Amps for Raidho D3's

wizard said:
Damping factor specs: All measured at 1 kHz.

Vitus RI-100 - 20
D'Agostino Mono - 55
Classe M400 - 100
Soulution 501 - 4000
Soulution 710 - 5600, at 100Hz 6900 and 10kHz 12500
FMA 711 II - 400
Burmester 909/911 - 2750
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Gryphon

Diablo - 380
Atilla - 55
 
Pass Xs

Damping factor and output current peak
Xs 300 - 50 and 50A
Xs 150 - 50 and 30A
 
wizard said:
Bravo output current - 44A peak, output voltage - 50V in 4 ohm.

Symphony output voltage - 40V in 4 ohm.
Slew rate - 38V up and 18V down.
Damping factor at 100Hz/1kHz/10kHz - 518/513/284
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wizard said:
Gryphon

Diablo - 380
Atilla - 55
Click to expand...

wizard said:
Pass Xs

Damping factor and output current peak
Xs 300 - 50 and 50A
Xs 150 - 50 and 30A
Click to expand...

wizard said:
Accuphase A-46 - 67 in 4 ohm.

The A-46 brochure says 500, a big difference from the spec above which is from a review.

P-6100 - 445 in 4 ohm. (brochure - 500)


Damping factor - Damping factor
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wizard, thanks for these. I've missed your informative posts and beautiful photos!
 
wizard said:
Gryphon

Diablo - 380
Atilla - 55
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Good info Wizard

What is a damping factor and do I need one?
Posted by Fynn Callum on June 26, 2013

If you have a loudspeaker and an amplifier connected together, you already have a damping factor and it’s been getting on doing it’s thing, but what is a damping factor and how can it determine your setup?
Springy speakers
When your amplifier sends a signal to your loudspeaker to make some noise, the speaker cone moves and pushes some air around to make a sound. Unfortunately, that’s not the end of it. After the speaker cone is forced away from its rest position it’s going to want to get back there, but it has momentum, so it overshoots on the other side. Near its resonant frequency, all this wobbling around can become quite pronounced.
This can often lead to ‘smearing’ of bass notes, as the speaker keeps moving around after the amplifier has told it to. To prevent this woolly softness and keep the bass ‘punchy’, this cone movement needs to be ‘damped’. The mechanical resistance of the speaker will take care of some of that, but can more be done?

So what is a damping factor?
Yes, there is more that can be done. If you think about it, there isn’t much difference between a loudspeaker and a dynamic microphone. So, when the speaker is moving, it’s also generating an electrical signal that heads back up to the amplifier in the same way that the diaphragm of a dynamic mic moves and generates a signal. This signal is called the ‘back electromotive force’ or back EMF.
The output stage of the amplifier presents an electrical load to the speaker, if that load is low, then there will be more current, which puts the brakes on that speaker movement and gives you that tight sound. An amplifier with a low output impedance in relation to the impedance of the speaker plus its cables presents such a load!
What does damping factor mean for my system?
With the very small output impedances of modern solid-state amplifiers, generally very little, you may not need to think about it. However, as damping factor is also affected by the impedance of your speaker cables, an investment in good quality, thick, low resistance speaker cables will reduce their impact on your damping factor.
Where things get a bit more interesting, is with valve amplifiers. As these are configured differently, and feature an output transformer, the output impedances are higher and therefore the damping factors are lower. But this may not necessarily be a bad thing, and the differences in damping factor are sometimes cited as being a contributor to the ‘valve amp’ sound, particularly when it comes to that most subjective of areas of sound- guitar amps.
 
Ok, but the part I was waiting for was what would be the ideal damping factor number & why?
 
sharkmouth said:
Ok, but the part I was waiting for was what would be the ideal damping factor number & why?
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My research shows anything north of 50 is ideal for MOST speakers. For Raidho's - I'm guessing 400+ - based solely on my own experience with the three amps. The one with a 440 damping factor controlled the woofers the best - but there was room for improvement.
 
