1. Join Now

    AVForums.com uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Finally have a Power AMP!

Discussion in 'AV Pre-Amp/Processors & Power Amps' started by Kazman, Apr 14, 2005.

  1. Kazman

    Kazman
    Well-known Member

    Joined:
    Jan 14, 2004
    Messages:
    5,252
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    86
    Location:
    Luton, Bedfordshire
    Ratings:
    +136
    Hi guys (and indeed girls if there are any here........ :blush: )

    I managed to get hold of a Rotel RB-985 Power Amp for a bargain price, it is the MkI not the MkII, so a bit old, but still a cracking amp.

    I'm going to buy leads and splitters tonight, just want to know if the splitters from Maplins would be good enough, as long as they have a solid connection to the pre out I'm assuming signal degradation should minimal right?

    Also, need to get hold of some decent interconnects so may need to stop off at a hi fi store on the way home too.

    My aim is to bi-amp the front two Quad 21L's and also power the Centre, using the Marantz SR7500 to just power the rears. Therefore need two splitters and 5 interconnects (I'm assuming standard phono stereo interconnect will be fine for this). I was initially going to go for a new Power Amp, but got the Rotel for such a bargain that I couldn't pass it up, think it will be nice little stop gap until I decide to do a full upgrade.

    I also wouldn't mind hearing about peoples thoughts on what I plan to do and their thoughts on the Rotel itself. Cheers :)
     
  2. Tejstar

    Tejstar
    Well-known Member

    Joined:
    Dec 4, 2002
    Messages:
    22,482
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    136
    Location:
    London
    Ratings:
    +990
    Nice one Kaz – looking forward to see how this improves the stereo performance on your Quads! Thinking of doing something similar myself, although have too many things on my ‘to-buy’ list at the mo! :)
     
  3. Daneel

    Daneel
    Active Member

    Joined:
    Dec 5, 2002
    Messages:
    2,813
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    68
    Location:
    London
    Ratings:
    +26
    I'd try single amping first. The splitting may negate any benefit derived from biamping.

    Also due to the different levels of gain between the power amp and your receiver you may find the rears are not matched to your fronts in terms of volume. I'm currently running my fronts biamped on the 1205A and the centre with the rears on the A23. Both power amps have the same gain. Moving the rears from the receiver to the power amp has improve surround effects just because of better volume matching.

    The Rotel may have adjustable gain, I'm not sure.

    Your speakers aren't that demanding so I'll be surprised if you hear much difference until high volume levels that would push your receiver. Then again I've not heard a Rotel before so I don't know how much sonic character they have. My Parasounds are fairly neutral.
     
  4. GFS AV

    GFS AV
    Banned

    Joined:
    Jan 28, 2005
    Messages:
    407
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    16
    Ratings:
    +0
    Just thought i'd share my plans too. The initial plan was to buy a 2nd hand Rotel RA-02 stereo amp with my Yamaha 640SE, using the the Rotel to power the fronts. I have since found out the Rotel is not suitable for my speakers.

    I have bought a Musical Fidelity X80 integrated amp instead. This is apparently fairly neutral sounding, so I have high hopes for this being well matched with my Yamaha. I will be connecting the Yamaha front L + R speaker outputs (phono) to the X80s inputs, **Kaz, i'd imagine you would do a similar connection with your Rotel** thus being able to operate the volume (including the front left and right) via the Yamaha. I am awaiting delivery of the X80. I will let you all know how I get on with it when it arrives. This should definately boost the overall system quite somewhat... hopefully.

    The main reason for the purchase is to improve the stereo performance with my Mordaunt-Short Avant 906s. Any improvements to the AV side will be a HUGE bonus!
     
  5. NikosF

    NikosF
    Active Member

    Joined:
    Mar 29, 2005
    Messages:
    131
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    18
    Ratings:
    +9
    I've got a Rotel 985 myself. I use it for center and surround speakers (and valve amps for my L and R fronts).

    It's a great amp. Power amp technology hasn't changed much (unlike pre-pros) - so there's nothing wrong with an older unit. Enjoy it.

