[Angel III]

I agree, the HD660 with OTL = crime. The HD 650 is a single body with the OTL. The HD660 with SS sound amazing. I recommend for the HD6 to try the dearVR MICRO plugin, inserting it in some tracks with the HD660 is fabulous. If you like the HD660s, I recommend trying the Austrian Audio Hi-X65, slightly more neutral middle, the high frequencies are perfectly tuned and not screaming. The bass range is very powerful when needed (they don't invent anything), layered and very analyzable.

 

[jonathan c]

I agree with most everything you have to say here but just want to point out that because of the 150 ohm impedance of the 660s drivers, they don't scale as well with an otl tube amp as the 600 and 6XX/650 which both have 300 ohm drivers. The 600 and 6XX/650 both "hit another gear" and scale considerably better when paired with otl tube amps. If you are running most solid state, tube hybrid, or transformer coupled tube amps the 660s is the technically superior phone. If you have or want to add an otl tube amp however, I still think the 600 and 6XX/650 are the way to go in the 600 family. Just my experience and personal preference. Of others my have different experiences and preferences.

~ Many OTL tube amplifiers have output impedance around 120 ohms - 150 ohms, right where the ‘stated’ (not ‘effective’) input impedance of the HD-660 lies. This is basically a damping factor of 1.
~ A quick ‘rule of thumb’ is that the ‘df’ should be 5 or more for appropriate control of a speaker/driver by an amplifier. With output impedances typically below 1 ohm - 10 ohms, solid-state headphone amplifiers present a better loading situation to the HD-660. Sonic flavours can and will vary thereafter…

EDIT: One OTL exception to the first point is the Schiit Valhalla II ($349). Its output impedance is: 3.5 ohms (low-gain setting) and 14.0 ohms (high-gain setting). Another exception is the Linear Tube Audio MZ3 ($3700). Its headphone output impedance is 2.0 ohms.

 

[CaptainFantastic]

~ Many OTL tube amplifiers have output impedance around 120 ohms - 150 ohms, right where the ‘stated’ (not ‘effective’) input impedance of the HD-660 lies. This is basically a damping factor of 1.
~ A quick ‘rule of thumb’ is that the ‘df’ should be 5 or more for appropriate control of a speaker/driver by an amplifier. With output impedances typically below 1 ohm - 10 ohms, solid-state headphone amplifiers present a better loading situation to the HD-660. Sonic flavours can and will vary thereafter…

I have been wondering about the math on this. I heard even that 8 should be the multiplier to achieve the right matching. But let's go with 5.

So then an OTL tube amp with output of 150 would have to be matched with a headphone sporting impedance of at least 750ohm? I even saw 300 output impedance on some amps. What does that suggest, that it would need a 1500 ohm headphone?

I do agree that my Crack sounds great with all my 300 ohm headphones. I understand it has a 188 ohm output impedance. This would suggest something far lower than 5.

Anyway, the technical side of this is not my area of expertise. Just wondering.

 

[jonathan c]

I have been wondering about the math on this. I heard even that 8 should be the multiplier to achieve the right matching. But let's go with 5.

So then an OTL tube amp with output of 150 would have to be matched with a headphone sporting impedance of at least 750ohm? I even saw 300 output impedance on some amps. What does that suggest, that it would need a 1500 ohm headphone?

I do agree that my Crack sounds great with all my 300 ohm headphones. I understand it has a 188 ohm output impedance. This would suggest something far lower than 5.

Anyway, the technical side of this is not my area of expertise. Just wondering.

There is no magical level for the ‘multiplier’ or the ‘damping factor’ above which everything in the sound crystallises. That level should probably be comfortably above one. I doubt that I could hear a difference, all else constant, between a ‘5-df’ amplifier and a ‘10-df’ amplifier……

 

[Ichos]

The Feliks Audio Euforia is absolutely great with the HD660s, although not a possible match due to the price difference.

 

[Luckyleo]

The Feliks Audio Euforia is absolutely great with the HD660s, although not a possible match due to the price difference.

I'm lucky enough to have many headphones, some 600ohm impedance, some 32 ohm, and many in between. For whatever reason, and completely unexpected based on the math discussions above, all my headphones sound at least as good on my OTL tube amp vs. when played via my SS amps. My Grado's sound fabulous on the OTL amp and shouldn't being only ~32 ohms impedance. Anyway, I'm one to listen to my ears and heart when listening to music, not so much measurements and mathematics. YMMV .......

