This amp can CHANGE your headphone's tuning - HDV-820

Output impedance and damping factor are two terms that seem to make or break an amp.. but what do they actually do and how important are they? Today I'm reviewing the HDV-820 and it's the perfect example to talk about both!
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[@pcm9969]

I love your explanation of input/output impedences. I would definitely like to see more tech videos. Headphones is a niche hobby and it's difficult to find a lot of technical information on the subject. The Harmon curves are something I learned about from your channel. Thanks!

[@sidesaladaudio]

Great video. These topics often get a lot of confusion in discussion, so an even more in depth video could be good as well.

[@thelastrhino2581]

Personally I am waiting for the amp you proclaimed changes everything.

[@PromeeThaBossHoss]

Putting in my vote for a deep dive on output impedance as well!

[@AggArms]

Thanks for this. Yes, I would definitely appreciate a longer video discussion of impedance, ideally with equations and calculations on the screen. Grazie

[@xyliss]

Although I agree that high output impedance isn't necessarily bad, it does make your amp less versatile, which isn't great for something at such a high price point (i.e. your point about consistency). Also, you can artificially increase output impedance by adding an inline resistor. Crinacle's project red is a good example of this. It's also a mod that people have occasionally done in the past. It's a less convenient way to EQ. It works fine, but also EQ is an easier method for the same effect.

[@Avruthlelbh]

Really gotta wonder why there are so many people strongly against EQ that have no problem with this stuff, and visa-versa. They're literally the same concept, you just control one through software and one through hardware.

[@enjoshi-godrez8775]

​@@Avruthlelbhthey know its devalues their gear. If you can make a a90 sound anyway you want, you wouldn't own anything else, so they habe to proclaim their much more expensive amps sound more natural. EQ gets in the way of that argument.

[@chungang7037]

@enjoshi-godrez8775 Also I hear a lot of pushback that EQ introduces distortion and people freak out at the mere mention of it whether audible or not and never bothering to test if they can hear a difference, it helps perpetuate the idea that if you want new sound you must get new gear, right down to USB and power cables. Dealers and marketing people regurgitate this often.

[@Avruthlelbh]

@@chungang7037 On a theoretical, on-paper level, everything makes a difference. But if someone is trying to find the "optimal USB", they should probably just look into XLR and call it a day.

[@hectorcolumbani6566]

I own the HDVA 600 (same amp , no dac great prices on used market) and love the sound of DT880-600, hd650, and grado hemp (the grado actually sounds great with high output impedance) through it. Great to see a video on amps with higher output impedance. Own several and they play well with most headphones.

[@camoturtle18]

Hyped for the tier list!!!

[@Sporting1210]

the thing i actually would be interested in is recording and mixing techniques and how they differ. Gear isnt really that important anymore to me personally. I found my sweet spot, and - never say never, i know - have a setup, that makes me very happy every day. What i keep wondering about is, why some recordings sound SO much better or different than others. As ONE example : There is a studio recording of Hadestown by Anais Mitchel, which differs from the original musical in several things. A. it features Justin Vermont as the male lead, which is awesom B. it doesnt feature the entire musical C. it sounds WAY better than the original recording. It was produced by Todd Sickafoose (Jazz musician, whom i knew and liked before) and mixed by Mike Napolitano( whom i didnt know, but he mixed several Ani DiFranco albums - among others ofc - and knowing that I NOW can hear the red string). It has a VERY distinct ...uhm...clean, detailed, natural, wide, stagy sound, that puzzles me every time. And i would love to know why. lets get away from the numbers and the graphs once in a while and venture into the actual sound structure. What makes a recording sound like it does? And why are some Sound engineers and producers apparently quite a bit different and/or ahead of the rest?

[@eruilluvitar]

This was great! Super informative! Are there many amps/DACs with frequency-variable output impedances?