    I would concur with the suggestion to try single amping first - all sorts of issues with bi-amping if you are not careful.
     
  6. GFS AV

    GFS AV
    Banned

    Joined:
    Jan 28, 2005
    Messages:
    407
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    16
    Ratings:
    +0
    Kaz, i'm sure this will sound great. But I can't quite understand why you've just bought such a nice amp, and you're only gonna use it for the rears. :confused:
     
  7. inzaman

    inzaman
    Moderator

    Joined:
    Dec 16, 2002
    Messages:
    7,874
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    136
    Location:
    Derby
    Ratings:
    +927
    How i read it the receiver will be used to power the rears not the Rotel.
     
  8. GFS AV

    GFS AV
    Banned

    Joined:
    Jan 28, 2005
    Messages:
    407
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    16
    Ratings:
    +0
    that's what I meant. A nice shiny new 7500, to be used just for rears????
     
  9. Harry T2

    Harry T2
    Active Member

    Joined:
    Jul 29, 2004
    Messages:
    482
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    18
    Ratings:
    +10
    Hi Kaz, that has taken a long time to go get the interconnects.

    I would also not bi-amp initially. I like to add one new component/change into my system to evaluate just that change. Adding multiple changes can "muddy" what exactly has made the change.

    Also, am I right that you are running a 5.1 system. Is there a facility on the Marantz to direct extra pre-outs into the Rotel without splitting (similar principle to using the Marantz to biamp your fronts)?
     
  10. Kobus

    Kobus
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    Kaz, when are we going to hear the results, ie strereo benefits etc.
     
  11. Kazman

    Kazman
    Well-known Member

    Joined:
    Jan 14, 2004
    Messages:
    5,252
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    86
    Location:
    Luton, Bedfordshire
    Ratings:
    +136
    Sorry guys, I STILL haven't got the interconnects. both my brother and sister are getting married in July (one at the begining of July and the other at the end of July) so home life has been very hectic.

    I will try my best to get something this week, but it is doubtful I will get any time this weekend, maybe on the bank holiday monday......fingers crossed!
     
  12. Kazman

    Kazman
    Well-known Member

    Joined:
    Jan 14, 2004
    Messages:
    5,252
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    86
    Location:
    Luton, Bedfordshire
    Ratings:
    +136
    :) I got the Rotel for a bargain price, so good a price that I would have been foolish to let it go :), hence why I bought it, the SR7500 is a cracker of an amplifier, but even it will not be able to match the biamping capability of this Rotel.....theoretically.

    Harry, unfortunately there are extra preouts, so splitting them is the only option. I'll be doing this in stages in a single setup session, hence why I want to make sure I can set aside a full day for this, and not do things bit by bit.

    First stage will be to use the current biamp functionality within the SR7500 itself, and compare this with standard amplification.

    I will then test the Rotel powering the speakers in normal mode, then will try it bi-amped, and from this I should be able to ascertain the best set up. I would rather do it all in one session as time is the biggest contribution to clouding a comparison and perception. Anyone wanting to give me a hand is more than welcome :):) :D
     
  13. Jules Tohpipi

    Jules Tohpipi
    Active Member

    Joined:
    Feb 4, 2004
    Messages:
    692
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    43
    Ratings:
    +140

    I have to politely, but strongly, take issue with all three points raised in this post.

    1. That a splitter will negate the difference of bi-amping.
    Not true. If one were to take a look inside all pre-amps offering twin outputs, then one will find a mechanical split to each of the ouputs. There are not separate runs (dual channel) topology throughout the product to the outputs. In all likelihood, the Maplin splitter will have better mechanical integrity than a PCB split. So there's no worries there, so long as one uses a good quality splitter - of which there are several on the market.

    2. "Your speakers aren't that demanding so I'll be surprised if you hear much difference until high volume levels that would push your receiver."
    Sorry, but this is to complete mis-understand the rationale behind bi-amping.