 

[Blackfyre]

Looking to replace my pads, I love the stock so I could just buy them again, but I've heard a lot of good things about the Dekoni pads and some bad experiences too.

Do they alter the sound signature by a lot? As an example, I've purchased the Brainwavz XL (Perforated) for my AD900X and they ruined the entire sound signature of that headphone, IMO everything sounded worse, from lows, to mids and highs. The only thing they improved, was the comfort compared to the Audio Technica stock.

Which of the Dekoni pads from those who have experienced them sound the most similar to stock, while increasing the comfort?

Price doesn't matter to me, but just for reference here are the options and prices in Australia:

1. Stock - $80
2. Dekoni Choice Suede - $80
3. Dekoni Audio Elite Velour - $90
4. Dekoni Audio Elite Fenestrated Sheepskin - $120
5. Other Dekoni options are available too.

 

[pietcux]

If you like the way this wonderful headphone sounds, do yourself a favor and stick to the stock pads. Every third party pad will only alter the sound significantly.

 

[Shane D]

~ Many OTL tube amplifiers have output impedance around 120 ohms - 150 ohms, right where the ‘stated’ (not ‘effective’) input impedance of the HD-660 lies. This is basically a damping factor of 1.
~ A quick ‘rule of thumb’ is that the ‘df’ should be 5 or more for appropriate control of a speaker/driver by an amplifier. With output impedances typically below 1 ohm - 10 ohms, solid-state headphone amplifiers present a better loading situation to the HD-660. Sonic flavours can and will vary thereafter…

EDIT: One OTL exception to the first point is the Schiit Valhalla II ($349). Its output impedance is: 3.5 ohms (low-gain setting) and 14.0 ohms (high-gain setting). Another exception is the Linear Tube Audio MZ3 ($3700). Its headphone output impedance is 2.0 ohms.

My exception to this would be the Little Dot Mark III. My Grado's sound great on this unit! And I didn't think the unit has the power to run the DT880 (600Ohm) properly. And I was changing the gain. HD6XX was fine as were the HD660's.

 

[SchwizzelKick66]

Looking to replace my pads, I love the stock so I could just buy them again, but I've heard a lot of good things about the Dekoni pads and some bad experiences too.

Do they alter the sound signature by a lot? As an example, I've purchased the Brainwavz XL (Perforated) for my AD900X and they ruined the entire sound signature of that headphone, IMO everything sounded worse, from lows, to mids and highs. The only thing they improved, was the comfort compared to the Audio Technica stock.

Which of the Dekoni pads from those who have experienced them sound the most similar to stock, while increasing the comfort?

Price doesn't matter to me, but just for reference here are the options and prices in Australia:

1. Stock - $80
2. Dekoni Choice Suede - $80
3. Dekoni Audio Elite Velour - $90
4. Dekoni Audio Elite Fenestrated Sheepskin - $120
5. Other Dekoni options are available too.

Stock pads always with Sennheisers IMO.

 

[CaptainFantastic]

Stock pads always with Sennheisers IMO.

I respect these opinions but I did a lot of testing on all of my Sennheisers (all of the 6-series) and I prefer the Elite Fenestrated Sheepskin pads on all of them. The graph on the Dekoni site is spot on, it really does what it promises IMHO. Of course it's a matter of preference, we all hear differently.

 

[equalspeace]

I respect these opinions but I did a lot of testing on all of my Sennheisers (all of the 6-series) and I prefer the Elite Fenestrated Sheepskin pads on all of them. The graph on the Dekoni site is spot on, it really does what it promises IMHO. Of course it's a matter of preference, we all hear differently.

When I first owned the 660s I tried the Dekoni sheepskin fenestrated pads on them and the sound became too dull to my ears, w all of the upper mids and treble frequencies brought down several notches. Stock for me all the way

 

[Blackfyre]

If you like the way this wonderful headphone sounds, do yourself a favor and stick to the stock pads. Every third party pad will only alter the sound significantly.

My exception to this would be the Little Dot Mark III. My Grado's sound great on this unit! And I didn't think the unit has the power to run the DT880 (600Ohm) properly. And I was changing the gain. HD6XX was fine as was the HD660's.

Stock pads always with Sennheisers IMO.

Thank you, I decided to go with the stock Sennheiser pads and headband. Since I already love everything about the headphones. I have to say, with how badly worn out the originals were with 3+ years of use, dare I say changing the pads brought some extra life back out of them too.

