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LA3A shootout: dual Urei hardware vs UAD / Waves / Black Rooster plugins - null tests
Old 1 week ago
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eugtone's Avatar

Thread Starter
LA3A shootout: dual Urei hardware vs UAD / Waves / Black Rooster plugins - null tests

In this shootout I compare a pair of Urei LA-3A compressors on compress mode to a variety of plugin emulations. The Ureis are NOT stereo linked.

1) It was very easy to make two hardware units nearly null completely
2) The plugins do not attack and release like the real thing, especially from 0 to extreme gain reduction levels
3) The harmonic overtones that the plugins produce are not correct

I began with a uncompressed.wav test file with a variety of signals at a variety of levels.

The shootout is performed by sending this test file out through a Liquid Saffire 56, via ADAT to SSL converters at 44.1khz to a patch bay and to the Ureis and then back in reverse. To understand how much error occurs via this round trip, I ran the test signal through this signal path and through a new API 550B on bypass and did a null test with the original file, which demonstrates the magnitude of error incurred by the AD/DA signal path. (converters_null_test.wav) This is much quieter than the subsequent plugin null tests which incur no signal path loss.

To avoid the conclusion that each HW unit is different and therefore how accurate could a plugin be to any particular HW unit, I ran the test signal through both of my LA-3As (no stereo link) and subtracted the two signals: dual_LA-3A_nulltest.wav. It was very easy to bring the two so close - the gain reduction knobs were set to 7 vs 6.3 or so. The gain knobs were very similar, at 3.4 each. The GR meters were looking similar when matched at these settings.

dual_LA3A.wav has left/right signals of the two units
dual_LA3A-nulltest.wav is the mono difference of those two signals

plugin tests next...
Attached Files

uncompressed.mp3 (2.72 MB, 289 views)

converters_null_test.mp3 (2.23 MB, 272 views)

dual_LA3A.mp3 (2.75 MB, 281 views)

dual_LA-3A-nulltest.mp3 (2.75 MB, 266 views)

Old 1 week ago
Gear Nut
eugtone's Avatar

Thread Starter
I then compared to Waves CLA3A, UAD LA3A and black rooster VLA-3A plugin emulations. mono results and null tests vs the left Urei compressor are attached. Settings were found manually by listening in null mode and trying to make the quietest signal. Much easier with the two real HW units.

Listen closely to the harmonics of the sine-wave signals at the end of the test - the harmonic overtones of the plugins are way different than the real thing. Finally, attached is an image showing a single sine wave going through the HW and the 3 plugins. The real HW shows four distinct overtones being produced (the note is held constant here, the gain reduction has stabilized and the GR is down around -10db).

The UAD has too much 3rd harmonic, no 2nd, and too much 4th it seems. The CLA and rooster only seem to add the 3rd harmonic, and not nearly enough.
Attached Thumbnails
LA3A shootout: dual Urei hardware vs UAD / Waves / Black Rooster plugins - null tests-harmonics_spectra.png  
Attached Files

CLA3A.mp3 (2.75 MB, 304 views)

UAD.mp3 (2.75 MB, 288 views)

rooster.mp3 (2.75 MB, 289 views)

CLA_null_test.mp3 (2.75 MB, 273 views)

UAD_null_test.mp3 (2.75 MB, 271 views)

rooster_null_test.mp3 (2.75 MB, 283 views)

Old 1 week ago
Gear Nut
eugtone's Avatar

Thread Starter
Old 1 week ago
Gear Nut
eugtone's Avatar

Thread Starter
Anyone out there still have a working Liquid Mix?

I haven't gotten mine going with Win 10. Would love to know if the LA-3A liquid mix model has the right harmonics or not. If you could run my test file and share I'd really appreciate it.
Old 4 days ago
Lives for gear
stinkyfingers's Avatar

Null tests aside, I find it interesting that none of the plugin emulations tested replicate the harmonic series of the (tested) hardware.
Would be cool to see some more tests/measurements of this type (different sine frequencies, maybe a sweep, frequency response, etc)
Old 4 days ago
Gear Nut
eugtone's Avatar

Thread Starter
short harmonics comparisons

You can really hear it here with Massive with a pure sin wave patch playing chords and the beating harmonics. Each LA3A on comp mode again, and sustaining just over 7dB reduction after the transients settle.
Attached Files

Urei.mp3 (722.8 KB, 118 views)

UAD.mp3 (722.8 KB, 113 views)

CLA.mp3 (722.8 KB, 113 views)

rooster.mp3 (722.8 KB, 114 views)

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