Review and Measurements of Cypher Labs Theorem 720 and Fiio Q1 DAC and Headphone Amp

[amirm]

Just to make sure I'm reading these correctly, since you are making a manual sweep the time is going to vary. But assuming you are doing your best to keep your speed consistent cutting the time in half should roughly correspond to the volume at 50%?

You are reading it correctly but that part I can't control from run to run. So ignore the rate of change. Just look at when the gain is at a horizontal step and then look at the deviation at that gain attenuation. How long that step goes on is not material then.

Here is a quick example of that:

Note that the vertical graph doesn't start from zero. I need to fix that. So for now you need to note that it starts around +9 db or so. In other words, "-20 db" is really "-29 db."

 

[RayDunzl]

Are you trying to create work for me Ray???

You're quite capable of doing that on your own.

My seedlings need to be transplanted

You may go play in the dirt now.

 

[mindbomb]

Anyway, what do you think of this type of measurement? It is quick for me to run other than having to be somewhat methodical about how I turn the volume control.

I love it. I am surprised that the performance is this good, as Fiio states this is a TOCOS brand potentiometer, and I thought they were used to cut costs and that performance would suffer.

Also, I also was bothered by the line FlipFlop mentioned. Beyerdynamic makes a 600 ohm and 250 ohm versions of their dt880 headphones for example, and they have the same efficiency in the db/mw.

 

[amirm]

Just to make sure I'm reading these correctly, since you are making a manual sweep the time is going to vary. But assuming you are doing your best to keep your speed consistent cutting the time in half should roughly correspond to the volume at 50%?

No, no. The volume reduction is on the vertical axis to the left. It doesn't matter how long it takes me to get to those attenuations (horizontal axis). Just look for one of those steps, look to the left and you see the attenuation. Then chase the navy blue on and its scale on the right for the channel imbalance at that same time frame. That is, the attenuation and channel imbalance are locked together as far as time.

 

[Timbo2]

No, no. The volume reduction is on the vertical axis to the left. It doesn't matter how long it takes me to get to those attenuations (horizontal axis). Just look for one of those steps, look to the left and you see the attenuation. Then chase the navy blue on and its scale on the right for the channel imbalance at that same time frame. That is, the attenuation and channel imbalance are locked together as far as time.

Thanks. I figured that out from your prior reply. Possibly you might want to do a manual 10 count or something at the indicated 50% mark. That would give you an idea what the attenuation and imbalance looks like from the device perspective. That would still be relatively easy to do.

 

[amirm]

The volume knobs are not linear and don't turn the same amount. So I really have no control over what they do other than starting at max volume and ending at min. I am using some discipline in how I time it but that is mostly to get a nice set of steps and no sudden jumps (although that can happen at the tail end).

 

[Timbo2]

The volume knobs are not linear and don't turn the same amount. So I really have no control over what they do other than starting at max volume and ending at min. I am using some discipline in how I time it but that is mostly to get a nice set of steps and no sudden jumps (although that can happen at the tail end).

Good points. It also will be interesting with a digital button control. Punch a step, count to three, rinse and repeat...

 

[Kyle / MrHeeHo]

I have a hunch that budget Chinese brands outperforming boutique American brands will become a trend.

I wonder if contacting FiiO for review units would work out, I have yet to hear of FiiO lashing back at reviewers for being negative and review units have been measured before http://ohm-image.net/data/audio/?tag=Fiio

 

[sssn]

Seems like a trend

Studio DACs > Chinese audiophile DACs > American audiophile DACs

 

[mindbomb]

Seems like a trend

Studio DACs > Chinese audiophile DACs > American audiophile DACs

hold on, let's not forget that audio gd review before we talk about chinese audiophile dacs being better

 

[sssn]

hold on, let's not forget that audio gd review before we talk about chinese audiophile dacs being better

Topping, SMSL and Fiio are fine though

 

[csir]

Amirm when you do a ab listening test between the RME and the Fiio can you tell them apart (I wouldn't bother asking most people this but you're always honest and critical about your ability to notice differences)? One test I'd like to be run is time to ear fatigue with different dacs/amps (also using different files, red book vs hi rez, vs 320). So far I only notice dynamic range compression affecting this but I also have never had anything nicer than the hifiman 602.

