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Blind test: we have a volunteer!!!

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amirm

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In the MQA thread I pointed out the OP had post a video where he made all kinds of observations about the sound of Schiit Magnius and how it was not a good product. Here it is if you want to (or can) watch it:


The reviewer responded that he is ready to do such a test so I thought I create a new thread on it:

I'm happy to take you up on this.

Let's say the Holo May vs topping e30 if that suits? Both measure >110dB sinad with no audible concerns raised on your review for the e30, will set the may to OS so that there's no inherent FR difference.

I'll volume match to 0.01dB etc.
Any other conditions or things you'd like me to put in place let me know and I'll accommodate them if possible. How many runs, any other checks, or detail the full procedure for the test if you'd like.

I have promised $1000 to his favorite charity if he gets such a test right.

Per above though, he is offering to test something else than what I asked as he no longer has the Magnius. So let's explore what we should have him test that he has access to.
 
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amirm

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Its a little trickier to do an amp blind test because I don't have a switcher that would go after the amp. So I'd need someone to manually swap the amp and even something like the sound of plugging In could potentially give away which amp is being used.

Whereas dac a switchbox or preamp can be used so its a fair bit easier.
??? You can use a simple AB headphone switcher. Feed both amps the same signal using an RCA splitter, match levels and you will be there.
 

Beershaun

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Looking forward to watching a solid blind test! Will be taking notes so I can do one myself with my stuff.:cool:
 

bboris77

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??? You can use a simple AB headphone switcher. Feed both amps the same signal using an RCA splitter, match levels and you will be there.

I may want to do this on my own for fun at some point. I just looked at a few of these simple devices. Damn, they look scary cheap. Do you have any suggestions? Perhaps time for a mini-roundup :) The last thing one would want is for one of these devices to add some unwanted crosstalk between the inputs thus invalidating the test.

Here are some candidates:

https://www.amazon.com/Nobsound-Aud...elector&qid=1622518036&sr=8-6#customerReviews

https://www.amazon.com/STEREO-Manua...keywords=3.5mm+selector&qid=1622518036&sr=8-3

https://www.amazon.com/3-5mm-Audio-...keywords=3.5mm+selector&qid=1622518484&sr=8-5

https://www.amazon.com/3-5mm-audio-...eywords=3.5mm+selector&qid=1622518484&sr=8-19
 
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amirm

amirm

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I don't have any of those switchers but once we decide we are going that way, I can buy one or more to test. I have one that I use that is really nice from functionality point of view but has some crosstalk.
 

bboris77

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Yea, that crosstalk is really a deal breaker since both channels would be run at a fairly high volume. It would be ideal to have something that totally mechanically disconnects the unused input and has separate grounds for each channel. I deliberately excluded anything that had a volume potentiometer to take that out of the equation.
 

Newman

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Would like to see actual measurement test results for the actual units used for this exercise. Check they work to spec and also FR difference between 10 Hz and 25 kHz.
 

Dennis Murphy

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Yea, that crosstalk is really a deal breaker since both channels would be run at a fairly high volume. It would be ideal to have something that totally mechanically disconnects the unused input and has separate grounds for each channel. I deliberately excluded anything that had a volume potentiometer to take that out of the equation.
Frank Van Alstine has a dead silent and transparent multi-function switcher that I've used at audio shows. It's a bit pricey, but Amir should really have one in his arsenal. :cool:
 
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amirm

amirm

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Frank Van Alstine has a dead silent and transparent multi-function switcher that I've used at audio shows. It's a bit pricey, but Amir should really have one in his arsenal. :cool:
I have sent him email twice about it and he has never answered.
 

trl

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May I suggest two things to consider, please?

- 1) Both channels should be measured properly with a True-RMS voltmeter or an oscilloscope and posted in the dedicated thread/test/review; playback signal should be mono, not stereo (or channel inputs should be reversed and output voltages should be remeasured for perfect accuracy between the two channels).
- 2) A/B or A/B/X tests should also be conducted in mono, not just in stereo.

Thank you!
 

solderdude

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A/B or A/B/X tests should also be conducted in mono

one can use the SU-9 and M500 in that case :D


The reviewer responded that he is ready to do such a test so I thought I create a new thread on it:

Who is going to administer, witness and check validity of the test ?

I secretly hope he can pass the test with scientific valid evidence. That would be good for charity and future discussions on the sound of DACs.

Are comparable filter settings going to be used or are different filters allowed ?
 
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Nomad

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With regards to the chosen devices, are we/you totally sure they are equal in terms of SINAD above x?

What is known about the quality control of these? The Topping E30 that was reviewed was send by Topping themselves so could at least have had some QC.
 

TimoJ

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When there are no differences, will we again hear that cables (audio and power), switches, relays and splitters effected "resolution" and caused it? And it doesn't make any difference if you measure that they have no effect, you will still hear the same argument.
 

richard12511

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I have sent him email twice about it and he has never answered.

Frank Van Alstine has a dead silent and transparent multi-function switcher that I've used at audio shows. It's a bit pricey, but Amir should really have one in his arsenal. :cool:

Not sure if we're talking about the same thing, but I purchased a Van Alstine ABX switcher last year. It was about $1000(iirc). I purchased it for the loudspeaker blinds I like to do from time to time, but it also can switch amps and sources. Unfortunately, when I purchased it, I was told that it was the very last one they had, and that the product was being discontinued. So, if we are indeed talking about the same device, then it may no longer be available :(.
 

jae

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I wonder if this is one of the guys always arguing with me in youtube comments. I also wonder how that goldpoint attenuator measures
 

abdo123

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for a double blind test neither you nor the 'helper' knows which DAC is playing at a certain moment.

you can't 'press the button' on your own, and the 'helper' cannot tell you he pushed the button. you can't hear him or see him push the button.

they must be in complete sync as well (Roon multizone?)
 

Music1969

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Per above though, he is offering to test something else than what I asked as he no longer has the Magnius.

Why doesn't he buy Magnius.

If he succeeds in the challenge, amir can pay for the value of Magnius in addition to the $1000 charity donation?

If he fails, he cops the cost :-(

This keeps it closer to what started the original discussion - about the Magnius
 

Lunafag

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I'd like to see how those multi kilobuck DACs fare against the apple dongle.
 
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