Come on dude, your entire commentary is science fiction. Beyerdynamic is KNOWN for their very bright treble. The T1, T2, dt1990, Amiron, T5P1, T5P2, t90, 770, 880, and 990, all have treble that is difficult for most to take. And some of those models are very easy to drive, yet still have big treble spikes. That’s simply their house sound up until very recently, where now they’re trying to change to be more consumer friendly.
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John_William, Which amps have you tried pairing Beyerdynamics with?
I have some DT880 on my head right now playing through some tubes and it sounds glorious. Just as driftingbunnies put it, as soon as you put the right amp on them they sound good.
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There must’ve been something that touched a nerve. I’m not sure what it is but let’s break this “science fiction” down.
- Yes, Beyers do have a beyer sound which have elevated treble. However, we are talking specifically about the T1 and not just all Beyers. If you want to talk about all Beyers then we should tackle that one by one. Let’s stick to the T1 right now.
- What about my statement is science fiction? The fact that T1’s get to 1k ohm impedance? The fact that they do better on OTL amplifiers? The fact that modern amps have been lowering the OI lower and lower in order to accommodate for Planars? The fact that low end dac/amps have glare that could make the treble situation worse? Instead of just flat out calling out my commentary science fiction, why don’t you tell me what you disagree with?
- Why don’t you tell us what experience you have with the T1 rather than just saying that they’re KNOWN for very bright treble. I also made this statement at the very beginning.
T1.1 is a very well balanced headphone. It was known as the jack of all trades when it came out compared to the HD800.
The HD800 has some pretty hot treble too. Why don’t we talk about how the SDR mod had to be created just to help with the 6khz peak? Why don’t we talk about the requirement for the HD800 to be on tubes to reach it’s full potential as well? I think we see a pattern here.
Dynamic drivers with higher impedance need larger voltage swings compared to hard to drive planars need more constant current. Based on the amps that are currently popular with headphone enthusiasts (mostly <$1k SS amps), there are a few things that they generally all have in common. They measure well, they’re opamp based, they have low OI, and they’re pretty weak at high impedances. They’re basically built for Planars that have low impedance and the measurebaters.
Let’s look at what the scene was back in 2010 when the T1/HD800 came out. They were the evolution of the previous TOTL HD600/650, DT880/990 etc etc. Orthodynamics/Planars were a thing but weren’t really that popular so a lot of people were using either studio amps, tube amps, or SS amps that didn’t really have OI specs. Have you ever tried a Utopia on a high OI amp? It makes the bass extremely bloaty. Do you know why? What happens when you put it on a low OI amp? Why does the Senn meme exist where if you throw a Senn on an expensive tube (high OI) amp, it sounds amazing? Why do HD800 owners insist that they need to be heard on tube? Are all these people delusional? Do they dabble in science fiction as well?
Beyers definitely catered to the pro market more which had plenty of 600 ohm headphones. Pro audio consumers were never worried about the high impedance cause that’s what all the studio gear was used to. If you look at the SPL Auditor/Phonitor, the OI was 120 ohms and sent more voltage the higher the impedance. Only due to the shift in budget gear and chifi did Beyers have to cater to the consumers since 600 ohm drivers will sound wonky without enough voltage/power.
Anyways, sorry for the long winded response but I’m curious what experience you had with the T1 and OTL amps that made you feel like you needed to be so snarky to someone you don’t know.
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Bear in mind, while the reactive impedance of the T1 exceeds 1kΩ, the real part - the resistance - is already over 500Ω. You would need an incredibly high output impedance to have a really significant change in the level of midbass (120Ω, referenced below, would boost the peak by about 1dB), and that’s still not going to change the level of treble relative to the midrange appreciably because the Z is much more constant above the resonance frequency.
I say the same thing any time someone says a given headphone requires more voltage: yes, that’s what we see in sensitivity measurements, because we do measurements of sensitivity with constant voltage sources. If your headphone takes 1Vrms to output 100dBSPL at 1khz, then that’s that, the question on the impedance side is whether it’s also going to require a herculean amount of current (as some low-Z-but-insensitive planars do).