    3. "Also due to the different levels of gain between the power amp and your receiver you may find the rears are not matched to your fronts in terms of volume. "
    Again, completely untrue. It's a common misconception that when you're in the speaker menus of the AV amp/processor, doing the test tones, that you are altering speaker VOLUMES. You are not - you are altering GAIN for each channel. Hence why many top-end processors say "Gain" next to the dB level. If you have correctly set this in the menu, then there is zero chance of the rears not being matched to the fronts in terms of volume - regardless of the individual gains of the power amps being used.

    On a final note: if you have been anywhere near the Quad (or indeed Wharfedale) rooms at the hi-fi shows for the last three or four years, then you will have witnessed a Quad CD-P (single set of variable outputs), complete with a pair of Puresonic splitters, driving a pair of 909s in bi-amp configuration. Various L series speakers have been used in bi-amp mode.

    :)
     
  14. Daneel

    Daneel
    Active Member

    Joined:
    Dec 5, 2002
    Messages:
    2,813
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    68
    Location:
    London
    Ratings:
    +26
    I have to politely, but strongly, take issue with all three points raised in your post. :)

    1. Knowing Kaz as I do, a high quality splitter isn't what he'll have to hand. However on this point given your condition of a good quality spliiter, I agree with your conclusion.

    2. That comment had nothing to do with biamping but was in reference to the Marantz vs the Rotel, I'm well aware of the reasons behind biamping.

    3. This was something I was unaware of and to be honest, I'm surprised if it's true. Do you have any links to back it up?

    The reason I say I'm surprised is because if you are really adjusting gain and not the absolute volume level then when using the internal amps of the receiver, you will only have a match at the volume level you calibrate at. As soon as you move away from that volume, the speakers will no longer be level matched because each will change volume by a different amount as you move the volume control due to different gain. That was exactly the point I was making. The only way I can see that this would work is if the level adjustment on the receiver worked absolutely for the internal amps and altered gain for the preouts.

    :)
     
  15. Kobus

    Kobus
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    Interesting point no 3. I would be surprised if todays top receivers do not have the gain adjusted at set-up to be relevant at all volume levels. What I mean by surprised is that todays computing/processing power would definitely allow for it, but if they have achieved it it unsure.
     
  16. Jules Tohpipi

    Jules Tohpipi
    Active Member

    Joined:
    Feb 4, 2004
    Messages:
    692
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    43
    Ratings:
    +140
    OK, what I think is causing your conceptual problem here – about a very straightforward piece of elementary circuit design – is that you are viewing this operation as an ‘adding and subtraction’ type function, rather than a multiplication function.

    Let’s have a look at the wrong way of conceptualising this first:
    You sit with your sound meter and notice that the rears have to be dropped 4dB on the AV amp. Hence, in your mind, 4dB becomes the magic number. So, you suppose that were you to turn the master volume down to half its level, then the AV amp is still going to knock 4dB off the rears again. But, you ponder to yourself ‘The rear power amp has a different gain, so that 4dB figure is no good to me anymore at the quieter level. Therefore, I need a power amp on the rears with the same gain as the fronts, because this stupid AV amp can’t work that out !’ All because you are working on the assumption that a fixed (not variable) amount is always being trimmed off the rears.

    Of course, this is exactly how it doesn’t work ! And this is why you don’t need to do tones at two different volume levels.

    The right way of conceptualising this:
    Lets suppose the rear power amp has twice as much gain as the front. The AV amp generates an internal test tone that is then passed to the gain controls of the AV amp. You note that you have to set the rear gain control to half the figure of the fronts.

    Purely for the sake of argument, let’s say that the fronts are set to 100dB (in the menu), and the rear is now set to 50dB. You play your film, and turn the master volume control down to half that you set the tones at. The AV amp now knows to reduce the front sound to 50db, and the rears to 25dB. It does not just blindly subtract 50dB off the rears, as it would in the scenario above (my profuse apologies to the electronic engineers here for the liberties I’m taking in use of units at this stage).