 

[csir]

Regarding "eyes" and crucial factor of "blind test"

. If youre looking youre failing.

While that's true I don't know if any switch boxes that alter what a and b is. That would be great. Problem with audio is you can't compare at the same time. Even with video testing if you have two screens and turn them on and off asynchronously it is much harder to determine differences. Amirm doesn't go into testing with massive expectations for differences so I think it's fair to ask if he notices anything since they tested differently.

 

[palamudin]

I

While that's true I don't know if any switch boxes that alter what a and b is. That would be great. Problem with audio is you can't compare at the same time. Even with video testing if you have two screens and turn them on and off asynchronously it is much harder to determine differences. Amirm doesn't go into testing with massive expectations for differences so I think it's fair to ask if he notices anything since they tested differently.

It was a post in a wrong topic but nice that you found something relevant in it <3

 

[amirm]

Amirm when you do a ab listening test between the RME and the Fiio can you tell them apart (I wouldn't bother asking most people this but you're always honest and critical about your ability to notice differences)? One test I'd like to be run is time to ear fatigue with different dacs/amps (also using different files, red book vs hi rez, vs 320). So far I only notice dynamic range compression affecting this but I also have never had anything nicer than the hifiman 602.

I have not done this test. When I get a chance I will try it.

 

[flipflop]

Amirm doesn't go into testing with massive expectations for differences

they tested differently

A bit contradictory

 

[csir]

A bit contradictory

What I mean is many people go into testing (by listening) with expectations about x DAC or y amp. Amirm's expectation bias almost goes the other way if you read many of his reviews he starts off by saying I wasn't expecting to hear differences and later confirms he could not discern differences. In healthcare studies this is often when breakthroughs are made as some unexpected variable is noticed. I don't think we'll see this in audio.

I do think though audio bias would be like the studies done with fMRI and wine drinking (where subjects are told about where the wine is made and why it's better who subsequently show greater excitation of areas of their brain that promote serotonin and dopamine release). In the end if you had someone test the wine for impurities and alcohol percent (maybe a few more things as well) and it tested well (like Amirm does for audio equipment) you could have a great story for that product and then the subjects would be happy with it.

 

[palamudin]

you could have a great story for that product and then the subjects would be happy with it.

I read this but think magico.

 

[flipflop]

Amirm's expectation bias

I'm glad you acknowledge it exists.

I do think though audio bias would be like the studies done with fMRI and wine drinking (where subjects are told about where the wine is made and why it's better who subsequently show greater excitation of areas of their brain that promote serotonin and dopamine release).

Audio reproduction studies related to psychological biases have been conducted:
http://seanolive.blogspot.com/2009/04/dishonesty-of-sighted-audio-product.html
http://www.aes.org/e-lib/browse.cfm?elib=14195

 

[csir]

I'm glad you acknowledge it exists.



Audio reproduction studies related to psychological biases have been conducted:
http://seanolive.blogspot.com/2009/04/dishonesty-of-sighted-audio-product.html
http://www.aes.org/e-lib/browse.cfm?elib=14195

It's funny that you sent an article from an author that had expectation bias interms of not thinking there would be a difference. Not that I disagree with him. I think he'll save me money over the years.

I liken it to the fact when my wife watches something in our bedroom on a 12 year old tv with Imo terrible picture quality and tells me it's about the same as our oled. In the store though when she could see the tv's at the same time compared to tv's the same age and in a closer cost bracket she thought it was much better. Unfortunately, we can't compare audio at the same time. When Ethan states that the signals are the same and nulled to zero or indistinguishable that may be because audio testing is flawed by the fact that we can't compare things by our ears accurately. So some of his tests would be like tracing out the figures or outlines of objects on the TV and saying they're the same so 10 feet away you can't tell a difference by the cheap tv. Sorry to go OT I just have a problem with some of the people on here and head fi that give Amirm crap for finding actual differences and saying we can't perceive them (I'm sure he's aware of roughly where our perceptive abilities are).

What about volume matching, listening to mono recordings, and plugging headphones into two different amp/dacs at the same time (left in DAC one right in DAC two). This seems like a better test. Obviously switching sides plugged in).