[raoultrifan]

@Oneminde, until @kintsaki will be able to reply, I've took the liberty to say few thoughts myself, hope you don't mind, regarding your 4)'s question:
- This mid-fi amp is mid-fi at most, and pairing it with these high resolution and detailed cans might give you lot of brightness and perhaps some noise too. TOSLINK is unusable and the +0.4dB trebles may not be perfect for the T60RP: https://www.stereophile.com/content/nad-d-3020-integrated-amplifier-measurements.
- These are not HE-5 or HE-6 cans, please don't use speakers out to drive them (you might try to DIY a resistive divider, although...not sure if this Class-D amp will like it). Get a cheap amp as Atom or THX AAA 789 and you'll be thrilled with the audio quality. Get to Digizoid and see the power needed to drive them.

 

[Oneminde]

@raoultrifan. No I don't mind you that you made a reply. The only reason I targeted kintsaki was because he started the damping factor debate.

I have to ask, when you - or others - talk about noise, what noise are you referring to ? and is there a difference between driving a headphone vs. loudspeakers in relationship to this noise ?

Digizoid returned these numbers using the 50 ohm and 92 dB/mW sensitivity.

Safe 85 dB/SPL - 0.45Vrms at 9mA = 4.05mW
Moderate 100 dB/SPL - 2.51Vrms at 50.2mA = 126mW
Fairly Loud 110dB/SPL - 7.94Vrms at 158.8mA = 1260.87mW
Very Loud 115 dB/SPL - 14.13Vrms at 282.6mA = 3993.14 mW
Painful 120 dB/SPL - 25.12Vrms at 502.4mA = 12620.29 mW

What is important here is that mW need is frequency dependent and the bulk of the need will be at the low end of the Fr spectra.

JDS Labs Atom - a fairly new amplifier:

Max Output @ 150Ω - 502 mW (8.66 VRMS)
Max Output @ 32Ω - 1 Watt (5.66 VRMS).

Lets speculate that you can reach roughly 900mW with the Tx0RP headphone, that should be - theoretically - be a very loud level, and probably beyond my own level. I typically listen between 75-95dB. So the JDS Atom is interesting, but so is the THX/AAA/789, too bad its ONLY available through Massdrop. I did make a request for it, so lets see when things happen.

- Oneminde

 

[Oneminde]

DMS and Zeos are both very happy with the Atom amp so it should stack up against other more expensive amps if one are on a budget. Zeos used the Dekoni Blue on the Atom and on high gain he is "maxed" out at half volume. So good to know.

 

[raoultrifan]

Based on https://www.fostexinternational.com/docs/products/T60RP.shtml#content-3-tab-tab it's dB/mW and not dB/V, very important actually! Like I said, don't connect these cans directly to speakers amp, these are not HE-5!

Digizoid says:

Listening Loudness Voltage Needed Current Needed Power Needed
Safe 85 dB SPL 0.1 Vrms 1.89 mA 0.19 mW
Moderate 100 dB SPL 0.58 Vrms 10.94 mA 6.35 mW
Fairly Loud 110 dB SPL 1.83 Vrms 34.53 mA 63.19 mW
Very Loud 115 dB SPL 3.25 Vrms 61.32 mA 199.29 mW
Painful 120 dB SPL 5.78 Vrms 109.06 mA 630.35 mW
Deafening 130 dB SPL 18.3 Vrms 6.3 W

Tyll here says 0.80mW @90dB, so:

Listening Loudness Voltage Needed Current Needed Power Needed
Safe 90 dB SPL 0.206 Vrms 0.8 mW
Moderate 100 dB SPL 0.652 Vrms 8 mW
Fairly Loud 110 dB SPL 2.06 Vrms 80 mW
Painful 120 dB SPL 6.52 Vrms 800 mW
123dB @ 1.6W
126dB @ 3.2W
Deafening 130 dB SPL 20.6 Vrms 8 W

Not much of a difference, but I tend to trust Tyll's measurements on this one. However, differences are tiny anyway...but your table is not good, hope nobody will use it as reference.

THX recommends an amp able to deliver 115dB @1m from speakers, about the same level is needed for headphones, even if we'll never listen to so much power. 115dB should not kill our ears if volume to the max. for 1 second (by mistake) and we'll also have enough power reserve and enough gain for high dynamic music or older tracks recorder around -6dB level. Normal to high listening level is usually an average around 85dB, that means having peaks around 105dB. I usually listen to this level, but after 1-2 hours I prefer to notch down the volume.

