[bigshot]

There was a master thread on DSPs in Sound Science. I just searched for it and couldn't find it. Does anyone else remember where that is?

This isn't the one I was thinking of, but it might be helpful. https://www.head-fi.org/threads/can-tube-sound-be-replicated-via-plugins.657769/

You're going to have to wade through the posts by people speaking purely in theory and look for ones who are actually doing this.

EDIT: I found the good thread. Pay attention to the posts by Strangelove424. He's got practical experience in this.
https://www.head-fi.org/threads/the-dsp-rolling-how-to-thread.867258/

 

[ADUHF]

Thanks- the best part of the Sound Science forum is that you all have great links to data, white papers, and other empirical information that is truly helpful and educational.

From the standpoint of sound quality (subjective), I think my RME DAC/amp combo sounds very good with my ZMF headphones. From the standpoint of power, sensitivity, dBr, and output (objective) all the numbers are indicative of more than adequate confirmation. I looked at Amir's data, which clearly indicated 310 mW was available on tap, which far exceeds what is required to run 300 Ohm headphones. He called this "superb" and given the math, I can see why. I'm quite perplexed at the guy who stated RME, which he also owns, is not sufficient to drive 300 Ohm headphones (he referenced Sennheiser HD800).

Out of pure curiosity, I may acquire/test drive/borrow (whatever works out) a solid state and tube headphone amp to see for myself. I did spend some time at the local HiFi shop with two high-end tube amps. I brought my RME and listened with my headphones to the DAC through each tube amp and then the DAC by itself, noting very little difference. The only thing I really picked up on was more presence in bass/sub-bass. Granted, I would like more time with a tube amp to listen further and take notes. I've been reading up on the THX 887, which some have paired with their RME. Many have stated it has resulted in some subjective improvements on their headphones.

Fwiw, "superb" for a DAC, and superb for a dedicated amp could be two different things. Alot of folks like more headroom on the latter. So that is why they will go the dedicated route. (Alot of audiophiles suffer from hearing loss as well, so that could possibly be another reason they like to be able to drive their headphones to somewhat ridiculous volumes.)

If it's 310 mW, btw, then you also have to ask... with what? (Edit: I see now this was already mentioned in one of your previous posts.) Because the available power depends on the load the amp is driving, as VNandor explained in his post. Amir knows his stuff though, and if he says it's superb, for a DAC/amp combo, then you can probably take that to the bank.

Another factor to consider is the type of content you'll be using with the headphones. That matters because most digital music content will have its loudness significantly boosted using some form of dynamic range compression. So content where the full dynamic range has been left more intact may require more volume.

Fwiw, my little $100 HA543 amp can apparently deliver around 300 mW per side (either left or right) with a 60 ohm load. And it seems to have more than enough power to drive my 250 ohm DT-770 headphones to fairly ear-splitting volumes with most of the music I listen to. There is the rare full-range recording made from a TV show and what have though where I'll have to lift the volume a bit more.

Re tube amps... That is not really one of my areas of expertise. But I believe some do have a somewhat warmer sound. Folks in the general forums will also talk alot about matching headphones and amps for the best sound. By which, I think they generally mean the tonal balance (ie more or less treble or bass, for example). So not all amps (esp. the tube type?) will have a totally flat response, as bigshot mentioned.

I'm sorry to keep comin back to it, but my HA543 has an "Enhance" feature, which will change it's frequency from a flat response, to a more U-shaped response which is boosted in the bass and treble. My DT-770's are already plenty boosted enough though at the ends, so I always leave it on the "flat" setting.

The parametric EQ features on your DAC should also give you the ability to design pretty much whatever sound signature you want for your headphones. So you don't really need a tube amp to get that. There are alot of audiophiles who prefer to eschew EQ-ing though. And getting their sound signatures in other ways, by either modding the headphones and/or by pairing it with a particular amp (or tube, for that matter) that has a little coloration that's a bit more to their liking. The parametric EQ features on your RME DAC should be very high-quality though. So there should be no noticeable loss in sound quality when using those.

Bigshot's idea of using DSP to emulate a tube sound is also interesting. If you just want to make some simple tweaks to the tonal balance though, then the on-board EQ controls on the DAC should be adequate for that.

 

[bigshot]

Tubes affect more than just response. They inject distortion at even order harmonics that are considered euphonic. They also can affect dynamics and create a punchier sound. I have nothing against that. If you like that, it is just as viable way to listen to music than clean. My only objection to tube amps is that they are not adjustable. You get the level of distortion that is hard wired into the design of the amp, and without hearing and comparing it to different levels, there is no way to determine if that is optimal for you. DSPs are completely adjustable and calibrated. You can dial in exactly what you like and tune by ear. Just buying a tube amp at random gives you random results, and that is the least efficient way to improve your sound.