I respect these opinions but I did a lot of testing on all of my Sennheisers (all of the 6-series) and I prefer the Elite Fenestrated Sheepskin pads on all of them. The graph on the Dekoni site is spot on, it really does what it promises IMHO. Of course it's a matter of preference, we all hear differently.

I might in a few months time try out the Elite Fenestrated Sheepskin pads, just to see how I might like or dislike them, but with the comments above and with my past horrible experience with the Brainwavz, I was put off from switching to non-stock pads. The key is I already enjoy everything about this headphone with the stock pads, but thanks for the input anyway.

When I first owned the 660s I tried the Dekoni sheepskin fenestrated pads on them and the sound became too dull to my ears, w all of the upper mids and treble frequencies brought down several notches. Stock for me all the way

Yes, that's what I feared might happen. Stuck with the stock, thank you.

 

[equalspeace]

Idk how I could be so wrong about the 660s all this time. FWIW after a lot of trial and error I think it's probably the most complete 6 series HP. It's really disappointing how much brain burn-in and bias can cloud an assessment haha

 

[Tripokaridos]

Looking to replace my pads, I love the stock so I could just buy them again, but I've heard a lot of good things about the Dekoni pads and some bad experiences too.

Do they alter the sound signature by a lot? As an example, I've purchased the Brainwavz XL (Perforated) for my AD900X and they ruined the entire sound signature of that headphone, IMO everything sounded worse, from lows, to mids and highs. The only thing they improved, was the comfort compared to the Audio Technica stock.

Which of the Dekoni pads from those who have experienced them sound the most similar to stock, while increasing the comfort?

Price doesn't matter to me, but just for reference here are the options and prices in Australia:

1. Stock - $80
2. Dekoni Choice Suede - $80
3. Dekoni Audio Elite Velour - $90
4. Dekoni Audio Elite Fenestrated Sheepskin - $120
5. Other Dekoni options are available too.

Like most people that love HD 6 line and want something to upgrade sound or esthetics i try a lot of aftermarkert Pads , Dekoni, Drop, Shure with Rings , BrainWavz with O rings .
All of them do change the sound some of them are terrible and some (sound different thats why i respect some opinions saying they like what they use ) .
Personally after trying most of them i am back to Stock pads, for some reasons ... A) I want to have the Stock sound of a Headphone because when i talk to people and compare my headphones i need to have the stock sound in my mind B) The stitches around the pads , The Stock Hybrid ones ( they are Hybrids because they use velour outside and pleather inside ) are none existant when they touch my face , most aftermarket pads have stitches in front of the pad , stock one doesnt . C) In my opinion i prefer the sound profile of the stock pads , trying different shape of pads like Sundara pads that have different thickness , they make a bit of bigger soundstage but i lose that in your head vocals that i like ( after all this is why i like HD 6 line if i want something else i just use something else) .
D) the Materials that are used are breathable and in my opinion the foam is just amazing because its fast ( no slow memory ) and is high air penetrated , other materials like Memmory , gel, or high intensity foam they last more time but they dont let the air escape like Stock foam does .

At the end its always about taste , but there is no aftermarket pad that sounds like Stock one , many have tried but none of them could make it if u search i have posted way back some photos and try some pads with rings or not .
Are the Stock pads perfect ? Nope they are not , yes i need more room but when i get it , it just destroy the sound , yeah i need Angled pads but again it destroys the sound, Do i need a type of foam like memory or high intensity that last forever ? Nope because again i know i lose something .
So After so many Years Sennheiser has already many different pads on other headphones , they have make changes on other series like Momentum for example but they dont Touch the HD6 pads , i guess they know something better than me .

Something that also some people say is that new Pads sound better , to me is something in the middle i like my pads after 200-300 hours of wearing because they brake in they get softer and they take a small shape of my head and sound a bit warmer , How much do they last ? I use everyday on my office on my work for 3-4 hours my HD650 for 18 months and honestly i dont see a reason to change them .

Lastly there is a small FL on 2021 pads they dont have black ring colour anymore , and they are a bit thicker on the walls ( but again after brake in they feel and sound exactly like the old ones ) .

So Get aftermarket pads if u have only one headphone and u need something different in sound , But if u think that getting a pad with Fenestrated leather , memory foam, that looks amazing and sounds the shame, then Nope it doesnt.