Mesa Mark III Cap Job

Shask

Well-known member
I am going to copy this from Harmony Central, since I know there are some Mark III fans here....



I finally decided I should do it.

I got the SED tubes last month. It helped, but the amp still seemed a little flat.

I got 7 new F&T caps today, and just got done replacing them. I still have a few small ones to order and install, but these probably did 98% of the change.

I can honestly say this amp is WAAAYY better. I still don't know if it is my favorite, and I cant say wouldn't sell it, but it is definitely much better. More bass, more gain, way more punch overall, and way less noise/ground hum.

Well worth $50 :thumbsup:

I'd advise people to look into replacing theirs if it hasn't been done. Mine is a red stripe, so half the caps had a date code of 1986, and half 1987.
 

Shask

Well-known member
No clips. I have been playing it all day :LOL: :LOL:

Yeah, I just bought the caps and did it. I would say even if you need a tech though, it would be a wise investment if yours is stock. I am pretty surprised at how much better it is. I was hoping to decrease noise/ground hum, but it really sounds much better overall.
 

blackba

Well-known member
I noticed a good change in my '66 Fender Champ when I changed the electrolytic caps.

I have thought about changing the caps in my Marshall 2553 or 1990 Mark IV, but both amps sound good, so not sure its worth it yet.

Did any of the caps in your mark III look bulged or bad?
 

Shask

Well-known member
blackba":1weowrr7 said:
I noticed a good change in my '66 Fender Champ when I changed the electrolytic caps.

I have thought about changing the caps in my Marshall 2553 or 1990 Mark IV, but both amps sound good, so not sure its worth it yet.

Did any of the caps in your mark III look bulged or bad?
No, they look fine. I still have them laying on my desk, and you would never notice an issue.

I did this mostly because I was really starting to get a lot of noise and ground hum. Way more than my other amps. I am surprised how much the tone improved. And, back to normal levels of ground hum :thumbsup:
 

Shask

Well-known member
blackba":nm7sgqtw said:
I noticed a good change in my '66 Fender Champ when I changed the electrolytic caps.

I have thought about changing the caps in my Marshall 2553 or 1990 Mark IV, but both amps sound good, so not sure its worth it yet.

Did any of the caps in your mark III look bulged or bad?
Oh, and I am not sure about the Mark IV. This has me looking at my 5150, and it is 1991-1992 (Block Logo). I know its about that 20 year mark, but I don't notice flat tone, no dynamics, or lots of extra noise, so I cant really find a reason to make me want to change them.
 

jhale667

New member
I want to give my MK III an overhaul too...it's an '86 red-stripe, tubes get changed regularly, but it's well overdue for a 100,000 mile tune up. ;) I'm not comfortable messing with wiring in amps, so I'm either going to take it to Mesa Hollywood or just straight back to the factory to have it "freshened up". Might have them do the Rhythm Channel Master Volume mod to it while it's there.
 

droptrd

Active member
I have an 86 purple stripe. Ive been thinking about this as well. Its getting like you said, "flat" sounding and loosing touch sensititivty some what even with tube changes. I have an early 5150 sig head thats really noisy. I get this weird transistor radio tuning sound behind notes. The board say 91 on it but I dont think thats right. Are the F&T caps the better ones to get?

Thinkin Im gonna try it myself. Just drain the caps with a 10K-50K resistor and swap em out right?
 

stephen sawall

Well-known member
Changing the caps is a lot like changing the oil in your car. You do not want to wait till there is a problem before it is changed. If they leak or are weak they can sound OK but straining other parts of the amp. The change is so slow you may not hear it. All of this can cause more damage to the amp. Think of it more of making sure you do not have more problems than improving sound. It does not matter how much the amp is used. They just have a shelf life.

The recommend age is 10 years.
 

droptrd

Active member
stephen sawall":248i4pbd said:
Changing the caps is a lot like changing the oil in your car. You do not want to wait till there is a problem before it is changed. If they leak or are weak they can sound OK but straining other parts of the amp. The change is so slow you may not hear it. All of this can cause more damage to the amp. Think of it more of making sure you do not have more problems than improving sound. It does not matter how much the amp is used. They just have a shelf life.

The recommend age is 10 years.
Thats the push i needed. Now im debating if I should try it myself or take it to a tech....
 

Shask

Well-known member
droptrd":2urlq4il said:
I have an 86 purple stripe. Ive been thinking about this as well. Its getting like you said, "flat" sounding and loosing touch sensititivty some what even with tube changes. I have an early 5150 sig head thats really noisy. I get this weird transistor radio tuning sound behind notes. The board say 91 on it but I dont think thats right. Are the F&T caps the better ones to get?

Thinkin Im gonna try it myself. Just drain the caps with a 10K-50K resistor and swap em out right?
Most people recommend F&T or Sprague.

My 5150 is dead quiet. I almost feel bad for thinking about selling it, lol. It is an old block logo. The original idea was to sell the Mark III or 5150, but it is soooo hard to decide! lol. I also have my Triple Recto sitting in between them...

Honestly, I would probably try to order the 5150 caps from Peavey. They are some weird short-fat caps that sit in the PCB. I don't know how hard it would be to find a direct replacement. Mesa just uses standard Axial caps that lay on the PCB's.

