Matching Diodes and Transistors—Squidward

[7'Swell]

Greetings everyone. Do the diodes and/or transistors in the Squidward pedal need to be matched in order for it to sound right? Thanks in advance.

 

[jcpst]

Hello- Chuck has a good thread about it around here.

Thread 'What's All This Matching Stuff About? - part 1'

Nov 25, 2020

People talk about matching transistors, but what do they mean?

There are a few instances in pedal circuits where matching transistor parameters to each other or to circuit requirements is essential for proper performance.

1. FET-based Phase-Shifters
Many Phase Shifters used JFETs as voltage-controlled resistors. The Phase 90 is a prime example. This schematic is from electrosmash.com. They have a very good explanation of how Phase-Shifters work, so I won't repeat all that here. They link to an article by R. G. Keen on JFET matching that is well worth reading...

• Chuck D. Bones
• Replies: 34
• Forum: Chucks Boneyard

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This post mentions matching the octave diodes for Vf in the squidward.

Post in thread 'What's All This Matching Stuff About? - part 1'

Nov 25, 2020

You ask a lotta questions for someone from New Zealand

Vbe matching: use a real transistor tester if you have one, otherwise measure base to emitter with the diode setting on your DMM. Get 'em as close as you can, preferably better than ±25mV.

Squidward & Tone Machine: match the octave diodes for Vf, same as above. Use 1% resistors.

• Chuck D. Bones

 

[7'Swell]

Thanks! That is helpful.