6G3 Circuit Question

My electronics basics are very old and rusty but it seems it would attenuate high frequencies on the normal channel (vs the bright channel w/o the cap)

 

It's a basic RC circuit to block specific frequencies. I think! A bit like a capacitor on a tone pot, in this case a variable resistor.

 

Everyone's right. It's a 'low-pass filter' or 'high-cut', and a pretty significant on at that. It's -3dB point is ~2KHz. The normal channel should be a heck of a lot darker sounding than the bright channel.

This amp doesn't have an actual 'bright channel' in the traditional sense but an 'anti-bright channel'. Where the highs are cut on the normal channel rather than boosted on the bight channel.

 

A cap on the plate resistor of preamp tube is used to control squealing. It works but really kills the highs.

 

another special thing about the 6G3 is that compared to the later Fenders (Blackface/Silverface) there is no separate grid leak to ground at the second gain stage
Also see the voltage divider used after that second stage in order to reduce the signal to a level that does not turn the thing into a distortion machine
It does do things differently but it works great - wish I had one

 

Like this? I only just got it back from the tec. I built it but left the final startup to him. The "Normal" channel is warmer, less toppy than the Bright channel, which is where the juice is. Volume halfway up equals creamy overdrive, and after that it gets more saturated rather than louder.

 

I think my idea of prettiest amps ever are from the Fender brownface era. That Strat/brownface Deluxe photo ^^ belongs on a calendar or something.

Really wishing I’d not passed up a pretty good deal on a brownface Princeton many years ago...I could have some socially distant fun with one of those right about now.

 

I bet jumpering the channels is very interesting. I really want to try a 6G3 - the circuit is very out of character for Fender.

Uncle Daddy, what speaker is in your amp?

 

I always thought that was an interesting way of doing things. I'll finally be able to hear it for myself one of these days when I finish mine. I'm embarrassed to say how long ago I started it...