# Footswitchable Cathode resisitor?



## analogteletube (Jan 26, 2011)

Dialing in my traynor yba2b!, I've already changed the caps, changed the slope resistor to 56k and dabbled with different cathode resistor values. Right now i've got a 4.7k cathode resistor and its almost perfect...except i would like a weensy bit more clean headroon somtimes. Using the low input for a footswitch jack, would it be better to put in a higher value resistor, and then switch another in parallel for a boost, or put two resistors in series and switch one out for a boost? Any help or even other wireing seggestions would be greatly appreciated!


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## Furtz (Nov 27, 2010)

I've done that with two parallel cathode resistors and bypass caps.
I just used a SPDT switch to ground either one. If you're using bypass caps, I think the parallel arrangement would be the way to go.
Not sure how the foot switch would work.


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## analogteletube (Jan 26, 2011)

Hey! Thanks for the reply! Can I ask why you would choose parallel? The Current range of traynor amps uses a dpdt footswitch with a 1/4 stereo cable, if wired up properly, using the the second input jack as a footswitch jack I think it should work? Please correct me if im wrong.


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## Furtz (Nov 27, 2010)

I used parallel because of the bypass caps. Caps in series result in less capacitance than either individual cap.
Here's the formula for total capacitance in series. CT = 1 / ((1 / C1) + (1 / C2) + (1 / C3)) 
If you're not using bypass caps, the series arrangement of resistors should work fine.
I've got an older YBA-2 with 6V6 power tubes that I've heavily modified. So far I've added an extra gain-stage with the unused half of V1, changed the phase inverter from paraphase to cathodyne. It's still a work in progress. Not anywhere near finished yet, but lots of fun.


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## analogteletube (Jan 26, 2011)

Lots of fun indeed! Mine is a 73 2xel84, already using both halfs of v1. What changes did cathodyne have on the sound ?


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## Furtz (Nov 27, 2010)

I'm far from an expert on phase inverters, but from what I've been reading, it's almost impossible to get a clean signal out of a paraphase setup. 
I changed it to cathodyne mainly to cut down some gain. I'm still not happy with the sound....I'm going for clean. Gonna try some different grid stoppers.
Check this out. Way too much money for me, but really nice.
http://kingston.kijiji.ca/c-buy-and...uitar-Mate-Reverb-Tube-Amp-W0QQAdIdZ264834610


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## analogteletube (Jan 26, 2011)

Beauty!, way out of my price range aswell! If your going for clean why don't you switch back to the single gain stage? From what i understand people add a second stage specifically to get more distortion?


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## Furtz (Nov 27, 2010)

You're probably right. I might just put it back to original and tweak from there. 
I figured that a single gain stage before the inverter was a little wimpy, and there was the unused section. Probably a mistake.
Will try to get back to it in the next few days.


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