[@masterxyr]

I recently got the Cayin IHA-6 and have been enjoying both its class A bit of warmth and the different output impedances' varying flavours. the build is also sweet

[@bobsykes]

Great topic! I think you put it clearly and simply enough I hope most of this channel's followers might understand. It is no surprise that this amp made the manufacturer's own flagship headphones sound better, they sell them as a package and why would they offer anything else? I'm looking forward to your company's tier list, mostly because I like to know what reviewers I respect and can relate to in terms of thier opinion of subjective sound think about a broad range of products. That helps me calibrate what you guys think of a new product versus what my own opinion might be.

[@AudioSuchti]

Love your Videos!

[@HitTheSplit]

I have the Emotiva BasX A-100, the headphone out on this thing has 200 Ohms of output impedance. Changes Grados into bass cannons.

[@mensrea1251]

Have the same. And yeah. 😂

[@andrewgiovannini6613]

I do the same thing with my Focal Clears, I love it. LOL

[@EvilSardine084]

Curious, what sub $1000 dac/amp combo (or 2 in 1) would you recommend for the Senn 660s1? Main use is gaming with music as secondary. :)

[@CThienV]

looking for a new unit to replace my Schiit Jotenheim as a Dac, Amp. Must have balanced preouts for studio monitors. Any ideas?

[@todescopfer]

Yeah, do the video about the rabbit hole!! We can never have too much explaining on complex topics.

[@marekkalina3450]

Hello, thank you very much for this video. Information about high output impedance was surprise for me, honestly. I am looking for DAC/AMP for headphones Hifiman HE 1000 SE. I have experience with AMP Chord Hugo 2 and Hugo TT2 but I am looking for AMP with balance connection possibilities. What is your opinion on combination Hifiman HE 1000 SE and Sennheiser HDV 820? Do you have experience with this combination? Do you have some recommendations about AMP for HE 1000 SE?

[@Undead.Musicphile]

I would love to see a video about headphone amps and how much power you really need to run high end IEMs and Headphones. I keep hearing so much conflicting stuff. Also a video about IEMs and Headphones with balanced cables/plugs and does it really make a huge sound difference when listening to them?

[@KXP70]

Was there a response change to the Fostex you tested?

[@sirhitsalot]

Don't the folks from Ampsandsound offer amps with different output impedances? Could you perhaps talk about their technology and what actually happens when plugging the same headphone into different outputs for say the Red October/Nautilus/Forge?

[@joseluishernandezseptien]

Thank you for this review DMS! I am interested in a video in-depth about damping factor. What cable are you using with the HD800S? Does the cable also affect the damping factor? I love my HDV 820 paired with the HD800S, it makes me feel they don’t need EQ anymore. I still like to tame down the 6K peak with EQ but it is a perfect match for those headphones.

[@user-nd1ef8xj6d]

I would love to see the impedance video

[@sjqideez6626]

Thanks for this DMS. The Kinki Studio Vision THR-1 is an unusual beast of a head amp, it has an output impedance of 50 ohms or 100 ohms.

[@MuhammadKharismawan]

I was interested with Audio Technica HA5050Honce, it has 4 jack with different output impedance, literally made for people to experiment which sound best with their gear. It's different way of versatility compared to Sony TA-ZH1ES which I am currently using.

[@atalo]

Can I connect it to my UAD X8 interface? Would you recomment it for a producer, I have the HD 800 S headphone already.

[@0rogontorogon]

It would be fun to compare this amp to the Feliks Euforia, an OTL that has a low output impedance (for an OTL) so it can also drive some planars. It asks the same question as the Sennheiser amp, but answers it through vacuum tube technology instead of solid state.

[@soulfulfool]

tubes are life, tubes are options, tubes are music

[@idigbebop]

What about the Emotiva GR-1. The price dropped to $199 recently. Do you have a review on these planned.

[@SileDevil]

any budget options with high output impedance that do that bass shelf bump in the FR ?