However, opamps have a hard time sinking and sourcing current - they are small integrated circuits with only so much space to spread heat, and designers who were on a tight budget for power consumption. A higher load impedance makes a speaker or headphone, for a given level of required voltage, easier to drive, and this is part of why older amplifiers using a single non-power opamp to drive headphones often did fine with the high impedance dynamics of earlier days, but had trouble with, for example, the HE6 and other equally insensitive designs that also required 100+mA of current to be thrown around (which only a fairly small number of opamps can do).
These days we’re blessed with a few more options for higher-current headphone driving integrated circuits than we used to have, but there’s a reason that discrete or hybrid amps continue to dominate the output power arms race in many cases - a $.05 transistor can deal with a lot more current than a fancy $3 opamp. Now, mind you, that’s more current than we actually benefit from, almost certainly, but specs races are what they are.
On the voltage side, however, the actual levels required by high Z headphones are very comfortably within the limits of an IC opamp with sufficient supply voltage. Many audio opamps can swing within about a volt of rails, meaning that even a standard +/-15V supply will take the T1 to around 125dBSPL per its specifications, so long as it can supply the rather humble 17~mA required, which many if not all signal opamps can do. Of course, the headphone won’t go that loud linearly, to say nothing of your poor ears, but driving a headphone with a DC coil resistance over 500Ω is not a hard situation for any opamp I’ve seen used for a headamp.
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Even though I love Gilmore based designed amps, I know Kevin Gilmore is against using opamps. source: A Pure Class A Dynamic Headphone Amplifier. – HeadWize Memorial
Are you stating that opamps cannot drive HE6? My RebelAmp has no problem driving my HE6SE V2 and it sounds better driving it compared to ALL of my discrete and hybrid amps that I own. I have quite a large collection that include many of the popular/hyped ones.
The RebelAmp has a discrete output stage, not opamp.
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If it is the case with a given amp-headphone combo that the amp cannot deliver the required current, what does that sound like? Does it just not get loud enough, is the FR affected, etc.?
Also if the amp has adjustable output impedance, will switching to a higher output impedance help?
@Mad_Economist Thank you for the response. I understand that there is the idea that numbers are numbers and that the numbers should give us the information that we need. I don’t think there is any argument against the T1 being loud enough with current day amplifiers. The question really is, why has the view on beyers (in this particular case the T1) changed so much from when it was released to where it is today.
Over and over again, I hear OMG beyer brightness, “stabby” ( 
you know who you are), etc etc. Based on the FR graphs, yes, there is more treble energy than something like a HD600. Was that something that was continuously harped on back in the 2000’s? Not really. So what has changed? Have ears evolved during that time? Has the progress we’ve seen in opamps and transistors solve our issues in audio? Is it just the difference in demographics with audio that changed the narrative?
I would like to reconcile the anecdotal evidence with the scientific evidence of not just me but many other audiophiles as to why something will sound better with tubes (seemingly high impedance dynamic headphones) vs solid state (low impedance planars). This isn’t new knowledge by any means. Is it because it’s easier to get for a lack of a better term “quality sound” out of lower power? Is it a synergy thing? (How do you explain synergy scientifically?) So many questions that I feel aren’t quite linked to what we see in graphs or aren’t quite explained well when it comes to what we measure vs what we hear.
There’s something that you never really talk about in your response. You never mentioned how it will sound. There is evidence that an opamp can provide enough voltage to get a T1 loud enough. I think there’s a hint that there shouldn’t be any change in sound when you said that “You would need an incredibly high output impedance to have a really significant change in the level of midbass (120Ω, referenced below, would boost the peak by about 1dB)”.
However, based on my experience with high impedance dynamics (sennheisers and beyers), there is a better sense of cohesiveness to the sound when used on tube amplifiers (not hybrids). Bass is better defined, there isn’t the straining or glare in the treble that seems to be very present in cheap SS amplifiers, and there’s a sense of holographic soundstage that you don’t get with SS. However, not all SS amps were bad. My beyers also did well with the SPL Auditor with an OI of 120ohm and their “120V rail reference technology” that outputs:
- 1,7W (+32,2dBm) @ 1 kHz and 600 Ohms connection
- 360mW (+25,6dBm) @ 1 kHz and 30 Ohms connection
As you can see, the power output at 600 ohms is much more than something like a topping A90 or any popular “high power” SS amplifier currently out in the market.
