"Fast amps" - really fast or a bogus marketing claim?
- Thread starter caesar
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Many people get confused by the term "speed." Remember amps must resct to thier input,
Spectral gve s this spec for thei amp:
Speed:
Risetime: less than 300 nanoseconds
Settling: 1.5 microseconds to -40 dB
Slew Rate: 600 volts/microsecond
Spectral gve s this spec for thei amp:
Speed:
Risetime: less than 300 nanoseconds
Settling: 1.5 microseconds to -40 dB
Slew Rate: 600 volts/microsecond
I have read a review of the Berning Quadrature Z monoblocks by 2 different editors of HiFi+...one of them wrote something like "i have never heard anyone complain about an amp being too fast." I think the point he was making was that the amp's job is simply to pass along the signal coming thru...with no way to speed up the music, make rim shots faster...he was basically suggesting that speed was one factor that allowed for transparency. What comes in...goes straight out without delay.
I think, in isolation, that concept makes sense to me. Obviously, there can be side effects in trying to design equipment to do this which might be deleterious, but i cannot imagine this one aspect alone can be bad. And i could imagine that this one aspect should be better...all else being equal.
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Not sure that I'd agree. Remember the adage speed kills
. Years ago was talking to Dan D'Agostino about that subject and he told me that he could and had designed ultra fast circuits but you woudn't want to hear them So maybe those ultra fast designs were eliminated in the design stages and never saw the light of the day.
i thought i knew what a fast amp sounded like.
then i listened to a 45 tube and then 2a3 tube both with mercury tube rectification. there are plenty of things those amps can't do. but the speed inside the note was a whole different thing than anything else i have heard. other tube amps i've heard were not like those two at all. and the best solid state amps i've heard can't quite do that either. the 45 tube was even slightly better than the 2a3 at this. a simply un-veiled window into the music....on a micro level.
too bad i'm not enamored by speakers that work on those types of amps.
then i listened to a 45 tube and then 2a3 tube both with mercury tube rectification. there are plenty of things those amps can't do. but the speed inside the note was a whole different thing than anything else i have heard. other tube amps i've heard were not like those two at all. and the best solid state amps i've heard can't quite do that either. the 45 tube was even slightly better than the 2a3 at this. a simply un-veiled window into the music....on a micro level.
too bad i'm not enamored by speakers that work on those types of amps.
Not sure that I'd agree. Remember the adage speed kills
So maybe those ultra fast designs were eliminated in the design stages and never saw the light of the day.
Hi Myles...i do think speed in and of itself is a good thing...but i think that sometimes (perhaps often) the path to get there comes with "side effects" or other unwanted aberrations. Lack of depth or tone of the note is one...even the Berning supposedly lacked just that teeny bit of depth of note...slightly shallow. But again, that is not the speed, but the unwanted side effect of the speed which is that the unit cannot be that fast and also provide the full depth of note. (personally, i'd take the depth of note a give up a little speed).
Speed - aka the ability to track the signal as best as possible w/o smearing - is a requisite for accurate reproduction, but not the only one; and it's extremely hard to implement in the SS domain. I have a feeling D'Agostino has finally mastered that too with his new amps. Some tubes - with up to 100MHz bandwidth - are the masters in this department, and everyone else an imitator; I think Mike Lavigne covered that best.
IN most tubes equipment the transformer is the limiting factor.. However large the bandwidth of the tubes used in the system it will have to contend with the transformers which by their very principle of operation slow down fast rising signals ... SS don't have that thus the lightning quickness of some of them . Spectral and Goldmund comes to mind.. again but also Krell and maybe other wide-bandwidth SS gear... Show me the rise time of the fastest tube amp and it's likely a multiple of many SS... For preamps I don't know, I haven't seen the rise times so ...
I am not sure i agree with the point. I would suppose that OTL are as fast as they come be but I have not seem the rise and settling time of an OTL gear so .. Subjectively they sound fast to me .. and if I were to go back to tubes.. it would be OTL. likely my favorite the Joule Electra "Rite of Passage".
I understand many here refutes the notion of measurements.. but the speed of an amp is a measurable quantity. Rise Time, Slew Rates and settling times are indications of the "speed" of an amp there may be more parameters but it remains that "speed" is measurable ..
