Tascam USB box vs. Martin D-16

January 12, 2008 5:45 PM

Tascam USB 122 + onboard factory-installed Martin acoustic pickup = lost signal. Wha?

I have a Tascam USB 122 breakout box that I use with Garageband to noodle around. Usually I record everything acoustically, close-miking the guitar and such with the lines going to the mic line-ins, and that's just fine.

Today, I was too lazy to set up the mics and just ran a quarter-inch patch from the butt of the guitar's factory-installed onboard jack to the quarter-inch-in on the Tascam. No matter what position the input switch was set to (line/guitar or mic) I couldn't get a consistent signal.

Running the patch through a pedal tuner, I did get consistent signal there. I did not dig out an amp as laziness was ruling the activity.

When I would -first- plug the patch in, a strum would produce clear, sweet ringing tones that were clearly showing signal and audible in the headphones. Then for no discernable reason, the signal would stop.

I swapped cables and all cables showed consistent signal on the tuner, with no discernable cutouts when subjected to the rigorous wiggle-and-fiddle test.

I did NOT disassemble or remove the pickup, and don't have papers that tell me what was installed. There is an easily accessible 9v battery visible through the sound hole, which I have not changed (but will as soon as I hit post).

Using two separate straight electrics into the quarter-inch jack produced satisfactory results.

I *think* the anomaly is a result of running what is essentially a mic off a quarter-inch plug with no intervening EQ or preamp. Still, I'm baffled by the initially successful signal. What gives?

posted by mwhybark to media & arts (6 comments total)

Have you tried plugging the guitar into the practise amp that I'm going to assume you handily have lying around?

If you don't have one, you could try plugging it into the hifi amplifier that I'm also going to assume you have lying around.

The sooner you can work out whether it's the guitar or the soundcard the better.
posted by Magnakai at 8:15 PM on January 12, 2008

that's weird. I've never had any problem putting a direct signal in there--my buddy was just doing it last night with his TASCAM portastudio. Usually guitar direct will do it. Are you trying left and right channels?
posted by Ironmouth at 9:20 PM on January 12, 2008

hmm, factory installed pickup? I didn't read the question well. Its a passive pickup. You probably need a preamp or phantom power, because the pickup is not powered. Preamp ought to do it just fine. If you have a preamp in your guitar, the 9V in it is definitely dead.

Looking at the specs of the US122L, it appears that there is no phantom power on the unit. You probably got some signal out of the tuner because of the power to the tuner from its 9V. Do what magnakai suggests, run it through your amp, then out through the back of the amp straight to the recorder. Or buy a preamp. You might get something out of the guitar if the 9V is replaced. Usually they have preamps in them.

Nothings busted, I'm certain.
posted by Ironmouth at 9:30 PM on January 12, 2008

Change the battery.

If that doesn't work, try putting the Tascam device on its own dedicated USB bus. If it's sharing a bus, especially with audio (headphones?) the performance may degrade.
posted by ikkyu2 at 2:32 PM on January 13, 2008

Battery change coming up (I didn't have one in the house and hadda go shopping). The version of the 122 I have does have phantom power, but that's presumably only available to the true three-prong mic inputs. I'll report back.

No amp handy (due purely to laziness, they are stashed away in the basement). Soon!
posted by mwhybark at 6:30 PM on January 13, 2008

Battery change solved all the problems. Thanks!
posted by mwhybark at 6:44 PM on January 15, 2008