I would have thought the biggest issues with a speaker amp are: Power on/off transients. The thud which a speaker handles relatively easily could blow out a headphone. Also connecting and disconnecting leads. You will need to follow a routine procedure for switching on and off - connect the headphones last and disconnect them first. Level control. A position that was a good listening level for speakers is now a "world's loudest band" competition for headphone listening. You can sometimes lower the input device, but if it's fed from a fixed level line in component, then unless you like to blast your ears, you're looking at the unbalanced region of the potentiometer. If your amp has digital level control, then this probably fixes this, and also the issue of being jump scared by scratchy potentiometer tracks. Noise floor. What was previously barely audible across the room with speakers is now relatively prominent with headphones, and during the quiet passages of a classical piece, it will sound like something's leaking air. Mains hum will be prominent too if there is any. I'm betting headphone amps put more effort into reducing this. With most headphone jacks you will be sharing a ground, which might cause an issue if using two mono-blocks, especially of different make and model. Headphones with detachable cable can have an independent ground to each ear.
Besides voltage or power output, I used an EQ with my headphones. Not a huge amount of boost to the given frequencies, but enough to bring them out. My aim was always to maximize the detail in the music, to get the truest flat response possible.
hello from argentina, sorry my bad english, got a question, got for decades a nad integrates amp 325bee (love it), did i need a headphone amp, or i spend more money on a dac? Great channel!
One thing for sure is searching for the right headphone amplifier is a pain in the buttlocks. After tons of research, I recently purchased the Sony TAZH1ES and I'm pleased with the results.
Paul you are a wealth of information and I sooooo much appreciated this from you plus you remind me of my dad who just celebrated their 63 Rd anniversary I though find you intertaining and yes I am an audiophile I've been around since acoustat and oracle turntables and kef when they were made in the UK +BIC plasma speakers etc Randall research cables should I go on custom speakers made here in my home town Toronto Canada but I assure you I'm getting my hands on those servo driven speakers of yours
Headphone amplifier power requirements are so low, that is possible to build small and comparatively cheap vacuum tubes amplifiers without output transformers and with tubes on both input and output stages. That's exactly what I've done: I like the sound much more than the solid state headphone amplifier I used before.
Love your videos Paul but I’ve had the opposite experience with discrete headphone amps. I find most of the discrete designs are worse than well implemented chips and only the very high-end discrete designs tend to outperform them. In the past this was probably different but today’s chips are very difficult to beat when put into a well designed circuit implementation IMO
You can build a simple circuit, three resistors per channel, that pads down the output of a power amp to be able to power headphones directly at a lower power. The amp sees eight ohms, the headphones see thirty-two or higher ohms, the power is attenuated.
You don't want the amp to see 8 ohms. Unless you have a power resistor and don't mind wasting a lot of power. Also must headphones actually perform better when driven from a low impedance, not 32 ohms.
Vintage audio gear just parks a high power resister at the output of the speaker amp. The sound is about as good as it gets and the gain is enough to blow the snot out of any phones. Dedicated headphone amp sections are just a scam to charge more money.
I've met three solutions for headphones driving. One obvious is driving by the same terminals of speaker. It forces do be careful not to turn volume up when headphones are plugged in. With speakers resistance 8 ohms and power of 50W, with disconnected speakers it can deliver pick voltage 20Volts or more . At this voltage power consumed by 35 ohm headphones equals about 10W which will damage them mechanically or thermally. . Average producers secure this by serial resistance which may be not beneficial for sound . Second is driving headphones by stage which is driving also power end. This may sometime lack enough power for headphones and due to overload of such double purpose stage show increased THD at bigger volume.. But at moderate listening it is at last safe and provides untouched quality. . . And third which seems best -dedicated small amplifier having enough power for headphones driven from preamp . It will be beneficial with THD and safe for headphones. I listen from speaker terminals -my power amps have little noise so it's not deficiency . Only in my two reel recorders I have based on discrete semiconductors dedicated headphone amplifiers which seem to work very good. Of course cordless headphones no need any driving amp, just right input voltage. .
You could also use a serial resistance with a resistor paralleling the load to lower the driving impedance. Since this means the resistors need to dissipate more power, you don't see it done.
