Tone stack - Traynor YGM-1 questions for smart amp guys

[GuitarStv]

So, I'm looking at the tone stack for my vintage Traynor here:



This seems very similar to the classic Fender/marshall tone stack:


With the treble cap being 330 (with a 1M pot), the bass cap being .1 (with a 250k pot) and the mids cap being .02 (along with an 18k resistor). The .001 cap next to volume is the presence from what I understand. Please correct me if I'm wrong here.



Now, the amp is uncomfortably bright sounding with everything stock. I have the bass set to max and the treble to minimum and it's very bright sounding with dark humbucker guitars. Clearly something has to change here . . . I suspect that the .001 uF presence cap is too large and the value should be cut in half or less to start reducing brightness. Makes sense, or am I missing something?

Would reducing the 18k resistor reduce mids for this amp?

 

[VanDerchuck]

Re: Tone stack - Traynor YGM-1 questions for smart amp guys

You could do a bunch of things. Personally I'd start with a small cap from lug 2 to ground on the volume pot. That might bleed off enough high end to tame the amp. It would be easiest mod that I can see from the schem presented. Try a number of different caps and see if that will work. You could also try different cathode bypass caps, either pin 3 or 8 of v1 depending on which side of the tube is used first. That way your tone stack stays in tact. Maybe these quick fixes will take care of it.

 

[BrianS.]

Re: Tone stack - Traynor YGM-1 questions for smart amp guys

I'm looking at a YGM-2 schematic and it shows the .001 cap connected to a "treble boost" switch. My YRM-1 has pretty much the same thing. Yours is hardwired to have the treble boost on all the time. I'd just lift one end of the .001 cap and see how it sounds. I know with my amp, it's way to bright with the treble boost engaged. Also, you'll notice that if you crank the volume all the way up, the .001 won't have any affect, as it is essentially bypassed.

Presence controls are always in the negative feedback circuit. Your amp does not have any negative feedback circuit.

Edit: also wanted to mention: I suppose it makes sense that they changed that part of the circuit into a "treble boost" after having too many complaints of the amp being too bright for a lot of folks. I suppose instead of eliminating it, it was turned into a "feature". A feature mainly used by rockers who had lost the ability to hear higher frequencies?

 

[GuitarStv]

Re: Tone stack - Traynor YGM-1 questions for smart amp guys

Hey, that's an idea. Since I put in the 3-prong power cord there's a ground reverse switch kicking around at the back that's doing nothing. I could switch the .001 cap on/off with that.

What exactly is presence then? I just thought it was very high treble.

 

[BrianS.]

Re: Tone stack - Traynor YGM-1 questions for smart amp guys

http://billmaudio.com/wp/?page_id=72

Try that.

 

[GuitarStv]

Re: Tone stack - Traynor YGM-1 questions for smart amp guys

Jesus, the more I learn about guitar amps the more weird everything gets.

The mids control acts as a volume control. The Treble control effects different frequencies depending on what the bass/mids are set to. The presence control changes the way the amp behaves rather than just making stuff brighter.

 

[BrianS.]

Re: Tone stack - Traynor YGM-1 questions for smart amp guys

There's a life lesson in there somewhere...

 

[GuitarStv]

Re: Tone stack - Traynor YGM-1 questions for smart amp guys

Never learn anything?

 

[BrianS.]

Re: Tone stack - Traynor YGM-1 questions for smart amp guys

Never learn anything?

That works!

 

[GuitarStv]

Re: Tone stack - Traynor YGM-1 questions for smart amp guys

Turns out just clipping that bright cap totally fixed the screamingly loud highs problem that was going on. The treble and bass tone controls don't appear to need any tweaking at all, and the amp sounds great with the stock speaker.