[Aleksandar R.]

Hi Alexander,
thanks for your answer. I had a curiosity, I use a tube amp with 2a3 valve, about 4 watts with 8 ohm output, but with the new ecla ca1a interface the volume is low, the Schiit jotR is a monster of power, there are minimum watt requirements and output impedance to make the ca1a work well with the ti1b?

The minimum, which I have here, is 2.5W. It's not quiet, but it just won't pass high peaks without clipping, so the satisfaction depends on the choice of music.

The power I'm talking about is what is developed by the amp at the chosen input of the TI.
For example, if the amp makes 5W at 8 Ohms, I will choose the 16 Ohms, where it will develop 2.5W.
If the amp makes 2.5W at 32 Ohms, and its not specified that it will work at 16 Ohms, I would choose that.

I don't know much about DNA amp, except what I can read in it's specs. It says it makes 1.8W at 50 Ohms and 900mW at 100 ohms. It doesn't specify any lower load impedance than that.
So, of it makes 1.8W at 50 Ohms, it just might work with 32 Ohms input on the TI, with increased power, but also increased distortion.

Also, there are some gain and output impedance settings.

I wouldn't be trying the 120 Ohms of output impedance as the TI doesn't have enough primary inductance to "couple" in bass at this high output impedance.
So, I'd try 8 ohms of output impedance at full gain and 3 Ohms of output impedance at -6dB gain (and crank up the volume).

BTW, I don't know how it is possible to choose the output impedance if there's really no feedback...Maybe by decoupling some Cathode resistors, perhaps...

 

[biscottino]

The minimum, which I have here, is 2.5W. It's not quiet, but it just won't pass high peaks without clipping, so the satisfaction depends on the choice of music.

The power I'm talking about is what is developed by the amp at the chosen input of the TI.
For example, if the amp makes 5W at 8 Ohms, I will choose the 16 Ohms, where it will develop 2.5W.
If the amp makes 2.5W at 32 Ohms, and its not specified that it will work at 16 Ohms, I would choose that.

I don't know much about DNA amp, except what I can read in it's specs. It says it makes 1.8W at 50 Ohms and 900mW at 100 ohms. It doesn't specify any lower load impedance than that.
So, of it makes 1.8W at 50 Ohms, it just might work with 32 Ohms input on the TI, with increased power, but also increased distortion.

Also, there are some gain and output impedance settings.

I wouldn't be trying the 120 Ohms of output impedance as the TI doesn't have enough primary inductance to "couple" in bass at this high output impedance.
So, I'd try 8 ohms of output impedance at full gain and 3 Ohms of output impedance at -6dB gain (and crank up the volume).

BTW, I don't know how it is possible to choose the output impedance if there's really no feedback...Maybe by decoupling some Cathode resistors, perhaps...

Hi Alex, thanks for your precious comsigli, actually I don't have the Stratus DNA, but an amp built here in Italy, a Megahertz 2a3 with about 4 watts at 8 ohms, and unfortunately I have to realize that the power is not enough. I noticed in a listening today, that unfortunately also the Sparkos Aries, of the good Andrew Spark that I love, when asked to listen at high volumes, goes into difficulty and has a bit of saturation that disappears if the volume is lowered a little. . So, the interface is ok, but the amplifier must still be very powerful, let's say in line with the most demanding orthodynamic.
The Schiit jotR, on the other hand, is flawless, and shoots out disco volumes without getting upset.
Connecting to this experience, I think that the good Amir with his Topping has pulled out of the Raal ca1a less than 50% of his real potential, it would have taken very little to change his mind.

 

[eboleyn]

The minimum, which I have here, is 2.5W. It's not quiet, but it just won't pass high peaks without clipping, so the satisfaction depends on the choice of music.

The power I'm talking about is what is developed by the amp at the chosen input of the TI.
For example, if the amp makes 5W at 8 Ohms, I will choose the 16 Ohms, where it will develop 2.5W.
If the amp makes 2.5W at 32 Ohms, and its not specified that it will work at 16 Ohms, I would choose that.

I don't know much about DNA amp, except what I can read in it's specs. It says it makes 1.8W at 50 Ohms and 900mW at 100 ohms. It doesn't specify any lower load impedance than that.
So, of it makes 1.8W at 50 Ohms, it just might work with 32 Ohms input on the TI, with increased power, but also increased distortion.

Also, there are some gain and output impedance settings.

