Rotel RB-1070 Amplifier Review

[TonyJZX]

its a bit silly to compare a current 50w digital amp that is what? 3kg? with a traditional 19" 12kg class A/B behemoth from 20yrs ago anyway

the rotel has about 3x the power and will sound like the well engineered battleship one would expect of that era, which actually isnt that long ago and really, are we expect that much better performance now from traditional class A/B in this price range?

 

[restorer-john]

Sadly there is a significant power on pop:

Can you clarify the noise bandwidth, weighting (if any) and whether the input is shorted (via the AP) or just 'silent'/no output from the AP's gen? I really like this 'new' turn on/off test. It covers a bunch of stuff in one recorder plot.

Also, with this particular Rotel amplifier, the section you have marked 'off' is not actually truly 'off'. The input is shorted (via a relay) and the output stage is likely still running as the rails collapse after power off. There would likely be another thump/transient event as it died out later (as the plot only ran 4 seconds after the switch off action)

But it's very useful and interesting that a 90mV switch-on 'pop' appears 'rather loud' isn't it?

 

[Deleted member 48726]

Good review. But I think it takes it away that the heat sinks are just for show. Kinda makes the thing look silly to me instead when I know the fact. But a good classic performer none the less.

 

[restorer-john]

Good review. But I think it takes it away that the heat sinks are just for show. Kinda makes the thing look silly to me instead when I know the fact. But a good classic performer none the less.

It was a strange decision back in the day for Rotel. None of the amplifiers used the front panel heatsinks except (IIRC) a three channel (THX?) unit.

 

[Tangband]

its a bit silly to compare a current 50w digital amp that is what? 3kg? with a traditional 19" 12kg class A/B behemoth from 20yrs ago anyway

the rotel has about 3x the power and will sound like the well engineered battleship one would expect of that era, which actually isnt that long ago and really, are we expect that much better performance now from traditional class A/B in this price range?

Weight has nothing to do with performance at 2023.
Agree that Topping pa5 is limited in power. But we have other comparisons with for example Hypex modules that trashes the Rotel completely and at the same time has lower weight and very high power output.
I dont understand this fascination for old class A/B technology in this thread. A SINAD of 80 dB is mediocre.

Read this - this hypex based amp weights 5,6 kilo (!)

Audiophonics HPA-S400ET Review (Stereo Amplifier)

This is a review and detailed measurements of the Audiophonics HPA-S400ET. It was sent to me by the company after member request and costs 1 490,00 € (US $1,638). I must say this is one of the best packaging of class D amplifiers (Purifi in this case) that I have seen! It is slick and has...

www.audiosciencereview.com

 

[amirm]

Can you clarify the noise bandwidth, weighting (if any) and whether the input is shorted (via the AP) or just 'silent'/no output from the AP's gen? I really like this 'new' turn on/off test. It covers a bunch of stuff in one recorder plot.

Not in front of my workstation but from what I recall, I set the bandwidth to 45 kHz. Sampling is 32 times a second. All wires are connected but of course, no source signal.

 

[Deleted member 48726]

Looks OK for a top view.

Wow, that's a lot of unused real estate.

 

[pma]

But it's very useful and interesting that a 90mV switch-on 'pop' appears 'rather loud' isn't it?

90mV is a lot. It rather depends on the length (and thus energy) in the spike.

 

[Andreas007]

Weight has nothing to do with performance at 2023.
Agree that Topping pa5 is limited in power. But we have other comparisons with for example Hypex modules that trashes the Rotel completely and at the same time has lower weight and very high power output.
I dont understand this fascination for old class A/B technology in this thread. A SINAD of 80 dB is mediocre.

Read this - this hypex based amp weights 5,6 kilo (!)

Audiophonics HPA-S400ET Review (Stereo Amplifier)

This is a review and detailed measurements of the Audiophonics HPA-S400ET. It was sent to me by the company after member request and costs 1 490,00 € (US $1,638). I must say this is one of the best packaging of class D amplifiers (Purifi in this case) that I have seen! It is slick and has...

www.audiosciencereview.com

View attachment 258726

I guess we got your point.
But let us also appreciate good engineering from the past.
Besides, there are a lot of examples of brand new amplifiers which perform worse than this Rotel. So, give it some credit.

 

[killdozzer]

Funny how, while reading the review, all the way to the end, I thought it wouldn't get recommended.

 

[Matias]

Nice retro review, but even used price, I would not recommend it nowadays. Just not competitive anymore. Sure maybe 20 years ago it was, but not now IMO.

 

[Sokel]

Weight has nothing to do with performance at 2023.

It does if you want to meet the upper specs of the modules,heatsinks are not light and one has to have some space to put them.

 

[Waxx]

Rotel always sounded good but not super clean, so it's no surprise for me that it measures that way. And for a 20 years old amplifier it's actually very good. I guess if you redesign the psu to modern standards it will sound a lot cleaner.

In my experience (i had that amp for a short time when i was trading a lot of second hand stuff) it's very solid and reliable. I bought it second hand very cheap as part of a bigger package (with a Luxman C-02 preamp that i still have and a pair of Kef Cadenza speakers i also sold after restauration) and was ready to fix it and clean it up.

