I queried Peter Schmacher, and this was his reply:
Impedance of the Vapor Audio Nimbus?
If he has not already done this for you — and from your responses i’d guess not — then you should contact him about it.
The high output impedance of your SET will interact with the non-flat impedance curve and cause frequency response aberrations. In theory your system should sound better and be more neutral afterwards.
dave
Live sound means that it sound like you are there.
Live orchestral recordings are the rule, not the exception. Usually very little mixing, compression or EQ on them.
Steve N.
Empirical Audio
Pete uses essentially the same amps I do, without my mods. I will email him, but I don't think it's necessary. He sold me the amps and the speakers.
Steve N.
Empirical Audio
Hi Dave,
The amps Steve uses are not high output impedance SETs. I have the same amps, and am intimately familiar with the circuit topology having consulted with the factory about its implementation. It has enough negative feedback, from the output side of the transformer, to offer good regulation for the modest impedance swings presented by Steve's pair of Nimbus.
In the future, don't assume that because it's SET that it has high output impedance.
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Thanx Peter for clearing that up. It is something Steve needs to be able to express if he is going to make claims about the transparency of his system for the purposes of doing comparisons. Otherwise the sharks around here will tear him apart.
Most SETs do not have negative feedback because the designers believe that it wipes out the very good low level detail extraction SETs are renowned for. Adding NFB will lower the output impedance and lower the measured distortion, but often at the expense of at least some of that which makes SETs outstanding.
May i ask what SET we are talking about?
dave
Most SETs do not have negative feedback because the designers believe that it wipes out the very good low level detail extraction SETs are renowned for. Adding NFB will lower the output impedance and lower the measured distortion, but often at the expense of at least some of that which makes SETs outstanding.
May i ask what SET we are talking about?
dave
The terminology "detail extraction" is likely a euphemism for 3rd harmonic generation. A little 3rd harmonic creates a perceptual experience of added detail, which can be enjoyable. But, it is not extracting so much as it is adding something that wasn't there to begin with. Can sound good though.
From personal experience, I could pick very subtle differences between dacs on a very good headphone setup. I built up a collection of headphones, dacs and headphone amplifiers, went to headphone meets etc and at this level, I could consistently pick between dacs on a blind a/b test
Fast forward 8 or so years and now with speakers i don't bother with external dacs. Speakers and rooms are by far the biggest limits, and when you compare detail monster headphones like electrostatic headphones, or something like the sony SA5000, there doesn't exist any speakers that even begin to approach those in detail retrieval
Fast forward 8 or so years and now with speakers i don't bother with external dacs. Speakers and rooms are by far the biggest limits, and when you compare detail monster headphones like electrostatic headphones, or something like the sony SA5000, there doesn't exist any speakers that even begin to approach those in detail retrieval
Retrieval, reproduction transduction? There is an electrical signal from an amplifier that transducers are supposed to accurately convert into mechanical motion, a process called transduction.
Retrieve is when something is fetched, such as book brought out from the stacks by a librarian, or a dog fetching a thrown stick. Speakers and headphones don't go fetch anything. So, don't think anything is made more clear by using words that don't accurately describe what is being done.
When i use it, it is definitely not, althou i usually use the term DDR (Downward Dynamic Range).
A combination of the triode being the most linear amplification device yet devised by man (VFETs/SITs come close), the output transformer being biased where it is most linear, usually no need for feedback all allow for the possibility of very high DDR. Execution is of course important — ie i have heard enuff overly syrupy SE 300Bs to shy off of them.
dave
Probably better descried as a device not losing or masking subtle information. The ability to retrieve the information from whatever is being fed to it.
dave
The ability to fetch the information from whatever is being fed into it? I don't see how any fetching occurs. The is a voltage produced by an amplifier that represents intended motion of the transducer diaphragm. Either the motion follows the voltage accurately or not. That's all there is, there is nothing additional to go fetch from the amplifier?
If the voltages are very small, or changes in the voltage are very small then these can be lost. Any device will lose some. Better ones will lose less. These small voltages/changes are the detail. Fetch is not the appropriate word to use, but it and similar have been embedded into the audiophile terminology.
BTW, you are assumming a voltage device. It couls also very well be a current device.
dave
BTW, you are assumming a voltage device. It couls also very well be a current device.
dave
Well, let's clarify a little bit about this before moving forward. SETs all employ negative feedback to some extent in their bias circuitry. They may not employ global feedback however, and that to me is a disadvantage. When operating class A which SETs do by definition there will be no low level detail lost because of modest feedback to linearize the output.
IMHO of course.
