extensive test results of 24bit flying calf a/d converter

[coaster]

yes, its 24bit. they make them that way now.

i found one for DIRT CHEEP on ebay and bought it, new in the shrinkwrapped box.

hooked up to my audiomedia 3 card, i have done some extensive testing of actual data, and subjective response.

my conclusions are scary!

hard testing data suggests a response curve that is poorer than the converters in the am3. this can be measured against various sources running through both converters (midiman and am3)

at this point i was convinced the am3 converters were better.

but i noticed that when i ran a MIX through both sets, the midiman sounded "better".

so i designed the following test to see what my response would be, as well as 10 other people in the audio world, and 5 people NOT in the audio world.

obviuosly there is some innacuracy in my test but bear with me till you hear the results.

the test:

burned a cd of three tracks for playback

track one: bounce to disc stereo file of a large session.

track two: the same bounce, played out the am3 card, recorded into the am3 card analog inputs- no mixer- just a direct connection.

track three: the same bounce, played out the am3 card, routed into the midiman, then into the spdif input of the am3. for this recording the session setup clock was changed to spdif.

listeners were NOT told what they would be listening to, or what the test was about, or even what type of results i was looking for at all. i figure this is the most accurate way to extract non-biased info from them.

the listener is played track 2 (am3conv)

then track three(midiman)

they can then switch back and forth from tracks 2 and 3 for a few listens.

14 people said track three was a better mix.

"why" i ask

it's cleaner, the guitar is louder, it sounds more like a record; were some responses.

1 person said track two was better. he offered no reason why.

at this point in the test i told the listener that they had listened to the same mix twice.

this confused everybody, and they swore they could hear a difference between the two (you can).

i then explained what the test was, that they were comparing two different converters.

they then wanted to know what track one contained.

i did not tell them, but then played all three tracks in a row.

all fifteen people agreed that track one was by far the worst of the three(this is where i get confused- this is the original bounce, and is what the other two tracks are generated from)

14 people said track three was the best, one person said track 2 was the best (the same guy as before)

THEN the final part of the test.

keep in mind that noone knows yet what tracks are what at all so far.

i asked them to identify which track (2 or 3) is more accurate to the sound of track 1.

every one tested could easily tell that track 2 was the most like track one.

so the results are so far:

14 people like the midiman track
1 person likes the am3 track
15 people dislike the original bounce
15 people could tell that the am3 track sounded the most like the original bounce

WOW!

this is not what i expected from this test!

what do you all think of this??????!!!!!

------------------
www.mp3.com/xtac
for the faint of goth

[This message has been edited by coaster (edited November 14, 2000).]

[evandaum]

Did you make SURE the levels were EXACTLY the same on all these transfers? I'd bet what they were hearing were subtle differences in gain, not actual differences between the converters. For this test to work, you have to be VERY anal about the level matching or all is lost.

-Evan


<BLOCKQUOTE><font size="1" face="Arial,Helvetica,sans-serif">quote:<HR>Originally posted by coaster:
yes, its 24bit. they make them that way now.

i found one for DIRT CHEEP on ebay and bought it, new in the shrinkwrapped box.

hooked up to my audiomedia 3 card, i have done some extensive testing of actual data, and subjective response.

my conclusions are scary!

hard testing data suggests a response curve that is poorer than the converters in the am3. this can be measured against various sources running through both converters (midiman and am3)

at this point i was convinced the am3 converters were better.

but i noticed that when i ran a MIX through both sets, the midiman sounded "better".

so i designed the following test to see what my response would be, as well as 10 other people in the audio world, and 5 people NOT in the audio world.

obviuosly there is some innacuracy in my test but bear with me till you hear the results.

the test:

burned a cd of three tracks for playback

track one: bounce to disc stereo file of a large session.

track two: the same bounce, played out the am3 card, recorded into the am3 card analog inputs- no mixer- just a direct connection.

track three: the same bounce, played out the am3 card, routed into the midiman, then into the spdif input of the am3. for this recording the session setup clock was changed to spdif.

listeners were NOT told what they would be listening to, or what the test was about, or even what type of results i was looking for at all. i figure this is the most accurate way to extract non-biased info from them.

the listener is played track 2 (am3conv)

then track three(midiman)

they can then switch back and forth from tracks 2 and 3 for a few listens.