Why does an amp need the resistance of speakers to keep from self-destructing? Furthermore I would like to know why it seems 4&8 ohms dominate? As I have also seen 16 ohms on an old Kenwood amp from the 90's, with a selector switch for the Transformer. Is it better too just select the lower impedance on the switch to use the whole Transformer instead of the tap? While in subwoofers they're striving for the lowest impedance? What gives? Beyond that, does the ohm load of a particular speaker actually change its sound? I really enjoy your show and I was wondering if you could answer these things for me? Jenna Orlowski from Dearborn Heights MI P.s. sorry if this message isn't constructed better my phone is giving me a lot of problems typing.
Hi Paul, Great video! Helped me understand a few things about resistance in loudspeakers, however its only added to my confusion about it's affect on sound. My knowledge on the subject comes from prior headphone related investigating. As I understand it, high resistance in headphones, 300-600ohms, have what is reffered to as a "tighter response" In a graph this lets the headphone more accurately represent a square wave than a lower resistance varient of the same model. Does this effect apply to speakers? and if so, how is it possible that some high end speakers have a 1ohm resistance? do they just sound sloppy? or is this reserved for the lower frequencies? Thanks for making these videos, its fantastic hearing the knowledge of someone as experienced as yourself. Hopefully you have the time to get back to me. :)
easier because the amp is less affected by things like THD when designed around operating at higher load? like an otl tube amp thanks again, I think you have cleared up my confusion.
Swashed, that's pretty much it. Lower current (higher impedance) is easier to design for. (To a point.) An OTL tube amp is very costly to implement for driving low impedances. Also the gain of bipolar transistors drops off as current increases.
tormaid I have already read headfi reviews & all the ruckus behind banning of nwavguy. I'm using O2 from 2012 & tested it on cheapest to expensive planar headphones, the O2 drives them effortlessly. It's hard to beat an open source well documented design , 30$ for DIY amp objectively vs amp costing K$ . Subjective reviews are totally different ball game though.
If you don't have a dac strongly consider an Audio-gd nfb-11 dac/amp. they have versions with both they're r2r(multi bit) and delta sigma dac, see this if you dont know about dac types. ua-cam.com/video/77DXMR3aVtc/v-deo.html can't go wrong with O2, i believe people like to swap the chip based amps in these to change sound so there's some cheap upgrades to play with down the line. I would also consider one of the cheaper little dot or schiit audio tube amps. I hope to buy a first watt j2 power amp soon just to drive my heavily modded he-6 headphones.
For the last part, discrete circuit is really really hard to get low distortion. They can measure well in thd but when you put a multitone sine waves and measure the td+n they will be horrible that's why they sound different. Some prefer the sound some don't.
Yep. It's the old discrete versus IC debate. One automatically assumes discrete is better. Which is just a bunch of marketing wank. A good discrete circuit can be better than an IC, but not always.
Here is another way to look at it Felix. Look at the difference between a normal loud speaker and headphones and what is required of them. A normal speaker has to fill a large space with sound, or a better term would be pressure. Sound is pressure waves. To do this you need a fairly large cone or surface. The lower the frequency normally the larger the surface which is why woofers are larger than tweeters (tweeters really don't need as much power in most cases). And also remember that sound rolls off at 6 db as the distance doubles. And in order to gain 3 db you need twice the power. So if your speaker is measured at 90 db at 1 meter with 1 watt of power this means at 6 meters you need 4 times the power for it to be just as loud at that distance. The farther away you sit the more power you need. They type of box and room you are in also play a part in it. As well as ambient noise you might need to overcome. So in order to do this you need drivers with a large mass, magnets and suspension to control them properly. All that mass still needs to damped and returned or they will destroy themselves and sound like garbage. To do this it means you need less resistance in the circuit and a fair amount of power to drive them. With headphones a lot of this isn't much of a problem anymore. They sit right next to your ears and are in a very closed space. So distance isn't an issue and neither is the size of the room. And they probably don't need to be as loud either. So now you can do the same thing with one much smaller driver that is far lighter and easier to control. No crossover network either. This requires MUCH less power so the resistance can be higher as well. It probably makes the amplifier easier to design as well. Think of it like a car if that is a good analogy for you. Speed would be your loudness, resistance would be the weight of your car. Horsepower and torque would be your voltage and amperage. To make your car go faster you need more horsepower. And the lighter the car the less horsepower and torque you need to get it there.
qwerty22 Yes, both are relevant. One cannot without the other. You need voltage to make current. But you drive a loudspeaker directly with current or indirectly with voltage via the impedance, which introduces all kinds of current distortion (by the inductance of the voice coil for instance and power compression).
