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Power amp

matthews290

Standard Member
I recently purchased a new pair of B&W CM8s. They have shown up some weaknesses of my Rega Mira amp at low volume. When the volume is turned up they sound fantastic but at low volume detail and bass is lost. Would a power amp solve this problem, plus this would also allow me to bi wire them. Any advise would be greatly appreciated. (CD player it Rega Planet, turntable is Rega P2. Cable Chord Cobra plus and QED anniversary)
 

Mr Pig

Well-known Member
It's not really an amp issue, some speakers are just like that. They just don't wake up until the volume is up a bit.

I once tried a pair of Linn Keilidhs at home and they were terrible in that respect. I wasn't very impressed with them generally actually but they sounded really shut-in and dead at low volume, you had to hammer them a bit to open them up.

A power amp will add power, so how will that help when you're hardly using any? You could try a more incisive amp brand, like Naim, but it won't fix it. Might just help a bit is all. Bottom line, it's the speakers.
 

a8ch

Active Member
I recently purchased a new pair of B&W CM8s. They have shown up some weaknesses of my Rega Mira amp at low volume. When the volume is turned up they sound fantastic but at low volume detail and bass is lost. Would a power amp solve this problem, plus this would also allow me to bi wire them. Any advise would be greatly appreciated. (CD player it Rega Planet, turntable is Rega P2. Cable Chord Cobra plus and QED anniversary)

In general yes, but it really depends on the power amps as they are not all the same, some may output less than your existing amp for example. You dont specify a budget, but if new is required the minimum I would say is the A500 studio reference amp from Behringer at £150.

I bought two and have bridged them outputting around 375 Watts RMS flat out! not that I have even come close to needing full volume tbf. It is a wonderful performer and portrays a lovely full range sound right down to an incredibly low volume... still providing a good respective bass weight! the sign of a good amp, and even with my current sucking electrostatic hybrid speakers on the end (<85dB sensitivity).

I cannot recommend them enough for the money. Adding a power amp would allow you to bi-amp by using your mira for the top end and the power amp for the bass/mid duty, if your cm8's allow, this is a better option to bi-wiring imo.
 
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Mr Pig

Well-known Member
I would say is the A500 studio reference amp from Behringer at £150.

I'm intrigued about this thing. One day I'll need to get a hold of one to try. My amp sounds fine but more power would be nice. I often play music quite loud and transistor amps close up and get shouty when pushed, I shut my amp down regularly.
 

amcluesent

Distinguished Member
>at low volume detail and bass is lost<

Human hearing is like that, hence the 'loudness' button on amps from back in the day.
 

a8ch

Active Member
>at low volume detail and bass is lost<

Human hearing is like that, hence the 'loudness' button on amps from back in the day.

Im with Mr Pig on this one, if a system is well balanced and matched a loudness control is not needed. Fwiw the only amp I have owned that had one (avr's excluded) was my first foot into hifi via a jvc jas11 in 1976, virtually every stereo amp I owned from there on just had a volume, balance and input selector, not even tone controls.

I'm intrigued about this thing. One day I'll need to get a hold of one to try. My amp sounds fine but more power would be nice. I often play music quite loud and transistor amps close up and get shouty when pushed, I shut my amp down regularly.
Well worth a listen. Not the last word in audio nirvana, but does a lot right tbh.
 
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mr_yogi

Well-known Member
One thing that might be worth a try is to use a braided speaker cable. I can't remember the ins and outs, but someone told me that they increase the impedence (or something) of the cable making the amp work harder for a given volume. Not sure I have this right and I've never tried it myself but it might be worth a go if you can find some cheapish braided cable? Hopefully someone else might be able to explain what I'm on about a bit better :laugh:
 

Mr Pig

Well-known Member
I can't remember, but they increase the impedence (or something) of the cable making the amp work harder

I don't think it's about what the amp is doing, think it's more a speaker characteristic. I've heard quite a few speakers that are like that, change character as the volume alters. Ones that open up as the volume increases, ones that sound nice at low volume but fall apart as they get louder. I find it really annoying and always try to have a system that sounds good at all volumes.
 

Finach2008

Standard Member
I'm using an arcam solo neo and at lower volumes my cm8s sound amazing but when turned up the amp seems to be struggling so looking at a power amp
 

alexs2

Distinguished Member
I don't think it's about what the amp is doing, think it's more a speaker characteristic. I've heard quite a few speakers that are like that, change character as the volume alters. Ones that open up as the volume increases, ones that sound nice at low volume but fall apart as they get louder. I find it really annoying and always try to have a system that sounds good at all volumes.

