The Amp Challenge Thread

[Hemisaurus]

This is for those of you who are not scared to take a soldering iron to your amp, if this is not you, look away now

I'm not quite sure that challenge is the right idea to use here, but I've got this vague idea for starting this thread, tell us what you don't like about the sound of your amp. We'll look for the schematics, and suggest, preferably just one, but no more than four at one time, of components you can change, or wiring you can mod to improve the sound.

You make the change or changes, tell us whether it sounds better or not, and we can start the process again

[dunwichamps]

This is for those of you who are not scared to take a soldering iron to your amp, if this is not you, look away now

I'm not quite sure that challenge is the right idea to use here, but I've got this vague idea for starting this thread, tell us what you don't like about the sound of your amp. We'll look for the schematics, and suggest, preferably just one, but no more than four at one time, of components you can change, or wiring you can mod to improve the sound.

You make the change or changes, tell us whether it sounds better or not, and we can start the process again

Message Approved By Dunwich Amps. services available

[justinhedrick]

i have a VTM 60. i want the high end to be less spikey.

[Hemisaurus]

Message Approved By Dunwich Amps. services available

Good, it will give us something to argue about, err I mean discuss

[Hemisaurus]

i have a VTM 60. i want the high end to be less spikey.

http://www.webphix.com/schematic%20heaven/www.schematicheaven.com/newamps/peavy_vtm_120.pdf

I hate this schematic

Justin remind me which input you use, and maybe give us some idea of your common settings.

[dunwichamps]

Remove C4 or C9, you can also remove the bright cap on the gain pots.

Another fix could be making a FX loop low pass filter, its simpler, passive and not built inside the amp

[Hemisaurus]

Sounds like a good starting point, you don't even need a soldering iron, unless you want to replace the caps again

Low Pass Filter means Tone Knob, a pot with a capacitor and a couple of jacks.

[dunwichamps]

Sounds like a good starting point, you don't even need a soldering iron, unless you want to replace the caps again

Low Pass Filter means Tone Knob, a pot with a capacitor and a couple of jacks.

you could even built a simple little pedal which had some kind of passive EQ that could tame the high end not the hardest thing to do persay

treble peaking caps are the first place to pick at with modern amp with a lot of top end bite, along with bright caps on pots. Beyond that your talking about making some high end shunt caps on grid wires or plate resistors

[rayinreverse]

Im going to recap my Butcher.
Would like to cut some of the highs. its a little too bright for me.
or maybe jsut do this to it.

http://www.davidsonamp.com/woodland_gallery/gallery_butcher.php

[dunwichamps]

Im going to recap my Butcher.
Would like to cut some of the highs. its a little too bright for me.
or maybe jsut do this to it.

http://www.davidsonamp.com/woodland_gallery/gallery_butcher.php

http://music-electronics-forum.com/attachments/11449d1288300024-peavey-butcher.pdf

Remove C6, C3, C15, C16, Try doing this one at a time, seeing what you like

assumption is you are using the high gain input

[Hemisaurus]

Sounds like a good starting point, you don't even need a soldering iron, unless you want to replace the caps again

Low Pass Filter means Tone Knob, a pot with a capacitor and a couple of jacks.

you could even built a simple little pedal which had some kind of passive EQ that could tame the high end not the hardest thing to do persay

treble peaking caps are the first place to pick at with modern amp with a lot of top end bite, along with bright caps on pots. Beyond that your talking about making some high end shunt caps on grid wires or plate resistors

What's wrong with changing the coupling cap values? Most modern guitar amps have them about a tenth of what they should be? I'd hit that after the bright caps, and before cathode bypass I was eyeing up C2,3,6,8,9 for replacement, but that was more than my four, but the bright caps are the simpler call.

[dunwichamps]

Sounds like a good starting point, you don't even need a soldering iron, unless you want to replace the caps again

Low Pass Filter means Tone Knob, a pot with a capacitor and a couple of jacks.

you could even built a simple little pedal which had some kind of passive EQ that could tame the high end not the hardest thing to do persay

treble peaking caps are the first place to pick at with modern amp with a lot of top end bite, along with bright caps on pots. Beyond that your talking about making some high end shunt caps on grid wires or plate resistors

What's wrong with changing the coupling cap values? Most modern guitar amps have them about a tenth of what they should be? I'd hit that after the bright caps, and before cathode bypass I was eyeing up C2,3,6,8,9 for replacement, but that was more than my four, but the bright caps are the simpler call.