However, we want a voltage source, not a current source, to provide that current. I think that's the point Paul was trying to make. If you want to be anal, one magnet being repelled (or attracted) to another magnetic drives the diaphragm.
Jerry, a voltage source does none of the things you've listed. However, a voltage source is better because that's what the design engineer had in mind when designing the headphones.
Because generic preamps and/or integrated amplifiers not always have well designed "specific" headphones outputs. For example, as a rule of thumb, the lower impedance the headphones output (compared to the headphones impedance), the better performance from your headphones you'll get. Specific headphone amplifiers usually have a very low impedance output. There are more reasons that have to do with circuitry design, etc. You don't get the same result by attenuating the signal generated by a 20, 40, 60 or 120 watts amp (destined to move a pair of speakers), than using a headphone amp which is designed to generate a low power signal destined to your headphones. Anyway, there are sweet synergies out there between some medium-high impedance headphones ( 300 ohms or more) and some standard amplifier headphones jacks. I'm very happy with my Sennheiser HD 580 / Arcam A 65 team (or maybe it's just my ignorance because I haven't tried anything better yet).
As an amateur audio electronics enthusiast, this information is awesome.
Yes, thank you Paul for the videos...
Loving the knowledge! Keep it up Paul. Many thanks.
I would have thought the biggest issues with a speaker amp are:
Power on/off transients. The thud which a speaker handles relatively easily could blow out a headphone. Also connecting and disconnecting leads. You will need to follow a routine procedure for switching on and off - connect the headphones last and disconnect them first.
Level control. A position that was a good listening level for speakers is now a "world's loudest band" competition for headphone listening. You can sometimes lower the input device, but if it's fed from a fixed level line in component, then unless you like to blast your ears, you're looking at the unbalanced region of the potentiometer. If your amp has digital level control, then this probably fixes this, and also the issue of being jump scared by scratchy potentiometer tracks.
Noise floor. What was previously barely audible across the room with speakers is now relatively prominent with headphones, and during the quiet passages of a classical piece, it will sound like something's leaking air. Mains hum will be prominent too if there is any. I'm betting headphone amps put more effort into reducing this.
With most headphone jacks you will be sharing a ground, which might cause an issue if using two mono-blocks, especially of different make and model. Headphones with detachable cable can have an independent ground to each ear.
Besides voltage or power output, I used an EQ with my headphones. Not a huge amount of boost to the given frequencies, but enough to bring them out. My aim was always to maximize the detail in the music, to get the truest flat response possible.
Thank you Paul for answer. Cheers from Poland
hello from argentina, sorry my bad english, got a question, got for decades a nad integrates amp 325bee (love it), did i need a headphone amp, or i spend more money on a dac? Great channel!
can i connect my dragonfly black from my laptop to a logitech z5500 speakers...?
One thing for sure is searching for the right headphone amplifier is a pain in the buttlocks. After tons of research, I recently purchased the Sony TAZH1ES and I'm pleased with the results.
Paul you are a wealth of information and I sooooo much appreciated this from you plus you remind me of my dad who just celebrated their 63 Rd anniversary I though find you intertaining and yes I am an audiophile I've been around since acoustat and oracle turntables and kef when they were made in the UK +BIC plasma speakers etc Randall research cables should I go on custom speakers made here in my home town Toronto Canada but I assure you I'm getting my hands on those servo driven speakers of yours
Headphone amplifier power requirements are so low, that is possible to build small and comparatively cheap vacuum tubes amplifiers without output transformers and with tubes on both input and output stages. That's exactly what I've done: I like the sound much more than the solid state headphone amplifier I used before.
Love your videos Paul but I’ve had the opposite experience with discrete headphone amps. I find most of the discrete designs are worse than well implemented chips and only the very high-end discrete designs tend to outperform them. In the past this was probably different but today’s chips are very difficult to beat when put into a well designed circuit implementation IMO
I LOVE my Phonitor 2.
Good question , sound quality wise .
Thanks for the video
Well then, first from Finland, possibly. Love the content. :)
hi Paul, all my videos sounds are designed just for headphones (3d surround)
i know you will enjoy them!
Thanks. Always wondered about this.
You can build a simple circuit, three resistors per channel, that pads down the output of a power amp to be able to power headphones directly at a lower power. The amp sees eight ohms, the headphones see thirty-two or higher ohms, the power is attenuated.
You don't want the amp to see 8 ohms. Unless you have a power resistor and don't mind wasting a lot of power. Also must headphones actually perform better when driven from a low impedance, not 32 ohms.