I think that's very true....your comment about the Linn Keilidhs above is what I'd found when I had a set,in that they need a LOT of power for a relatively small speaker,and don't really open up until the wick is turned up a bit.

That does change when you have them converted to active,so I'd imagine the passive crossover has a lot to do with that problem.

My current speakers are a set of B&W 805s which also require power,but are not too bad at low volumes,and Quad ESL57s,which of course don't do high volumes at all.

I don't use tone controls usually(although it's easy to argue that RoomEQ and digital filters on the AV system are simply very sophisticated tone controls) and the stereo side of the system has none of that.

Transistor amps when they approach clipping can get to sound pretty hard or harsh,whereas many valve amps have a far softer clipping characteristic....I'm not using that as a recommendation for valve amps,which have their own set of problems,or even for high powered Class A S/s amps,as it seems no one type is ideal.
 

alexs2

Distinguished Member
To be fair to the Keilidhs, and many other Linn speakers like the Kaber, they only really came into their own when active.

Totally agree...the Kaber was one that absolutely needed active to overcome the sloppy bass in passive form.

I loved the Keilidhs in active form,and more so the Keltiks which as you will know were active only.
The problem I had with those was room matching in a very old timber framed house,which eventually prompted their sale.
 

Mr Pig

Well-known Member
To be fair to the Keilidhs, and many other Linn speakers like the Kaber, they only really came into their own when active.

I agree but you have to ask, what's the point of that?

For me the question was not, 'can the Keilidh be forced into working well?' but 'why is the Keilidh worse than the Kan?'. Having speakers that only worked active was not some great achievement, as Linn might have liked us to think. It was more an indication of the weakness of the designs. In that era Linn consistently made speakers that were worse than the ones they'd built before. Keltiks sound ok, well yes but so they blinkin should considering what you need to drive them with. But if you've had enough experience with Isobariks you'll know that they are a fundamentally better speaker.

Transistor amps when they approach clipping can get to sound pretty hard or harsh,whereas many valve amps have a far softer clipping characteristic

I think the truth is that you are right, neither is ideal. Personally, I prefer transistor amps but I'm not preaching about it. I like valve amps too and understand why people might choose them. It's just a case of what you want out of your system and music. I want my system to sound like a really good PA system, bold, punchy and commanding. I think Quad ELS57s are absolutely beautiful speakers but I couldn't live with them because they don't suit the kind of music and volume I like. Doesn't make them bad, just not for everyone.
 

alexs2

Distinguished Member
I agree but you have to ask, what's the point of that?

For me the question was not, 'can the Keilidh be forced into working well?' but 'why is the Keilidh worse than the Kan?'. Having speakers that only worked active was not some great achievement, as Linn might have liked us to think. It was more an indication of the weakness of the designs. In that era Linn consistently made speakers that were worse than the ones they'd built before. Keltiks sound ok, well yes but so they blinkin should considering what you need to drive them with. But if you've had enough experience with Isobariks you'll know that they are a fundamentally better speaker.



I think the truth is that you are right, neither is ideal. Personally, I prefer transistor amps but I'm not preaching about it. I like valve amps too and understand why people might choose them. It's just a case of what you want out of your system and music. I want my system to sound like a really good PA system, bold, punchy and commanding. I think Quad ELS57s are absolutely beautiful speakers but I couldn't live with them because they don't suit the kind of music and volume I like. Doesn't make them bad, just not for everyone.

It is all just horses for courses,or personal preferences I guess.

And so...Keltiks first,my friend!....I loved the Isobariks when they came out,and the sound of those triamped with Naims was always one of the highlights of any of the shows I went to.

Sadly then,even if I could have bought the speakers,I couldn't have afforded the amps,so when a set of Keltiks appeared at the right price many years later,I bought them.

The Keltiks need a huge amount of power(mine were triamped with what will probably sound an odd choice...Krell KMA100s for the bass,Krell KSA 100 for the midrange,and Tube Technology Genesis monoblocs for the top,and in the right room it worked very well,but meant into that load,about 400+w/channel).

I like both the S/s amps I have,and the valve ones....it's just that I wouldn't use them all in the same conditions,or the same speakers perhaps.

The Krells will drive anything,and never complain,but the Quads sound and work best with valve amps,and that's what I use for them.....
Either Quad IIs,which are very soft and smooth,or more often WAD 300Bs which are more open and have a bit more power.

For rock and so on,I use the Krells and B&Ws,and as I've said before,if I could find a good set of Scintillas,and didn't need to worry about the ribbons needing repairing,I'd have them.
 

