Modding an Amp to Have a More Usabale Midrange

[LooseCannon]

I have a duncan convertible amp and it's a very midrangy amp, it's all mids. Turning the midrange knob has almost no effect on the tone and i'm using an eq pedal in the loop to take away some of the midrange but i'm still not happy with the tone. Is there a way to mod it so the mids knob will affect the tone like it should?

 

[Foeburner]

Re: Modding an Amp to Have a More Usabale Midrange

Yea, just change the cap before the pot

 

[LooseCannon]

Re: Modding an Amp to Have a More Usabale Midrange

To what value?

 

[ES350]

Re: Modding an Amp to Have a More Usabale Midrange

Does it work differently now then it did when you bought it?
Unfortunately, without a schematic, there isn't any way to tell you what component to change or what value to use...take it to a tech.
Or maybe you just need a different amp...

 

[LooseCannon]

Re: Modding an Amp to Have a More Usabale Midrange

Well there are some schematics here: http://www.diyguitarist.com/GuitarAmps/SD-Convertible/Schematics.htm

I'd appriciate it if you could help me.

 

[frankfalbo]

Re: Modding an Amp to Have a More Usabale Midrange

My assumption is that the Duncan Convertible tone stack is Fendery in nature. The cap value will have an impact, but I think the best solution for you is a parametric EQ in the loop, instead of the graphic pedal. It's not because the graphic cuts the mid bands into sections either. Lots of people will tell you graphics are bad for guitar tone. They're sort of right, but that's not the essence of why I'm telling you in your situation to get a parametric. What you need is an active boost/cut midrange that you can tailor to the frequency area you want affected. A variable Q would be a huge plus. In this case, the variable Q parametric mid band becomes the midrange knob you've always wanted. In other words, the right way to address the Convertible issue would be if you could install an active sweepable midrange tone control. But since you can't, the external para-mid would do the trick beautifully.

Edit: Also because you say the amp is midrangey, a 3-band parametric EQ would give you an active boost on the highs and lows as well. If the Convertible tone stack is Fendery as I suspect, then you're really just getting a passive cut.

 

[More-Gear-Than-Skill]

Re: Modding an Amp to Have a More Usabale Midrange

fat humbuckers in the guitar might also make the issue worse.

 

[LooseCannon]

Re: Modding an Amp to Have a More Usabale Midrange

Will moving the tone stack after the gain stage make a big difference?

 

[LooseCannon]

Re: Modding an Amp to Have a More Usabale Midrange

Anyone?

 

[Boogie Bill]

Re: Modding an Amp to Have a More Usabale Midrange

I don't like the idea of mucking around in your amp--you could kill yourself if you don't know what you are doing. The voltages in that amp are LETHAL.

You need to discuss any modification to your amp with a knowledgeable technician, and have someone who is skilled and competent service your amp.

There may be a modification that could easily be done, or the amp may simply need servicing and repair.

And it could also be a design flaw in that amp. There's probably a reason why those amps haven't been produced for a long time. My advice wold be to service the amp, and if it doesn't meet your standards after that, find a better amp.

But don't go digging around in your amp with a screwdriver and a hare-brained idea--you might find yourself switching from the guitar--to a harp!

Bill

 

[ES350]

Re: Modding an Amp to Have a More Usabale Midrange

Well, the tone stack is SS driven ala Music Man amps, doesn't use Fender/Marshall style component values, and it's a very bad idea to start mucking around in a PCB amp if you don't have a clear objective in mind and the skills to accomplish it...take it to a tech or sell it.

***standard disclaimer here concerning lethal voltages present***

 

[LooseCannon]

Re: Modding an Amp to Have a More Usabale Midrange

Well there's an explanation exactly how to do that mod on the same site:
Remove wires to TC1 and TC2 completely, and jumper those 3 posts together. Run a wire from each MV1 and MV2 white to corresponding center lug on the treble pots, then run a lead from the 0.1uF caps in the PCB, after removing the lug facing the front out of the board with needlenose pliers and a soldering iron, to the tone stack, between the treble and mid pots, right of the 100k resistors. Then you're done.

Doesn't look too complicated.

 

[More-Gear-Than-Skill]

Re: Modding an Amp to Have a More Usabale Midrange

...you might find yourself switching from the guitar--to a harp!

Bill

:chairfall :bowdown: :chairfall :chairfall :chairfall :chairfall :chairfall
That's on the assumption he's going to heaven! Perhaps he's headed where the Tritone Diabolicus rules.... :saeek::saeek::saeek:

 

[ES350]

Re: Modding an Amp to Have a More Usabale Midrange

Well, drain the caps and have at it.

 

[LooseCannon]

Re: Modding an Amp to Have a More Usabale Midrange

I have a couple more questions if you guys could help me: What does it mean to jumper 3 posts together? What does it mean to run a lead? And how do I drain the filter caps?

 

[ES350]

Re: Modding an Amp to Have a More Usabale Midrange

I see you can cut and paste, but if you don't know what a lead or a jumper is...take it to a tech or sell it.

 

[LooseCannon]

Re: Modding an Amp to Have a More Usabale Midrange

Actually i'm having trouble with understanding the terms in english, so if you can please explaine them to me.

 

[ES350]

Re: Modding an Amp to Have a More Usabale Midrange

I apologize if English is not your native language, but here's the deal:

1. High voltage components of amps are deadly---no joke, it can kill you.
2. There are safe procedures to use when working on amps that have to be followed.
3. One needs a good working knowledge of electronics, have the appropriate tools, practice safe work habits, and be able to read a schematic and troubleshoot. It is a technical skill.
4. A passing second-hand familiarity with all the above is not sufficient to do the job effectively and safely.
5. Walking you through this procedure makes me partly responsible, in an ethical sense, for whatever mishaps may occur either to the amp or yourself.

No thanks---take it to a tech or sell it.