As far as you changing them, it is hard to say. Depends on how good you are at soldering. They can be tricky because Mesa uses double sided plated through PCB's, so there are some locations you are soldering, where you cant see half of what you are soldering. You DONT want to remove the PCB. It would be a huge pain. You would HAVE to remove the PCB in a 5150.

I actually have a few more small ones I need to order...
 

Shask

Well-known member
Oh, and for a 5150 (And probably many amps), you definitely need a ritual. I clean every jack with a cord dunked in rubbing alcohol. EVERY jack, even those weird ones on he back you never use, because they will do funny things.

I also do this will all the tube sockets, except I dunk a tube in rubbing alcohol, and plug a tube in and out a few times.

I also open it, and plug/unplug all the ribbon cables a few times, and clean all the pots.

I have had mine for about 9 years now, and it is definitely one of the better ones I have heard. It used to sound like a seashore in the background, but giving it a good cleaning made almost all of it go away. Come to think of it, I haven't done this in a few years, and it is still dead quiet. Even quieter than my Mesas.

You might try that before you go crazy with cap changes.
 

droptrd

Active member
Shask":3ak1dlnt said:
Oh, and for a 5150 (And probably many amps), you definitely need a ritual. I clean every jack with a cord dunked in rubbing alcohol. EVERY jack, even those weird ones on he back you never use, because they will do funny things.

I also do this will all the tube sockets, except I dunk a tube in rubbing alcohol, and plug a tube in and out a few times.

I also open it, and plug/unplug all the ribbon cables a few times, and clean all the pots.

I have had mine for about 9 years now, and it is definitely one of the better ones I have heard. It used to sound like a seashore in the background, but giving it a good cleaning made almost all of it go away. Come to think of it, I haven't done this in a few years, and it is still dead quiet. Even quieter than my Mesas.

You might try that before you go crazy with cap changes.
Cool man. Thanks for the info. I think Ill start with a cleaning on the 5150 and go from there. :rock:
 

droptrd

Active member
Just recaped my Mark III. F&T caps from tube depot. I also gave the amp a full cleaning. It really did improve the tone and performance of the amp. Brought alot of mids out of the amp. So i have a bit of tweaking ahead of me now. Im glad I did it. $55 in caps and about 20-30 min to swap them in after I drained the old caps to zero.

after I was done and played around with it for a while, I started swaping V1 tubes. Went from JJ to TS to ruby then to a mullard RI. Ive never liked the mullards in any amp ive had but they scream in the Mark III. Added tons of gain. I love it.

So all in all it was a good tone day. New caps and a different V1 really did breathe new life into my amp. :rock:
 

jlbaxe

Active member
I took my '86 Mk III to an amp tech a few years ago for the reverb not working and he went over the amp and replaced a lot of caps and stuff. Sounded great then I just re-tubed it a few months ago and WOW even better sounding now. :thumbsup:
 

droptrd

Active member
my purple stripe said 3-86 on the chasis. It was probably due. My noisey 5150 is next. It sounds great but its very noisy and it was the transistor radio sound faintly behind the notes. cant hear it with chords but you can with single notes.
 

stephen sawall

Well-known member
droptrd":1e14rkkl said:
Just recaped my Mark III. F&T caps from tube depot. I also gave the amp a full cleaning. It really did improve the tone and performance of the amp. Brought alot of mids out of the amp. So i have a bit of tweaking ahead of me now. Im glad I did it. $55 in caps and about 20-30 min to swap them in after I drained the old caps to zero.

after I was done and played around with it for a while, I started swaping V1 tubes. Went from JJ to TS to ruby then to a mullard RI. Ive never liked the mullards in any amp ive had but they scream in the Mark III. Added tons of gain. I love it.

So all in all it was a good tone day. New caps and a different V1 really did breathe new life into my amp. :rock:

Did it effect the punch and feel ?
 

peterc52

Well-known member
Have anyone changed caps in a Mk IV? If so could they make at little how to-guide? I know how to solder, and want to see if I can change them myself.
:)
 

Shask

Well-known member
droptrd":2kp3wss1 said:
Just recaped my Mark III. F&T caps from tube depot. I also gave the amp a full cleaning. It really did improve the tone and performance of the amp. Brought alot of mids out of the amp. So i have a bit of tweaking ahead of me now. Im glad I did it. $55 in caps and about 20-30 min to swap them in after I drained the old caps to zero.

after I was done and played around with it for a while, I started swaping V1 tubes. Went from JJ to TS to ruby then to a mullard RI. Ive never liked the mullards in any amp ive had but they scream in the Mark III. Added tons of gain. I love it.

So all in all it was a good tone day. New caps and a different V1 really did breathe new life into my amp. :rock:
:thumbsup:

I still need to order and replace a few of the small electrolytic caps on the board.

I still think the amp is way better than it was. I have a few C9's and a few JJ's in mine. Nothing awesome but I put a new one in there and swapped around and didn't notice a difference, so I left what was in there, in there. It is definitely the best it has been in the last 5 years I have owned it.

I am still comparing all my amps a lot, lol. I am still not 100% on keeping it. I can get similar tones out of the orange channel on my Recto. but either way, it is still an awesome amp.
 
Top