14 people said track three was a better mix.

"why" i ask

it's cleaner, the guitar is louder, it sounds more like a record; were some responses.

1 person said track two was better. he offered no reason why.

at this point in the test i told the listener that they had listened to the same mix twice.

this confused everybody, and they swore they could hear a difference between the two (you can).

i then explained what the test was, that they were comparing two different converters.

they then wanted to know what track one contained.

i did not tell them, but then played all three tracks in a row.

all fifteen people agreed that track one was by far the worst of the three(this is where i get confused- this is the original bounce, and is what the other two tracks are generated from)

14 people said track three was the best, one person said track 2 was the best (the same guy as before)

THEN the final part of the test.

keep in mind that noone knows yet what tracks are what at all so far.

i asked them to identify which track (2 or 3) is more accurate to the sound of track 1.

every one tested could easily tell that track 2 was the most like track one.

so the results are so far:

14 people like the midiman track
1 person likes the am3 track
15 people dislike the original bounce
15 people could tell that the am3 track sounded the most like the original bounce

WOW!

this is not what i expected from this test!

what do you all think of this??????!!!!!

<HR></BLOCKQUOTE>

[lwilliam]

I would suspect the same thing: subtle gain differences. Almost invariably, people like the "louder" of two mixes - if they are essentially the same mix. Even a difference of .5 db would certainly skew the results.

In 3D Audio's mic preamp shootout, they were very careful to match levels to within .1 db with some expensive, custom-built level-matching equipment.

I find it hard to believe that another generation of A/D would result in people liking the mix more - if I understood your results correctly.

Just my opinion...and as you know, opinions vary.


------------------
LW

[coaster]

the mixes for all intents and purposes are the same level. the levels matched on the screen as the information was passed out of an into pro tools.

to me, they sound the same level too.

several of the listeners said that track three sounded louder.

i think the differenmces between the tracks have mostly to do with frequency response.

track three sounds "warmer" and "clearer" but not louder.

i dont find track three to be 'better' at all.

i think it sounds just like the converters in a DA-88. 'plasticy' is how i would describe the sound. upper bass seems less noticible with the midiman. there is a lack of definition in the area of 250-400 hz (my opinion of course-no hard data), where a lot of musical information is. we are VERY sensitive to this area.

also the midiman converters have a noticable dip in the mids. i dont know where. in the 'spice center' maybe in the area of 1.6-2.4k.

i think these reasons are why people "like" track three, but find track two more accurate to the original.

i think people are hearing the "color" of the midiman converters, good or bad as it is.

i dont know if i like it better or not. i did NOT like them better at first. i dont think they are as accurate as the digidesign converters.

i just noticed that they sound different, and did a test to see what other peoples perception's were.

track three does indeed sound more "mastered" than track two, and by that i mean it sounds altered, maybe more compressed.

indeed a strange cam of worms for me to deal with.

BTW i found doing a similiar test that the 001's converters are indeed more "spicey" than the am3. i again dont know that they are "better", just noticably cleaner to my ears.

i have done further testing on a different project, comparing the midiman converters to my sharp md15 minidisc converters, and the converters in a tascam da(40?) dat machine, and find the midimans are much more real and clean sounding than the dat recorders converters and overwhemingly better than the md15 converters.

this test was again flawed, and relied on "judgement" instead of hard data.

but in the end, arent we really convinced by our judement?

just my 2cents

------------------
www.mp3.com/xtac
for the faint of goth

[Jeff D.]

coaster,

Occasionally I'll try out a piece of gear that immedately jumps out as being superior for a certian situations - those are the ones I try to buy.

For example, I'm listening to a CD thru a borrowed Apogee PSX-100 converter right now. Holy Cow! (not the flying type though) - this thing is awesome. The guy I borrowed it from may not get it back! It makes my KRK speakers sound better - I was about to buy Genelecs, but with this convertor I'm happy with the speakers I've got. And the Digi001 sounds much wider and deeper when played thru the D/A converter.

If the Flying cow gives you that "wow that's a big improvement!" sound on your tracks then I'd keep it for those situations. If you have to strain to hear the difference between it and an AMIII, then I'd be heading back to Guitar Center myself...

But of course most of this stuff is subjective. If it helps you make better music, then go for it!

Good luck,

Jeff D.