Princeton 6G2 dead tremolo

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Phil_S
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Re: Princeton 6G2 dead tremolo

Post by Phil_S »

Will V. wrote:...The cap can is a JJ replacement, and you can see the somewhat poorly enlarged hole in the chassis...
This kind of thing tends to bother me. It's fugly. I suppose prevailing wisdom would be to leave well enough alone as you can't see it unless you look inside. If that was mine, I'd fix it by running a step bit into it to clean it up and hope the hole is right sized enough to hold the can cap. Maybe it's a good thing that it's not mine!
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tony hunt
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Re: Princeton 6G2 dead tremolo

Post by tony hunt »

This type is called a phase shift oscillator. There are lots of good old texts out there, but try this one which is more for guitar amp use:
Designing Phase Shift Oscillators for Tremolo Circuits by Aiken.

As already stated above in previous posts
1. You need a strong 12AX7
2. The phase shift cap values are critical and that the 0.02 still blocks DC.
3. The footswitch is there to turn off and on, but also to kick the oscillator into life. Aiken explains that well.
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rp
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Re: Princeton 6G2 dead tremolo

Post by rp »

Phil_S wrote:This kind of thing tends to bother me. It's fugly.
Yeh, blah, pity too as exact or adequate 1" cans have been around from CE forever, you need to go buy a soldering pistol or huge iron, but still. The Ampocratic oath - first do no harm.

I had one of these, untouched mint w/ a factory unsoldered resistor on the back of the trem pot - worked fine till it didn't. Someone here recently mentioned a brown deluxe with a factory unsoldered resitor. Might want to check yours. Maybe Lupe was having a hard time at home during the Brown years, or there was an internal conspiracy to bring Leo down - luckily it was foiled.
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