Hi Jimmy,
>Much thanks guys. I never knew what all that MIDI stuff did. I just
>used the volume knobs. Difficult doing that live. So that's what the
>MIDI thru does. Cool. You'd never know I've been using MIDI synths
>for over 15 years.
You're far from alone. You'd be surprised at how many synth owners know absolutely nothing about MIDI.
For complete closure: The MIDI Thru jack is supposed to be nothing more than a perfect copy of MIDI In. It was added to the specification because MIDI cannot be connected in a "Y" fashion like you would use to connect a mono synth to both channels of a stereo amp. (MIDI is designed as one-output-connected-to-one-input.) The Thru provides another way to get the master data to Device #2, etc. by connecting the Thru of each device in the chain to the next In. The Thru is optional in the MIDI specification, but most keyboards and modules provide the feature; sometimes the Thru and Out a sent to one jack, with a switch or software selection to choose one of the two items.
Some keyboards merge the data from the In with other data created by the synth/module, or merge two Ins to one output. This useful feature is actually outside the MIDI specification, but is often seen on master keyboards and modules that add knobs and switches. Usually, this merging is done on the Out jack, leaving the Thru as simply a copy of whatever arrived at the In jack. It's useful to understand the difference between merged Out and Thru.
Each Thru adds a small delay to the data, so if you are connecting more than say, 6-9 devices, you may start to hear a little lag between the time when the key is pressed and the time you hear actual sound from the synth or module, or between the attack of Device #1 and Device #7. Whether this lag is bothersome -- or even noticeable -- depends both on your playing style, the kinds of sounds and layers you are using, and any additional processing (merging, etc.) added by the devices. A velocity-sensitive keyboard adds some delay by just measuring the speed of the key hit, so you may already be compensating for a bit of delay in your keyboards.
If you are using more than 3-4 devices, many people purchase a device called a "thru box" that has one In and many Thrus; this way, all of the down-line devices have only one, equal Thru delay.
Regards,
-BW
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Bruce Wahler
Ashby Solutions™
http://music.ashbysolutions.com978.386.7389 voice/fax
bruce@...