Integrated amp run with power amp

[johnandchris]

Hi. I currently own a rotel ra-971 mk 2 integrated amp which i am happy with. I am running a standard marantz cd5400 (eventually i will modify). I have managed to get my hands on a rotel rb-970bx power amplifier and am planning to run it alongside the 971. My plan is to use the power amp to run the bass on my speakers (bi-wirable tdl nucleus 2) and the integrated to run the tweeters. I am using my own design and manufactured solid silver interconnects and solid silver speaker cable.

Will running the power amp cause any problems, it is in full working order. Any advice will be gratefully accepted, and advice on mods for my 3 components would also be great.

Best audio forum out there by the way.

Anyone got a linn sondek sp12 for sale (cheap) or advice on an equivalent turntable on a budget.
Thanks
John

 

[AndrewT]

Check to see that the gain of the power amp matches the gain of the power amp section of the integrated.
If not then the two halves of the crossover will be fed with different voltage levels and will make the speakers sound odd.

 

[johnandchris]

Thanks for the reply. I am really new to this modifying and i am not an electronics expert. You speak of gain, what is it, and how do i measure/change the gain. I have the manuals for both with the technical spec at the end so if someone can point me in the right direction i would be grateful.

With my new setup, it does appear to have smoother power, however once turned past halfway my speaker start to distort (i gues to do with the imbalance in gain????. I have wired the power amp to the bass speakers and the integrated to the treble. is this the right way round????

My speakers (which i guess are the weakest part of my setup) are tdl nucleus 2. Do they have a crossover and if so is it worth me taking it out. I have heard that if the crossover is in place then you are not really bi-amping.

Sorry to be a pain and ask really dumb questions, but i want to get the most from my system without spending too much money.,

Grateful of any help

John

 

[AndrewT]

Firstly, two amplifiers each driving one half of a passive crossover into a two driver speaker is bi-amping.
In the US (and maybe other countries) they use the term bi-amping to mean active speakers.

Distortion coming in as you raise the volume is nothing to do with a gain mismatch. You are either overloading the amplifier/s or overloading the speakers.

To check the gain, either read the spec sheet for the two amps or use a fixed frequency voltage source and measure the amplifier output voltage.

I would be more inclined to blame the Rotels rather than the TDLs for poor sound quality, but then I'm pro British and anti far eastern and that's mostly down to poor customer support and deliberate obsolescence to con the unknowing public to part with too much money too often.

 

[johnandchris]

Thanks for the reply. My difficulty in the gain question is not knowing what it is says in the specs. I have compared the two amps and most bits are the same. What in particular should i compare. At no point in the manual is gain mentioned.
Regards
JOhn

 

[johnandchris]

I guess what i am trying to ask is do i gain anything by adding the power amp. I am pleased with the 971-mk 11. I have heard that the 970 models were not well received but the 971 were superb for the price. Am i wasting my time bi-amping with the 970 if it is indeed inferior to the 971. The only reason i am bi-amping is that i got the 970 for next to nothing.

Am i doing something just for the sake of soing something ???????

Any advice gratefully received by a confused beginner audiphile (hopefully)

Regards
John

 

[AndrewT]

Hi,
I prefer bi-amping.
You get the dual benefit of bi-wiring and reduced loading on the amplifier.
Both these seem to help sound quality.

 

[johnandchris]

Thanks for the reply Andrew.

I think i will leave them hooked up together then. I have the power amp driving the bass speakers and the integrated driving the treble. Is this the right way around??

Also, , how do i (in lames terms), check the gain. I have a mulimeter and very basic knowledge of ho to use it. The manuals do not mention gain, and are identical in ev ery way in specs, apart from the signal to noise ratio (whatever that is) which shows that the integrated has >95 db and the power amp has 116. Is this gain????? and if so how do i adjust the gain to match.

I really am grateful for you taking the time to help out a beginner, but i suppose everyone has to start somewhere.
Regards
John.

PS. if i am going to remove the crossover from my speakers, what does it look like, is it worth doing, and is there anything i should know before i start.

 

[AndrewT]

No, don't remove the crossover until you are ready to start a much bigger project.
Go and find the ESP site and read about bi-amping and active speakers and similar topics he has there.
If the balance between treble and bass is unaltered when the speakers are driven by a single amp and then the twin amps then that indicates that gain is very similar.
Some manufacturers deliberately set up their range of products this way.