I strongly believe that when it comes to fidelity, we have largely solved the problem with digital audio and solid state amps and DACs. The future of improving sound won't be cleaner and cleaner, because it's clear that that makes no audible difference. I can pull out my $40 Walmart DVD player to play a CD and it's the same as running the same file through my $1200 DAC/amp. The future is in signal processing... tailoring the sound to our own tastes, making it work well within our own living rooms, and sweetening mixes that weren't lavished with love in the first place. DSPs are the way to do that.

 

[ADUHF]

I guess some people also don't consider a dac to be a "dacamp" in the technical sense, unless it includes some type of analog audio inputs, as well as digital inputs. Not really sure about that though.

 

[bigshot]

A DAC converts from digital to analogue. It can capture from analogue to digital too, but not all DACs do that. An amp is a separate thing. It can be combined into the same case as the DAC, but it's a separate bit of circuitry. It isn't that complicated.

 

[skhan007]

Understood. I suppose the only real way for me to know is to test drive some amps being fed by my DAC and do the swap of the headphone cable back and forth. For example, I listen to my headphones with a pretty low dB, as evidenced by a spectrum analyzer app (about 60 dB). If I had a separate headphone amp and low to low/moderate volumes, would it sound any different than my DAC/amp combo unit (the RME)? I believe there's no way to know until I test drive one. In my reading, and putting EQ benefits aside, many have asserted soundstage, separation, and other intangibles are enhanced with certain solid state or tube amps. That really appeals to me, assuming I can hear the improvement in an A/B test. I'm really curious, actually.

 

[VNandor]

That really appeals to me, assuming I can hear the improvement in an A/B test. I'm really curious, actually.

Make sure you volume match the two amps properly. People can pick up on tiny volume differences even if it's as low as 0.3~0.5dB. This could make the two amps sound different even though the only difference between them is the volume. If you aren't aware of proper volume matching, you could end up (wrongfully) attributing the changes in sound to the amps instead of the slightly different volume levels.

 

[ADUHF]

Understood. I suppose the only real way for me to know is to test drive some amps being fed by my DAC and do the swap of the headphone cable back and forth. For example, I listen to my headphones with a pretty low dB, as evidenced by a spectrum analyzer app (about 60 dB). If I had a separate headphone amp and low to low/moderate volumes, would it sound any different than my DAC/amp combo unit (the RME)? I believe there's no way to know until I test drive one. In my reading, and putting EQ benefits aside, many have asserted soundstage, separation, and other intangibles are enhanced with certain solid state or tube amps. That really appeals to me, assuming I can hear the improvement in an A/B test. I'm really curious, actually.

What VNandor said.

Assuming you have adequate volume, then to the best of my knowledge, there are really only three other major factors that can influence said intangibles on the amp side. And those would be noise, distortion, and frequency response. There could be some variability on those things with tube amps. Probably much less so when comparing two good solid state amps.

If you don't like the sound of a totally flat frequency response, then you have the ability to change that on your amp with the EQ controls. Alot of folks don't have that luxury... At least not built directly into their amp. That leaves noise and distortion.

Solid state amps can vary in terms of their noise and distortion levels. The variations between those things on higher quality solid states, like your RME, is likely to be incredibly small though, from the standpoint of human perception. So as a general rule, on a well-designed amp, it really should be a non-issue. (There are always the rare exceptions though to such rules.)

Distortion can start to become noticeable if the impedances on the amp and headphones are not properly bridged. So that could potentially also account for some of the claims of differences on solid state amps. And some listeners may also like a bit of noise or distortion in their sound. And might therefore give a better assessment to an amp which has a bit more of those things than to one which does not. Distortion and noise are generally considered to be detrimental though to the type of sound quality characteristics that you mentioned above, such as sound stage, separation, imaging, clarity, and so on. So the less you have of those things, generally the better.

 

[ADUHF]

Other factors that might possibly effect the quality or accuracy of the stereo imaging are phasing issues, and the left/right balance of the volume control. I would think that both of those would be well-mitigated on most higher quality solid state amps though.

Some amp designers will go to greater lengths to ensure that the left-right stereo balance stays more accurate across the different volume ranges. Or include a user adjustment for this. And it appears that your RME has this on its remote, via the L and R buttons (which is pretty cool).

I'm less knowledgeable on the subject of phasing. But have heard from others here that some EQ's can possibly effect that. Whether that is the kind of thing that could be noticeable though on a unit like your RME, I don't really know (though am somewhat doubtful). Maybe bigshot, VNandor or some of the other folk here could comment on that.

 

[bigshot]

Patch through a switch box so you can do a direct A/B swap without plugging and unplugging. Auditory memory for similar sounds can last as few as a couple of seconds. They have inexpensive ones at Amazon.