    Everything is done in proportion – in this case a half for the rears (to compensate for the double gain of the rear power amp). It doesn’t matter what level you actually do your test tone at, because for any given test tone level the rears are going to be twice as loud as the fronts. The gain controls inside all AV amps are done on a multiplication (percentage) basis, rather than an absolute subtraction basis. Why? Because the operation is done by potentiometers, not resistors ! At all times you are setting the RELATIVE levels of the speakers, and that percentage is retained in all the volume adjustments – hence why you need only do this at one volume level. For example: if I do the test with the master control on 10 and all the gain controls set flat, then the fronts measure 10 and the rears measure a 20, then I don’t need to do the test again at 20 on the master to know that the rears are going to measure 40 whilst the fronts are on 20. All I need know is reduce the rears by 50% to get the two to match, and that’s what the AV amps do.

    And if the theory isn’t convincing you (which it should because potentiometers are covered right down in O level Physics !), then note that there’s not a single AV processor/amp on the market that asks you to calibrate at two different volume levels. Not the Lexicons, Meridians, TAGs, Yamahas, nowt. Despite all their other fancy algorithms for room settings, delays, etc, etc. At no point is a ‘double check offered’ of calibrating at two different levels – for the computer to then go off and calculate the gains of your amps.

    So Kazman can safely add his Rotel amp, safe in the knowledge that his AV system is correcting already for gain discrepancies in the power amps.
     
  17. Daneel

    Daneel
    Active Member

    Joined:
    Dec 5, 2002
    Messages:
    2,813
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    68
    Location:
    London
    Ratings:
    +26
    Hrm. It seems I'm not making myself clear, your last post did not tell me anything I didn't know already.

    There is only one place that my understanding can be flawed, and if it is, my last post on point 3 is a lot of crap. It comes down to this.

    If, as in your first example, the rears need a 4dB drop when calibrated at 80dB, so 80dB fronts and 76dB rears. What drop is required to get the levels to match at 40dB? It is 4, 2 or somthing else due to the exponential scale of the dB? I'm going to have a think about it.

    My last post assumes it is 4 and which means that if it is gain being adjusted, the volume level will be incorrect. If that assumption is wrong then the rest of my post is also wrong.

    On further reflection I think 4 is wrong but I'm not sure that 2 is right.
     
  18. Harry T2

    Harry T2
    Active Member

    Joined:
    Jul 29, 2004
    Messages:
    482
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    18
    Ratings:
    +10
    Thank you Lost Cause.

    It does make sense. It is just that I had never put the theory into practice into how it worked.
     
  19. Daneel

    Daneel
    Active Member

    Joined:
    Dec 5, 2002
    Messages:
    2,813
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    68
    Location:
    London
    Ratings:
    +26
    Having talked to a friend I'm going back to 4dB and my original post being correct. Another of my friends is "the guru" on this stuff so I'll wait for his reply before giving a complete description of what is correct and why.
     
  20. Jules Tohpipi

    Jules Tohpipi
    Active Member

    Joined:
    Feb 4, 2004
    Messages:
    692
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    43
    Ratings:
    +140
    I put the apology about the mis-use of the units in quite deliberately, because I was treating the dB scale as linear for the benefit of the simplifying the explanation (which was long enough already).

    I've thought of a more simple explanation of all this in the meanwhile, which I'll post if it turns out your 'guru' also believes that two reference points are required to calibrate a system featuring power amps with different gains, or if indeed he believes a balance can be achieved at all in that scenario...
     
  21. Daneel

    Daneel
    Active Member

    Joined:
    Dec 5, 2002
    Messages:
    2,813
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    68
    Location:
    London
    Ratings:
    +26
    The general consensus seems to be that a 4dB drop is required at all volume levels as I stated in the first place. I never said anything about two reference points being needed.

    Leave the power amps gain question alone for now and go back to just the receiver using its own amps (all of equal gain). I don't think your "simplification" of the dB scale helped with my understanding of your explanation as its logarithmic nature plays a part in this.

    In fact I think we are both saying the same thing on this part but going about it differently. As I said in the first line of this response a 4dB drop would be required at all levels, not scaled as in your example of 100 and 50; and 50 and 25.

    Please post your second explanation. BTW perhaps using a 3dB drop would make things easier (3dB increase = double the power. Leave the perceived volume change alone :)).
     
