bigshot
Headphoneus Supremus
Yeah, I know it’s kind of obvious, but I thought I’d mention it. You really don’t need to worry about inputs. They’re designed to accept line level.
Headphone & Amp Impedance Questions? Find the answers here!
- Thread starter proton007
- Start date
HBryant
New Head-Fier
I heard the amp should match the amp. For instance a 300ohn driver should be paired with OLT amps for best sound. and a low impedance driver like 30 or 63 or what ever should be fine with almost any amp.
VNandor
500+ Head-Fier
- Joined
- Oct 17, 2014
- Posts
- 805
- Likes
- 418
Are you sure you are remembering that correctly? While the impedance is not the only property that dictates what amp is a good match for it, in general, it is harder to find an amp that delivers high fidelity signal to a low impedance driver than the other way around. I think it would be important clear up what is meant by best sound. It's entirely possible that some person really likes how OTL tube amps sound with high impedance headphones however, the signal the OTL amp delivers is unlikely to be higher fidelity than what could be delivered by most solid-state amps into high impedance headphones.
Guys, please, help me with this as I feel that I am not able to comprehend this topic.
I somehow dont get why headphones with lower impedance drivers can be harder to "drive/pair/synergy" with the whole chain, than the higher impedance ones. Specifically, I am interested in my situation - currently, I have a RME ADI-2 DAC FS (AKM) that I use as a AMP/DAC without any other amplification. Out of it, I listen through a ten year old Beyerdynamic DT880 250Ohm, which this thing drives (at least to my ears) perfectly, -20dB is the maximum (with HI-POWER mode) that I can reasonably listen to music without hurting my ears. Sound is as expected from these headphones.
Now, after all these years, I purchased Fostex TH-909 headphones (on their way to me, should be here next week) as the TH900 were a dream of mine for the last decade and these seem to be a nice middle ground between the Beyer and Fostex closed-back sound. However, I have read some polarizing opinions on the internet. Some say that the RME is perfect thing for TH900/909 without any additional amp needed, and the EQ being cherry on top. Some say that it would benefit from some sort of tube amp, to use RME as a DAC only, and some say that it is absolutely bad pairing, that the RME sounds too clinical, piercing, harsh, etc... and that the best thing I can do is to get something like Chord Hugo2 and so on.
Well, for one, I despise Chord products for their schmoozing-snake-oil type of marketing & exterior design that is aesthetically stuck somewhere around 2000s era "Gaming" PC Cases, but I must admit that I keep thinking about it. I know that I am probably overreacting & best thing will be just to wait and try them out once they arrive, but I would like local science-based opinion, just to keep myself out of going down the rabbit hole, searching for some improvement that will never come.
For instance this YouTube review:
I am a rookie in this audiophile world, but some of arguments made in that video are just ridiculous.
TL;DR: Are the Fostex TH900 / TH909 (Or just any low impedance headphones) really that hard to drive & DAC / AMP dependent? Is there really a point in chasing the perfect synergy, perfect chain combination from the power cord to the headphone cable and everything in between (this is rather sarcasm, I actually understand the principle of digital signal and the nonsense of expensive USB cables), or is it just another claim of guys that would be debunked after a short blind test? Is there any point of doing any upgrade beyond the existing RME device?
I somehow dont get why headphones with lower impedance drivers can be harder to "drive/pair/synergy" with the whole chain, than the higher impedance ones. Specifically, I am interested in my situation - currently, I have a RME ADI-2 DAC FS (AKM) that I use as a AMP/DAC without any other amplification. Out of it, I listen through a ten year old Beyerdynamic DT880 250Ohm, which this thing drives (at least to my ears) perfectly, -20dB is the maximum (with HI-POWER mode) that I can reasonably listen to music without hurting my ears. Sound is as expected from these headphones.
Now, after all these years, I purchased Fostex TH-909 headphones (on their way to me, should be here next week) as the TH900 were a dream of mine for the last decade and these seem to be a nice middle ground between the Beyer and Fostex closed-back sound. However, I have read some polarizing opinions on the internet. Some say that the RME is perfect thing for TH900/909 without any additional amp needed, and the EQ being cherry on top. Some say that it would benefit from some sort of tube amp, to use RME as a DAC only, and some say that it is absolutely bad pairing, that the RME sounds too clinical, piercing, harsh, etc... and that the best thing I can do is to get something like Chord Hugo2 and so on.
