[Chastity]

AMTs were taken off Ebay, and mp.com has them at full price, so meh.

 

[Metal-Fi]

I do not know what's the strategy - if there is any - behind these price variations, and of course I cannot say that I appreciate them, having purchased the AMT at full price, but...I am putting these beast cans under scrutiny again during the last days and, despite the grand I spent, I can't really complain. No EQ, no polyfill mod, just burn-in: the AMTs keep improving and shaping an addictive sound.

 

[Chastity]

I do not know what's the strategy - if there is any - behind these price variations, and of course I cannot say that I appreciate them, having purchased the AMT at full price, but...I am putting these beast cans under scrutiny again during the last days and, despite the grand I spent, I can't really complain. No EQ, no polyfill mod, just burn-in: the AMTs keep improving and shaping an addictive sound.

You can be like @hottyson and get 1-2 pairs for "just in case" when they go on sale again down to $450.

 

[hottyson]

You can be like @hottyson and get 1-2 pairs for "just in case" when they go on sale again down to $450.

I have multiples of Monoprice M1570. Crazy cheap sales in the past, but I might have to pick up another pair of Monoprice AMT someday if the sale price goes crazy low again.
.
Multiples of Koss KSC75 and PortaPro and SportaPro. Portable bargain$.
Two pairs of HiFiMan HE6se V2. But, one needs to consider an expensive known to pair well with amp as part of the equation.
Two pairs of Sennheiser HD-600. The most important staple headphone of any collection. Especially if one has tube amps or multiple good amps.
More people should consider purchasing more than one of HiFiMan HE6se V2 and Sennheiser HD-600. They are THAT GOOD for the $ when they are on sale.

 

[Chastity]

More people should consider purchasing more than one of HiFiMan HE6se V2 and Sennheiser HD-600.

I would like to introduce you to my nearly 30-yr old set of HD-580. Sporting indestructible Dekoni Elite Velour pads, and replaced headband cushion, and a balanced cable:

(Yes, I got tired of paying the Sennheiser tax and buying new pads every 2-3 years at $50 a pop for OEM replacements because the polyfill in them collapses on itself)

 

[Fibre101]

After some time with this headphone, It is beginning to become one of my favorites. One thing I've noticed is that it scales up quiet nicely with better gear and source chains.

 

[giuca70]

has anyone else tried this mod before? if so what were your results?

my AMT was the subject of a 3rd acoustic revision, which had the aim of arriving at a middle ground between the stock version (excessive rumbles) and the version with acrylic filaments to fill the internal indirect resonance chamber (no rumbles) .

Simple UHU Patafix (removable like acrylate wire) to deafen the internal and indirect reverberation chamber. Sound balance is good, headstage, space.
.

 

[Chastity]

Curious to hear who here considers their AMT's to be their endgame?

 

[dmagnan]

Curious to hear who here considers their AMT's to be their endgame?

I do. I've had numerous different SOA TOTL headphones, mostly planar magnetic, and the superb voice coil driver Sennheiser HD800S as modified by Stefan Audio Arts, but the AMT always beats them for immersivity into the sound field, resolution, transparency and bass quality. I've not tried some of the very most expensive alternatives especially ones like the Susvara that require a very high power headphone amp.

 

[giuca70]

Perhaps it represents one of the headphones with a compelling stage representation, similar to reality, with a large space between the instruments, a bit like listening to an orchestra or an event live.
One of the planars that I also define as true is the Hifiman HE6seV2, omnivorous enough, with the right setup it is perhaps superior in definition, but we are talking about obvious differences.
My 3rd modification on the AMT is the compendium of the first 2.
The first time I filled the back of the driver with acrylic filament, stopping any reverberation, the bass dried up.
in the second modification I balanced the cable with a total of 192 copper cores, and here the need arose to make it less of a monitor.
So the 3rd modification was to remove the acrylic and insert UHT Patafix, an adherent, malleable, light rubber, which reinforces the external pavilion by deafening it, limiting the vibrations of the basket, and at the same time dampening excess reverberations.
The result is an extended three-dimensional aria, rich in even harmonics, without those reverberations and vibrations that made the bass ugly, now more ethereal and real than ever before.