Mike said:
I would love to! But, tubes anywhere in the chain (except phono stage!) - I found to be less than ideal for the Raidho's.
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Mike...from a technical standpoint, tubes in the pre should not mean less woofer control and woolly bass in the D3s. All the pre is doing is outputting a small 2V signal to the amps which is where all the work is done to apply another stage of gain and amplification and driving the speakers. I am not questioning what you are hearing but my guess is there was probably a mismatch between the Ref 10 and the SS amps you used than the issue being tubes in the chain in the preamp stage. In any case, I generally think it's better to keep pre and amp matched from same manufacturer anyway, so I am not trying to dissuade you from selling the Ref 10 but just trying to point out that you're not liking the Ref 10 with the SS amps you tried on the D3s probably has less to do with tubes in the Ref 10 and more likely a mismatch (impedance and otherwise) with the SS amps you tried. Just my 2c and speculation on the subject.

By the way, are the D3s displacing the Aidas in the big rig or are they going into the family room?
 
cmalak said:
Mike...from a technical standpoint, tubes in the pre should not mean less woofer control and woolly bass in the D3s. All the pre is doing is outputting a small 2V signal to the amps which is where all the work is done to apply another stage of gain and amplification and driving the speakers. I am not questioning what you are hearing but my guess is there was probably a mismatch between the Ref 10 and the SS amps you used than the issue being tubes in the chain in the preamp stage. In any case, I generally think it's better to keep pre and amp matched from same manufacturer anyway, so I am not trying to dissuade you from selling the Ref 10 but just trying to point out that you're not liking the Ref 10 with the SS amps you tried on the D3s probably has less to do with tubes in the Ref 10 and more likely a mismatch (impedance and otherwise) with the SS amps you tried. Just my 2c and speculation on the subject.

By the way, are the D3s displacing the Aidas in the big rig or are they going into the family room?
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Cyril - I know! It made no sense to me either. But it did. But, yes, same manufacturer is best.

As to your other question - TBD.
 
From Raidho website
Amplification > 50 W (Though we have seen excellent results with small tube amplifiers)
I wonder what tube amplication are they using
 
iamhifi said:
From Raidho website
Amplification > 50 W (Though we have seen excellent results with small tube amplifiers)
I wonder what tube amplication are they using
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VAC and VTL. I'm sure they sound fine with light jazz and classical! Anything else and you can.....forget it IMO.
 
A high damping factor isn't the only spec one should looking for when selecting an amplifier.

Also look for high slew rate and high output current.

High rise and fall slew rate means a very fast amp with very good control of the drivers on a speaker.
Not too high like Spectral with a 650V slew rate - not uses a filter at the output, means it need a filter inside the speaker cable, if not use cables with a built in filter the amp will oscillate/blow.

Amps with low output impedance, for example Boulder 2050 and Gryphon Mephisto - both have 0,02 ohm output impedance.
2050 is using feedback, Gryphon say they have Zero global feedback, but they are using local feedback with that low output impedance spec.

True zero feedback amps have higher output impedance - around 0,2 ohm and higher, many of them still have outstanding bass and control even with a damping factor of only 15.

Actually one of the best amps I've heard with a outstanding bass and control have a slew rate of 60V, 100A output current, 0,33 ohms output impedance and a damping factor of 25.
The damping factor is 25 from 100Hz to 10Khz - this is a very good spec, many amps have different damping factor specs on the different freq. responses.
 
wizard said:
A high damping factor isn't the only spec one should looking for when selecting an amplifier.

Also look for high slew rate and high output current.

High rise and fall slew rate means a very fast amp with very good control of the drivers on a speaker.
Not too high like Spectral with a 650V slew rate - not uses a filter at the output, means it need a filter inside the speaker cable, if not use cables with a built in filter the amp will oscillate/blow.

Amps with low output impedance, for example Boulder 2050 and Gryphon Mephisto - both have 0,02 ohm output impedance.
2050 is using feedback, Gryphon say they have Zero global feedback, but they are using local feedback with that low output impedance spec.

True zero feedback amps have higher output impedance - around 0,2 ohm and higher, many of them still have outstanding bass and control even with a damping factor of only 15.

Actually one of the best amps I've heard with a outstanding bass and control have a slew rate of 60V, 100A output current, 0,33 ohms output impedance and a damping factor of 25.
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Thanks Wizard!! What amp was that?
 
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