Talkbox... won't talk

Strat_a_tat_tat

I've got one of these wee beasties...

https://www.andertons.co.uk/mxr-talk-box-guitar-effects-pedal

Only gets occasional use (one song per gig - at some gigs)... but, lately, has started cutting out randomly. Sound just disappears for a second or two (but I guess it's not the footswitch... as that would cause the sound to divert to my amp for the period of the cut out).

Have checked voltage being delivered by the MXR supplied wallwart... appears to be OK (18.3 volts... from an 18 volt rated supply).

I tend to run the device with the volume and gain set fairly high... could that be a problem?

Thanks.

impmann

Could it be a crackly pot/track causing the sound to break up/cut out?

Strat_a_tat_tat

impmann said:

Could it be a crackly pot/track causing the sound to break up/cut out?

Thanks. I'll spray some Servisol in the pots... and see if that helps.

ICBM

Strat_a_tat_tat said:

Sound just disappears for a second or two (but I guess it's not the footswitch... as that would cause the sound to divert to my amp for the period of the cut out).

No it wouldn't - unless it's a switch operating a relay or electronic soft-switching circuit then it will just make the sound to the Talk Box cut out. For it to divert the sound back to the amp the switch would have to physically change over.

It could be other things, but the switch is definitely the first suspect.

Strat_a_tat_tat

@ICBM. Thanks for the reply. When operating correctly, the footswitch switches the signal between... going straight to the amp (bypassing the talkbox) and going to the speaker in the talkbox - instead of the guitar amp (and hence the sound goes from the talkbox speaker... up the tube... and into my mouth that's placed next to a microphone.)  So that's why I'd have thought a fault in the switch would have toggled between the two states. Am I missing something?

ICBM

Strat_a_tat_tat said:

@ICBM. Thanks for the reply. When operating correctly, the footswitch switches the signal between... going straight to the amp (bypassing the talkbox) and going to the speaker in the talkbox - instead of the guitar amp (and hence the sound goes from the talkbox speaker... up the tube... and into my mouth that's placed next to a microphone.)  So that's why I'd have thought a fault in the switch would have toggled between the two states. Am I missing something?

If the switch is a mechanical one in the signal path, then it either passes signal to the amp or the Talk Box. If it's in the 'Talk Box' position signal cannot get to the amp, unless the switch is physically changed. If there's a bit of dirt or corrosion in the contact for the Talk Box, it will cut the signal out.

It would only revert to the amp if the switch is not in the signal path but instead operates a relay or an electronic version of one, so that a bad contact in the switch causes the switching circuit to flip to the other state.

In the original Heil Sound Talk Box, the switch is mechanical and in the signal path. I can't be sure about the MXR since I've never seen inside one, but it's the same type of switch.

Strat_a_tat_tat

@ICBM. Many thanks for the explanation. I'll get my screwdrivers and Servisol out!  Cheers.

sgosden

Shine a lamp in its face, and in your best "Nazi in a war film" accent, shout: 

"ZE HAVE ZAYS OF MAKING YOU TALK"