[@blorg8206]

(1) any low OI amp plus an impedance adapter (2) Qudelix 5K and add it with EQ

[@criptocolorlightstech5292]

Can u make a video showing us how to connect the sennheiser hdv 820 with the sennheiser hd800s using a balanced xlr4 connected to the ps5 that would be so helpful '' show us how to connect the Hdv 820 and hd800s to the ps5 to get the best sound possible '' with the best cables''

[@LilBruh76]

from 2:28 - 3:10 I think some of the editing is just gone. maybe that's intentional or not but it would be great if there were visual graphs or whatnot.

[@DesFTW_]

I had experience with this when I was trying a pair of hifiman anandas. I still had a topping a30 (non-pro) amp, which has a high output impedance. The headphones sounded hollow and lifeless, and the HD 6xx were better in almost every regard on this amp. Now with a JDS labs atom amp 2, I get a massively improved sound out of the hifiman's but only a tiny improvement on the 6xx

[@Farpun]

Videos I'd like to see in the future...reviews of ZMF headphones.

[@Valyraen0341]

I'd love a deep dive into this topic, trying to understand all of this with google is rough to say the least 😅

[@KojiCO-ConvinceM]

Owned both of these units, the one prior, and this, genuinely built beautifully, and it’s very unique sounding in regards to headphones. I really had a bad experience with it, and holographic nature and stage was fantastic. But the market has truly moved on from 2018, and this was released in 2014 I believe, from memory, I think I would still own one very hard to find though in good condition Still sad, I sold mine

[@whoofman2013]

Did you mean to say you "really had a bad experience" or "rarely had a bad experience"?

[@ant1kryst]

would it be the same effect if you use a 40 ohm impedance adapter? theoretically i mean... on a neutral sounding amp.

[@Jamie-666]

A very good question.

[@jusmirtic]

Yes, just adding an impedance adapter would achieve the same result. It might be harder to find a balanced impedance adapter with great channel matching, but adapters would still give you way more flexibility than an amp with high output impedance. If you ask me high output impedance on an amp is just bad. You can improve other metrics for the cost if you don't aim for low output impedance but the impedance itself is still a clear negative. If there are headphones that you clearly prefer with like this, you should just find the impedance that you like the most and permanently mod the headphones themselves to achieve the new tuning. Makes them harder to drive, but I'd say applying it to headphones no matter the source makes much more sense than applying it to a source no matter the headphones.

[@blorg8206]

@@jusmirtic I have a Hiby 20Ω balanced impedance adapter (IA02) with as far as I can measure perfect channel balance. I don't think that's particularly difficult.

[@high-captain-BaLrog]

A head to head comparison video with budget headphone in the sub $200 category would be nice now that the holiday season is coming up either here on your personal channels High ish priority please

[@solrq8349]

Did anyone used it with susvara + does this amp output more current than normal amolifiers?

[@JohnBelcastro]

Have a great weekend. Love to see the kid on video. Wife and I waiting on grandkids.

[@eruilluvitar]

Also, for the tier list, the only thing I care about is how good Resolve looks with a hat on over the headphones

[@madd5]

Price?

[@r1p2m32]

Please tell more about this output impedance mystery! My HD660s changed its character after I added a cheap wall-powered amp between DAC and headphones. Battery-powered amps were not enough. Sound lost all harshness and ears don't get tired -- ever.

[@razisn]

Probably more to do with the portable amp you have been using running out of current.

[@r1p2m32]

@@razisn I suspected the same, but Fiio A5 should have been ok, by numbers.

[@chronos4573]

I admire your prowess of the EE aspect of headphones, I can understand some of what your saying but unfortunately I need the Barney Beginner explanation written in crayons to keep up with you. LOL

[@Damien_N]

Solid state tube amp - this sounds like a good way to describe the Sony TAZ

[@carminedesanto6746]

GM ☕️..yea’ I love my AUDEZE LCDX 2021 ..on music ( without vocals ..mostly) but if I want to play something more vocal centric..the Sen’s 650 come into play ..and still not perfect…FR is always a thing ..and it’s always been a thing in this headphone hobby..we’re all looking for a unicorn 🦄 that does EVERYTHING..that won’t break the bank. Sorry for the rant ..oh ,my amp Bryston BHA-1 ….. Have a great weekend.