I wouldn't be trying the 120 Ohms of output impedance as the TI doesn't have enough primary inductance to "couple" in bass at this high output impedance.
So, I'd try 8 ohms of output impedance at full gain and 3 Ohms of output impedance at -6dB gain (and crank up the volume).

BTW, I don't know how it is possible to choose the output impedance if there's really no feedback...Maybe by decoupling some Cathode resistors, perhaps...

As a comment on the power "required", I think it depends a lot on your average listening level.

If you like quiet listening like myself, then a low-powered amp producing 1-ish watt at 16 or 32 Ohms is probably fine. Frankly I was using a 1 watt amp for my SR-1a with the old resistor interface (which is probably about 14db lower volume) and it worked pretty well, and only very occasionally did I care. Switching to a Schiit Magnius (which delivers 6+ watts into low impedance cleanly), made me never have any clipping issues.

For my CA-1a + TI-1a adapter, I'm using that same Schiit Magnius, and with the TI-1a adapter that is overkill for me, haha.

 

[Aleksandar R.]

Having some great time at Warsaw Audio Video Show 2022! Fantastic people and great vibes!

I'm very happy to have met the Ferrum Audio people!
OOR + TI1b + CA1a = incredible power, dynamic and detail!
Thumbs up!

 

[deafenears]

@Resolve posted some measurements and evaluation notes.

 

[Beagle]

@Resolve posted some measurements and evaluation notes.

Seems a bit odd to have to seriously EQ a $2500 ($3410.36 CDN) headphone, no? Or is this yet another indicator that it is seemingly impossible to design and build a ‘perfect’ headphone?

 

[jlbrach]

you dont have to,everyone has different hearing abilities and different subjective likes and dislikes

 

[Polygonhell]

Seems a bit odd to have to seriously EQ a $2500 ($3410.36 CDN) headphone, no? Or is this yet another indicator that it is seemingly impossible to design and build a ‘perfect’ headphone?

Doesn't really need EQ IMO, resolve is very picky on frequency response.
I personally find it about the least interesting part of a headphones presentation (as long as it's not totally borked).
The closed pads were terrible to me, but because of the loss of openness and speed of presentation, the Coffee bean pads I really like.
Out of the Box I do think the combination of the treble presentation and speed can be a bit much for some. I felt they mellowed out over probably the first 100 hours or so.
I like them and don't use EQ.

FWIW with the TI-1A I do think they are pretty source picky, I liked them on both the WA33, and my EC Studio T, but really thought they lacked a lot on the DNA, just not a good match for the latter's very laid back presentation.

 

[Beagle]

Doesn't really need EQ IMO, resolve is very picky on frequency response.
I personally find it about the least interesting part of a headphones presentation (as long as it's not totally borked).
The closed pads were terrible to me, but because of the loss of openness and speed of presentation, the Coffee bean pads I really like.
Out of the Box I do think the combination of the treble presentation and speed can be a bit much for some. I felt they mellowed out over probably the first 100 hours or so.
I like them and don't use EQ.

It sounds more like a signature that will be ‘interpreted’ differently by different people. But the speed, open presentation and dynamics definitely sound appealing.

 

[Resolve]

Seems a bit odd to have to seriously EQ a $2500 ($3410.36 CDN) headphone, no? Or is this yet another indicator that it is seemingly impossible to design and build a ‘perfect’ headphone?

On the contrary, the majority of 'well-measuring headphones' (in scare quotes for a reason) are actually under $500. It's in the high end that you get all kinds of esoteric tunings. There are a number of reasons for this, like more boutique equipment being tuned primarily by ear or to suit the preferences of those behind the equipment, or the use of unique technology - for whatever benefits it might bring - also can entail some quirky outcomes. Not in all cases, and you can see that with the likes of the HiFiMAN Susvara and a number of others, but you do end up having a wider spread of tunings, which is naturally going to mean lower mass appeal. And it also makes sense if you think those of us who are going to be more scrutinizing for their sound quality (maybe those of us willing to go to the higher end of the market) will have more particular and specific preferences - or more closely look for things that fit their unique HRTF.

In this case, it's EQ required - for me - but by no means is that going to necessarily be EQ required for everyone. My only request is that before passing judgment you try it out and see if you prefer it on/off. And then also that those who might be put off by the tuning result here don't skip this one, because the sense of speed and intangibles really does make it worthwhile.

