Tascam DR-05 ticking noises

Exactly as downloaded.

--
~ Adrian Tuddenham ~ 
(Remove the ".invalid"s and add ".co.uk" to reply) 
www.poppyrecords.co.uk

That is correct - or at least I have never noticed it. I'm guessing it is because:

1) I never use the internal mics for professional work and rarely use them at all. 2) When I do use the mics, nowhere is quiet enough to show up the effect. 3) I would record from the mics with the gain at a level where just the pre-amp noise floor prevented the effect.

I tried it with a 'double-ender' 3.5mm screened jack lead about a foot long, with nothing connected to the far end. The effect also happens with the same lead plugged into a passive mixer and also on a longer lead with a built-in 12dB attenuator, fed from a powered mixer

I have also used a passive distribution box with separate L and R inputs (P.O. 315 jacks) taking line level from the mic pre-amp (floating and battery-powered) and delivering signals to two 3.5mm output plugs, one attenuated by 12 dB and one by 24 dB for the two recorders.

I had to do that on one occasion, but it is time-consuming taking out the clicks by hand. I would rather tackle the problem at source if at all possible.

...or add a bit of hiss to dither it.

...or add a sub-audio signal.

...or never turn the recording gain right down and let the pre-amp noise floor take care of it..

I haven't looked to see if new software is downloadable for that model - but I suspect this is more likely to be a hardware fault.

--
~ Adrian Tuddenham ~ 
(Remove the ".invalid"s and add ".co.uk" to reply) 
www.poppyrecords.co.uk

te:

e

no

d \

That's true, but if my solution works, it won't require any intervention to prevent that spurious noise.

Years ago, I had a customer with a Vizio flat TV that would start, run five seconds, and shut down. Turns out it was set to the PC input awaiting a t iming signal, and when finding none, shut down as most computer monitors wi ll. There was no way to change the input during the short time it was on. I connected a PC to it, it stayed on, and I put it back on "TV" mode and s ent it back with instructions to be careful about switching inputs.

A month later, it was back with the same problem. Seems when switching inp uts to watch a DVD, they again paused over the PC input and the TV shut dow n.

I ended up finding a timing signal on the board, cap coupled it to a transi stor, and fed that to the back of the PC jack to fool it to think an active PC was connected. That fixed that. From then on, it would stay on regard less of where the input was set.

A software change would have fixed it, but there was no help from Vizio.

Did you contact them? It does kind of sound like it's a software issue. M aybe when it detects zero signal, it may do something odd, like recycle one of the ICs.

try connecting an audio signal generator do create say a 1 kHz sine tone.

slowly drop the level. at some level the clicks will start.

observe the tone during the clicks for clues. Does the tone change in anyway due to the clicks?

Also with the external input connected to nothing, do the clicks change depending on if the external input is open vs shorted or terminated?

These recorders often apply a few volts of DC power to the input to power mics.

Put a scope on the input line and see if the spikes are actually present on the input line. Or connect the input to another audio input that you can listen to , do the spikes come OUT the audio input?

If you apply a small DC signal to the input through a current limiting resistor , will that stop the spikes? Try both polarities?

Is there a schematic available?

mark

also, the wave file posted shows clicks in both L and R, is it bot or just L?

Also the clicks in the wav file are alternating polarity, up then down then up etc. might mean something to you

mark

Can you read the IC numbers relating to preamps, then perhaps find a generic operational problem with it, outside of Tascam. A datasheet would let you find the main rails and perhaps there is some space to add some chip caps across the rails in that arra.