But outside some cosmetic (removing dust inside and out and grease on the outside) I had to do nothing on this device that was then 11 years old. It was also sold fast for a good price at that time (500€). New price was 700€ at the time it was sold down here. The original owner replaced his Luxman M-02 amp with it, and he liked it a lot more, altough the Luxman is still way more expensive second hand, and certainly new back in the 1980's. When he sold it to me he replaced the set with Bryston (pre)amps and modern Kef tower speakers (i don't remember the model). I did not need such a amp at that time, otherwise i would have kept it like i did with the Luxman preamp.

 

[pma]

Nice retro review, but even used price, I would not recommend it nowadays. Just not competitive anymore. Sure maybe 20 years ago it was, but not now IMO.

The sound of this and similar amplifiers has never been transparent enough, even compared to contemporary measures. Just a good, reasonably priced and reasonably engineered commercial home audio product, nothing more.

 

[Matias]

It does if you want to meet the upper specs of the modules,heatsinks are not light and one has to have some space to put them.

Even if you care about maximizing continuous power on synthetic tests that have nothing to do with real music, still heavy heatsinks are not necessarily the way to go.

Vera Audio P400/1000 Review (Amplifier)

This is a review and detailed measurements of the Vera Audio P400/1000 Hypex NC500 based amplifier. It was sent to me by the company and costs 26 000 NOK ex VAT (US $2934). The case is milled from solid aluminum and has a nice quality and look to it. It is also quite heavy for a class D amp...

www.audiosciencereview.com

 

[Sokel]

Even if you care about maximizing continuous power on synthetic tests that have nothing to do with real music, still heavy heatsinks are not necessarily the way to go.

Vera Audio P400/1000 Review (Amplifier)

This is a review and detailed measurements of the Vera Audio P400/1000 Hypex NC500 based amplifier. It was sent to me by the company and costs 26 000 NOK ex VAT (US $2934). The case is milled from solid aluminum and has a nice quality and look to it. It is also quite heavy for a class D amp...

www.audiosciencereview.com

I don't mean they have to be 30Kg.
For example the highly praised Audiophonics Purifi is about 6-7 kilos and I consider it's thermal capabilities the bare minimum.
It's not only about power if you use it hard,it's about longevity too.

Edit:Just saw that Vera is about 9 kilos and uses it's case for heatsinking.Same thing,Rotel is about 2 kilos more (with all the cosmetics) ?

 

[DSJR]

Hmm not very impressed. Compared with the topping pa5 with tpa 3251 chip inside ( same chip as my Aiyima a04 ) , the Topping pa5 outperform* the Rotel below clipping point. Lots of power with the Rotel though.

*In my experience, such differences is something that you can hear, to. The tpa3251 based amplifier will sound clearer.

View attachment 258707View attachment 258708

Most high end amps back then performed similarly or even worse than this one, but look at the distortion pattern - audibly harmless second harmonic with odd orders above that well down and subsequent harmonics declining in a straight line to 20k and no doubt beyond! I bet it's a heck of a lot 'cleaner' at supersonic frequencies too than the new wave of wonder-whizz-boxes this site wets itself over? Got to say I like the seemingly simple and symmetrical circuits used there which should be easy to maintain I suspect.

Rotel amps always 'sounded' just fine in a domestic system but kind of got themselves a 'mid price' reputation over here, so would be largely ignored by the 'high end badge collectors' of which there are still a goodly few I think.

Thanks for reviewing this - should help for people after a good used solid buy. That Audiophonics amp with graphs shown above is many multiples of the expected price of this Rotel currently and let's be absolutely honest, that Topping dinky-box is hardly in the same *usage* ballpark now, is it as I'd suggest it's more for basic small desktop systems really?

 

[Ralf Stocker]

The main problem with these toroidal transformers amps is the hum pickup, which can be seen in the poor thd+n readings in every test. Is there a way to shield it?

 

[DanielT]

Rotel amplifiers are incredibly reliable, conservatively rated, well made, well priced and a joy to use and own. I have many Rotel pieces from the same era and before as this amplifier. Noise (residual) is not their strongest attribute, but in practice, is not noticed.

You can't put Topping and Rotel in the same sentence on my opinion. One brand is legendary for all the above attributes, the other has a long way to go....

What you say is probably true because you are familiar with and have knowledge of amplifiers, but does it apply to all Rotel amplifier model/ series? This is what peanuts writes about Rotel's asx series, #3 in the thread:

mind the input impedance of the asx series, its horrible and partially broke 3 out of 4 outputs on my minidsp 2x4HD.

Recommendations / Suggestions for one: Low power amp 5-15 W?

Do you have any good suggestions for one? Fine clean, low distortion watts. Operating from about 2000 Hz up to 17 kHz. New or used amp does not matter. Can imagine up to 20 W, possibly.:).....5 nice W might also be enough. :) ...... The amplifier will drive/power two...

audiosciencereview.com

Edit:
Addendum, thanks Amir! It was an interesting review with detailed measurements.

 

[Ageve]

Something meeting it's specs after 20 years....well,that's what I call good engineering and respect to user.
And will probably work many more with some care.

Thanks Amir!

They use high quality parts, including capacitors from Nippon Chemicon and BHC (now Kemet). The most common problem with aging RB-1080s and 1090s is the relays. Other than that, very reliable.

I have a RB-1080 from 1998, and it still works fine. I have a RB-1590 as well.

Putting aside noise floor which is rather high, the units transfer function is one of the best I have ever seen:

This is the RB-1080, for comparison.

(from a Swedish Hifi magazine):

210/375/575W (8/4/2 ohms)