My adventures with the RM1080

[Andrew Pratt]

I still haven't really spent a whole lot of time listening to my new 1080 but one thing that I did notice is that my level of "hum" jumped a great deal over the amps I had before. Now I did have a grounding block on my satelite feed already so I didn't think that would be the issue but as soon as I removed the RG6 cable from my Sat receiver it was instant quiet. So I added a better ground to the grounding block and that has now reduced it to a much lower level then it was previously so I'm happy now with it. I guess it just points out that the 1080 is more sensetive to grounding problems then the 1075...but that it can be fixed by getting to the source of the problem which for me was the satelite cable.

[Bing Fung]

Andrew, I made a ground isolator from 2 Balens transformers that I inserted between the cable feed and my Digital cable box. It has removed all ground related Hums, and did not degrade the video signal at all.

Either than or get a cheater plug :P







You can buy these in a 75 ohm - 75 ohm so you only need one, however I had these 75 ohm - 300 ohms lying around.

[jlee]

Hey Bing, where did you buy those transformers and that nice jacketing?

[Bing Fung]

Jlee, the Transformers can be bought at any electronics supply house like Radio Shack. I actually found these in my Dad's video junk box. Like father like son I suppose :wink:


The mesh sleeving, I had our local B&E electronics order in for a project I was working on many years ago.

you could try These Guys

[DrBoom]

I guess it just points out that the 1080 is more sensetive to grounding problems then the 1075...

Seems kinda obvious seeing how the RMB1075 is NOT grounded :B
I had a horrible buzz too the first time I hooked up my Parasound, it's the only grounded thing in my entire system.
Either use a cheater plug to lift the ground, or remove/decouple any antenna or satellite leads from your system.
As bing suggests you can do this with a ground loop isolator device.
I have one too, worked like a charm.

Looks a bit different though and cost me around €30 or something.
Includes both inductive (transformer) and capactive decoupling for maximum efficiency.

[DrJRapp]

Andrew

Congrats!...it's about time you caught up with the rest of us.....LOL You'll love the 1080 after about 90 hours of use.

[Tha Freak]

Andrew!!.. :T

It is the amp I have in mind for my 2ch set up in my house (move in in spring )...

Do you use it in the HT or for music?

If for music, what preamp you have?

And How much should I espect to pay in 6 months?

[Andrew Pratt]

Tha Freak its use in my media room to run the front two speakers using the 1098 as the pre amp and i doubt you'll pry it from my hands in 6 months....although that 1090 looks sweet

[Azeke]

Tha Freak its use in my media room to run the front two speakers using the 1098 as the pre amp and i doubt you'll pry it from my hands in 6 months....although that 1090 looks sweet

Congratulations, Andrew. I am sorry to hear about your mis-adventure.

I've been looking at the RB-1090, based on previous threads and curiousity, but I am not going to get bitten by the upgraditis bug, at least for now .

Let us know how you like it. I read in a review recently that one gentleman traded his in after two weeks (did he allow it time to break-in?), and rated it a three. Everyone else gave it a five in value rating, go figure.

Enjoy your toy,

Azeke

[Andrew Pratt]

I am sorry to hear about your mis-adventure.

Oh it wasn't that big a deal just meant I had to properly ground my system which will benefit the rest of the gear too so its time well spent. I might try BingTech's solution as well since it'll be cheap and easy to do...plus I love to tinker

[Tha Freak]

...and i doubt you'll pry it from my hands in 6 months....

:rofl:

Nope...I mean How much should I pay in 6 months for a brand new!! (ie how much does it cont now...and are the prices subject to go down)

What pre-amp (Rotel or non-Rotel) is a good match...??

And I will have to have radio on that (for the GF :roll: )...separate tuner or integrated one?

[Andrew Pratt]

The best tuners are seperate units with the best being old units from the glory days of radio. The 1080 lists for $1499 cdn at the moment and will likely remain at that price..though the introduction of Rotels digital amps might change that to some degree but that's all speculation at this point.

I'll let the other guys chime in with 2 channel pre amp recomendations though as they're more familar with them then I am.

[Azeke]

Just blew my left channel fuses again, bummer (third time). I will have to replace the fuses tonight. I am no longer going to use the dreaded 12 Volt trigger.

Maybe I should contact Rotel again, so I can be upgraded.

Edit: I have contacted Rotel and requested the 8.3 amp slow blow fuses, hopefully that will correct my issue.

Any comments or suggestions are welcomed.

Regards,

Azeke

[Andrew Pratt]

i've been using the amp trigger on mine without a problem so far. I also just heard from Rotel that the 1080 should do about 360 watts into 4 ohms and that the reason its not listed on the website is that they used the old 991 electrical certification for the new 1080 and the 991 was never tested at 4 ohms. Anyway that's a ton of current into my 4 ohm mains :yesnod:

[MattCXII]

Some of the posts in this topic are the exact reason why I stayed away from the RB 1080 and went with Bryston. I love the Rotel gear that I have but with the amount of problems this amp has seen it just doesn't seem worth it to spend that kind of money on a lemon product.

That might sound harsh but I don't think I should expect to be blowing fuses 3x on a product that is supposed to be ready for the consumer market.

[DrBoom]

Look at the measured results from this Stereophile review I found
Too bad it's only with 1 channel driven, but it still shows how powerful the output transistors are.
I doubt it would get these numbers with 2-channels driven because the power supply won't be able to deliver this much power into 2 channels at once.
Very impressive anyway.

Using the conventional 1% THD definition of clipping, the Rotel puts out 291W into 8 ohms with one channel driven (24.6dBW), 558W into 4 ohms (24dBW), and even 800W into 2 ohms (23dBW)!

[Mitchell]

My 1080 is on its way back from Rotel. Supposedly it has the upgraded fuses and capacitors. They turned it around pretty quickly and hopefully this will be the last of the blown fuse problem.

[Azeke]

My 1080 is on its way back from Rotel. Supposedly it has the upgraded fuses and capacitors. They turned it around pretty quickly and hopefully this will be the last of the blown fuse problem.

Please keep us informed Mitchell.

I have also responded to your PM, thanks for the update.

Regards,

Azeke

[NMG]

I haven't had any blown fuses in mine (I've had it over 3 years now), although I haven't used the 12 volt trigger either. I've just been using the old fashioned power button

[Taito]

I've been using 12V trigger no probs -RC1070 switching 1080, 1080 switching RCD1072.

Different batches, or just lucky?

-Ben