Rotel Power Amp Mods to RB-991?

[sulapovi]

Hi,

Has any one carried out modifications/upgrades to RB991 stereo power amp. I wish to tweak the PS stage with new Caps, rectifiers etc.. to improve the quality of sound. Any suggestions pls..

[KathyMason]

So far, I've never heard of any Rotel amp modified, maybe you can't improve their sound if already using the best internals?

[lvhung]

Expense of mods is usually much more expensive than the cost of original unit

[sulapovi]

Dear Kathy & lvhung,

I'm even planning to upgrade to RB1080 from RB991. But I've not listened to 1080 yet & as per bookspecs both are almost identical.

My doubt is would this upgrade to RB1080 from RB991 fetch me lot sonically? By any chance, has 1080 got better quality components than 991. Power is not the concern since both are rated same. Is it advisable to upgrade keeping the costs in consideration (I loose heavily by trading 991 + 've to invest diff of $$ for buying 1080) Rqst for your opinions/suggestions,

rgds

[Andrew Pratt]

All I know is the things didn't change enough from the 991 to the 1080 to warrant sending the amp back to Lucas for re-evaluation for THX approval. That's not to say they didn't improve things here or there just that fundamentally they're more alike then different.

[KathyMason]

sulapovi, I wish I could be of more help to you but I’m using a RB-1090 and I don’t know what the difference would be between the RB-1080 and the RB-991. I’ve never had the chance to hear a RB-991.

Ok....... I took a look at some internal pictures of the RB-1080 and the RB-991 and they look identical inside. I doubt there is a difference, so I think Andrew is right, and he would know. I think I would stick with the RB-991 and the THX stamp as you know doesn’t really mean anything, so it wouldn't be an upgrade for you.

[sulapovi]

Hi Andrew & Kathay, you are right & I too feel same. When I was talking about Sonic qualities of 991 few of my friends were suggesting me to go for 1080, but, I had my own doubt that I would not be benefited much. Thanks for the opinions.

I know RB1090 is in different leage & it's Rotel's flagship amp & worth investment.

[Iliya20]

Even though this is the old thread I am so outraged that I've decided to reply anyway. "RB-1080 is the upgrade." You guys must be kidding. Does any of you guys read Stereophile? Just compare the measurements for RB-991 and RB-1080. Especially harmonics distortion spectrum. The 1080 is just garbage in comparison. Do you know that 991 uses famous for their high quality the Black Gate capacitors and 1080 does not as those caps are no longer being made? Only a madman would exchange 991 for 1080.

Here is the proof: 268W output from RB-991 vs. 153W from RB-1080