Help on mixing Linn amps (warning: contains maths and noobishness in equal measure)

[MnM]

From the faq:

Can I use a mixture of different amplifiers in my system?
You can mix different Linn power amplifier models in your system with no problem as all Linn power amplifiers have very similar gain settings.

From the Chakra manual:

Peak output voltage: 29-30V (C x100 range), 41V (C x200 range)
Max output power @ 4 ohms: 100W vs 200W

Aktiv gain range, all models: 7dB

I'm trying to get my head around this - I reckon this means that the power gain of an Akurate amp is twice that of a Majik, which in dB is 10*log(200/100) = 3dB. In audibility terms, if 10dB broadly corresponds to a perceived doubling of loudness, 3dB is around 2^0.3 = 25% louder, which should be audible (I read that a 1dB change is just noticeable to the human ear). The 7db range of adjustment accommodates this, no problem, though the range of adjustment left for other reasons may be reduced. It suddenly seems very generous, the 7dB adjustment on the crossover, when the diff between Majik and Akurate amps is 3dB.

Is that more or less along the right lines, or heinously off?

Any help much appreciated,
Matt

[ToneDeff]

I would say that it is all pretty much irrelevant. the amps all output music at a similar volume and the adjustment on the cards is to cut or boost treble or bass to suit room acoustics.

Tone.

[whizz]

The gain for all Linn amps is the same, you are looking for a difference that is not there!

[rowlandhills]

As I said on another thread, gain is not related to power!

Look at http://www.linn.co.uk/faq_power_amplifiers which says:

Can I use a mixture of different amplifiers in my system?
You can mix different Linn power amplifier models in your system with no problem as all Linn power amplifiers have very similar gain settings. There may be complications if Linn power amplifiers were to be mixed with other brands in an audio system and this may also compromise sonic performance.

[DanielE]

(2010-03-03 16:39)MnM Wrote:  From the faq:

Can I use a mixture of different amplifiers in my system?
You can mix different Linn power amplifier models in your system with no problem as all Linn power amplifiers have very similar gain settings.

From the Chakra manual:

Peak output voltage: 29-30V (C x100 range), 41V (C x200 range)
Max output power @ 4 ohms: 100W vs 200W

Aktiv gain range, all models: 7dB

I'm trying to get my head around this - I reckon this means that the power gain of an Akurate amp is twice that of a Majik, which in dB is 10*log(200/100) = 3dB. In audibility terms, if 10dB broadly corresponds to a perceived doubling of loudness, 3dB is around 2^0.3 = 25% louder, which should be audible (I read that a 1dB change is just noticeable to the human ear). The 7db range of adjustment accommodates this, no problem, though the range of adjustment left for other reasons may be reduced. It suddenly seems very generous, the 7dB adjustment on the crossover, when the diff between Majik and Akurate amps is 3dB.

Is that more or less along the right lines, or heinously off?

Any help much appreciated,
Matt

HI Matt,

I see where you are coming from, and how you have drawn these conclusions, but you are not quite right.

The gain is the multiplication factor of the input signal, (in the case of Linn amplification 27 times) and this is the same across our power amplification range. So a 1V peak input signal will give you a 27V peak output signal.

The difference between the Majik and Akurate Power amplifiers in terms of power output refers to the maximum possible output Voltage (Rated as 100W and 200W respectively into a 4 Ohm load).
You have quite rightly quoted the Peak output voltages and the related power outputs. As a result of the different maximum output voltages, the Majik X100 will start to clip at a lower input signal level than the Akurate X200. (If you look in the manual at the Input level for clipping [phono models] you will see that the x100 is rated as 790mV rms* whereas the x200 is rated as 1.1V rms)

The 7dB of gain adjustment allows the installer to tweak the levels of a multi amped or Aktiv system to optimise the response of their system in their room.

I hope that has cleared things up a bit for you,

Regards

Dan.

*It looks to me like there is a typographical error in the manual regarding the levels of the x100 and without having one to hand to measure I would have thought (by calculation at least) that 790mV is the correct value rather than the 755mV quoted for the 2100 and 3100, but please don't hold me to that as I haven't measured it.

[MnM]

Gotcha - thanks Daniel and all. I had thought along those lines (the clipping figures must be there for a reason) but hadn't quite got there.

Rowland, sorry if it looked like I'd ignored your reply - I hadn't - but I couldn't see what you got in return for the extra power. I get it now - it lets you turn up the dial.

Cheers,
Matt

[rowlandhills]

(2010-03-03 17:34)MnM Wrote:  Rowland, sorry if it looked like I'd ignored your reply - I hadn't - but I couldn't see what you got in return for the extra power. I get it now - it lets you turn up the dial.

No worries. I hadn't actually realised that it was you who asked it in the other thread

[Warren]

This brings up an issue I've been curious about, mixing input sockets: phono and balanced.

The default gain for phono is 28.6db, for balanced it is 22.6db. And there are only two overlapping values: 25.6 and 26.6.

Does this mean amps of different input sockets can't be easily mixed?

[rowlandhills]

(2010-03-03 21:57)Warren Wrote:  This brings up an issue I've been curious about, mixing input sockets: phono and balanced.

The default gain for phono is 28.6db, for balanced it is 22.6db. And there are only two overlapping values: 25.6 and 26.6.

Does this mean amps of different input sockets can't be easily mixed?

Interesting. Whilst my system has been offline due to building work, I've purchased a c4200 from House of Linn and been assured that if I run the singal from Kinos to two channels of 6100 (unbalanced)and then on to the c4200 (balanced) then I should have no gain problems. If I were to add another balanced amp or want to run the signal into the balanced amp and onto the phono, then to match phono gain apparently I would need to dial in either -3dB on the phono amp of +3dB on the balanced amp.

All of the above said, I've not yet tried connecting it all up and listening...hopefully this weekend!

[DanielE]

(2010-03-04 00:32)rowlandhills Wrote:  

(2010-03-03 21:57)Warren Wrote:  This brings up an issue I've been curious about, mixing input sockets: phono and balanced.

The default gain for phono is 28.6db, for balanced it is 22.6db. And there are only two overlapping values: 25.6 and 26.6.

Does this mean amps of different input sockets can't be easily mixed?

Interesting. Whilst my system has been offline due to building work, I've purchased a c4200 from House of Linn and been assured that if I run the singal from Kinos to two channels of 6100 (unbalanced)and then on to the c4200 (balanced) then I should have no gain problems. If I were to add another balanced amp or want to run the signal into the balanced amp and onto the phono, then to match phono gain apparently I would need to dial in either -3dB on the phono amp of +3dB on the balanced amp.

All of the above said, I've not yet tried connecting it all up and listening...hopefully this weekend!

Hi Roland, and Warren too,

It is possible to mix different input types, but as you (Roland) have correctly stated above you need to reduce the gain of the phono amp by 3dB and boost the XLR amp by 3dB thereby reducing your relative gain adjustment to 1dB. In most cases (not all), the gain adjustment stays pretty much at factory defaults, so you are unlikely to run in to much of a problem.

Regards

Dan.