Atom is measuring perfect and should be able to deliver 1W/channel but no more than 8.66V RMS (in our case 7.3V RMS/1W, so a bit over 120dB for T50RPmk3 and T60RP ), as 1W is max. dissipation power for it's output buffer.

 

[Oneminde]

@raoultrifan Got it. My impression with the Atom is that while it is not the most powerful, it has an outstanding S/N and THD performance for $100 (or in my case, roughly $130 with VAT). So nice recommendation and thank you. While watching the DMS review, he mentioned the K.G Dynali alt. Dynali Mk.2 as a good amp. Which made me curious, so dug up some info which I will go over and perhaps build one.

Regarding the T50 and T60. For a while, several members here was debating that the T60 and newer Tx0RP Mk.3 had a Mk4 driver. Is this still the case or are they using the same driver ? - One of the reasons I ask is that I am considering purchasing either the T20RP Mk.3 or the T50RP Mk.3 alongside the T60, to make sure I don't miss anything during my journey in discovering what each version has to offer. Is it a cup material thing which gives the T60 its advantage in clarity, soundstage etc or is it multiple factors which has to be uncovered. In any case and in terms of discovering things with regards to modding, the T20RP Mk.3 should be the start since there are larger control over the bass slots in the cups and how open/closed off they are.

- Oneminde

 

[raoultrifan]

I feel the same way about Atom myself, very good price, extremely good THD+N indeed. At this moment, Atom might be the best band for the buck for a 2 x 1 Watt amplifier.
Also, if you're looking for a combo DAC/headamp, this month you might get Burson PLAY for only $249 (shipping included) which is a steal for a 2 x 2 Watts Class-A amplifier made around 8 powerful transistors and a decent ES9018K2M. Not sure how much this offer will be available, probably couple of months only, till they'll get rid of entire stock, but this is probably best buck for the bang for a combo like this.

My guess would be that T50RP-mk3 and T60RP are sharing the same drivers, also Fostex specs indicates that, but can't be 110% sure about that.

 

[Oneminde]

Regarding amps, the Atom made it on my list alongside THX/AAA/789, possibly Neurochrome HP-1 and I will also look into Kevin Gilmore amps for dynamic/planar. I am already researching K.G energizers for my upcoming electrostatic cans project. Rgarding driver, unless there is a hidden change, they should be the same since same part number.

DAC's, oh my. Here I am considering dual mono AK4497 sigma-delta or Soekris R2R.

 

[raoultrifan]

Neurochrome is measuring perfectly and also delivering lot of power. Also, Kevin Gilmore amp is impressive in specs and lot of folks loved the sound too.

Seems that Soekris R2R is one of the best measuring R2R DACs out there; if you could give it a listen before making the purchase it would be better (some people don't love the R2R sound).
BTW, if you can find an AK4497 device having good measurements, please let me know...I'm kinda interested too. Thanks!

 

[Oneminde]

I don't know much about the K.G Dynalo just yet but I know Kevin is praised for his designs in the electrostatic community. So looking forward to investigating it.

Regarding R2R, in the past, before Sigma-Delta and multibit, that is what company's used (mid 80's cd players) and many swear by these vintage cd players to this day. Most high end DAC's use R2R and FPGA. While I listened to the Focal Utopia, it was hooked up to a Chord Electronics Dave DAC which use this tech, just like Soekres DAM. While that session was uhm, well, very limited to one headphone and not other headphones, loudspeakers, other amps etc, it is very difficult to make an objective statement if it was pleasing or not. But non the less, having both a competent R2R and Sigma-Delta DAC is interesting and I know of no better than the AK4490/4497 sigma-delta and the Soekris DAM to take on this task.

Regarding the AK4490/4497 dac, I was introduced to it via Dimdim's Blog. So I will provide you and others with a link to his blog and to the diyaudio dev project. Best of all is that the AK dac is dual mono, aka discrete... I love discrete
PS: Dimdim is also using the Soekris DAC

http://www.dimdim.gr/tag/ak4490/

Dual Mono DAC AK4490/AK4497
https://www.diyaudio.com/forums/digital-line-level/286051-dual-mono-dac-ak4490-ak4497.html

We live in a truly amazing time where acoustic nirvana is within reach for most mortal individual. Sure, there are products on the market that one can only dream of and I got tired of that. Once you find a competent circuit and components, you can go all in on the design and achieve that dream product.

- Oneminde

 

[Asahi Templar]

If you want a dual AKM4497 you should wait for Topping to release their D70. Based on previous DACs it will likely be one of the best performers and be a good value for some one who wants super hi end performance. I would expect it to be a much better performer than a DIY design.

