RB-990-BX Crackling Sounds Left Channel

[polaris26]

Hello all - I just found this forum. I hope someone here can help me. A while ago I purchased a used RB 990 BX Rotel power amp and it sounded amazing when I got it. More recently, it has developed a nasty habit of emitting an intermittent sharp snapping crackle from the left channel. This comes and goes and sometimes I can get it to lessen or go away, especially after I play the amp with some volume for some time. My speakers are very efficient so this is usually very loud and not always possible. I have read other people with similar problems with other Rotel gear from around the net and on this site. I am assuming this was not uncommon for Rotel equipment. I would like to have this fixed since I love the amp. My question is where can I take it to make sure that I will get the proper service for the amp? I know there is an authorized repair facility about two hours from my location. I have read however that someone with Rotel problems like this took their amp to a supposedly authorized repairer (I am guessing not in warranty) and the problem kept coming back after it was 'fixed'. I would like this fixed right the first time. Does anyone know what was the cause of this problem in the Rotel designs? Bad solder? Bad capacitors? Something else? I have read of someone talking about a processor board being bad but I assume my power amp doesn't have such a board. I know it is not uncommon for otherwise excellent consumer electronics designs to be hamstrung by penny pinching manufacturers trying to save a few cents on parts, solder, etc. I don't know if this was case at Rotel. I am hoping someone knows of common source(s) for these problems and I won't have to reinvent the wheel, as it were - it sounds like I am not the only person who has had these symptoms. I am in north east PA USA, and if anyone has a suggestion of where to get this fixed properly I would be most appreciative.

thanks,
Dave

[wkhanna]

Hi Dave.

Welcome, & sorry to hear you are having issues with your amp.
I too, have an RB-990 BX amp.
It is a V good amp, IMHO.

However, any RB-990 is getting a little 'long in the tooth' by now.
No matter how good (or bad) a product is made, time will eventually take its toll.
And age will effect components whether they are used constantly or only occasionally.
Now might be a good time & a cost-effective course of action to consider having a restoration performed on your unit.

Some of our good members may have some suggestions on things you might try at home to diagnose & possibly repair your amp.
I am sure they will chime in soon.

For repair service, I would guess that Rotel Service Facility charges may be a bit on the higher end of the scale.

I can tell you that Tom & Anders at Vintage HiFi of Pittsburgh are highly qualified, friendly & always willing to offer trustworthy advice, & have performed exemplary repairs, modifications & upgrades on my equipment the equipment of my friends including an RB-1090 & other Rotel gear. Note that their hours are later in the evening than most & they are relatively close to you.

PS. Have you thoroughly vetted your system to be sure the problem is emanating from the amp & not a pre-amp, source component or speaker?

[polaris26]

Hi Bill -

Thanks for the response. I hear the crackle when nothing except speakers is connected to the amp, and it hasn't happened with any of the other amps I have used with this system. The speakers are Klipsch Chorus II and I have not had any other problems with them. I am pretty sure the problem is the amp. I can check out Vintage Hi Fi in Pittsburgh, although it is too far to drive back and forth to (about 5 hours one way) and I am a little reluctant to ship the amp. I would love to have the amp restored, but properly, not by someone shotgun-replacing components. I saw an add once for a Rotel amp where the seller claimed he had had it gone over by Rotel but other than the listings for authorized service I was not sure what he was talking about. Is there one main servicing center in the US that would perform this type of 'restoration' or upgrading work on older Rotel gear? It is a great amp, and so far (on my budget) is the best solid state amp with the Klipsch speakers I've heard.

Dave

[wkhanna]

I would love to have the amp restored, but properly, not by someone shotgun-replacing components. ......

Vintage HiFi was solicited by Rotel to become one of their few authorized service centers due to both their qualifications & reputation. Tom turned down the proposition because he felt his customers would be paying an extra premium simply for the Rotel endorsement since the customer costs would necessarily then be higher than what he normally charges. He is one of the few authorized by Bod Carver to work on his equipment & just last month got back from the annual 7-day 'fest' in N Carolina where Bob Carver, Tom & some of the other geeks from around the country spend the week designing & tweaking all forms of equipment. It is their idea of a vacation!?!?

Is there one main servicing center in the US that would perform this type of 'restoration' or upgrading work on older Rotel gear?

Dan (PewterTA) our moderator on the Digital Audio forum, who, BTW, has developed some well proven modifications for Rotel amps, has a contact at the main Rotel service center. We will have to get him to give us some info.

Regarding 'upgrading', an authorized service center would most likely not perform any modifications, only refurbishment.

I am a little reluctant to ship the amp

My experience is if the unit is well packaged (double boxed) & insured for actual value, there is little to be concerned over. Especially with something like an amp which is fairly robust.

[madmac]

Sounds like your digital board is going. Eventually it will pop more often and then fail to work altogether. Try setting the amp to 'analog bypass' mode. This bypasses all digital processing and will likely sound better as well as fix your popping issue. However in that mode, you will lose any surround sound (If your amp offers it), tone controls, and you will have to feed it only analog signals via RCA cords.

Fixing it will be a dicey issue and Rotel fixed my amp under warranty only for it to fail again the same day I got it back.

