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DIY A-E conversion with DSPT - Questions

Posted: Sat Feb 08, 2014 10:25 pm
by kremonte
I'm trying to do an A-E conversion on the cheap and I'm planning the hardware to order, trying to keep the total hardware bill under $100. I'm planning on running without a module (using DSPT and AD only) and using a Surface Pro to host the DAW. It's not a powerhouse but does have a core i5 CPU and 4GB of RAM, and crucially, its only input is single USB 3.0 port. My plan is to connect a USB hub and fill it with $2 USB thumb-sized audio interfaces, each with a single mono mic in, to connect each trigger.

I've dumbed down my idealized 16-sensor setup to one with only 10 and won't bother handling the hihat. I've read that DSPT can only handle choking of dual-zone cymbals: Would this simply be a cymbal with a sensor bow and one on the bell? I've seen DIY cymbal setups that use a single sensor, and then another piece of cymbal on the underside to short one channel to choke it. Which method is best for DSPT?

I know the setup is foolish for many reasons (all processing on a tablet, ADC done by $2 cards, using a dozen USB devices and they're all audio cards on the same hub), but I reckon I can get to a workable latency for practice drumming in my home, worst case I'll just buy a module or interface down the line and my equipment is already wired. Has anyone heard of a similar setup to this?

Re: DIY A-E conversion with DSPT - Questions

Posted: Sun Feb 09, 2014 12:33 am
by Rob
While very interesting, I don't think this will work stricktly because AFIAK you can't use more than one audio interface with your DAW at a time. To keep your setup neat and simple, I would have to recommend the Alesis Trigger IO.

Re: DIY A-E conversion with DSPT - Questions

Posted: Sun Feb 09, 2014 2:01 am
by kremonte
Using ASIO4ALL drivers I was able to use 3 USB audio interfaces concurrently in Reaper, I don't see why that wouldn't work with more devices. The each USB device is enabled in the ASIO4ALL control panel and then the entire range of inputs is assigned through the ASIO configuration panel in Reaper.

I may move to an Alesis Trigger iO if I find that the DAC quality of the cheap interfaces is unacceptable, but I've tried with 3 similar interfaces (creative x-fi go x2 plus an older box-style creative usb sound blaster) and they worked in synchrony.

Would you have any input as to preferred cymbal construction for choking in DSPT? I have an old broken cymbal I can cut up to use as contacts, but simply wiring two piezos would be easier.

Re: DIY A-E conversion with DSPT - Questions

Posted: Mon Feb 10, 2014 3:54 am
by Rob
To get full cymbal support (including chocking) in DSPT, you need to use one of the supported cymbal which are all piezo / switch type pads.

While the DSPT can't use the switch in the same way a hardware module does, it can read bleed that gets spilled into the switch channel from the piezo. This method is a bit limited as the choke has to arrive while the peizo is still vibrating (perhaps up to 750 ms after a hit).

Some Roland cymbals (can't remember which offhand) actually producing a a very measurable buzzing in the switch channel whenever they are chocked and as a result work a lot better as a choke can be registered even in the absence of vibration on the piezo channel.

Regards,
Rob