_MIMAS Stereo Calibration
Generally there are a lot of problems when it comes to proper level matching for two mono units which are supposed to work in stereo. For FET type compressors it is even more complex. This tutorial will get You through simple steps on how to configure levels of two WesAudio _MIMAS units.
Few things to note:
- _MIMAS is the first product in our portfolio, it went through a lot of changes on the digital management level – both improvements and adaptations due to some parts restrictions.
- Some of the below features may be not available for Your revision. There are following features added relevant for this tutorial:
- High resolution management of input and output level (not mandatory for matching, but helps units to get closer in level).
- Metering after first level potentiometer – Mandatory for this tutorial, and it was added in revision 1.5.
What You will need:
- 2 x _MIMAS in chassis connected to GCon service (via direct USB or through the _TITAN).
- Audio interface connected to the chassis.
- Sine Wave signal generator plug-in (available in most DAWs).
- DAW (any DAW will do).
1. First You need to open GConManager in admin mode, to do so, please head to our FAQ section: https://wesaudio.com/faq/
2. Admin mode enables special functionalities which are used during WesAudio units calibration. Please go to the _CONFIG app and select the 1st _MIMAS unit. You should see some strange parameters on the right side of the screen – it is good to write down those parameters as a backup for each unit You are going to calibrate.
3. Now please open DAW, and insert the WesAudio _MIMAS (stereo) plug-in somewhere in the session (it doesn’t matter where the instance will be created). Now:
- Connect plug-in to the HW units.
- Select Compression OFF.
- Select Metering to IN.
- And send a signal from the signal generator so the meter on both units will show around 0dBu. If this level isn’t possible from Your audio interface, it can be lower, but ideally should be between -3 and 0 dBu due to the resolution restrictions.
- Both meters should show exactly the same value – if the values are different:
- Either signal getting to units is not even (most probable)
- Or something is wrong with the internal unit circuit (very unlikely as input metering is just after the transformer).
- Either way if those values are different, just send us an eMail to email@example.com
4. Now we need to head to GConManager in ADMIN mode, and enable “METER AFTER VCA IN” checkbox and “VU ADC MONITORING” checkbox, to do so:
- Enable the check boxes for first selected unit,
Hit “APPLY” button,
- You will notice that in the plug-in meter value will change and if you move the INPUT knob, the meter position will also change – it will react to any input potentiometer modification.
- IMPORTANT: If meter position doesn’t move upon INPUT modifications, most likely Your revision doesn’t support this functionality, and You won’t be able to configure Your units through this tutorial.
- Now repeat those steps for the second unit.
5. Now set INPUT knob in the position so VU IN Meter on one of the units will show -3 dBu:
- If units show the same values, ignore this point, and go further to the next step.
- If second unit shows different value, we need to tweek it for this unit:
- Please note that we are not changing configuration of the unit which is set to -3 dBu – so this unit configuration will remain as is – we will change only the second unit configuration, and it will be referred to as “second unit” – it doesn’t mean it is worse, or it looses, we just need to call it somehow!
- Select the first unit (correctly set to -3dB) in GConManager ADMIN Mode, and write down ADC monitoring (VU_MONITOR) values which are notified by the software – those values will jump, but it should be no more than 3-5 values total.
- Select the second unit in GConManager ADMIN mode.
- There are two parameters that we can use:
- VCA IN SHIFT change will affect the value in around 0.5 dB steps. The higher the value the higher the signal.
- VCA IN SHIFT – High Resolution: decreases the signal based on values 0-3 – which provides additional attenuation of 0-0.5dB (high resolution step) – IMPORTANT – please note – if this parameter doesn’t change the output on the meter and on VU_MONITOR – it means that Your revision doesn’t support this functionality, and You have to use VCA IN SHIFT only.
- Now tweak those parameters to get as close as possible to -3dB on the meter, and VU_MONITOR values that You had on the first unit.
6. Now when we are certain that input levels are matched, we can proceed to the output calibration.
7. First we need to disable “METER AFTER VCA IN” and “VU ADC MONITORING” for both units – disable the checkbox, and hit the apply button for each unit.
8. Meter should be as it was previously set up – so 0dBu unless You had to feed a unit with different levels (this is monitoring before the input level control).
9. Switch Metering in the plug-in to OUT.
10. Now set OUTPUT knob in the position so VU IN Meter on one of the units will show -3 dBu and use the same description as above with following differences:
- Instead of VU_MONITOR You can use any meter in the DAW or on Your audio interface.
NOTE: -3 dBu on the _MIMAS meter would mean 20dBu signal which may be very high for some converters, so if You see Your converters are clipping, use lower signal on _MIMAS – can be -5 dBu for instance.
- Parameters which should be used to tweak the signal: “VCA OUT SHIFT” / “VCA OUT SHIFT – High Resolution” – but rules are exactly the same as for the INPUT.
Now after modifications You should see meters in exactly the same spot:
In case of any issues, please contact firstname.lastname@example.org
_MIMAS GR calibration
FET design in particular very often requires metering levels tweaking – _MIMAS is no exception – Gain reduction metering reference level needs to be calibrated from time to time.It is not rare situation that _MIMAS will start lightning up gain reduction LEDs on the front panel even if there is no signal present.
To calibrate metering few very easy steps need to be follow:
1) Please power ON the Chassis with _MIMAS inside, and wait about 20 minutes for unit to properly warm up.
2)Now Gain reduction trimmer needs to be adjusted – please power OFF chassis and remove _MIMAS unit from the chassis.
3) If You are in situation that LED is lighting up without any signal – trimmer should be adjusted counter clockwise HALF a circle as below:
4) If for any reason gain reduction on the unit doesn’t show gain reduction when it is in fact occurring, trimmer should be adjusted HALF a CIRCLE clockwise as below:
5) Now _MIMAS unit still doesn’t show properly gain reduction, please go through this procedure again from point 2.