You should be careful about comparing measurements from different sources to each other, they all use different measurement rigs and arent directly comparable.

T60 use the same driver as the T50RP does, there isnt a mark 4 one out as of yet. The differences between the T50 and T60 are the baffle foam, cable connector, earpads and the wooden cups. Though I would love for Fostex to make a new larger planar driver, 50mm or more to compete with the Hifiman ones. The 38mm size is a weakness of the RP driver IMO.

The ATOM and the THX 789 will be the absolute best amps for the T60 at their price points. They are killer values. If you want an all in one the Burson Play or Playmate are excellenent as well as Raoultrifan mentioned.

You dont need a speaker amp for a T60, just a amp able to deliver current well which all the previously mentioned amps do.

 

[Oneminde]

f you want a dual AKM4497 you should wait for Topping to release their D70. Based on previous DACs it will likely be one of the best performers and be a good value for some one who wants super hi end performance. I would expect it to be a much better performer than a DIY design.

Nice of you to drop in, here is a cup of coffee for you to sip on

The new Topping D70 certainly does look really nice, no argue there and maybe just maybe a tad better than a diy dual mono version. But wouldn't it be fun to do one... I can always pour my energy and money in some diy amp's and purchase a ready made dac, with the benefit of not having to worry. And it also seems as my hunch was right, Asahi Kasei Microdevices does make the finest delta-sigma dac there is and to top it of, I just read that they are releasing a new one, even better than the AK4497EQ. Enter the AK4499EQ. I wonder if the differences are notable for a normal human being. The 4497 is already the best according to many, but as they say - better is better.

https://www.akm.com/akm/en/product/datasheet1/?partno=AK4499EQ&link_id=link5073

You should be careful about comparing measurements from different sources to each other, they all use different measurement rigs and arent directly comparable.

You are absolutely right, so I am not going to defend anything. The reason I merged the measurements was simply put, to get an idea of how the T50RP Mk.3 compare to the RBH HP-2 in terms of bass response, and according to the merger, I am a happy camper .. lol, but ... real life is different. With the modding possebility's and custom Fr response and all.

Which bring me to another section. you mention; "Though I would love for Fostex to make a new larger planar driver, 50mm or more to compete with the Hifiman ones" - I have not listened to Hifiman planars, only Audeze and I did not like Audeze. But since there is a huge difference between dynamic drivers, one cannot judge all planar by one company and model (LCD-2). So, since we are on the topic of different and vs. Let me ask you, have you listened to Sundara and HE400i and if so, how do they compare to the Fostex Tx0RP line ??? - I get that there is a HUGE price difference between Fostex and Hifiman and for many, probably too huge of a difference, then there is the charm of modding, adjusting the soundscape to ones own liking etc etc. Its not difficult to mod the Tx0RP line to be worth $300-500 and that puts you right on the same playing field as the Hifiman - and there has been talks about using 2 Fostex drivers in each cup in this thread (waiting on that one). I have modding ideas myself which build upon the T60RP, but that is for another time.

Thanks for adding or confirming the dif between the 50 and 60, this makes it easier for me to just jump on the 50 and go from there.

Regarding amps, JDS Labs Atom, THX/AAA/789 and Neurochrome hp-1 over at audiosciencereview.com gets grave reviews and is most certainly sailing to the top. 3 different price ranges with the HP-1 landing at roughly $1200 for the ready made one. The PCB alone is roughly $250 which is $99 shy of the THX/AAA/789 which could end up as the end game headphone amp. But they are all OP Amp amplifiers compared to Dynalo (Mk.2) / Dynahi which is FET and class A, so it play in a different league ... get it... play ...

- Oneminde

- EDIT -
There is also the M1060 or M1060C with upgraded driver which we could add to the Fostex / Hifiman vs debate.

 

[Asahi Templar]

Nice of you to drop in, here is a cup of coffee for you to sip on

The new Topping D70 certainly does look really nice, no argue there and maybe just maybe a tad better than a diy dual mono version. But wouldn't it be fun to do one... I can always pour my energy and money in some diy amp's and purchase a ready made dac, with the benefit of not having to worry. And it also seems as my hunch was right, Asahi Kasei Microdevices does make the finest delta-sigma dac there is and to top it of, I just read that they are releasing a new one, even better than the AK4497EQ. Enter the AK4499EQ. I wonder if the differences are notable for a normal human being. The 4497 is already the best according to many, but as they say - better is better.

https://www.akm.com/akm/en/product/datasheet1/?partno=AK4499EQ&link_id=link5073


You are absolutely right, so I am not going to defend anything. The reason I merged the measurements was simply put, to get an idea of how the T50RP Mk.3 compare to the RBH HP-2 in terms of bass response, and according to the merger, I am a happy camper .. lol, but ... real life is different. With the modding possebility's and custom Fr response and all.