[@oioi873]

My HD800s on ifi zen dac v2 or Chord Mojo 2 sound great but the HDV820 with them blows those two out of the water.....synergy at work I guess

[@mikeg2491]

I actually collect brand amps for this reason, they all bring a unique sound signature but also play well with their house HPs

[@sennheiser]

We indeed designed it to be versatile enough to bring non-Sennheiser headphones to life, but a terrific pairing for those that wear the namesake. Thank you for watching and commenting!

[@kamiztar]

Only if there were headphone amp with adjustable output impedance so headphone sound can be tuned to your liking (instead of being forced to default output impedance)

[@philipp594]

There should be a tool that does the calculation for you and gives suggestions, all the measurments are out there anyway.

[@zoltantoth1566]

What is a "solid state tube amp"?

[@willielast]

Hybrids

[@JTB--]

I preferred the headphone hobby when $1K to $1500 was considered expensive HP's and gear. Things have gotten so expensive I've kinda lost interest

[@sephondranzer]

Honestly as far as amplifiers go, that has only improved with time. The HDV-820 is really really old and it has been notoriously bad and expensive even when it was new… They just really chose to give an old shitty amp a fresh new and positive outlook for no good reason.

[@chungang7037]

@@sephondranzer it is an odd choice, considering the price and the age of the amp

[@zoltantoth1566]

Are you sure about the output impedance damping factor, about it being a FR change only, not a decay change? If it is true then this is a big thing. I thought "damping" in physics mean a phenomenon in which the amplitude of a wave is decreased by a force that it proportional to the amplitude of the wave. More shortly: i thought more damping generates faster decay.

[@bobsykes]

You are correct.

[@GrumpiestKitten]

Fixed high output impedance is bad because it makes EQ difficult and especially multi-way IEMs will typically sound worse. It's fine when there is a toggle for output impedance like on the teac ha501, Beyerdynamic A2 or the AT-HA5050H from audio technica.

[@chungang7037]

interesting, I didn't know the A2 had a toggle for that

[@lummond]

Please please please try 10+ BA driver IEMs with this amp and measure the frequency response. You will be shocked.

[@bc8251]

The HDV820 is a good match for HD800 Series cans, I have HD800 early S/No, HD800S, and HD820. I wouldn't opt for functions over sound quality.

[@christospakyriakou]

If I buy the HD800S without the HDV820 will I lose a lot from the sound quality? It is very expensive, so it it worth it? Does it drastically make a difference?

[@magdavelas]

I use my HD800S with a less expensive Chord Mojo (original version) for years. It's a good combination for me. Unfortunately, I don't know how much better it would be with a much more expensive DAC/amp. However, for example, Darko Audio does not believe the uber-premium Chord DAVE is compatible with the HD800S. kzbin.info/www/bejne/fZTUm2SZm6mCpqssi=af4lfv3pY4PQRq7q

[@joseluishernandezseptien]

The stage is smaller on the Mojo 2 than on the HDV820. Mojo 2 has the better DAC though but if I had to pick. I have not found anything better than the HDV820 specifically for the HD800S. I have lived with both units for two years now.

[@ahmedsafa91]

As far as i know High impedance hp needs higher voltage with less cureent to drive as intended.. low impedance ones such planar hp with low sentivity needs more current not voltage.. thats why senns. Prefers tube amps or amp with high output impedance which decreses current .

[@razisn]

You got things upside down. Amps do not decrease or increase current. Amps provide as much current as their load requires, up to the limit of their capability. The same applies to the mains sockets in your house..

