Guyatone - VT-2 Tremolo

B3ar · Post by **B3ar** » 15 Feb 2010, 04:11

Anyone got schematics of this or the VT-3? I've got a VT-2 that's gone a bit dodgy (intermittent trem effect) and was never that great to start, so mods are also quite welcome. Not an opto-type so far as I can tell.

lolbou · Post by **lolbou** » 15 Feb 2010, 08:29

Could you provide pics?

Bernardduur · Post by **Bernardduur** » 15 Feb 2010, 09:53

Ask guyatone! They gave me all the schematics I needed!

B3ar · Post by **B3ar** » 15 Feb 2010, 21:57

Asked Guyatone for schematics this morning, no response yet.

I can take pictures, but I was pretty sure I needed a higher post count to put them up. It is a cramped layout, so I'm not sure how helpful pics are to trace without some disassembly -- for example, there's a SIP chip so buried that I can't see any markings on it through the other components.

B3ar · Post by **B3ar** » 16 Feb 2010, 03:57

Got a schematic from Guyatone. Happens to be the same as this one. Changes from VT-2 to VT-3 are marked on it -- the crossed-out component values are VT-2, though I can't find D5 on my board. (The "Rate" pot is the crossed out value, so I'm guessing it's not a VT-2 in a VT-3 case.)

FYI, Godlyke (the U.S. distributor) will do non-warranty service for $35 plus freight for in-production pedals. Which means not mine.

Is there an idiot's guide to troubleshooting this sort of circuit?

: Re: Guyatone VT-2 Tremolo schematic

: Re: Guyatone VT-2 Tremolo schematic

B3ar · Post by **B3ar** » 20 Feb 2010, 21:26

Hah -- finally got around to giving a go of troubleshooting it and it instantly cleared up. Why? Previous owner had taken the insulator off of the metal bottom plate. The circuit must have been grounding out. Works just fine without the plate. Simplest troubleshooting ever.

Any suggestions of a good thin insulating material to put on the bottom plate?

I'm assuming doing the updates to VT-3 specs will help performance a bit, especially changing the taper of the rate knob. Not enough of the sweep for the useful range of speed -- goes from nothing to robotically fast in a very short sweep. And the depth range is too small, IMO, going up to a moderate effect, but I like my trem deep.

lolbou · Post by **lolbou** » 20 Feb 2010, 22:05

B3ar wrote:Simplest troubleshooting ever

I once changed a melted fuse. Even easier to spot...

B3ar wrote:gestions of a good thin insulating material to put on the bottom plate?

OHP film maybe?

Guyatone - VT-2 Tremolo [schematic]