  22. Daneel

    Daneel
    Active Member

    Joined:
    Dec 5, 2002
    Messages:
    2,813
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    68
    Location:
    London
    Ratings:
    +26
    Let me see if I can type up my own example.

    AV amp running two channels both with 20dB gain on each.

    Input signal on both left and right is 60dB.

    The measured output via SPL meter is L:80dB, R:83dB.

    To correct for this we reduce the right channel by 3 to 17dB gain (yes we are adjusting gain, the point of contention I had with you was that this was not constant in your example, it moved from 50 to 25 which confused the heck out of me).

    Now output is L:80dB, R:80dB.

    We reduce input volume to 20dB, the gain on the amps is still 20 and 17dB respectively (no scaling) and the measured output is 40dB from each speaker.

    [BTW when we adjust the gain on the receiver are we changing preamp gain or power amp gain? In order for matching to occur the way you say it does when you add the power amp, it has to be preamp otherwise changing the setting on the power amp driven channel has no effect which from experience, I know to be untrue]
     
  23. Jules Tohpipi

    Jules Tohpipi
    Active Member

    Joined:
    Feb 4, 2004
    Messages:
    692
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    43
    Ratings:
    +140
    OK, I'm totally confused now !

    I hesitated for a long time on the original example I gave, because I didn't know how good your knowledge of the dB scale is (or gain), so I treated it in a linear way. Big mistake in hindsight.

    Just to rewind here to see if we are actually debating the same point, because I'm no longer sure.

    You said:

    "Also due to the different levels of gain between the power amp and your receiver you may find the rears are not matched to your fronts in terms of volume."

    I took that to mean the following: because the rear power amp has a different gain, then you will find that you can only get the levels to match for one particular (master) volume setting. And that as soon as you move away from that (master) volume level setting, you'll find that the rears will be playing at a different volume to the fronts. Hence, if you did the test tones again - at a different (master) volume setting - then the rears would no longer measure the same as the fronts. And this difference would be caused by the rear power amp having a different gain to the front amp. Therefore, you ought to use a power amp on the rear with the same gain as the fronts, otherwise the rears are always going to be a bit out compared with the fronts - unless, of course, you select the identical volume that you chose when using the test tones. Hence why you asked if the Rotel had adjustable gain ?

    So, is that what you meant, am I interpreting your comments correctly ? Because I'm not sure now !
     
  24. Daneel

    Daneel
    Active Member

    Joined:
    Dec 5, 2002
    Messages:
    2,813
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    68
    Location:
    London
    Ratings:
    +26
    Lost cause, my original point 3 the way I put it was indeed incorrect. The strange thing is that my understanding of the workings behind it I think are fine.

    My conclusion of power and receiver gain not being equal means you can't get a volume match other than at the level you calibrate at was wrong. I think I picked this up from posts by others at my inception into audio about 3 years ago. Since then my knowledge has grown considerably but it didn't occur to me that I should re-evaluate some of the things I thought I knew.

    I think we are in agreement about the way things work and your simplification confused me. Thank you for making me think through it and realise my conclusion was wrong. :)
     
  25. Jules Tohpipi

    Jules Tohpipi
    Active Member

    Joined:
    Feb 4, 2004
    Messages:
    692
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    43
    Ratings:
    +140
    Groovy-woovy ! Yes, that early example (using numbers) went disasterously wrong I think. I should have found an analogy rather than simplifying the units into something they're not.

    Your last post tied it all in actually, and I now understand what you were driving at, and 4dB was the correct figure. I'm also glad we're agreed that the pre-section can adjust for different gains in the power amp.

    Interesting debate - just the kind of thing that keeps us coming back to these forums.
     
  26. Kazman

    Kazman
    Well-known Member

    Joined:
    Jan 14, 2004
    Messages:
    5,252
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    86
    Location:
    Luton, Bedfordshire
    Ratings:
    +136
    Ladies, please :)

    Anyway, back to the topic :)

    I bought some cables yesterday, unfortunately it didn't work.

