Amp mods

Pre Recto days. Boogie modified Fenders, Mark I-IV, Dual Calibers, etc

Moderators: Guitarzan, Grandor, ned, Platypus

Do you mod your amp?

Yes
21
72%
No
8
28%
 
Total votes: 29

edmiller9999
Mark I
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Amp mods

Post by edmiller9999 » Tue Dec 14, 2010 11:48 am

It seems like there's a lot of discussion here on amp modifications. I, personally, have a Mk IV and would never, ever consider modifying it. However, I'm interested to see how many of you have done so.

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screamingdaisy
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Re: Amp mods

Post by screamingdaisy » Tue Dec 14, 2010 12:47 pm

For me, the trick has always been to figure out how Mesa actually intended the amp to be used as I find that once you have that figured out it opens up a lot of possibilities.
Ignore the hype and trust your ears. Play more, buy less = better tone.

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crguti
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Re: Amp mods

Post by crguti » Tue Dec 14, 2010 3:39 pm

I did simple mods to my DC-5. Now it's the perfect amp.

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SonicProvocateur
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Re: Amp mods

Post by SonicProvocateur » Tue Dec 14, 2010 4:19 pm

Mark III -> R2 volume mod, must have for total balance.

Anything else seems very to taste. I could live without the +mod, presence mod, bias mod, or the odd and end resistor mod for changing voicings.

I would never however switch out my lovely tranny for a Mercury. Seems like blasphemy.
1994 Mark III Blue Stripe 60 watt, R2 vol mod
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mreeve25
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Re: Amp mods

Post by mreeve25 » Tue Dec 14, 2010 6:05 pm

SonicProvocateur wrote:

"my lovely tranny"
:lol:

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SonicProvocateur
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Re: Amp mods

Post by SonicProvocateur » Tue Dec 14, 2010 6:15 pm

:lol:

We came in lulz for all mankind!
1994 Mark III Blue Stripe 60 watt, R2 vol mod
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zodiac272
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Re: Amp mods

Post by zodiac272 » Tue Dec 14, 2010 10:52 pm

if moding a IIC to a IIC+ counts, then yes count me in

scott
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Mark IIC+ HRG
Mesa 2:90
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chipaudette
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Re: Amp mods

Post by chipaudette » Wed Dec 15, 2010 7:15 am

I've got a IIC that was upgraded to a IIC+ by MikeB at Mesa. It's got a 60/100 watt combo with GEQ and reverb. I use both the combo speaker and a Thiele cab that I have.

After playing with it for a while I found that it didn't have quite enough sizzle for my taste. Therefore, I made a (easily reversible) modification to the amp that added a switch in the back (I used the hole for the slave out jack). The switch cuts on the 1000pF capacitor that jumps across the plate resistor of the last lead channel gain stage. The cap here is one of the main circuit differences between the IIC+, the III, and the IV. Using a 3-position switch, I've got all three values, which is 1000pF, none, and 500pF, respectively. I find that I use the 1000pF most of the time, the "none" setting rarely, and the 500pF a decent amount of time. To anyone but me, it's a fairly subtle mod. To my ears, though, it makes a decent difference and it's a fun mod to have. The extra bite and sizzle really helps put me in a metal mood.

The other (easily reversible) mod that I did to my amp was to swap out the mid pot for a mod pot from a Mark III...in other words, one that is pull switchable. When I pull the pot, I can have another function. I've chosen to do a mod that alludes to the IIC++ mod, which is to add a cathode cap onto the tube stage at the mix point between the clean channel signal path and the lead channel signal path. When engaged, it can add some serious compression and fizz to the sound, if that's what you're feeling like. After the novelty of it wore off, though, I hardly ever use it...it is just too mushy. If I used the pull-switch to activate some relays or LDRs, maybe I could bring in and out more elements into the circuit, but as it stands, I wouldn't do this mod again. I'll probably undo it the next time I'm in the amp (which is rare these days).

Those are the mods that I've done. Anyone else got some good ones?