Mr Pig

Well-known Member
The Keltiks were triamped with Krell KMA100s for the bass,Krell KSA 100 for the midrange,and Tube Technology Genesis monoblocs for the top

Yip, that is odd. I'm surprised Linn didn't send the boys round to educate you in the error of your ways and remove the speakers upon failure to comply! I've seen people drive Isobariks with Krell, even valve amps would you believe, but I don't think I've ever heard of anyone doing that with Keltiks.

Again though, it's not about the fact that you can get them to work, it's the fact that they're worse than Isobariks. You can get Briks to sing both passive and active. I remember talking to a dealer at the time who said that Isobariks were too expensive to make and Linn were quite happy to source cheaper bits, I think the Keltic drivers were made by Tonegen?
 

alexs2

Distinguished Member
Yip, that is odd. I'm surprised Linn didn't send the boys round to educate you in the error of your ways and remove the speakers upon failure to comply! I've seen people drive Isobariks with Krell, even valve amps would you believe, but I don't think I've ever heard of anyone doing that with Keltiks.

Again though, it's not about the fact that you can get them to work, it's the fact that they're worse than Isobariks. You can get Briks to sing both passive and active. I remember talking to a dealer at the time who said that Isobariks were too expensive to make and Linn were quite happy to source cheaper bits, I think the Keltic drivers were made by Tonegen?

I know...I like to be the first to try something at times.

It was a combination that actually worked superbly well,as it had the sweetness of tubes at the top end where power wasnt essential,but the Krells to drive the bass and mid.

Linn did try to persuade me to use their own amps(it would have been 3 Klouts at that time) but as I already had the Krells,there was no way I'd have moved to a lower powered amp setup.

I think you're right about Tonegen for the midrange,but if I remember it was Linn's take on the Kef B139 for the bass,and the tweeter I can't remember,other than there was a ceramic upgrade along the way.
 

Mr Pig

Well-known Member
I think you're right about Tonegen for the midrange,but if I remember it was Linn's take on the Kef B139 for the bass,and the tweeter I can't remember

I think Tonegen made all three drivers, the bass unit I assume they copied the look of the Kef driver, I don't know, but it wasn't a Kef driver. It was a cost cutting game though, the speakers were built to a price. I don't like any of the Linn speakers from that era, Keltic, Nexus, etc. They're not bad as such but not as good as their older speakers.

I think the thing was that the Nexus was a really safe, middle-of-the-road sort of sound but they sold shedloads of them so maybe thought they were onto a good thing. For whatever reason Linn Hi-Fi got real boring real fast.

I say I don't like any of them but that's a lie. I thought the Tukan was pretty nice, and it uses the mid and trebble drivers from the Keltik!

Linn did try to persuade me to use their own amps

Yeah, you don't say! ;0) The arrogance of Linn as a company is outstanding.
 

alexs2

Distinguished Member
I think Tonegen made all three drivers, the bass unit I assume they copied the look of the Kef driver, I don't know, but it wasn't a Kef driver. It was a cost cutting game though, the speakers were built to a price. I don't like any of the Linn speakers from that era, Keltic, Nexus, etc. They're not bad as such but not as good as their older speakers.

I think the thing was that the Nexus was a really safe, middle-of-the-road sort of sound but they sold shedloads of them so maybe thought they were onto a good thing. For whatever reason Linn Hi-Fi got real boring real fast.

I say I don't like any of them but that's a lie. I thought the Tukan was pretty nice, and it uses the mid and trebble drivers from the Keltik!



Yeah, you don't say! ;0) The arrogance of Linn as a company is outstanding.

I don't know the origin of the other drivers,but the elliptical bass had obvious parallels with the B139.

I remember how alive the first Kan sounded,coloured obviously,but really good rythmically.

I should perhaps have qualified my statement about persuasion as it was the local dealership that did that,but by then I'd already sorted out an active crossover solution using the Tunebox from my old Keilidhs....I didn't need help with that!
 

Mr Pig

Well-known Member
I don't know the origin of the other drivers,but the elliptical bass had obvious parallels with the B139.

I think the obvious was where the similarity ended. It just looked like the B139. Whether that was deliberate or not I don't know but an elliptical driver is handy if you're making and isobaric loading speaker as you can get the inside driver through the hole for the outside one! Can't do that with a round driver, as witnessed by the plastic mounting plate on the Sara.

I remember how alive the first Kan sounded,coloured obviously,but really good rhythmically.

Yes, they got progressively cleaner and less coloured but progressively less fun. Relative though, they were all great and still miles better than most of the other small speakers around at the time. And a lot of the big ones.
 

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