[ez53436]

Interesting, so essentially the amp is meant to keep distortion at the lowest possible level. And amps amplify the sound to a higher level, but by turning the volume knob you can actually only reduce the amplified signal strength (if that's what it's called) since the max is 0 dB? I think I understand that correctly. I was thinking that it was more like 0 dB to +10 dB or something. So could you honestly say that you've noticed an amp around my price range that has made a difference in anything besides volume and distortion? I want to know if it will create a better sense of instrument separation, smoothness of mids, tighter bass, clearer treble, wider soundstage, more detail, etc. Thanks again!

 

[ProtegeManiac]

  Interesting, so essentially the amp is meant to keep distortion at the lowest possible level. And amps amplify the sound to a higher level, but by turning the volume knob you can actually only reduce the amplified signal strength (if that's what it's called) since the max is 0 dB? I think I understand that correctly. I was thinking that it was more like 0 dB to +10 dB or something.

 

No, like I said, gain is more of a multiplier factor. I already forgot the actual math for it since I wasn't listening back during physics class in high school (my idea of "gain" back then was just "turn up that Mesa Boogie duuuuuuuuude!!!"), but when I said default/high gain is at 0dB, it doesn't mean it can't go past 0dB effectively, it's just that the ratio of how much louder it can make the signal at every degree of turn of the knob is what is effectively "0dB." At the low gain setting of -10dB, it's only "-10dB" relative to 0dB, but depending on the headphone efficiency, it will still get a lot louder given it's amplifying the input signal. The end result at the headphone is that my HD600 can still pretty much hit 95dB at low gain mode, and I've clocked it at 102dB at high gain (1khz sine wave).

 

  So could you honestly say that you've noticed an amp around my price range that has made a difference in anything besides volume and distortion? I want to know if it will create a better sense of instrument separation, smoothness of mids, tighter bass, clearer treble, wider soundstage, more detail, etc. Thanks again!

 

An amp doesn't really "create" these better than what the headphone contributes to it, but if the headphones were connected to an amp or device with a high THD* driving them, then any amp with considerably less distortion should** sound better. Unfortunately it's difficult to measure the actual THD when the headphones or speakers are already involved since the transducers' coloration comes into play, but under lab conditions amplifier THD can be measured given the output power, and output power and impedance can be graphed as well. If you have those on any and all amplifiers you'll compare, then it's easy to see which one should sound a lot cleaner.

 

The problem is that unlike Headroom's archive of headphones' frequency response graphs (that it can overlay with several headphones for comparison), we don't have those for amplifiers.


*Distortion doesn't actually have to sound like "distortion," like how one can easily tell how over-excursion sounds like, which is a "thwackk!!!" on the trailing edge of the notes of lower freq drivers
**"Should," because in some cases people like the kind of distortion a certain amp has - for example the euphonic distortion made by some vacuum tubes and enhanced/emphasized by certain circuit designs.
 
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Missed this one, sorry:
 

  Hi! Thanks for comments. One remark though - quote from Schiit website: " Like Bifrost, Modi 2 Uber offers USB, Toslink, and RCA inputs, each individually selectable via a front-panel button."

 
Oh that refers to what others would normally refer to as "coaxial," the other kind of SPDIF transmission hardware (the other being optical/toslink, as in the other Modi).
 

  I was considering Little Dot due to great reviews and tube rolling option - I thought maybe this is something i would like to experiment with in future. But again - does it make sense when streaming? If it is sensible only with higher bandwith sources, then perhaps Modi+Vali is indeed the way to go.

Thanks again! 
 

 

To be perfectly honest I'm not a fan of rolling tubes, or even op-amps. A lot of people tend to roll them to get a flavor that isn't neutral for example, like making it sound warmer (and between many of them, the question is, "how much warmer" does each want it to go). And if a manufacturer didn't ship it with a tube or op-amp that makes for a neutral circuit in the first place, then...well...they themselves kind of miss the idea that an amp is just meant to amplify, not color the signal.

 

[billybob_jcv]

I think experimenting with things like tube rolling & op amp rolling is fine - as long as you keep your perspective and manage your expectations. I think psychoacoustics is a very powerful influencer and it takes a very, very disciplined person to overcome the preconceived bias we bring to the table. If you have researched for weeks reading what other people say about specific tubes or op amps, agonized over the buying decision, then finally pulled the trigger and spent your money - there are some VERY powerful expectations being set. I am NOT saying there is no difference when different amps, op amps or tubes are used - I'm just saying that it might be very difficult to separate the expectations from reality, and that I prefer to spend my time and money on the actual headphones & IEMs that *do* show significant tangible and measurable differences in the sound they produce. I have a hard time believing I can hear the difference between 0.01% THD and 0.05% THD, but I *know* I can hear a difference in two headphones that have a 6 dB difference in response between 100 - 500 Hz. IMHO, the amp's job is to meet the voltage and current demands of the headphones with clean, uncolored power. The headphone's job is to produce the sound signature I prefer. Simple, right?