• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). Come here to have fun, be ready to be teased and not take online life too seriously. We now measure and review equipment for free! Click here for details.

Blind test: we have a volunteer!!!

Status
Not open for further replies.

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
34,615
Likes
125,907
Location
Seattle Area
#1
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.
 
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
34,615
Likes
125,907
Location
Seattle Area
Thread Starter #2
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

Major Contributor
Forum Donor
Joined
Oct 3, 2019
Messages
1,088
Likes
1,002
#3
Looking forward to watching a solid blind test! Will be taking notes so I can do one myself with my stuff.:cool:
 

bboris77

Senior Member
Joined
Oct 23, 2018
Messages
372
Likes
769
#4
??? 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
 
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
34,615
Likes
125,907
Location
Seattle Area
Thread Starter #5
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

Senior Member
Joined
Oct 23, 2018
Messages
372
Likes
769
#6
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.
 

Dennis Murphy

Addicted to Fun and Learning
Technical Expert
Joined
Mar 17, 2020
Messages
634
Likes
2,515
#8
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:
 
OP
amirm

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
34,615
Likes
125,907
Location
Seattle Area
Thread Starter #9
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

Major Contributor
King of Mods
Joined
Feb 28, 2018
Messages
1,541
Likes
1,614
Location
Iasi, RO
#12
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

Major Contributor
Joined
Jul 21, 2018
Messages
9,546
Likes
20,439
Location
The Neverlands
#13
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 ?
 
Last edited:
Joined
Apr 12, 2021
Messages
22
Likes
17
#14
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

Active Member
Joined
Dec 9, 2019
Messages
249
Likes
187
Location
Finland
#15
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

Major Contributor
Forum Donor
Joined
Jan 23, 2020
Messages
3,838
Likes
5,415
#16
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

Addicted to Fun and Learning
Joined
Dec 2, 2019
Messages
530
Likes
541
#17
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

Major Contributor
Forum Donor
Joined
Nov 15, 2020
Messages
3,190
Likes
2,779
Location
Brussels, Belgium
#18
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

Major Contributor
Joined
Feb 19, 2018
Messages
1,936
Likes
974
#19
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
 
Status
Not open for further replies.
Top Bottom