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Simulating G&L PTB circuit

PostPosted: 05 May 2018, 04:40
by ramonmaruko
I am trying to simulate the G&L PTB circuit as shown in the schematic that was previously available in the G&L website.

I am having trouble getting the treble cut to work. The treble stays the same regardless of the value of VR2. Any hints as to why it isn't working would be nice. Thank you!

VR1 = Bass cut
VR2 = Treble cut
VR3 = Volume

ptb.png

Re: Simulating G&L PTB circuit

PostPosted: 05 May 2018, 08:16
by george giblet
You have drawn the circuit incorrectly.

Even if it was drawn correctly the simulation would not work. The treble control relies on the fact the pickup impedance is present. You have a voltage source. If you load a voltage source you do not change its output voltage. You need to add a pickup impedance model.

Re: Simulating G&L PTB circuit

PostPosted: 05 May 2018, 08:38
by ramonmaruko
Ah right, one of the pins of VR2 should be connected to the input and not to ground. Thank you!

As you've said it still won't simulate correctly. I'll see if I can find a model online.

Re: Simulating G&L PTB circuit

PostPosted: 06 May 2018, 15:19
by FiveseveN
Well you've tied both ends to ground. Look at the referenced schematic again (it's a normal guitar "tone control").
Edit: oops, I messed the replies above. For what it's worth, here's what I use for pickup simulation: