# Rotel RB-890 Amp's Oil-Filled Caps



## ironglen (Mar 4, 2009)

Hey, anyone own or have knowledge of this particular Rotel 2 ch amp? I was about to purchase one and the only info I can find is a brief owner's manual that had only the most basic specs, and no maintenance info or otherwise. A picture of the innards shows a large toroidal transformer along with 4 huge capacitors that have heavy gauge wire connecting everything to the side-mounted circuit boards, chips, and cooling fins, which appears a bit dated compared to pcb commonly found in newer electronics. I don't even know how old this amp is as searching online has resulted in zero additional information. Any help appreciated.


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## Jungle Jack (Jul 28, 2009)

If you could show a picture of the Front Panel, it would help greatly. It kinda looks like a RB990, but I am by no means positive.


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## ironglen (Mar 4, 2009)

I should have known JJ would be the guy to ask: man you know your equipment!

A couple more pics...what I'm most concerned about are the caps. Still on the fence regarding cosmetics (scratches on top)


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## Jungle Jack (Jul 28, 2009)

Hello,
I somehow missed the Title of the Thread. Rotel is great about keeping Parts for older Amplifiers should you need to replace the Capacitors. I am guessing you were able to procure the amp for an excellent price. They make excellent Amplifiers.
Cheers,
JJ


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## ironglen (Mar 4, 2009)

Well, does $200 sound good? I know these Rotel's sell for quite a bit, even used. The faceplate looks good, the top not so good (you can see scratches on the top front in the pictures), so they are not pristine by any means...the manual states 160w/ch 8 ohms, 360 bridged 8 ohms and it weighs 28.7 lbs with 800w input power which looked comparable to higher power amps in their lineup.


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## Jungle Jack (Jul 28, 2009)

ironglen said:


> Well, does $200 sound good? I know these Rotel's sell for quite a bit, even used. The faceplate looks good, the top not so good (you can see scratches on the top front in the pictures), so they are not pristine by any means...the manual states 160w/ch 8 ohms, 360 bridged 8 ohms and it weighs 28.7 lbs with 800w input power which looked comparable to higher power amps in their lineup.


Provided it works well, it seems to be a very fair deal. Rotel makes excellent Amplifiers. Also, you could always take off the Face Plate, Sand off the Paint, and Refinish it. Also, Magic Markers work surprisingly well.


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## ironglen (Mar 4, 2009)

Thanks JJ for the information; it's good to hear that a company takes care of older equipment-parts needs.


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## martinusher (Feb 7, 2012)

I've got one open on my bench at the moment.

Those are not oil-filled capacitors, they're just large electrolytics, part of the power supply. The amplifier is rated at 120 watts per channel into 8 ohms and from its internal construction I'd guess that this rating was conservative. It looks as if it will give many decades of trouble free service.

This sort of design dates from the late 70s / early 80s. I haven't got an amplifier schematic but its pretty easy to see how it all fits together. Its nothing exotic (nothing like, for example a Quad 405 from that era), just a well designed generic amplifier, and it should give adequate to good performance. The one I'm looking at belongs to a friend who uses it to drive his patio speakers; it works well in that application.

I think the owner may have bought it new; if he's got anything to add then I'll add it to this thread.


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## ironglen (Mar 4, 2009)

Oh well, I'll have to look for another as I passed up on that particular amp as I was still uncertain. Thanks for the info!


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## Jungle Jack (Jul 28, 2009)

Hello,
My personal fave used amplifiers in relation to value/performance/durability are any of the Mondial Designs era Aragon and Acurus. Made in America, excellent Parts Quality, with most of the runs of the Amplifiers being built at Manufacturers doing Military/Medical Electronics, and more. Often you can find Acurus Amplifiers for a very good price as they were the Budget Line of Mondial. It ended when Klipsch owned them where it was only Aragon and only 2 Mondial era Aragon Amplifiers were offered in the 8008MKII and Palladium Monoblocks. From that era those are the only Amplifiers I really was so enthusiastic about.
Cheers,
JJ


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