Changing coupling caps is another option, however this is also going to change the structure of the gain more IMO, as letting in more low end will get you some more wooly clipping. Nothing wrong with that. treble peaking caps and bright caps are just simpler to eliminate and you do not have to then buy 400-630V replacement caps for the coupling

the reason coupling caps are so small in modern amp is to avoid blocking distortion and excessive grid current since they never fucking using grid stoppers!!!

[rayinreverse]

Im going to recap my Butcher.
Would like to cut some of the highs. its a little too bright for me.
or maybe jsut do this to it.

http://www.davidsonamp.com/woodland_gallery/gallery_butcher.php

http://music-electronics-forum.com/attachments/11449d1288300024-peavey-butcher.pdf

Remove C6, C3, C15, C16, Try doing this one at a time, seeing what you like

assumption is you are using the high gain input

yes using high gain input. I was thinking of changing values of those caps, but you think just remove all together?

[dunwichamps]

Im going to recap my Butcher.
Would like to cut some of the highs. its a little too bright for me.
or maybe jsut do this to it.

http://www.davidsonamp.com/woodland_gallery/gallery_butcher.php

http://music-electronics-forum.com/attachments/11449d1288300024-peavey-butcher.pdf

Remove C6, C3, C15, C16, Try doing this one at a time, seeing what you like

assumption is you are using the high gain input

yes using high gain input. I was thinking of changing values of those caps, but you think just remove all together?

The function of C6, C15, and C16 are for treble peaking, they bypass resistive dividers to increase treble response, increasing them will let in more signal but will not cut high end. You could increase C3 to something say 10uF to 25uF but this will also increase gain at lower frequencies

Just change one of them, test, then move on if its not enough

[Hemisaurus]

What's wrong with changing the coupling cap values? Most modern guitar amps have them about a tenth of what they should be? I'd hit that after the bright caps, and before cathode bypass I was eyeing up C2,3,6,8,9 for replacement, but that was more than my four, but the bright caps are the simpler call.

I hate having to repeat myself

[dunwichamps]

What's wrong with changing the coupling cap values? Most modern guitar amps have them about a tenth of what they should be? I'd hit that after the bright caps, and before cathode bypass I was eyeing up C2,3,6,8,9 for replacement, but that was more than my four, but the bright caps are the simpler call.

I hate having to repeat myself

I missed it, sorry man. If people are looking for a thicker sound, bumping up those couplers will work.

[Hemisaurus]

Yeah, but your right, cutting out treble bleed first is easier and takes our the ice-pick.

[dunwichamps]

Yeah, but your right, cutting out treble bleed first is easier and takes our the ice-pick.

In my own shit I use a 220-330 pF bright cap on the gain pots but nothing else in the amp. I also use some plate snub caps to bring down the noise floor as well

this thread shall be the Hemi vs Nick thread hahahaha

[Hemisaurus]

Naw, we're in agreement so far, if you stop to read the thread properly

Cheap bastards, we used to call those bright switches, and give people a chance to turn them off

[dunwichamps]

Naw, we're in agreement so far, if you stop to read the thread properly

Cheap bastards, we used to call those bright switches, and give people a chance to turn them off

I usually dont like much bypassing on the pots, just a touch to maintain a little clarity. Gone are the days of Fender bright switches!!

[Hemisaurus]

Not you, I meant the plethora of bright caps in current production amps.

I really liked the Music Man Deep switch, it actually bypassed the coupling cap, which working from memory is only safe because it was an op-amp output into the phase inverter

[Chovie D]

befoer anyone opens up their amp, please learn how to do it safely. learn how to discharge caps, and buy a voltmeter.

[dunwichamps]

Not you, I meant the plethora of bright caps in current production amps.

I really liked the Music Man Deep switch, it actually bypassed the coupling cap, which working from memory is only safe because it was an op-amp output into the phase inverter

you could have a deep switch even on a normal gain stage, have a small coupling cap (10nF or whatever) in parallel with a a 47nF cap which is inseries with a 1meg resistor. Just use a switch to shunt the resistor and you can get a Deep mode

[Hemisaurus]

.022 is a pretty common coupling cap value, I'd cheerfully up that to .1 or even .22

of course my brain is generally working like this

[dunwichamps]

just watch out for blocking/grid current