Well, for one, I despise Chord products for their schmoozing-snake-oil type of marketing & exterior design that is aesthetically stuck somewhere around 2000s era "Gaming" PC Cases, but I must admit that I keep thinking about it. I know that I am probably overreacting & best thing will be just to wait and try them out once they arrive, but I would like local science-based opinion, just to keep myself out of going down the rabbit hole, searching for some improvement that will never come.
For instance this YouTube review:
I am a rookie in this audiophile world, but some of arguments made in that video are just ridiculous.
TL;DR: Are the Fostex TH900 / TH909 (Or just any low impedance headphones) really that hard to drive & DAC / AMP dependent? Is there really a point in chasing the perfect synergy, perfect chain combination from the power cord to the headphone cable and everything in between (this is rather sarcasm, I actually understand the principle of digital signal and the nonsense of expensive USB cables), or is it just another claim of guys that would be debunked after a short blind test? Is there any point of doing any upgrade beyond the existing RME device?
bigshot
Headphoneus Supremus
Most of what you read about amping is hogwash. In general, low ohms/high sensitivity mean less need for amping and vice versa. You can get someone to help you here with the math and see what the numbers say. If I was you, I wouldn't think about buying an amp until I've heard the cans myself. If they sound good to you and get loud enough, they are good. The amount of response variation from one make and model of headphone to another is huge compared to the difference between amped and not amped with a lot of models, and the number of models that require specific kinds of amping are even smaller. (Those are usually IEMs)
Bret Halford
500+ Head-Fier
Congrats on your 909!
I have a 909 as well as an ADI-2. (and a problem, I know)
The Foster biodynamic driver is quite sensitive and low impedance. In many ways, they behave similarly to IEMs in that they are sensitive to amplifier over-saturation (hiss). I have never had any issues running them from my ADI-2. The IEM output's ultra low noise floor makes it particularly good for sensitive loads like this in theory, but I don't recall hearing any noise on the normal phones output either (I don't believe I've bothered trying them with extreme power).
In contrast, both my THX amp and my Schiit Magnius produce audible hissing on their XLR output with either Fostex 90x, exactly as they do for many of my sensitive IEMs. It's pretty silly to be amping to those levels anyway for something so sensitive to be honest.
So not really a case of any synergy or pairing, more just avoiding super high power amps.
As for deliberate coloration from tubes, if you want to explore that route with Fostex, just make sure to avoid OTL ('proper' tube amps) and stick with a hybrid amp that just uses the tube in the pre amp stage. The former has high output impedance and is mainly throwing voltage around, neither of which is great for something like the Fostex. A hybrid will add coloration from the tube stage, but the output solid state stage is going to handle the current needs of a low impedance load much better.
I am certainly of a mindset that I'd rather deliberately alter the sound signature via the RME's EQ or digital EQ rather than fumble blindly with injecting different flavors of harmonic noise, but those with the interest and money are welcome to do so.
bigshot
Headphoneus Supremus
If it's low impedance and high sensitivity, it might not need amping at all. My Oppo PM-1s are 32 ohm / 102dB and they plug right into my iPhone without needing anything.
Last edited:
castleofargh
Sound Science Forum Moderator
- Joined
- Jul 2, 2011
- Posts
- 10,456
- Likes
- 6,081
Based on specs alone, it seems like @Bret Halford treating the TH-909 like an IEM is the right call. 25ohm, getting loud with just 1volt, it's more of a not too sensitive IEM than it is a typical desktop headphone. High(voltage) gain amps will not bring much good to the table, while some could bring trouble, so I wouldn't look too much in that particular direction. For the RME, I would use a low gain option with that headphone. I'm not sure that it matters, but in general, use high gain options on amps, DAC/amps only when you find yourself needing it to go louder that what low gain gives you. Most of the time, low gain gives the same thing or slightly better signal. And for low impedance headphone (or IEMs), the odds are the low gain was made to address possible issues for those.
Tube amps seem like bad advice. Many devices aim at being high voltage gain into high impedance loads, and quite a few designs are straight up bad for low impedance headphones. Of course, if your personal preference is fairly distorted classic tube sound, then that's what you like and there is no point in going for something else. But by default, that headphone would seem like a bad choice to go chase that particular taste in audio.
