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Taming the treble bite on my Plexi

When I switched guitars to my strat, my normal channel is far to bright even with the tone control rolled right back.

Is a roll-off cap placed parallel with the plate resistor the best approach to kill this shrillness ??
If so, what values would you recommend ? ( .001uF )

thanks...

btw... my wife thinks that this is best resolved by getting rid of extra guitars. - how wrong is that

Just try snipping the 500 pf treble cap at one end and opening it up. That's on the Volume control. Make it more like an sIII.

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Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

It's nice to have that extra bite available with a darker sounding guitar, IMO.

You could use a switch to lift one end of that cap out of circuit, either a mini panel mount, or a pull-pot for your vol control. Or you could use a different value cap, and with some trial and error find a value that suits all of your guitars. Or if this a 4-input 2-channel, use a jumper cable across the channels so you can dial in some of the dark channel along with the bright and balance it out to your liking depending on which guitar you're using. Just a couple ideas.

Are we talking reissue with PCB, reissue handwire, vintage?

craigB has some good advice there, specially the pull pot option.

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Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

Thanks CraigB and Stephen,

I did remove the 500pf treble cap, and was thinking of replacing it with a differenet value cap, but I was going to wait until I played-out with my new amp to get a feel of how well it cuts through the mix.

The push/pull pot is a great idea, that I'll definately be using.

The question is... Where is the best place to order small quantities of electronic components from ?? ps. I live in Canada

cheers,

Brian

I think playing it in context with your band is the best way to go before doing anything more to it.

If it's a PCB reissue, I can't remember from the one I owned years ago if it used regular full-size pots, or if they're PCB-mounted mini-pots. If it's full-size pots with leads to the PCB, CTS makes a 1MA with SPST pull switch, and that would be a very easy, non-invasive mod. They're $8.95 from the co. I buy from in Arizona, but I usually just have my local guitar shop order single pieces for me (as part of their larger order for other people) so I'm not paying $10 shipping for a $10 item. If you don't mind waiting, that might be the way to go.

Another consideration is what speakers you're playing through. It's going to be brighter with newer Celestion(s) as opposed to, say, greenbacks.

CraigB

I presume we're talking about one of Trinity's 18W Plexi amps here, so there wouldn't be any PCB. I would have thought the best place for pull-switch pot would be the Treble control, since this is related to the amp's treble response. If you use the 1M pot recommended by Craig, connecting either a 300k or 330k resistor across its two outer lugs will give you the right value for the treble control - ie in the range of 220k to 250k.

Off Topic tangent: Hey Craig, great to see you here! It's been some time since you used to post on AX84. I always liked your very cool Atlas Tweed and Windchime amps, and I know that quite a few of these 6V6/Spitfire-ish amps have been built by other folks too.

For those who don't know what I'm talking about, check out Craig's personal amp page - www.geocities.com/craigbbbb/index.html DenissF's soundclip of his Atlas is on http://members.cox.net/dennisfweb/sound/MSQN2SHRT.mp3

Normal programming will now resume....

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Great tones come in small glass jars!

Ah, see, I should be looking at where I'm posting, right? I'm thinking, "Who's going to drill a hole in the front panel of a vintage plexi for a switch?" But for a non-vintage, I like using an SPST to pull that bright cap off the volume control, or a DPDT to pick between two values, or even better an on-off-on for two values or no bright cap if there's room to install.

Hey, Phil, it's nice to be back.

Normal programming needs to resume...

Yes, I too built one of Craigs Atlas Tweeds!

This treble in this query is related to the Normal channel, which has a 500 pf on it.

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Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

SPAM!!