 

[Fibre101]

Perhaps it represents one of the headphones with a compelling stage representation, similar to reality, with a large space between the instruments, a bit like listening to an orchestra or an event live.
One of the planars that I also define as true is the Hifiman HE6seV2, omnivorous enough, with the right setup it is perhaps superior in definition, but we are talking about obvious differences.
My 3rd modification on the AMT is the compendium of the first 2.
The first time I filled the back of the driver with acrylic filament, stopping any reverberation, the bass dried up.
in the second modification I balanced the cable with a total of 192 copper cores, and here the need arose to make it less of a monitor.
So the 3rd modification was to remove the acrylic and insert UHT Patafix, an adherent, malleable, light rubber, which reinforces the external pavilion by deafening it, limiting the vibrations of the basket, and at the same time dampening excess reverberations.
The result is an extended three-dimensional aria, rich in even harmonics, without those reverberations and vibrations that made the bass ugly, now more ethereal and real than ever before.

tried the uht patafix mod and its exactly as you described. thank you!

 

[Metal-Fi]

The "Patafix" mod is something that I also tried (yes, I am kind of curious when it comes to headphone tweaking). Unfortunately, I didn't find this modification to be truly beneficial, essentially for these two main downsides:

- The AMTs have of course lots of space to be covered inside its earcups. Therefore, the necessary quantity of adhesive rubber must be consequentially high. This added an extra 60 grams to the headphones weight, which is already massive per se;
- The mod effectively absorbs the excess of reverberations and "booms", but also makes the AMTs sound "congested" and somewhat "closed".

So, I personally found this mod to be less appropriate than the polyfill one.

Now a few more words about tweaking possibilities for the AMTs, for those who feel their frequency response is a bit too much on the "wonky" side.
In general I am not a fan of EQ, as I prefer "physical" tweaks (changing earpads, adding some damping material, etc) instead of digital ones. I said earlier that the AMTs can sound addictive as they are, and this is true but...switching from this headphone to more neutral ones makes evident that what makes the AMTs addictive is a handful of tonal colorations that make the whole picture actually wrong, but yet so enjoyable. This reminds me of certain snacks: their taste is addictive, but you know there's just something wrong with that - and getting back to "healthy" food will make that apparent after a few bites.
This food comparison may sound a bit too resolute, and in fact I am not saying that the AMTs colorations are "unhealthy" as those snacks, but if I try to A/B them with, say, HD800S, the latter bring me back to reality. Yes, burn in improved the AMTs tonal balance, but not as much as I hoped - and I didn't want to open the earcups again to tweak the headphones once more. So, I compared the frequency response plots found on the SoundGuys and SoundStageSolo reviews and started adding some filters in order to make the bass more or less flat down to 20 Hz (I am not into the Harman bass shelf) and to fill all the gaps in the 1.5 khZ - 4 kHz range, plus a couple of extra peaks in the treble. Below the presets:

Preamp: -7.5 dB
Filter 1: ON PK Fc 1500 Hz Gain 3.0 dB Q 1.5
Filter 2: ON PK Fc 2000 Hz Gain 2.0 dB Q 3.0
Filter 3: ON PK Fc 2500 Hz Gain 6.0 dB Q 2.0
Filter 4: ON PK Fc 4000 Hz Gain 3.0 dB Q 2.0
Filter 5: ON PK Fc 6500 Hz Gain 2.5 dB Q 3.5
Filter 6: ON PK Fc 9500 Hz Gain 2.0 dB Q 4.0
Filter 7: ON LS FC 50 Hz Gain 3.0 dB Q 1.25
Filter 8: ON LS FC 25 Hz Gain 4.5 dB Q 1.25


This is done just by hands and by ear, but it seems to work greatly. The change in tonal balance is...dramatic. It seems to switch from a boomy closed-back headphone to a fully open design. It turns out that the stock midrange response is truly lacking. Now I have a healthy handful of natural reverberations and harmonics, the boominess and the dullness are gone. Natural, open-wide and spacious sound that can keep up even with the most extreme Metal albums.

Hope this helps!