Even beyerdynamics own A20 has an output impedance of 120 ohms which Zach from ZMF recommends as a SS amp for his ZMF headphones since those headphones are all 300 ohms. The A20 isn’t really the best amplifier but the higher OI does seem to match better.
OK so based on my experience, I can see a two things happening.
- Audiophiles are just delusional. We make up things to make us feel better and there isn’t really any difference to what we are hearing. We are attracted to the tube glow and that’s about it. We love to spend money on useless things because we have convinced ourselves that it is better, therefore it is better.
- There are highly intelligent audiophiles that have discovered that pairing a tube amplifier or something with a higher OI sounds better with high impedance headphones (possibly due to more efficient power transfer). Due to the characteristics of the tube, it will also enhance certain aspects of the headphone that isn’t present when paired with a SS amplifier. For some reason, this knowledge only resides in people who have been in audio for a long time and who have tried many different things.
What I find kind of interesting is that there is so much more hate for beyers than there are for other old brands like ultrasone, grado, akg, audio-technica, etc etc. When I used to go to head-fi meets in the early 2010’s there wasn’t this hate for the brand. However, brands like audeze and hifiman didn’t really exist back then either. While my reasoning as to why there was a change could be false, I think the fact that tubes/dynamics and SS/planars has been confirmed time and time again. I’d love to understand why we hear what we’re hearing and if there are easier ways to determine which components will sound better when paired with a specific transducer.
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In my experience, it varies by driver technology. Even very cheap and weak amps can be “loud” in sense of measured decibels and comfortable listening levels, but the headphone’s tone and timbre will suffer.
Dynamic drivers tend to lose high and low end extension, and also suffer in definition and bass control. They become hissy or glare in the highs (but this may be a function of bad amp design rather than current per se; bad amps can cause issues in many ways).
High-current planar headphones are more likely to play too softly on a weak amp, but often reach a reasonable volume (e.g., 70 or 75 dB). They tend to lose details and dynamics and resemble rough impressionistic art (i.e., rough colored blobs) rather than realistic art. It’s akin to puzzle pieces laid out in the right places on a table but not connected as a finished puzzle.
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Why does it have to be limited to one of these two options? I think it’s some of both of those, but I disagree with the implied sentiment that someone is less intelligent because they don’t like tubes or state that they don’t hear differences when listening to them. Many of us enthusiasts hear differences when using a good tube amp (myself included), but that doesn’t mean we’re more intelligent or better than those that dislike tubes or struggle to hear differences; some may not find the difference in sound worth making the change either, and it doesn’t make them a less credible audiophile/enthusiast (as your # 2 point implies).
If you want to get technical, the added distortion of the tubes actually degrades the signal, does it not? But we audiophiles don’t care because it sounds better, right!? So, objectively it’s not better, but subjectively it may be; but can one or the other be definitively correct? I personally believe that my own subjective experience trumps everything, even if I’m not really hearing a difference but only think I am; as long as I am happy, who cares. With that said, objectively I may be proven wrong - and that’s okay because my happiness is more important.
I think the bigger issue here is that we, as audiophiles, tend to get too defensive when someone doesn’t hear things the way we do, or simply disagrees with our experiences. If someone hears something differently than I do, good for them; why argue, insisting they’re wrong? Sure, some people are misinformed or less experienced, but I think we should assist in helping them gain more knowledge and experience rather than claim they’re wrong or we’re just more intelligent.
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Per my experience I don’t agree with either bullet. A huge percentage of my purchases were driven by a desire to minimize and avoid fatigue over long listening sessions. Some setups lead to hiss, tinnitus, or flat-out pain. This can start within seconds or emerge after an hour or more. It can follow from the driver, the amp, or the DAC.
To my ears, fatigue has three causes. These include: (1) excessive or randomized treble, (2) closed-cup air pressure fatigue, and (3) sharp/abrupt transitions between notes. EQ, better DACs, cleaner amps, better headphone drivers, and balanced setups all help with #1, only open cups can avoid #2, while some drivers and tube harmonics help to smooth transitions (#3) versus SS amps.
Hmmm. I’d have said that about Grado rather than Beyer. All of the above have a treble bias, and some are meant for studio production rather than audiophile pleasure listening.