About how much "improvement" you could find by going down a particular rabbit hole, the possibility always exists, even more so when I do not know what you in particular might consider improvement (or not). I would however advise taking online talks about that with a grain of skepticism. It's the internet, between paid "influencers", people parroting what they heard, fanboys who tell you that their stuff is the answer for everything even when they don't understand what you're asking, and straight up overconfident fools, someone will be talking out of his ass while acting like he knows exactly what you need. It's the 6th law of thermodynamic or something.
Objectively speaking, Chord made mostly quality products(I also hate the looks, and Rob's rational to justify his poorly tested ideas on subjective stuff is alarming). Going there because someone told you to, could rapidly end up 8k$ into it with the super thingy that does the gazillion taps and delays everything by 3 days so that more of the inaudible stuff can be accurate, the special oversampler that's used in the chain because???, and you, still not sure what was the problem you were supposed to have in the first place or if it's solved. I just wouldn't recommend going there. Again, nothing wrong with Chord products, but they also aren't expensive magical panacea. They mostly just go endlessly further in a direction pretty much all designers, researchers and engineers have long said, "here is where it stops being relevant, let's go that much beyond for safety and call it a day". I can hear myself making new friends as I type, but that's my opinion on what Chord does that's special.
gregorio
Headphoneus Supremus
- Joined
- Feb 14, 2008
- Posts
- 6,864
- Likes
- 4,105
Ideally you want the HP input impedance to be about 8 (or more) times higher than the output impedance of your amp. Failure to achieve this 8x ratio can result in distortion/incorrect frequency response. So in the case of HPs with a 32 Ohm impedance you would be good to go with an amp that had a 4 Ohm output. Unfortunately it’s not necessarily that simple because that 32 Ohm HP specification is an average. In some parts of the freq spectrum it may have 100 Ohm impedance, in others it might have less than 10 Ohm impedance, in which case our 4 Ohm amp could distort in those <10 Ohm freq ranges. However, your ADI has a very low output impedance (around 0.1 Ohm if I remember correctly), so the 909’s would have to drop well below 1 Ohm to cause any problems, which would be a very poor design and very unlikely. So you can pretty much forget this as a potential issue.
Sensitivity could be an issue. With such sensitive HPs the very low amp output levels can cause improper gain-staging, resulting in noise or channel imbalance problems. If I remember correctly, the ADI’s have quite a complex gain setting structure. This increases the chances you can avoid noise or other issues such as channel imbalance but increases the opportunity for poor gain-staging (which could cause those issues). For example, moderate or high analogue amplification with very high digital attenuation (a very low digital output level) or little/no digital attenuation with very low analogue amplification. You’ll have to play around with your ADI’s settings but I’d be surprised if you can’t find a combination of settings which produce an accurate/high fidelity result without audible noise or other issues.
Yep, it’s common to find audiophiles making incorrect assertions and sometimes even the exact opposite of the facts. The 909’s have very low impedance for HPs, more like the impedance of IEMs, while tube amps naturally have a high output impedance (although some tube amp topologies can achieve lower impedances). So a tube amp in this case would be the worst choice, unless you like distortion/a poor freq response.
IME, “too clinical” in audiophile terminology actually means “very accurate”. Many audiophiles appear accustomed to over-hyped/distorted bass (and other issues) or these plus poor room acoustics issues with speakers. Accurate playback can therefore seem somewhat shocking/unusual and that’s when they come out with this effectively nonsense terminology. Some types of music are sometimes deliberately mixed or mastered to be somewhat piercing or harsh, accurate reproduction will obviously reproduce that harshness. You have a choice (with accurate playback), enjoy it as intended or apply EQ to taste.
Yep, again completely typical of audiophile reviews. They’re typically made by people with little factual understanding of sound/audio, for audiophiles with even less understanding. The more you learn the actual facts, the more ridiculous you’ll recognise these audiophile reviews to be.
No point going through all the ridiculousness in the video but I particularly enjoyed the repeated reference to Hans Zimmer and real acoustic instruments in film scores. Hans Zimmer is famous within the industry for his use of synthesiser/sampled instrumentation and pioneering the augmentation of real instruments/whole orchestras with sampled orchestras. Gladiator being the first major example of this technique of orchestra enhancement in a film score, a technique he employed on every subsequent orchestral film score as far as I’m aware. So the reviewer couldn’t have picked a worse example!!
G
Last edited:
Wow, did not expect such extensive explanation, thank you all! So, having my mind at peace now, knowing that the RME is everything that I need & that there is no need for spending money on tube amps, I cannot wait for the cans to arrive 
In the meantime, I should probably learn how to use the EQ function, applying the Oratory1990´s preset for my DT880 to see if it gets any better.
