Mark III, IV caps NEVER need to be replaced???

[Mark Fore]

Hey all, I just went to the Mesa store in Hollywood the other day and asked about a recap for a pristine, very early first run Mark IVA. The guy replied and then checked with the resident expert in back to confirm:

"Anything post Mark IIC+ was after Mesa switched the the type of caps used in their amps and so anything after Mark IIC+'s (Mark III, IV's etc.) DON'T EVER need to be recapped." He said all I needed to do was to replace the tubes.(????)

This is the first time I had ever heard this so I'm posting it here to see if anyone else had heard this. Of course, I would like it to be true, but if caps are being replaced on everything under the sun from what is posted here, thee are a lot of unneeded cap jobs being done.

 

[boogiemon]

...pretty sure that's inaccurate

MB replaced some caps in my MIII just recently

 

[Podicle]

Last time I had my red stripe Mark III (circa 1986) at the tech, who is one of the most respected amp builders and repairers in Australia, I asked him to do a recap while it was in, even though the caps looked fine. He essentially laughed me off and dismissed it as a fad. I directed him to various posts on this forum, and he pointed out that in almost every case the amp had had a re-tube/bias or some other mod done, which almost certainly accounted for any difference in tone.

I have no first-hand experience of cap replacement, but can just pass on the experience of someone who builds high-end amps as his day job.

btw, my amp sounds absolutely fine.

 

[zebpedersen]

Very interesting indeed.

A friend of mine took his IVa - one of the very first in the UK - to a tech a couple of years ago for a "make-it-sound-new-again" 15-20 year service/tune up and while he changed tubes, pots and parts in the switching mechanism, the caps were unchanged.

 

[droptrd]

My local amp guru Dave Lancaster of Lancaster Amplification recommends a cap change every 10 years.

http://www.detailaudio.com/dave.html

Its funny how there are some many different opinions on the matter.

 

[MrMarkIII]

Some guys, including very knowledgeable and reputable amp gurus on this very forum, subscribe to the "10 year cap change whether it needs it or not" school of thought.
Then there's this guy, Bendinelli is his name I think, who won't replace caps unless they really are shot.
It's kind of a "preventative medicine" approach versus a "If it ain't broke, don't fix it" philosophy.
You pays your money, you takes your chances.

 

[JOEY B.]

You pays your money, you takes your chances.

Mike has never tried to sell me something that I didn't need, even when he could have. This includes capacitors, Mark III+ mod, etc.......... 8) I can't say enough GOOD things about Mike and Susan and their business practices. Top Notch.

 

[FJA Mods]

When a cap shorts and takes the power transformer or choke out with it you won't think him not changing the caps was doing you much of a favor. Electrolytic caps have a life expectency for a reason. It's not something any tech made up, the manufacturer does. 10-15 years is the time to start considering it. There is no way anyone can predict an exact failure date. Every cap that failed today was working yesterday. All electrolytic caps will fail at some point. I have never re-capped and amp and had the owner tell me it sounded worse, in fact they always notice an improvement.
Jerry

 

[swbo101]

Are there any warning signs for caps going bad or do they just go out in a blaze of glory? Just wondering.

 

[aaronlyon]

Are there any warning signs for caps going bad or do they just go out in a blaze of glory? Just wondering.

Some obvious signs: ends are bulging, goo is dripping out, corrosion is evident. Smoke...

 

[Restless Rocks]

Okay sooooo.... who has ever seen first hand a FAILED cap in a MkIII or IV?


Anybody?











Anybody?



















Me neither!!!

 

[swbo101]

I'm bringing my Mark IV in to a tech b/c it started smoking recently.... and I had some volume drops right before. When I do..I'll let you know if it was the caps burning or a screen resistor.

 

[Mark Fore]

A couple years ago, I sent in my '97 Mark IV to Mesa to have it serviced after reading on this forum that a 10 year checkup/cap job is a must-have. They sent it back without doing anything to it (they did check it first before arriving at that conclusion).

So to answer the question, has anyone ever had bad caps on a Mark IV, for me the answer is no. And the debate rages on.

 

[MrMarkIII]

Let's ask more questions:
Who has had a cap change, and what were the results?
1. How old is the amp?
2. What exactly was replaced? Electrolytics? Filters? Other components?
3. What are the tonal improvements?
Enquiring minds want to know!

 

[droptrd]

Let's ask more questions:
Who has had a cap change, and what were the results?
1. How old is the amp?
2. What exactly was replaced? Electrolytics? Filters? Other components?
3. What are the tonal improvements?
Enquiring minds want to know!

86' purple stripe

replaced the filter caps only

clean tone improved. improved feel of entire amp. brought out highs and mids = clarity and chord def. extended lowend but tighter in feel. and all amp noise and hiss is COMPLETELY gone. nothing but guitar hum now. even with the gain cranked. Single notes sound full and strong with no weird sounds behind them.


The amp was getting wet towel syndrone even with new tubes. It was just getting flat and dull.

Replaced the filter caps. $55 well spent

 

[Mark Fore]

I just talked to Val King of King Amplification, the leading amp guy in the area and asked him this question as well as told him what the Mesa Hollywood rep told me last week. He said, "if it is electrolitic, then it has 7-12 years of life in them." He also said something that made sense, "Have you ever seen a NOS cap for sale?" :lol:

So... one more vote for replacing caps after a period of time from a qualified tech.

 

[wnstardis]

The only caps that need replacing would be power supply filter caps.
These are not part of the tone shaping circuits, but filter out the 60 cycle from the DC power rail. They will, however give some indication that they are getting "leaky". There will be an overall hum, even with nothing plugged into the input jack.

Amps which have been in long term storage are the ones that fail most frequently. One can "re-form" the cap by powering the amp with a variac and slowly raising the voltage until it reaches nominal AC line value.

 

[okgb]

i Agree , that as the power supply [ ripple smoothening filter ]
if the caps are going you'd think the amp [ and you ] would experience
more hum as a symptom .
I have an early mkIII that i hadn't played much for a few years and when
i dug it out didn't sound like i remember [ in fact pretty crappy ]
But i can't afford to send it back if it's just placibo

 

[herrball]

Here goes another cap question....

In the recent issue of Recording Magazine, Larry Carlton mentions his loss of tone inhis original boogies and MB having to do a re-cap. The new amps coming out didn't have the mojo of his original boogies and he didn't want to have to deal with re-caps. This , and the incredible sound of a Dumble is what drove him to change. So the question is....

Is the cap replacement unique to a few tube amp manufacturers or is it across the board over time? Does the fact that Dumble encases his amps innards with an epoxy goop to hide the circuitry prevent the caps from drying out?
My MKIII Blue stripe has not been recapped and I'm questioning getting another amp. ( Fuchs or Ceriatone). I love the amp but already have a DC5 for high gain sounds. I love the sound of my MKIII but am considering the long-term cost of ownership if caps are part of the deal every ten years.

Just looking for some technical thoughts since I'm a non-technical guy.

Thanks guys.

 

[okgb]

But Caps don't necessarily need to be changed just because they are old
I recently spent 50.00 on psu caps for my no strip mkIII and
if anything it tightened up the sound where i was happier for it
to be " looser " in feel . It didn't really have much hum , which is
a tell tale sign of caps starting to not do their job .
So if you don't care or it doesn't matter moneywise change em
but think of it more as maintenance