no power coming into the amps, I don't think there's any chance that it is a relay in the amp that is clicking.

In fact, the Rotel powerstrip is the only thing in that rack that has any AC power at all when the system is off (being the only component plugged directly into an outlet). So it would appear that the offensive relay is in fact in my trusty six year old RLC-900.

It's not surprising the relay sound fooled me, as it would be logical for Rotel to have used the same relays in lots of their equipment. After thinking about it, the relay sounds from the RLC-900, RB-981, and RB-991 are all practically identical.

Guess it wasn't a bad ebay seller after all. My string of good fortune there remains uninterrupted! I'm also encouraged by this discovery, since it now seems very likely that simply replacing the particular relay that is quirky should solve the problem. I'll contact the techie at Rotel and see if they can suggest a method for troubleshooting to find just which one. Being that it still happens when the powerstrip isn't receiving a trigger signal, that probably narrows it down considerably.

 

[Jim_P]

Your culprit is probably whichever output connection you started using when this whole clicking thing started.

 

[RichardHOS]

Due to the limited number of power amplifier outlets on the RLC-900 (just two), I'm using a power strip connected to just one of those outlets and all four amplifiers connected to that strip. I know the combined amplifiers' maximum power draw is above the combined power amp output rating on the RLC-900, but I never turn the volume up past what I would guess is just a few tens of watts or so at most.

It is still possible though that the addition of that last 991 was too much for that output relay. But, seeing as how I hear the clicking even when the amps and RLC is powered down, my guess is that it is an input relay, not an output relay. Could be wrong. I'm going to call the Rotel guy this morning and see what he has to say.

 

[Jim_P]

My guess is that the relay is going out and either it'll stay on (or off) all the time.

By the way, I've got a RB991 coming in today.

I'll be using it to drive my rear center channel in a 6.1/7.1 configuration. My other channels are being driven by a Rotel RMB-1095 (5*200) which I've been very pleased with.

Now I have to decide if I should get an electrician in for another outlet.

 

[RichardHOS]

Bah! :frowning:

So I missed the tech guy today... I'll try to catch him next week.

Last night I noticed (as I posted above) that I heard the relay clicking when the system was powered down. Tonight I noticed that after powering down I would get a few clicks, one every couple of minutes. So I patiently sat beside my rack intently listening to my line conditioner.

To my surprise, I'm almost positive it was the amplifier above that made the offensive click! Since there's only one amp above the RLC, I thankfully don't have to guess which one it was.

But now I'm back in confusion mode. I thought the 991's had a shunt to drain capacitors after AC power is removed. If so, then HITH can a relay make any noise once everything is dead? Or perhaps even more mystifying, how could it make several repeated noises with no power?!?

Perhaps I'm mistaken and there isn't a shunt... or perhaps it is the culprit and isn't draining the caps. In either case, it sounds like I need to talk to someone more knowledgeable before I start poking around in there. RLC with bad relay = not so bad. 991 with bad relay and potentially 60000uF live capacitance = :frowning:

 

[Jim_P]

Have you tried removing the 991 from the rack and connecting (power only) it in another room. That should help identify the offending component.

You really need to know for sure which component is causing the clicking sound before taking the big hammer to it.(figure of speach only).

Hopefully it isn't a combination of connecting the 991 to the RLC that's causing the problem.

You wouldn't happen to be using any cheater plugs to avoid ground loop hum? If so, maybe this could affect the capacitors from discharging.

 

[RichardHOS]

lol, this is really a mystery. No, I haven't had a chance yet to set the suspect amp up in a different room for observation... I think tomorrow I should have time to do that.

I'm beginning to suspect it might be something different than what I had originally thought. I've notice over the past 24 hours of use that I hear the clicking a few times within the first hour or so the system is powered up, and then it seems to be quiet or perhaps a random click after a couple of hours. It also seems to consistently click several times after the system is powered down. If the system has been on for a few hours, and I shut it down and power it right back up... no clicks.

You know what that sounds like?!? Thermal expansion! I've noticed that the 991's run quite a bit warmer than my 981's do. I'm beginning to wonder if the heat isn't causing expansion between two parts that are screwed together, which "slip" against each other like a mini-earthquake kind of thing. It would seem to fit the observations. And with carefully paying more attention to the sound, I've noticed it is slightly more metallic and ringing than the relay on/off clicks... and it's not always a constant volume, whereas the relays are.

That the two sounds are similar wouldn't be surprising, since both would cause ringing in the chassis/case.

lol, I feel like Sherlock Holmes! Perhaps just loosening or tightening a few screws will solve the problem. I'll find out tomorrow.

 

[Jim_P]

Had to go check. My 991 is warmer than the 1095. So that must be normal. It does not click, however.

 

[RichardHOS]

If it is thermal expansion, playing with the tightness of a few screws might be all that's needed. Hopefully this afternoon I'll get a chance to spend some time with it.

 

[Jim_P]

Hey Richard:

I added a Panamax Max 5100 (power conditioner)to my system last week and started getting the occasional click with my 991 as you described.

Didn't click without the power conditioner.

I think it has something to do with the RB-991 was not designed to be turned off by removing the power as we are doing with our line conditioners. If you think about it, the power switch on the 991 is still on. I bet the capacitor(s) is not discharging which migh also explain why turning on both amps at the the same time doesn't dim the room lights as they did the first time I powered them on through the line conditioner. I think I'll experiment with turning the power button off on the front of the 991 to see if that eliminates the occassional click sound. I haven't noticed mine clicking while its actually playing.

Did you make any progress on yours???

Jim

P.S. You didn't sell me your 991 did you??lol