BTW, I wonder if there is any other market that is so filled with this mumbo-jumbo, snake oil and such type of products and marketing. One must be really careful about gathering opinions and objective information on this stuff.
In the meantime, I should probably learn how to use the EQ function, applying the Oratory1990´s preset for my DT880 to see if it gets any better.BTW, I wonder if there is any other market that is so filled with this mumbo-jumbo, snake oil and such type of products and marketing. One must be really careful about gathering opinions and objective information on this stuff.
gregorio
Headphoneus Supremus
- Joined
- Feb 14, 2008
- Posts
- 6,864
- Likes
- 4,105
Yes there is, the market that the original snake oil was aimed at, the market for alternative health/medicine, diets, etc. At least many audiophile products are only a waste of money, some of the health products are not only a waste of money but sometimes also dangerous.
Indeed and that can be difficult because the vast majority of audiophile resources are based on and/or rely on snake oil marketing.
G
mbphotox
100+ Head-Fier
to be fair, a lot of the time, your money buys you hardware that is in some way or another "faulty" and causes distortions, jitter, and other sometimes audible defects.
In that sense, audiophile gear is often removed from "Hi-Fi" (high fidelity) gear, where the sole purpose should be to "reproduce the recording as it was made".
(and that opens up another can of worms, because people's ears are different, taste supposedly matters, and "would you want it to sound like it did to whoever mastered the recording or the way it sounded in the studio before it even entered the chain of microphones, amplifiers, recorders, etc.?"
All that said, unless a DAC or Amplifier is absolute junk, its impact on the sound cannot and should not ever be as great as shifting your headphones around on your head or changing something about the pads. (or, god forbid, wearing glasses/having your hair under your earpads
)
I feel like there's some similarity to hobbyists cyclists with 10kg overweight shelling out thousands of dollars to cut the weight of the frame by 500g.
In that sense, audiophile gear is often removed from "Hi-Fi" (high fidelity) gear, where the sole purpose should be to "reproduce the recording as it was made".
(and that opens up another can of worms, because people's ears are different, taste supposedly matters, and "would you want it to sound like it did to whoever mastered the recording or the way it sounded in the studio before it even entered the chain of microphones, amplifiers, recorders, etc.?"
All that said, unless a DAC or Amplifier is absolute junk, its impact on the sound cannot and should not ever be as great as shifting your headphones around on your head or changing something about the pads. (or, god forbid, wearing glasses/having your hair under your earpads
)I feel like there's some similarity to hobbyists cyclists with 10kg overweight shelling out thousands of dollars to cut the weight of the frame by 500g.
bigshot
Headphoneus Supremus
I don’t think audibly colored audiophile equipment is very common except for tube amps. I’ve been asking for a DAC that produces different sound not related to impedance for a long time, and can’t find anything except for NOS DACs.
mbphotox
100+ Head-Fier
if you go over to "audiosciencereview", you'll find a disturbingly high number of DACs that actually produce audible distortions, noise, and jitter.
it's even worse for amps.
(by audible, I mean in the -60dB range, not anywhere close to the +/-10dB you have in FR curves on headphones.)
bigshot
Headphoneus Supremus
You're mistaken. -60dB isn't audible under music even at loud listening levels, and no jitter gets anywhere close to that. Besides, a DAC that has a noise level of -60dB won't have a dynamic range that meets spec for digital audio. When was the last time you saw a DAC that just did 10 bit audio? Distortion just isn't an issue with DACs. Whoever gave you all this info is wrong.
The problem is that a lot of audiophiles don't know which measurements correspond with audible thresholds. They massage the numbers to suit themselves and impress others with their "superhuman hearing ability". The easy way to tell is to do a simple controlled listening test. If you can find a DAC that sounds clearly different, let me know. I think you'll be hard pressed to find a DAC that isn't well into the range of overkill for transparency.
The problem is that a lot of audiophiles don't know which measurements correspond with audible thresholds. They massage the numbers to suit themselves and impress others with their "superhuman hearing ability". The easy way to tell is to do a simple controlled listening test. If you can find a DAC that sounds clearly different, let me know. I think you'll be hard pressed to find a DAC that isn't well into the range of overkill for transparency.
Last edited:
Users who are viewing this thread