No, since the attenuation changes with the headphone's impedance curve you'll get a skewed requency response.
Vintage audio gear just parks a high power resister at the output of the speaker amp. The sound is about as good as it gets and the gain is enough to blow the snot out of any phones. Dedicated headphone amp sections are just a scam to charge more money.
all my amps have a headphone jack ..full size not 3.5 rubbish
I've met three solutions for headphones driving. One obvious is driving by the same terminals of speaker. It forces do be careful not to turn volume up when headphones are plugged in. With speakers resistance 8 ohms and power of 50W, with disconnected speakers it can deliver pick voltage 20Volts or more . At this voltage power consumed by 35 ohm headphones equals about 10W which will damage them mechanically or thermally. . Average producers secure this by serial resistance which may be not beneficial for sound . Second is driving headphones by stage which is driving also power end. This may sometime lack enough power for headphones and due to overload of such double purpose stage show increased THD at bigger volume.. But at moderate listening it is at last safe and provides untouched quality. . . And third which seems best -dedicated small amplifier having enough power for headphones driven from preamp . It will be beneficial with THD and safe for headphones. I listen from speaker terminals -my power amps have little noise so it's not deficiency . Only in my two reel recorders I have based on discrete semiconductors dedicated headphone amplifiers which seem to work very good. Of course cordless headphones no need any driving amp, just right input voltage. .
You could also use a serial resistance with a resistor paralleling the load to lower the driving impedance. Since this means the resistors need to dissipate more power, you don't see it done.
Why does an amp need the resistance of speakers to keep from self-destructing?
Furthermore I would like to know why it seems 4&8 ohms dominate? As I have also seen 16 ohms on an old Kenwood amp from the 90's, with a selector switch for the Transformer.
Is it better too just select the lower impedance on the switch to use the whole Transformer instead of the tap?
While in subwoofers they're striving for the lowest impedance?
What gives?
Beyond that, does the ohm load of a particular speaker actually change its sound?
I really enjoy your show and I was wondering if you could answer these things for me?
Jenna Orlowski from Dearborn Heights MI
P.s.
sorry if this message isn't constructed better my phone is giving me a lot of problems typing.
You seem like the person to ask about this stuff 😉
Hi Paul, Great video!
Helped me understand a few things about resistance in loudspeakers, however its only added to my confusion about it's affect on sound. My knowledge on the subject comes from prior headphone related investigating. As I understand it, high resistance in headphones, 300-600ohms, have what is reffered to as a "tighter response"
In a graph this lets the headphone more accurately represent a square wave than a lower resistance varient of the same model.
Does this effect apply to speakers? and if so, how is it possible that some high end speakers have a 1ohm resistance? do they just sound sloppy? or is this reserved for the lower frequencies?
Thanks for making these videos, its fantastic hearing the knowledge of someone as experienced as yourself.
Hopefully you have the time to get back to me. :)
Impedance has nothing to do with a "tighter" response. There is no causative relationship there.
Thanks, what then is the benefit of high impedence headphones?
Easier load for an amplifier to drive. Especially an opamp IC.
easier because the amp is less affected by things like THD when designed around operating at higher load? like an otl tube amp
thanks again, I think you have cleared up my confusion.
Swashed, that's pretty much it. Lower current (higher impedance) is easier to design for. (To a point.) An OTL tube amp is very costly to implement for driving low impedances. Also the gain of bipolar transistors drops off as current increases.
Can i use Our hifi amp for my headphones or do i a heaphone amp ?
Hi Paul, nice image crop! : )
Cheers! Bang on
HI. A have a pair of Sennheiser hd 650's, any budget headphone amp recommendations to properly drive these beauties?
Simon go for objective 2 amp, read nwavguy on blogspot
Thank you, Roger Walter
Roger Walter nwavguy is a hack. Go read recommendation threads on head-fi and superbestaudiofriends.
tormaid I have already read headfi reviews & all the ruckus behind banning of nwavguy. I'm using O2 from 2012 & tested it on cheapest to expensive planar headphones, the O2 drives them effortlessly. It's hard to beat an open source well documented design , 30$ for DIY amp objectively vs amp costing K$ . Subjective reviews are totally different ball game though.
If you don't have a dac strongly consider an Audio-gd nfb-11 dac/amp. they have versions with both they're r2r(multi bit) and delta sigma dac, see this if you dont know about dac types. ua-cam.com/video/77DXMR3aVtc/v-deo.html
can't go wrong with O2, i believe people like to swap the chip based amps in these to change sound so there's some cheap upgrades to play with down the line. I would also consider one of the cheaper little dot or schiit audio tube amps.