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Sorry, I’m not quite sure how that disagrees with the points I made. Those two points are to show different conclusions that are possible. I believe your answer is showing that you agree with the second point. That everything you’ve tried, you’ve experienced a pattern that fatigue can be reduced and that some drivers work better with tube harmonics vs SS amps, the exact point that I was making.
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I objected to this part:
Many differences can be readily apparent within moments to an hour. The differences were obvious to me from the very start of testing audiophile grade headphones, and when I owned only consumer headphones.
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This is the issue with quotes. The knowledge is that high impedance dynamic driver headphones will be driven properly but tube amps or possibly high OI SS amplifiers. The knowledge is not whether or not tube/ss amps make a difference.
I’ve seen plenty of people try to use a WA33 with susvara and ask why it sounds flat. Also plenty of people asking why others are suggesting a speaker amp with susvara. Time and time again, BHC is recommended as a first time tube amp for sennheiser users. I don’t think these recommendations come out of nowhere. I’m certainly not the first one to make them.
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AMB the designer:
“There are opamps in there, probably on the bottom side of the PCB. The topology is similar to a two-channel M³, except instead of a Vbe multiplier to set the output MOSFET bias, it uses a complementary current mirror circuit that I published on head-fi many years ago. The guy behind Rebel Audio contacted me about the use of my I.P. after the fact, but I let him go ahead without royalty or compensation, as long as he provides credit to AMB and me in his documentation and website.”
Source: AMB Laboratories DIY Audio Forums • View topic - Rebel amp using amb designs?
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While I am not sure that these posts all belong in this thread, as there is a mixture of subjective vs objective and tubes vs SS), I’m pretty sure it is not really relevant to @Resolve 's headphone list.
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From Morsel the other designer:
“DIP single channel opamps (AD8610 or OPA627 recommended)”
Source: M³ Headphone Amplifier
I was just quoting the RebelAmp site itself, which states “with a discrete output stage”.
Clearly that leaves room for the use of opamps elsewhere in the path (input stage?), but I have no idea how that pertains to current delivery to the headphones. Perhaps @Mad_Economist has some insights?
When a device is unable to sink or source enough current, you get clipping. The exact “style” of clipping will vary by the device - the classic expectation is that solid state stuff “hard clips” with a very rapid transition into nonlinearity, whereas tubes “soft clip”, but in practice there are cases and designs where a transistor is going to more slowly become nonlinear in its output at higher current.
No matter what the exact change to the waveform, however, the result is distortion, and accept no other answer there - if you are unable to source or sink enough current to produce the voltage waveform, you will have significant distortion, and if you don’t have distortion, you are not out of current.
Raising the output impedance will reduce the odds of clipping by lowering current transfer - but it’s also going to limit your maximum output level for exactly the same reason. So I suppose it depends on what “helping” is.
Bear in mind, headphones have, overall, become more severely - and rightly - judged in that period. In the early 2000s you had a lot more apologia for the blatantly uneven treble of Grado and Ultrasone designs than you see these days as well - so much so, I would argue, that the prominence of both brands has fallen massively from those days. Beyer continues to catch flak to some extent because it continues to command a reasonable market share while maintaining its characteristically off treble in most models.
Let’s say, for a moment, that there is a characteristic sound to amplifier topologies. I don’t accept that contention, to be clear, but let’s say for the sake of argument that that’s the case, unquestioned. In that scenario, it would be pretty damn near impossible to say how an opamp-based amplifier would sound, because opamps are extremely diverse devices. There are a vast number of different ideas and clever tricks employed by different IC opamp designers to achieve different goals, driven by the really bloodthirsty competition in the IC market that has no real parallel in discrete designs.
That being the case, I think we should start from a position of skepticism when someone contends that there are fundamental commonalities in how IC-based designs sound, but perhaps I’m veering from topic…
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There are opamps in the M3 design, but they aren’t the output stage, they’re the gain stage. Highlighted here is the output stage, which consists of a conventional push-pull pair of power MOSFETs
If the RebelAmp is the same, then it has a discrete output stage as well.
Edit: That is, the opamp is driving the output stage, the output stage drives the headphones - the impedance facing the opamp is the input Z of the output stage, which will be quite high, so it doesn’t need to source or sink substantial current. The transistors there are going the “heavy lifting” of driving the headphone coils.
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