Which bring me to another section. you mention; "Though I would love for Fostex to make a new larger planar driver, 50mm or more to compete with the Hifiman ones" - I have not listened to Hifiman planars, only Audeze and I did not like Audeze. But since there is a huge difference between dynamic drivers, one cannot judge all planar by one company and model (LCD-2). So, since we are on the topic of different and vs. Let me ask you, have you listened to Sundara and HE400i and if so, how do they compare to the Fostex Tx0RP line ??? - I get that there is a HUGE price difference between Fostex and Hifiman and for many, probably too huge of a difference, then there is the charm of modding, adjusting the soundscape to ones own liking etc etc. Its not difficult to mod the Tx0RP line to be worth $300-500 and that puts you right on the same playing field as the Hifiman - and there has been talks about using 2 Fostex drivers in each cup in this thread (waiting on that one). I have modding ideas myself which build upon the T60RP, but that is for another time.

Thanks for adding or confirming the dif between the 50 and 60, this makes it easier for me to just jump on the 50 and go from there.

Regarding amps, JDS Labs Atom, THX/AAA/789 and Neurochrome hp-1 over at audiosciencereview.com gets grave reviews and is most certainly sailing to the top. 3 different price ranges with the HP-1 landing at roughly $1200 for the ready made one. The PCB alone is roughly $250 which is $99 shy of the THX/AAA/789 which could end up as the end game headphone amp. But they are all OP Amp amplifiers compared to Dynalo (Mk.2) / Dynahi which is FET and class A, so it play in a different league ... get it... play ...

- Oneminde

- EDIT -
There is also the M1060 or M1060C with upgraded driver which we could add to the Fostex / Hifiman vs debate.

The AK4499 is very new and it will be quite some time before people figure out how to implement it properly, so I would personally wait before investing in a DAC based on it. I cant find the article for it but here in Japan they had a article about the AK4499 that showed off the AKM implementation to get that record setting SNR and it was quite complex looking circuitry. The implementation of a DAC matters much more than the chip itself. A poorly implemented AK4499 will likely perform worse than a well implemented 4497.

It also doesnt have any new filters or features compared to the 4497 that I can find. One of the nifty things the 4497 has over the lower end chip is that it features a low-dispersion short delay filter which the lower end models do not have. No idea if it makes any audible difference but its always fun to have more filters.

if you happen to go to CES 2019 in Vegas you can apparently try it there!

I have heard the Hifiman 400i,4xx and HE560 and I prefer the T60RP with no EQ being used. The Fostex RP drivers do a better job in the 1-4k region which I think is the most important region to get right. All the Hifiman models mentioned have large dips at 2k and a lot of energy around 4k that is offputting to me. However fixed with EQ they are very good, and probably better than the RP drivers on a technical level in that they have lower distortion in the bass likely due to the larger driver size.

I personally will never buy Monoprice products as I dont like supporting their practices. As I understand it their drivers are reversed engineered Audeze drivers. They also suffer from unplesant ringing according to a lot of people.

If you want to get into modding the base T50 is certainly a better choice as there is a ton of documentation out there for modding those. The T60 RP is better if you just want to buy a pair of headphones and have it be great out the box.

I dont think OP amps degrade sound in anyway as long as they are good quality and you dont have to spend much to get good quality ones. The NJR and TI op amps are excellent and cheap.

 

[raoultrifan]

Impressive specs, seems better than anything out there, really glad to see that. Going dual-mono from IN to OUT will get -140dB Dynamic Range, so...really close to Audio Precision measurement limit. Looking further to see first measurements of a DAC with this chip...and the price, of course.

https://www.diyaudio.com/forums/digital-source/330506-ak4497-wont-flagship-anymore-3.html - here's the datasheet as well.

 

[Oneminde]

The 4499 will be very interesting but it will take a while before we start seeing some proper dac's using this chip. OP Amp is in no way a bad choice, look at the amps that get a typical high score and most of them will use an OP Amp. NJR and TI makes really nice ones and they do sound different, so OP Amp rolling is certainly a thing one can do.

Until I can purchase my Fostex headphone, I will lurk in the background and spend some time with other modding threads.

- Oneminde

 

[Oneminde]

By the way, has anyone tested the Dekoni Audio Angled Hybrid Ear Pad ? it looks very comfortable.

https://dekoniaudio.com/product/dek...-pad-designed-for-the-dekoni-blue-100mm-wide/