Spare hole, what mod?

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NippleWrestler
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Spare hole, what mod?

Post by NippleWrestler »

By changing the fx loop on my Mesa dc10 from parallel to series the mix knob is now redundant (it's out the circuit). As such, there's a hole on the back of the amp where that pot once lived, meaning there's scope for something back there.

Any ideas on what's a fun useful mod to install?

I wondered about a variable nfb control (like a resonance mod), or a cold clipper switch, or variable slope resistor... Something like that but if there's something you guys have used that's interesting id love to hear.

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Re: Spare hole, what mod?

Post by StrummersOfThunder »

Pencil sharpener?
Cigar cutter ?
Somewhere to sheath your conductors baton ?

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Re: Spare hole, what mod?

Post by Optical »

Hmm. The nfb is fairly strong so you might get an interesting result from changing it up.
There's lots of 'more gain' mods you could do on the lead channel. For voicing, try a 1M pot in place of the 470k that's in parallel with the 2n2 in the peaker after the first stage. On the lead channel, could also try a pot in place of the fixed treble control on the pseudo tone stack mesa have in there for a bit of voicing and gain control.

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Re: Spare hole, what mod?

Post by robthemac »

Reverb dwell,? Might be technically tricky, but a control that I wish more amps had.
Jops wrote: Sun Sep 18, 2022 7:46 am Spring is the comic sans of reverbs anyway.

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Re: Spare hole, what mod?

Post by StrummersOfThunder »

robthemac wrote: Mon Nov 18, 2024 9:16 am Reverb dwell,? Might be technically tricky, but a control that I wish more amps had.
What is the amp circuit in the vibroking ?

Be tempting to do a single channel ab763 with a 6g15 verb …

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Re: Spare hole, what mod?

Post by NippleWrestler »

Optical wrote: Mon Nov 18, 2024 9:13 am Hmm. The nfb is fairly strong so you might get an interesting result from changing it up.
There's lots of 'more gain' mods you could do on the lead channel. For voicing, try a 1M pot in place of the 470k that's in parallel with the 2n2 in the peaker after the first stage. On the lead channel, could also try a pot in place of the fixed treble control on the pseudo tone stack mesa have in there for a bit of voicing and gain control.
There's enough gain in their already tbh, at least for what I like to play. The voicing is also generally fine too and there's a Marshall style tone stack and a graphic EQ to shape it more.

I found the mention of the pot in place of the fixed treble control interesting though, that would be the 2x100k resistors here? Or the 750k?

Another thought I had was just to bypass this fixed tone stack altogether, although by simulating it it seems to add a bit of upper mid snarl which is quite welcome tbh.
Screenshot 2024-11-18 102945.png
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Re: Spare hole, what mod?

Post by jeremyb »

Damn, I thought by the title my skills would be required :-(
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Re: Spare hole, what mod?

Post by Jay »

NippleWrestler wrote: Mon Nov 18, 2024 9:32 am
Optical wrote: Mon Nov 18, 2024 9:13 am Hmm. The nfb is fairly strong so you might get an interesting result from changing it up.
There's lots of 'more gain' mods you could do on the lead channel. For voicing, try a 1M pot in place of the 470k that's in parallel with the 2n2 in the peaker after the first stage. On the lead channel, could also try a pot in place of the fixed treble control on the pseudo tone stack mesa have in there for a bit of voicing and gain control.
There's enough gain in their already tbh, at least for what I like to play. The voicing is also generally fine too and there's a Marshall style tone stack and a graphic EQ to shape it more.

I found the mention of the pot in place of the fixed treble control interesting though, that would be the 2x100k resistors here? Or the 750k?

Screenshot 2024-11-18 102945.png
The 750k and gain pot form a voltage divider. For a treble pot replace the 2x100k and 1x15k pot with a 250k pot.

Change the next 15k resistor for a 250k bass pot and the 62k resistor for a 25k Mid pot and voila, you have a typical Fender tonestack

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Re: Spare hole, what mod?

Post by NippleWrestler »

Jay wrote: Mon Nov 18, 2024 10:45 am
NippleWrestler wrote: Mon Nov 18, 2024 9:32 am
Optical wrote: Mon Nov 18, 2024 9:13 am Hmm. The nfb is fairly strong so you might get an interesting result from changing it up.
There's lots of 'more gain' mods you could do on the lead channel. For voicing, try a 1M pot in place of the 470k that's in parallel with the 2n2 in the peaker after the first stage. On the lead channel, could also try a pot in place of the fixed treble control on the pseudo tone stack mesa have in there for a bit of voicing and gain control.
There's enough gain in their already tbh, at least for what I like to play. The voicing is also generally fine too and there's a Marshall style tone stack and a graphic EQ to shape it more.

I found the mention of the pot in place of the fixed treble control interesting though, that would be the 2x100k resistors here? Or the 750k?

Screenshot 2024-11-18 102945.png
The 750k and gain pot form a voltage divider. For a treble pot replace the 2x100k and 1x15k pot with a 250k pot.

Change the next 15k resistor for a 250k bass pot and the 62k resistor for a 25k Mid pot and voila, you have a typical Fender tonestack
Yeah its a fixed thing pushing the upper mids. Downstream from there is your typical Marshall stack, albeit with the Mesa 82k slope resistor.

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Re: Spare hole, what mod?

Post by murky »

Bravo! Always hated that parallel loop!

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Re: Spare hole, what mod?

Post by Bg »

StrummersOfThunder wrote: Mon Nov 18, 2024 9:11 am Somewhere to sheath your conductors baton ?
Is that a euphemism?
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