Chip

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gonzo
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Re: Amp mods

Post by gonzo » Fri Dec 17, 2010 10:20 am

i changed out the caps on BASS control, took out .047 cap, put in .022.
tightened up the bass control nicely, still never take it over 2, but before that, it sat on zero.



next mod: tweak values on the phase invertor section.

chipaudette
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Re: Amp mods

Post by chipaudette » Fri Dec 17, 2010 10:50 am

[quote="gonzo"]i changed out the caps on BASS control, took out .047 cap, put in .022.
tightened up the bass control nicely, still never take it over 2, but before that, it sat on zero.

Is this on your Mark 2B? Does the 2B have the "Pull Shift" on the bass? If not, I can totally understand swapping the bass cap. If you do have the pull shift, then I'm a little surprised that you feel that you have too much bass. With my bass pot pushed in, I often find it a touch too thin...especially on the clean channel. Every guitar and amp is different, so you (of course) know what sounds best to you...I'm just surprised.

Cool. I like it when people are bold enough to mod their amps to suit their own taste. More people should take control of their hardware that way...as long as they don't electrocute themselves in the process.

:)

Chip

tonejam
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Re: Amp mods

Post by tonejam » Fri Dec 17, 2010 10:44 pm

I've replaced the reverb tank in my Studio 22+ with a full size one. I use a 12AY7 tube in V1, which helps balance volume when switching to overdrive. I've had a mod (kit from Londonpower) which provides a master volume control, reducing the voltage on the output tubes(among other things). This is a GREAT mod when used subtly, makes the amp better for coffee shop volume levels. Lastly, I've replaced the speaker with a Weber alnico Blue Dog.
The amp now does everything I want. Would NEVER sell it!

Monsta-Tone
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Re: Amp mods

Post by Monsta-Tone » Sat Dec 18, 2010 12:10 pm

:lol: Guess everybody knows my stance, but I'll take a shot anyway! :lol:

Not all of us can afford a IIC+.
I found a way to take the average Mesa entry level amp, like the DC or the Studio or Caliber, etc. and turn them into the fire breathing monsters that their big brothers are. Simple as that.

If you have an amp that you love the clean tone on and wish the lead tone was better (or vice-versa), and if you are tired of changing amps constantly looking for what ever tone you are after, then it makes more sense to mod the amp you have. I don't like making extra holes and de-valuing the amp's future resale though. Although, my Heartbreaker has a couple of extra holes up front! :mrgreen:


As for transformers, well, it's a matter of personal taste. I have found personally, that Mesa tends to under size their output transformers because of the amount of coil saturation that occurs when the amp is used. I personally do not like this form of distortion. If you have an amp that you are satisfied with, it does not make sense to change the OT. Changing the OT on my Maverick is about the only mod that I have done to the lead channel and it basically made the amp come to life. I felt that the lead tone was incredibly lacking before. Now it really sings.
Elvis said.......
Amp techs do get shocked. :shock:

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dangit
Mark I
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Re: Amp mods

Post by dangit » Sun Jan 16, 2011 1:47 pm

yes

i had a tech install ftswitchability for effects loop on bot my studio .22+ combos so i can switch the loop in/out
i used to love that-haven't used it in a long time

i put alnico blue dog in one of the .22's
nice
although the stock mesa spkr was fine

also had a tech put the ftswitch drive mod in my lss
cool
Dangit!

LSS 1X12 W Drive Footswitch Mod; Reeder Mod #1
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scottcrud
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Re: Amp mods

Post by scottcrud » Sun Jan 16, 2011 9:45 pm

Both my .50 Caliber +'s have had one or both transformers replaced. One with a true 50 watt Mercury Magnetic output transformer.
I took the other one to Kendrick Amps back in 98 and had Gerald install 100 watt output and power transformer, as well as 2 6550's instead of 2 6L6's.
1990 .50 Cal+ highly modded "Frankenstein" Long Head
1988 .50 Cal+ Andy "Monstatone" Turner modded Long Head
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littlephil
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Re: Amp mods

Post by littlephil » Mon Jan 17, 2011 12:48 am

I'd never mod my IV. It sounds perfect as it is anyway :D

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