(Edited to fix some typos)

 

[Fibre101]

The "Patafix" mod is something that I also tried (yes, I am kind of curious when it comes to headphone tweaking). Unfortunately, I didn't find this modification to be truly beneficial, essentially for these two main downsides:

- The AMTs have of course lots of space to be covered inside its earcups. Therefore, the necessary quantity of adhesive rubber must be consequentially high. This added an extra 60 grams to the headphones weight, which is already massive per se;
- The mod effectively absorbs the excess of reverberations and "booms", but also makes the AMTs sound "congested" and somewhat "closed".

So, I personally found this mod to be less appropriate than the polyfill one.

Now a few more words about tweaking possibilities for the AMTs, for those who feel their frequency response is a bit too much on the "wonky" side.
In general I am not a fan of EQ, as I prefer "physical" tweaks (changing earpads, adding some damping material, etc) instead of digital ones. I said earlier that the AMTs can sound addictive as they are, and this is true but...switching from this headphone to more neutral ones makes evident that what makes the AMTs addictive is a handful of tonal colorations that make the whole picture actually wrong, but yet so enjoyable. This reminds me of certain snacks: their taste is addictive, but you know there's just something wrong with that - and getting back to "healthy" food will make that apparent after a few bites.
This food comparison may sound a bit too resolute, and in fact I am not saying that the AMTs colorations are "unhealthy" as those snacks, but if I try to A/B them with, say, HD800S, the latter bring me back to reality. Yes, burn in improved the AMTs tonal balance, but not as much as I hoped - and I didn't want to open the earcups again to tweak the headphones once more. So, I compared the frequency response plots found on the SoundGuys and SoundStageSolo reviews and started adding some filters in order to make the bass more or less flat down to 20 Hz (I am not into the Harman bass shelf) and to fill all the gaps in the 1.5 khZ - 4 kHz range, plus a couple of extra peaks in the treble. Below the presets:

Preamp: -7.5 dB
Filter 1: ON PK Fc 1500 Hz Gain 3.0 dB Q 1.5
Filter 2: ON PK Fc 2000 Hz Gain 2.0 dB Q 3.0
Filter 3: ON PK Fc 2500 Hz Gain 6.0 dB Q 2.0
Filter 4: ON PK Fc 4000 Hz Gain 3.0 dB Q 2.0
Filter 5: ON PK Fc 6500 Hz Gain 2.5 dB Q 3.5
Filter 6: ON PK Fc 9500 Hz Gain 2.0 dB Q 4.0
Filter 7: ON LS FC 50 Hz Gain 3.0 dB Q 1.25
Filter 8: ON LS FC 25 Hz Gain 4.5 dB Q 1.25


This is done just by hands and by ear, but it seems to work greatly. The change in tonal balance is...dramatic. It seems to switch from a boomy closed-back headphone to a fully open design. It turns out that the stock midrange response is truly lacking. Now I have a healthy handful of natural reverberations and harmonics, the boominess and the dullness are gone. Natural, open-wide and spacious sound that can keep up even with the most extreme Metal albums.

Hope this helps!

(Edited to fix some typos)

I agree that the sound-stage is a bit intimate after the mod but with the use of eq, it can balance out. Also, even though they are a bit congested, the AMT's have this weird satisfying imaging that kinda makes up for it. The resonance in the stock form made the bass feel it a bit flat and less complete overall. I haven't tried stock form in a while though. I think your eq sounds great with the mod as well. I've always EQ'd headphones no matter how good they are in stock form.

May I ask, what gear your using to run the AMT?

 

[Metal-Fi]

I agree that the sound-stage is a bit intimate after the mod but with the use of eq, it can balance out. Also, even though they are a bit congested, the AMT's have this weird satisfying imaging that kinda makes up for it. The resonance in the stock form made the bass feel it a bit flat and less complete overall. I haven't tried stock form in a while though. I think your eq sounds great with the mod as well. I've always EQ'd headphones no matter how good they are in stock form.

May I ask, what gear your using to run the AMT?

I have a Violectric stack, V850 + V281.
I agree on the "weird" yet satisfying imaging - it's part of the addictiveness I was talking about.

 

[Fibre101]

I think that's a great stack. I have a master 9 and r8 dac from audio gd. The master 9 has 9 watts into 40 ohms and it throws a wide stage with any headphone I use. So I guess it helps with the already intimate soundstage of the AMTs.