If you find a difference, let me know. I'm looking for a DAC or player that sounds clearly different. I've tested dozens of my own components of all types and I've never found one, and I've never run across a person who has done a controlled test who has. I've found plenty of people who are willing to claim it without doing any tests however, and people that will talk at length about differences they have never heard themselves. A lot of audiophilia is parroting what other people say in forums. That's why it's a good exercise in skepticism to find out for yourself by doing a line level matched, direct A/B switched blind test.

 

[gimmeheadroom]

Thanks- if I’m understanding the math, my RME is indeed capable of driving my 300 Ohm headphones, correct? In a search, I noted a reviewer graphing results showing the RME it’s capable of 310 mW with a 300 Ohm Load, which he called “superb.”

Regarding the criticism I received, the member was clear in pointing out that I’m inexperienced and shouldn’t be stating the RME can drive my headphones. This is in an RME thread, so he’s an owner as well and seems set in the requirement of a separate amp. Pretty deflating, but I’ll get over it.

That's not what I said. You made a general statement about a pile of 300 ohm headphones and also some that were much lower impedance that the RME drove them well.

My point is not that you are incapable of saying what you like, obviously nobody can tell you that.

What I said was without hearing the cans out of an amp that everybody agrees drives them well you don't have a generally useful definition of "well." Just because they sound fine to you, without any experience and without any basis for comparison as you yourself also noted, does not mean anything. Maybe you're shorting yourself and missing out of the experience you would get with enough amp.

To drive cans well does not just mean volume. High impedance dynamics can sound flat and lifeless even when loud enough. You can't get answers from calculations. You have to have experience with a bunch of gear. This, and not your impression, is what's missing from your proclamation.

 

[skhan007]

That's not what I said. You made a general statement about a pile of 300 ohm headphones and also some that were much lower impedance that the RME drove them well.

My point is not that you are incapable of saying what you like, obviously nobody can tell you that.

What I said was without hearing the cans out of an amp that everybody agrees drives them well you don't have a generally useful definition of "well." Just because they sound fine to you, without any experience and without any basis for comparison as you yourself also noted, does not mean anything. Maybe you're shorting yourself and missing out of the experience you would get with enough amp.

To drive cans well does not just mean volume. High impedance dynamics can sound flat and lifeless even when loud enough. You can't get answers from calculations. You have to have experience with a bunch of gear. This, and not your impression, is what's missing from your proclamation.

OK, I can understand what you're saying here. The initial post you made that I took issue with, did not come off constructively when I read it. I took the statements as critical, based on the wording:

But to make an absolute statement like "the ADI-2 has no problem at all driving these 300 Ohm headphones. In high power mode, it does very well with these headphones." in a vacuum without having listened to those headphones out of the amps people claim you must use is just misleading to people who read that. First we read that guy had one pair of audiophile headphones and not much experience. Then a couple days later we read a broad proclamation about what does or doesn't work well. What's wrong with this picture?

I'm not in a vacuum, I have listened to my ADI-2 through two different high-end tube amps, and I concluded (although I'm new to HiFi, I'm not new to musicianship, studio work, and professional recording) that my headphones were sufficiently driven by the ADI-2. I'm not trying to be difficult with you here, but you quoted my words, stated I'm somehow misleading people (not sure how, as it was my opinion on my headphones with my gear). Sorry- what did you mean in your statement above about 'a general statement about a pile of 300 Ohm headphones and some that were much lower impedance'? Could that have been someone else, as I don't recall referencing a pile of headphones or different impedances, as I don't own a pile or any beyond my two at 300 Ohms. You might be referring to the ones I tried out at the hifi shop. Yes, the Audeze headphones were not driven all that great by the ADI-2, but other ones were to my ears. You clearly want something from me and my posts that I'm not delivering, so I'm at a loss. I posted my findings from my trip to a hifi shop. I guess that somehow misleads people? I don't think that's the case at all. People are not inherently naive and are not going to believe things just because somebody posted it on a thread. Also the 'broad proclamation of what works well or doesn't work well.' I don't know what you're referring to here, as I don't recall doing any such thing. Please clarify, if possible. Thanks.

 

[bigshot]

I would say that ultimately, if it sounds good to him, that is all that matters. Accuracy is a good place to start, but everyone has their own preferences. When it comes to response curves for headphones, there is no "correct" curve, certainly not like with speakers. It's a range. There's no reason to get upset over a dB or two here or there if that is what he prefers. He's said he's interested in tube amps. That should tell you that he is aiming for euphonics, not accuracy.

Honestly, these theoretical quibbles make no sense in the real world. I don't think any halfway decent solid state amp that is designed to push 600 ohm headphones well enough is going to have a much different response than any other. Is there any other rating out there that is more of a standard than 600 ohm? Sennheiser, AKG, Beyer... That is what most headphone amps are made to suit, at least for listening at home. And for portable, a lot of headphones don't need amps at all.