[@ChrisStoneinator]

ALL amps measurably change the sound. (I mean, change? Versus what reference for a start, you can't listen WITHOUT an amp) Just because it's within margin of error on a frequency response plot, doesn't mean it's not measurable, and sure as hell doesn't mean it's not audible. Headphone enthusiasts need to get wise, too many of them not getting their money's worth. Another way of looking at the impedance problem: the amp's output and the headphone are essentially in a potential divider arrangement as they're in series. In a constant high-Z scenario, as the headphone's impedance increases, it gains a greater share of the voltage, ergo more power (P=V^2/R, the power is more or less proportional to impedance) and vice versa. Couple this with driver efficiency/resonance effects and any deliberate mechanical damping and you more or less have your FR graph.

[@razisn]

Experience (at least subjective) from the speaker world suggests that too low a damping factor results also in bass sounding flabby and under controlled, contradicting what you said about only frequency response being influenced. on top of that, it can lead to the amp running out of current capability (as much power is wasted at the amp output) resulting in clipping. Btw rule of thumb for audio designers has long been that a damping factor of 10 should be just enough but that should apply to the load's worst case scenario not the nominal impedance, no real need for extremely high DF. The HDV820 falls NOMINALLY just short of that when driving 300ohm HPs so I guess it's DF is too low in the worst case scenario even for them. Sen did that in purpose to enhance the bass performance of their bass deficient high Z HPs.

[@NanoDex]

Does anyone have measurements of the same headphone on various gear swapped out systematically? It would be interesting to see how much change there is, what the average change might be, basically see how much is our own BS and how much is real. I wonder too if there are more differences in the timing areas of sound, as what I usually notice changing between gear or amps often is some changes in sound stage / imaging /placement. One sound will come from one place on a setup and another with the same source, headphones, but a different amp. Or just going from like device to like device, sound between DAPS or dac/amps. Is there measurable differences or are we all full of you know what??

[@enjoshi-godrez8775]

​@@GREQReviewsmeasured them on what. You don't have a spectrometer. Lmao

[@enjoshi-godrez8775]

@@GREQReviews no its not at all OK. The minidsp has so many artifacting problems. Lmao

[@enjoshi-godrez8775]

@@GREQReviews there is a much larger problem in your methodology anyway. Your measurement can't account for changes in Dampning factor or slew rate, the phenomenon in which the amplitude of a wave is decreased by a force that it proportional to the amplitude of the wave. The damping generates faster decay. All amplifiers have a different factor. In fact frequency response can be calculated from the impulse response (by performing a fourier transform). That's how frequency response is "measured": you calculate the impulse response from cross-correlation of the stimulus with the recording and then perform a fourier transform. Any change to the impulse response necessarily results in a change to the frequency response as well. "waterfall plots" (cumulative spectral decay) do the same thing - perform an FFT of a short portion of the impulse response aka, how damping factor changes the impulse. Any change to the impulse response necessarily shows up in both the CSD plot as well as the frequency response plote. HOWEVER, none of this is visible in a FR graph, even though it is FR, as in its snap shot that you see it can only describe how much attenuation/accentuation it has for each frequency, but it does not describe, for example, *playing one frequency would cause another harmonic frequency to appear* , aka nonlinear transformation. That is FR, but can only be done with a spectrometer analysing the music single verses the the impulse response, which you haven't tested because they are just the snap shots. Thats is a fallacious use of FR graphs for the reasons stated above. There could absolutely be a change in sound even when the snap shot looks identical. Because it doesn't prove the FR didn't change the actual impulse response, which IS FR.

[@enjoshi-godrez8775]

@@GREQReviews your methodology is fallacious, objectively so.

[@enjoshi-godrez8775]

@@GREQReviews no thats a really toxic attitude. You were wrong about your methodology leading to your conclusion yet you defend it anyway. Your defending evidence that is false. Thats never acceptable no matter what excuses you give.