    I was originally going to buy some splitters, and some interconnects, nice and simple, but I saw no decent interconnects at Maplins, I did see some 3.5mm single output into a dual phono output so I thought "hmmm, this should work if I use a phono to 3.5mm converter.

    I double checked with the cable guy at the store, and he assured me that it would work............erm, no! :p

    I only had a signal coming through one of the phono cables, not both, so I have to go back to the original plan, find some decent splitters and decent interconnects. Hope Maplins take back the cable after their advice. I only had the bass drivers being driven due to this, I will say that the bass cones were driven very well though, well controlled and tighter, that was evident straight away. Looking forward to getting the right cables now and setting it up properly.
     
  27. Daneel

    Daneel
    Active Member

    Joined:
    Dec 5, 2002
    Messages:
    2,813
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    68
    Location:
    London
    Ratings:
    +26
    Kaz,

    We were in topic, just at rather more depth than you might expect :)

    Now this is OT -

    I'm having lots of fun in the US. I demoed some Kef Ref 203s yesterday, not bad at all, but not much better than my 926. The only thing that really stood out was precussion instruments, they seemed to sit much wider in the soundstage than I'm used to. I'm going to put that down to the super-tweeter on a hunch. I'm going to listen to some Magpans today and maybe some electrostatics when I'm in NYC at the end of the week. I've been wanting to hear these speakers for a long time but they are so hard to find in the UK.
     
  28. Kazman

    Kazman
    Well-known Member

    Joined:
    Jan 14, 2004
    Messages:
    5,252
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    86
    Location:
    Luton, Bedfordshire
    Ratings:
    +136
    Right, finally got it all set up yesterday, and yes, it does sound superb, there is a greater element of control which apparent immediately, but, it isn't a giant leap forward. It's difficult to quantify, no change in the upper echelons of the frequency range, but the bass has certainly tightened up a tad, and even seems a little more dynamic.

    The amount of which isn't as much as I was expecting though. The Marantz amps in the SR7500 are superb for a sub £1000 AV Integrated Amplifier. What is annoying though is that there seems to be a bit of a hum eminating from the two main front speakers, it is really only audible when everything else is off though, so isn't too much of an issue, is there anyway I can get rid of it with a mains filter of some sort, as I suspect it may be a ground loop issue.
     
  29. Harry T2

    Harry T2
    Active Member

    Joined:
    Jul 29, 2004
    Messages:
    482
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    18
    Ratings:
    +10
    Hi Kaz.

    Glad to hear that it is all hooked up and sounding better.

    I am suprised that you were expecting a "night and day" type of improvement, cause as you said, the Marantz is pretty handy itself. There is not much room for the Rotel to take you.

    Your hum may also be an RF interference. Are the Marantz and Rotel place close to each other?
     
  30. Kazman

    Kazman
    Well-known Member

    Joined:
    Jan 14, 2004
    Messages:
    5,252
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    86
    Location:
    Luton, Bedfordshire
    Ratings:
    +136
    Hi Harry,

    Wasn't expecting a night and day difference, just a little better than I am getting, I'm happy with the improvement, but was hoping for a bit more, anyway, some good news :)

    I've tracked down the culprit of the hum, it appears to be a dodgy interconnect. I've also decided to power the centre with the Marantz, the tonality is very similar to the Rotels, but I prefer the dialogue presentation through the SR7500 (one of its strongest points), it is more transparent as well as warm, where the Rotels is a bit muddy by comparison surprisingly, so I'm taking the dodgy cable out to get rid of the hum, and just having the front L/R two bi amped :) :D

    The Rotel is certainly working well with the Quad 21L's though :D The only thing I find REALLY annoying is connecting the bare cable to the speaker terminals on it, it is such a pain, as the cables are not terminated in any way, they just slip out of the binding posts :mad: took me bloody ages to get them all secure :mad: think of getting some spade connectors or banana plugs for them.

    Another question I have which was mentioned to me was the overall tonality/sound type of a system, what is more responsible? The processing part of things or the amplification? I'm suspect speaker type on the front stage is more important.

    Thanks in advance peeps :)
     

Share This Page

Loading...