The whole subject of amps is WAY overinflated at Head-Fi. It really isn't that difficult, and making it a baseball bat to hit someone over the head with doesn't help. He isn't concerned with accuracy and he has an amp that works for him. There's no reason to make a big stink over theoretical stuff that almost certainly doesn't apply in his case. He could spend a grand and get a fancy solid state amp, and it wouldn't sound any better to him than any other solid state amp. The headphones make much more of an impact on the sound than the amp does... orders of magnitude more. And if he is interested in tube amps, accuracy isn't a consideration for him at all. He's defined his criteria pretty clearly.

 

[gimmeheadroom]

I would say that ultimately, if it sounds good to him, that is all that matters. Accuracy is a good place to start, but everyone has their own preferences. When it comes to response curves for headphones, there is no "correct" curve, certainly not like with speakers. It's a range. There's no reason to get upset over a dB or two here or there if that is what he prefers.

I agree with that right up until the point he makes a proclamation that the RME drives 300 ohm headphones well, since I know it does not.

Nobody can say what somebody else likes, that much is clear. But it is untenable to make broad statements with no basis for comparison. That kind of statement can be harmful when it causes somebody to make an expensive, misinformed purchasing decision based on somebody claiming this or that without the experience to know what the gear is capable of. One post he says he has no experience with audiophile headphones. A few posts later and he knows everything. That's just not the way it works.

Yeah, we get it that when you hear great gear you're amazed. But you didn't hear enough of it to generalize yet.

OK, I can understand what you're saying here. The initial post you made that I took issue with, did not come off constructively when I read it. I took the statements as critical, based on the wording:

But to make an absolute statement like "the ADI-2 has no problem at all driving these 300 Ohm headphones. In high power mode, it does very well with these headphones." in a vacuum without having listened to those headphones out of the amps people claim you must use is just misleading to people who read that. First we read that guy had one pair of audiophile headphones and not much experience. Then a couple days later we read a broad proclamation about what does or doesn't work well. What's wrong with this picture?

Because it does not make sense for a guy who has never heard good gear to make broad declarations like you did. You have no standing.

You got the RME, a known great DAC, and a pair of ZMF cans, known great cans. Did you expect them to sound like crap? Of course they will be impressive.

But maybe they are far from their limits and would sound even better with enough amp.

I'm not in a vacuum, I have listened to my ADI-2 through two different high-end tube amps,

I don't remember seeing this statement and you didn't name the amps. What we want and what is useful is not your opinion in a vaccum, but your impressions of specific gear and what you already own or have spent a lot of time with so we can understand where you're coming from.

and I concluded (although I'm new to HiFi, I'm not new to musicianship, studio work, and professional recording) that my headphones were sufficiently driven by the ADI-2. I'm not trying to be difficult with you here, but you quoted my words, stated I'm somehow misleading people (not sure how, as it was my opinion on my headphones with my gear). Sorry- what did you mean in your statement above about 'a general statement about a pile of 300 Ohm headphones and some that were much lower impedance'? Could that have been someone else, as I don't recall referencing a pile of headphones or different impedances, as I don't own a pile or any beyond my two at 300 Ohms. You might be referring to the ones I tried out at the hifi shop. Yes, the Audeze headphones were not driven all that great by the ADI-2, but other ones were to my ears. Also the 'broad proclamation of what works well or doesn't work well.' I don't know what you're referring to here, as I don't recall doing any such thing. Please clarify, if possible. Thanks.

Ok, pro gear is notorious for not driving headphones well, you haven't said anything convincing yet.

I'm an ex musician also, was first piano in college dance band, played fills in brass, woodwinds in orchestra and marching band. Have been tested numerous times and have perfect pitch. Done recordings of garage bands. Played weddings. I'll put my ears up against anybody elses. That's not what the issue is. The issue is lack of basis for sweeping statements which you made.

Yes, it was the list of cans you listed that you heard at the shop. The sentence seemed to suggest the ones you listed were all 300 ohms and your comment here does nothing to change that.

It is misleading to make the blanket statement that the RME drives 300 ohm headphones well. It just does not. It might drive them better than something else, but it does a poor enough job compared to other amps I have, some not very expensive, for me to know that it's not helpful to declare what you declared.

The Audeze cans are low impedance and to my ears the RME does drive those well (at least the 2C and 3F which I have). I do prefer the 3F out of a Lyr 2 but the RME does a very good job with both of those.

 

[bigshot]

What is the problem with RME with 300 ohm cans? You say they don't work well together, but you don't say what the problem is or offer any measurements to show the difference. What are we talking about? Volume? Response? Distortion? How much? This isn't my specialty, but I'd be interested to hear specifics instead of a blanket dismissal of a blanket statement.

And I would suggest getting rid of the unnecessary swagger and aggressiveness. That doesn't go over well here.