[@SheepDude-qp7ux]

My favourite science teacher

[@aidencoder]

Topping 4 life yo

[@el_arte]

No, that definition of impedance is incorrect, impedance is not voltage / current. But some of the explanation is somehow correct. Lastly, high output impedance has no benefit and amps should not alter FR, EQ is much cheaper for that.

[@arghadeepmisra7865]

TA26/S with 650 - Please give a one word judgement of yours

[@trilingualkid]

this sound like a violectric 281

[@n8tivet3ch96]

if you do make that video about impedance I would watch it.

[@Farpun]

Just use EQ

[@leviathan5207]

EQ can do the same, but better and for free....

[@lechiffre5078]

At $5000, I’d expect it to be able to enjoy the music for me.

[@enjoshi-godrez8775]

Its $2700 but still

[@lechiffre5078]

@@enjoshi-godrez8775 Unfortunately our monopoly money here in Canada doesn’t go very far. With the exchange, the usual extra rip off prices and excessive taxes, it comes out to 5 Gs. 😒

[@enjoshi-godrez8775]

@lechiffre5078 Hay, could be worse. You could be upside-down where the prices are even more so.

[@enjoshi-godrez8775]

@lechiffre5078 you know, I lived in Singapore for a while, and despite SGD being only 10% stronger than AUD, we paid the same numerical value as products in America. Well, everything that was non-essential. lol

[@ashb6225]

"impedance is a relationship of voltage and current"" current is the actual movement of electrons through a circuit" " voltage is what most people think of as electricity" sorry but "voltage is what most people think of as electricity" is absolute crap and then i realised that this is just another youtube video thats pretending to know what its talking about . 100% disappointing unsubscibed .

[@hypnoz7871]

DSP can do infinite things better than this for free. Why do people keep wanting to mess with the signal via the amp is beyond me.

[@enjoshi-godrez8775]

Bro, you've unlocked the forbidden knowledge 😂. Too bad normalising purchase validation addiction is preferable for audiophiles, or indeed any addict.

[@hirohito2219]

The value of the HDV820 is poor given the high cost and mediocre performance at best. What's worse, there's audible background hiss with sensitive headphones. If you want high output impedance you may as well use impedance adapters with low OI amps. You can even buy a range of different impedance adapters for different headphones. With the HDV820, you're stuck with its 45ohm high OI.

[@joseluishernandezseptien]

It performs well to my ears, specially when it is paired with the HD800S - which it is pretty much its main intended use. This comment I am replying to sounds as if it is coming from the camp of measurements and actually zero listening… but hey… to each their own. Peace.

[@enjoshi-godrez8775]

​@joseluishernandez8795 passive aggressiveness a common trait of addicts. Please go back to headfi with the other purchase validation addicts.

[@joseluishernandezseptien]

⁠@@enjoshi-godrez8775 Hi sorry, I didn’t see this! Hope you are doing well.

[@enjoshi-godrez8775]

@@joseluishernandezseptien thank you. It's pretty tough being a jam 1 guy living in a harmen 2019 world, don't you think?

[@joseluishernandezseptien]

@@enjoshi-godrez8775 Hi again! What does it mean being a Jam 1 guy? Yes, the attachment to the Harman curve/cult/religion/way of living 🤭 that sure its tough. I am glad that they are now showing a range within Harman and not just one line.

[@brash_hown]

2:27 Could you really not be assed to take five seconds to look up a pic of the HD6XX💀

[@joaoguilhermenextlevel302]

I tested this amp eith my he6 se v2 and it was awful, my headphones became VERY bright, to the point that it annoyed me! Hd800s and hd820 too became brighter, but probably, since it eas my first listen to both, they probably are bright by themselves and i didn't know it

[@sebasprieto9673]

Why buy a super expensive amp just for the high OI when you can get the same result with digital or analog EQ ? Real question

[@kentbergstrom3020]

It amazes me that in 2024 Audiophiles are still trying to match amps, DACs and cables to their headphones when you can do it for free with Parametric EQ.

[@WyattOShea]

Joshua Valour