[wkhanna]

Hi Dan.

I am not aware of a 'digital' board on an RB-990bx solid state 2ch amp.

link to owners manual

[PewterTA]

If you send it to Vintage, they definitely like when you include this... Service Manual

I had my RB-1090 fixed by Tom and Anders... great work and it's been FLAWLESS since they repaired it. And at $120 (plus a $40 tip on my behalf to Anders) sure beat the $150 shipping to Rotel, plus $150 to look at it, and then the price of parts -- they were willing to waive labor). So I basically saved half on the cost for the same repair (actually probably better) than sending to to Ohio or middle of PA for me.

And it should be noted that Anders fixed a problem with Bob Carver's Amp that BOB couldn't figure out. Plus the upgrades that Tom and Anders have come up with for the C-19, Bob is certifying as a mod that "must be done." And Vintage is the only shop to do it.

So I can highly recommend them.

I agree a double walled box and some good foam packaging and the amp should be fine!

If you want me to update the amp with the few little mods to it I do... it does help make the amp sound better. At least every amp I've done has gotten some decent improvements.

You could ship it to me, I can do the mods and then drop it off at Vintage for them to do the real repairs and they can send it back to you. Of course, if you want to do that, just make sure that you confirm with Tom that, that is what you're going to do.

[polaris26]

UPDATE -

Yes friends it actually took this long for me to get my beloved amp back. Unfortunately the story has not gone so well for me.

In hindsight, I should have boxed up the amp and shipped it to Vintage. Instead, I wanted to find somewhere close enough to drop it off in person. I checked the Rotel website and found a short list of 'authorized' service centers. There was one a few hours from me, so I decided to hand-deliver the amp to them.

Very long story short, I just yesterday drove back to pick up the amp (four months later). The service center had initially had problems sourcing OEM parts, and then had all sorts of problems with the amp overheating and taking out the new components they had just installed. Finally the other week they claimed they had the problem completely resolved, and had run the amp for a week, no problems, and it was ready to pick up.

I got it home and connected it to my beloved Altec Lansing Model 19 speakers (big mistake) and turned it on. It popped a 15 amp breaker in my basement almost instantly. I disconnected the speakers and the preamp, and tried again. This time all was well so I reconnected the speakers and the preamp and proceeded to listen to a familiar CD. The amp played ok although something about the sound seemed off, but I couldn't quite put my finger on what was not right.

I changed CD's and turned the volume up a little bit more. All of a sudden, the left speaker's sound changed dramatically and I suspected something was blown. I turned down the volume and got near the speaker and smelled a horrible smell. It seems both the woofer and tweeter are fried!? This is an expensive fix.

My question now is what to do next. I am thinking of getting legal representation to resolve this. So far I am out the initial cost of the amp, plus another $300 it cost for the repair, plus who knows what it would cost to repair the vintage Altec speaker, assuming it even can be repaired! This really has turned out to be a nightmare. And yes, I deeply regret not taking the proffered advice!


Dave

[madmac]

Oh Dave......I am so sorry for your woes!!. The Altec Lancing's your referring to sound old. If so, . The chances of getting replacement drivers are slim to none. If they are repairable (Doubt it), the sound will not be the same again. What is the impedance of those speakers??.

As for the amp....sure you can scream and probably get them to try and fix it again for free, but that's not going to get your speaker back unfortunately.

As I mentioned before, you have to evaluate the current value of the amp and speakers to establish weather they are worth fixing before shelling out big dollars for repairs. Have you called the repair shop to advise them what happened?.

I would be very interested to know what happens next??!!.

[wkhanna]

Dave,
So sorry to hear of this nightmare of experiences!

My advice would be to first contact the shop.
Tell them, in a calm voice with no added expletives or emotion exactly what happened when you got the amp back.
See if they offer to fix the amp or at least refund your money for the repairs.
If they do not make any reasonable offers on their own, don't get aggressive with them on the phone, play it calm & cool.
If they are an 'authorized' Rotel repair center, contact Rotel.
Tell them what happened.
The shop is more likely to offer some sort of compensation if Rotel tells them to, rather you yelling a screaming 'law suite' over the phone.

AFA the speakers, it is quite possible replacement driver are available.
Google is your friend.
Also, Tom at Vintage HiFi of Pgh will have a vast amount of experience & knowledge on what your options are regarding the Altec Lansing's.

[polaris26]

Hello friends,

This is what happened so far - I contacted a gentleman with Rotel service up in MA and after I explained what had happened, he very generously offered to take the amp for free service and even offered to send me a shipping container. I am just trying to see at this point if the service center who worked on my amp previously will accept the findings of Rotel service in MA, I.E. if Rotel says the amp could have caused damage to the speaker, will the service center who did the work originally be willing to reimburse me either for the service cost or the speaker. So at this point I am waiting to see how that goes - I will say so far I am highly impressed by how Rotel in MA handled this situation, and I wish I would have called them up originally, as they are going way out of their way to help me with this totally out-of-warranty service situation. They also indicated that the center I had do the work had had another complaint about it in the past, and if they get too many complaints the would drop them as an authorized repair center.

Dave