 

[Stax 7]

On the contrary, the majority of 'well-measuring headphones' (in scare quotes for a reason) are actually under $500. It's in the high end that you get all kinds of esoteric tunings. There are a number of reasons for this, like more boutique equipment being tuned primarily by ear or to suit the preferences of those behind the equipment, or the use of unique technology - for whatever benefits it might bring - also can entail some quirky outcomes. Not in all cases, and you can see that with the likes of the HiFiMAN Susvara and a number of others, but you do end up having a wider spread of tunings, which is naturally going to mean lower mass appeal. And it also makes sense if you think those of us who are going to be more scrutinizing for their sound quality (maybe those of us willing to go to the higher end of the market) will have more particular and specific preferences - or more closely look for things that fit their unique HRTF.

In this case, it's EQ required - for me - but by no means is that going to necessarily be EQ required for everyone. My only request is that before passing judgment you try it out and see if you prefer it on/off. And then also that those who might be put off by the tuning result here don't skip this one, because the sense of speed and intangibles really does make it worthwhile.

Raal advised 200hour run in for the ribbon on the CA1

 

[Aleksandar R.]

Seems a bit odd to have to seriously EQ a $2500 ($3410.36 CDN) headphone, no? Or is this yet another indicator that it is seemingly impossible to design and build a ‘perfect’ headphone?

You're very much right about that!

The thing is that the closed environment within the chamber created by our skull, pads and headphone body, is a pretty unnatural thing to have between us and the sound we need to hear.
Our ears are made to listen without being cupped.
Basically, it is a very unnatural and unwanted acoustical environment in the vicinity of our ears. That creates a whole bunch of issues with the response.

For example, our open-baffle headpones SR1 don't have such problems and the response is nice and smooth.
Using the same driver (only shorter), looks completely different when you mount an ear-chamber around it.
Sure, you get bass, but you trade-in a few thing in midrange for it.

If we over-use acoustical tools (absorption, resonators, etc,) to correct for what happens in the ear-chamber, we would ruin the clean impulse response and ruin the sound beyond repair, but yes, it would get pretty flat on frequency response.
Unfortunately, sounding boring, compressed, dirty...

The approach was to let the sound from the ear-chamber leak out as fast as possible, hence the open cell foam pads without wrapping in leather, large gaps top and bottom...

That helps in frequency response, but doesn't completely solve the flatness, but more importantly, it's the cleanest possible way to preserve the clarity and dynamics in sound.

So, the things that we value the most in sound, are not being sacrificed.

The logic is that if EQ these days is so easily implemented and costs nothing, I'd rather give you the fastest, most detailed and most dynamical sound, to which you apply the wanted EQ, according to your taste and preferences, than sacrifice things that are so hard to get.

Ribbon as a technology allows us to get the finesse and detail of e-stats with power and punch of planars, but only if we don't over-do the acoustical tools around the driver, so we figured that if necessary, the user may do the EQ for free, and get rewarded for TOTL performance at half the price, or better.

 

[Aleksandar R.]

I must add about the EQ,

I've tried a lot to tweak the EQ, but if I follow the measurements, it always ends up badly.
The presence region gets too shouty, or I get weird, totally un-musical (hever happens in real life) character of sounds, like it's some really bad recording.
To me personally, EQing to follow the target curve, never-ever brought any benefits in musical presentation. Things just became unnatural.
I've had much better luck with some other headphones, but they were all nicely sealed and sounded more crowded and congested in midrange from the get-go.

Seems to me that since the measurements are steady-state, meaning averaged after all the resonances and reflections settled after a while, do not truly represent what we hear.

Music lives, the tones are changing at a faster pace than measurement would want, so there is a lot of direct sound that we hear before everything settles to a measured curve.

So, I end up with just a few touch-ups, and only with amps with tone balance tilted upwards. I do it only as much as it brings something to the table, that's the important criteria.
Do not strictly follow measured curves. Move in that direction, of course, but only add as much as it benefits the musical presentation.

My recommendation fro CA-1a with "coffee-bean" pads is just -2dB at 1.2k and -5dB at 5k, and only on bright sounding, punchy amps.
The level of effortlessness they have, doesn't really make things better with EQing more than that.

 

[Beagle]

This actually sounds very musically appetizing.

 

[Resolve]

The logic is that if EQ these days is so easily implemented and costs nothing, I'd rather give you the fastest, most detailed and most dynamical sound, to which you apply the wanted EQ, according to your taste and preferences, than sacrifice things that are so hard to get.

This is great to hear! I very much appreciate this approach.