I hope to buy a first watt j2 power amp soon just to drive my heavily modded he-6 headphones.
You can turn any power amp into a headphone amp with a pair of matched 480 Ohm 1watt resistors, simple as that.
@Joshua Atkinson costs £2 to do
For the last part, discrete circuit is really really hard to get low distortion. They can measure well in thd but when you put a multitone sine waves and measure the td+n they will be horrible that's why they sound different. Some prefer the sound some don't.
Yep. It's the old discrete versus IC debate. One automatically assumes discrete is better. Which is just a bunch of marketing wank. A good discrete circuit can be better than an IC, but not always.
Maybe you’d consider a lower-power ~50watt power plant for headphone gear ;)
.....and definitely some beefy cables!! :)
so a speaker amp is just a headphone amp that can push a lot more Amps to create a Voltage to drive the voice coils ... neat
Here is another way to look at it Felix. Look at the difference between a normal loud speaker and headphones and what is required of them. A normal speaker has to fill a large space with sound, or a better term would be pressure. Sound is pressure waves. To do this you need a fairly large cone or surface. The lower the frequency normally the larger the surface which is why woofers are larger than tweeters (tweeters really don't need as much power in most cases). And also remember that sound rolls off at 6 db as the distance doubles. And in order to gain 3 db you need twice the power. So if your speaker is measured at 90 db at 1 meter with 1 watt of power this means at 6 meters you need 4 times the power for it to be just as loud at that distance. The farther away you sit the more power you need. They type of box and room you are in also play a part in it. As well as ambient noise you might need to overcome. So in order to do this you need drivers with a large mass, magnets and suspension to control them properly. All that mass still needs to damped and returned or they will destroy themselves and sound like garbage. To do this it means you need less resistance in the circuit and a fair amount of power to drive them.
With headphones a lot of this isn't much of a problem anymore. They sit right next to your ears and are in a very closed space. So distance isn't an issue and neither is the size of the room. And they probably don't need to be as loud either. So now you can do the same thing with one much smaller driver that is far lighter and easier to control. No crossover network either. This requires MUCH less power so the resistance can be higher as well. It probably makes the amplifier easier to design as well. Think of it like a car if that is a good analogy for you. Speed would be your loudness, resistance would be the weight of your car. Horsepower and torque would be your voltage and amperage. To make your car go faster you need more horsepower. And the lighter the car the less horsepower and torque you need to get it there.
It reminds me the Ohms law, but my headphone is 300ohms.
Sorry Paul, it is not the voltage but the current that moves the diaphragm.
Can you drive a speaker at 0 volts? No. Both are relevant.
qwerty22
Yes, both are relevant. One cannot without the other. You need voltage to make current.
But you drive a loudspeaker directly with current or indirectly with voltage via the impedance, which introduces all kinds of current distortion (by the inductance of the voice coil for instance and power compression).
However, we want a voltage source, not a current source, to provide that current. I think that's the point Paul was trying to make. If you want to be anal, one magnet being repelled (or attracted) to another magnetic drives the diaphragm.
Mister Hat Why do we want a voltage source, when a voltage source introduces distortion, compression and even (distorting) feedback?
Jerry, a voltage source does none of the things you've listed. However, a voltage source is better because that's what the design engineer had in mind when designing the headphones.
Why have a headphone amplifier when you can have a speaker amp which can be used with headphones?
Because generic preamps and/or integrated amplifiers not always have well designed "specific" headphones outputs. For example, as a rule of thumb, the lower impedance the headphones output (compared to the headphones impedance), the better performance from your headphones you'll get. Specific headphone amplifiers usually have a very low impedance output. There are more reasons that have to do with circuitry design, etc. You don't get the same result by attenuating the signal generated by a 20, 40, 60 or 120 watts amp (destined to move a pair of speakers), than using a headphone amp which is designed to generate a low power signal destined to your headphones. Anyway, there are sweet synergies out there between some medium-high impedance headphones ( 300 ohms or more) and some standard amplifier headphones jacks. I'm very happy with my Sennheiser HD 580 / Arcam A 65 team (or maybe it's just my ignorance because I haven't tried anything better yet).
I guess there are no Class D headphone amplifiers?
From🇳🇿
I strongly suggest reading nwavguy on blogspot.
first