If one wants to see this as a subjective quality then anything goes ... and in that realm one can "decide" that the Dynaco ST-70 is "faster" than the Spectral DMA-360
Having now heard both the D'Agostino monos and the stereo...i agree, Ack. I spent more time with the monos, but more time comparing units with the Stereo...this amp is incredibly in its precision, speed, transparency...but maintaining that deep into the note sweetness. I was just saying above that some amps get speed but you lose that ultimate deep in the note sweetness in the treble...but i was shocked at how the stereo managed to do this. Aside from my Gryphon Colosseum, i would say the Momentum could be my favorite SS amp. I certainly preferred what i heard to the Boulder 2060...which i think is tremendous...but without a proper shoot-out, i would not say anything definitive...other than that my instinct tells me the momentum is sweeter while equally transparent/quick. It might even be a touch faster but again too close to call. What i do not know is how much all-out grunt the Momentum has compared with Boulder and Gryphon which are both beasts. I bet, based on D'Agostino, the Momentums are beasts as well...just have not tried.
Hi
I do not have any problem with listening tests they have their validity. It is difficult however for me to take what manufacturers say for the Godspell. They are far from unbiased.
I like Spectral gear and they do sound fast to me more so than any tube I have heard and the measurements confirm my (and others) subjective impressions. I haven't heard a Goldmund design for a while but has had a very good experience with the Mimesis 9 in my own system, I evaluated it for a while but decided not to keep it .. it didn't sound better to my ears than other SS among them the fabulous Spectral DMA-180.
I do not have any problem with listening tests they have their validity. It is difficult however for me to take what manufacturers say for the Godspell. They are far from unbiased.
I like Spectral gear and they do sound fast to me more so than any tube I have heard and the measurements confirm my (and others) subjective impressions. I haven't heard a Goldmund design for a while but has had a very good experience with the Mimesis 9 in my own system, I evaluated it for a while but decided not to keep it .. it didn't sound better to my ears than other SS among them the fabulous Spectral DMA-180.
I think you misinterpreted what I said. I spoke about the speed of some tubes and you took it to mean amp and preamp implementations. I don't know which impl is faster but the point about xformers is valid
I think the word "speed" might need to be defined in context of this discussion.
I interpret it as some others have, which is the 'reaction time' an amp has in being able to delivery current and voltage in response to a musical impulse.
In this case, wouldn't you be able to look at it very simplistically: the 'speed' or 'reaction time' of an amp needs to be greater than the quickest rise/impulse you would ever see in a musical passage. If it is equal or slower you might experience 'smearing' which means the original recorded signal is not faithfully reproduced. In this case, as someone else has said you cannot have an amp that is too fast.
I interpret it as some others have, which is the 'reaction time' an amp has in being able to delivery current and voltage in response to a musical impulse.
In this case, wouldn't you be able to look at it very simplistically: the 'speed' or 'reaction time' of an amp needs to be greater than the quickest rise/impulse you would ever see in a musical passage. If it is equal or slower you might experience 'smearing' which means the original recorded signal is not faithfully reproduced. In this case, as someone else has said you cannot have an amp that is too fast.
Ack
I don't think I misinterpreted your statement
If you were talking about the fact that tubes can have larger bandwidth than SS I may grant it to you but to quote you posted
IN the context of absolute hyper speed (Read Radar or higher) that is a maybe in the context of Audio Amps it's not true.. SS with large bandwidth are almost routine.
Then you referred to the D'Agostino amp
These would lead me or anyone that you are talking about audio amps and not the intrinsic qualities of tubes in fact that is the context of this discussion I would think. To that I replied that for tubes amplifier regardless of the intrinsic qualities of the tubes used they gould go to Gigahertz the transformers will limit the speed .. then I added that if you're talking about subjective impression of speed then all bets are off...
So as AudioExplorations stated you might want to define the word "speed" in the context of this discussion.
Is there audible latency in amps? If you're not playing the instrument into a microphone, then hearing it played back through the system so you have a point of reference, how do you even know there is latency? What does it sound like? When I think of slew rate, or "speed" in an amp, I think of the very clear, crisp attack of percussive transients. But after reading "the speed inside the note," I'm not sure I know what you're talking about at all.
Tim
Tim
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