And before someone makes the claim that no negative feedback sounds better, how about that old blind test to see if the discerning ear can really hear the difference and determine a preference? I know when I was auditioning the amplifier back in 2012, the consensus among those that heard it was that stock, with very little feedback, was not the preferred configuration. Adjusting the feedback to obtain a lower overall gain greatly improved the SNR which is an obvious audible benefit.
The SET in question employs the 805AT output tube driven by an EL34 and a 6SN7 input tube, though Steve may have changed the input and driver tube compliment.
I clearly haven't had enough coffee today, but that is just nitpicking, like most of this thread.
That was just another perspective, one that I think is rational and grounded, compared to most of the other opinions i see
A meaty tube designed for Class C transmitter use. I have 5 of them stashed away.
The quality of an amp is so dependent on execution i have learned not to pre-judge.
You aren’t going to give us a brand name? Or are they diy (builder)?
dave
I have too. Most amps have poor power delivery, slow tubes and other issues, like non-linear transformers that saturate, class B, A/B etc..
My amps are not like this or I would have never changed from SS to tubes.
Steve N.
Empirical Audio
Arte Forma made the original point-to-point prototypes that I modded. The new version is commercially available, but uses a circuit board. Still sounds very good though. DC-coupled.
Due Volte
Steve N.
Empirical Audio
Hi,
I was looking for a cheap DAC upgrade to fit into a CD changer, so your interesting test result came just in time. So I ordered the FiiO from Amazon and ran some private, nonscientific A/B tests, just with matched levels.
The FiiO was heard right out of the box, no fancy burn in period. It performed surprisingly well, on a similar level as my Maranz CD67Mk II OSE build in DAC , a Marvel DAC and an upgraded „DAC in the Box“. “Well performing” for me basically means there is nothing to criticize, nothing missing and no ugly sounding parts, that sometimes may occur, even for fractions of a second, but clearly reproduce-able.
My „reverences“ sure are no high end gear, but satisfy my basic needs.
In this sense, the FiiO is a very surprising little piece of electronic, even more for it´s price.
The interesting part came when I tried the optical connection on the FiiO. The sound degraded, almost as switching from stereo to mono.
So in your test set up, it would be interesting if you can hear an very significant difference, when you go from coax to the optical input, just on the FiiO.
If not, there might be something wrong in your whole set up. I personally mistrust the nanoDIGI DSP, but this might just be due to an unlucky personal experience.
The FiiO “Taishan DO3K” with full name, to me seems to be a logical construction of the better kind.
The input CS 8416 straightens out the input signal, the CS 344C DAC decodes and the LMV 358 op-amp gives a well decoupled, strong output signal. There could be much less in the little box. Concentrating the parts on a very small PCB might not be a disadvantage, too.
Maybe, if a DAC´s output reaches a certain quality level, there is no better than just plain perfect. This would lead to the conclusion, that the heard differences between good DAC´s are more for taste than real improvement. I think tubes in modern HIFI mostly have this purpose, if aesthetic views are ignored.
I was looking for a cheap DAC upgrade to fit into a CD changer, so your interesting test result came just in time. So I ordered the FiiO from Amazon and ran some private, nonscientific A/B tests, just with matched levels.
The FiiO was heard right out of the box, no fancy burn in period. It performed surprisingly well, on a similar level as my Maranz CD67Mk II OSE build in DAC , a Marvel DAC and an upgraded „DAC in the Box“. “Well performing” for me basically means there is nothing to criticize, nothing missing and no ugly sounding parts, that sometimes may occur, even for fractions of a second, but clearly reproduce-able.
My „reverences“ sure are no high end gear, but satisfy my basic needs.
In this sense, the FiiO is a very surprising little piece of electronic, even more for it´s price.
The interesting part came when I tried the optical connection on the FiiO. The sound degraded, almost as switching from stereo to mono.
So in your test set up, it would be interesting if you can hear an very significant difference, when you go from coax to the optical input, just on the FiiO.
If not, there might be something wrong in your whole set up. I personally mistrust the nanoDIGI DSP, but this might just be due to an unlucky personal experience.
The FiiO “Taishan DO3K” with full name, to me seems to be a logical construction of the better kind.
The input CS 8416 straightens out the input signal, the CS 344C DAC decodes and the LMV 358 op-amp gives a well decoupled, strong output signal. There could be much less in the little box. Concentrating the parts on a very small PCB might not be a disadvantage, too.
Maybe, if a DAC´s output reaches a certain quality level, there is no better than just plain perfect. This would lead to the conclusion, that the heard differences between good DAC´s are more for taste than real improvement. I think tubes in modern HIFI mostly have this purpose, if aesthetic views are ignored.