Solid State Guitar Amp Forum | DIY Guitar Amplifiers

Solid State Amplifiers => Preamps and Effects => Topic started by: ChewyNasalPrize on November 14, 2013, 09:32:26 PM

Title: Tube Works Blue Tube Replacement Switch
Post by: ChewyNasalPrize on November 14, 2013, 09:32:26 PM
Anybody know what kind of switch will work in this?

I picked up a basic SPST on/off switch at Home Depot but it doesn't work.

The original works but it is starting to fail. Sometimes it clicks but doesn't actually switch.

Thanks.
Title: Re: Tube Works Blue Tube Replacement Switch
Post by: J M Fahey on November 15, 2013, 10:55:31 PM
*Start* by looking what kind of switch it has and how is it wired.
Title: Re: Tube Works Blue Tube Replacement Switch
Post by: ChewyNasalPrize on November 15, 2013, 11:56:20 PM
The switch has six prongs on it but only two have wires connected to them. I've tried contacting Genz Benz a couple of times to get part info but so far they have only sent emails telling me that they got my emails and someone will be emailing me soon....... that's been a while.
Title: Re: Tube Works Blue Tube Replacement Switch
Post by: Roly on November 16, 2013, 06:34:23 AM
Pix are a great help.
Title: Re: Tube Works Blue Tube Replacement Switch
Post by: teemuk on November 16, 2013, 07:03:08 AM
According to schematics, the switch is simple SPST momentary -type switch.

QuoteThe switch has six prongs on it but only two have wires connected to them.

So they had DPDT momentary switches on stock and for SPST function they only needed to use two terminals of them.

The switch itself hooks up to a solid-state flip flop circuit, which further on controls channel switching FETs and indicator LEDs. The momentary switch basically provides a voltage pulse that makes the flip flop circuit change its state, a non-momentary switch would be an incorrect (and probably non-working) replacement for such circuit.

Additionally, have you verified the problem is the switch, not the solid-state switching logic?
Title: Re: Tube Works Blue Tube Replacement Switch
Post by: ChewyNasalPrize on November 16, 2013, 04:23:07 PM
Hey- no I haven't verified it is the switch- I just made the assumption it was the switch.

I think I need to try a momentary switch then?
Title: Re: Tube Works Blue Tube Replacement Switch
Post by: Roly on November 17, 2013, 05:04:08 AM
Quote from: ChewyNasalPrize on November 16, 2013, 04:23:07 PM
Hey- no I haven't verified it is the switch- I just made the assumption it was the switch.

I think I need to try a momentary switch then?

I've always found it best to determine what a fault actually is before fixing it.    8)
Title: Re: Tube Works Blue Tube Replacement Switch
Post by: ChewyNasalPrize on November 17, 2013, 02:38:28 PM
Well, picked up a momentary SPST switch at the electronics store for $3 and that fixed it. So it was definitely the switch.  :dbtu:

For $3 it was worth a try for a possible fix and a definite for at least ruling the switch out as the problem.

Thanks for the help guys!  8)