MKIII recap anyone?

[Helping Friendly]

I just ordered some new F&T caps tonight for the filter section and coupling section.  It's the 4 x 220uf and 3 x 30uf caps in the MK III.  Has anyone recapped their boogies recently?  If so did you notice a difference?  I couldn't help to think it was time since the ones in my purple stripe are pushing 30 years! I will report back after I install them if your interested. Would love to hear your experiences as well.

[Walker done done]

I just ordered some new F&T caps tonight for the filter section and coupling section.  It's the 4 x 220uf and 3 x 30uf caps in the MK III.  Has anyone recapped their boogies recently?  If so did you notice a difference?  I couldn't help to think it was time since the ones in my purple stripe are pushing 30 years! I will report back after I install them if your interested. Would love to hear your experiences as well.

I haven't but also have a purple stripe so would be very interested to hear about your findings. Thanks for the thread!

[Heady Jam Fan]

I brought my Red Stripe to my local tech about 2 years ago and he said it didn't need a recap. Though he tends to leave caps even if they are past the 10 year mark as long as they measure fine, aren't visually bad, and the amp sounds good. More recently, I brought him my Silverface Deluxe Reverb and he said the same thing - the caps were fine. The caps on the SFDR were also original - from 1974!. I had ended up doing a cap job to it.

Replacing the filter caps gave the amp more bite, punch and volume at the cost of some smoothness. I also replaced the cathode bias caps that improved the tone a bit too - it sounded a bit harsher at first as well, but, either other adjustments I did, or some 'burn-in' smoothed the amp out a bit again. I also replaced the bias cap and tried a couple different values (didn't really notice a difference in feel).

It definitely made a difference, but its 6 and 1/2 dozen if it was "better." I also blackfaced my DR which made an incredible difference - much tighter bass, more 'air' and midrange, less headroom.

I expect a recap on a Mesa would have a similar effect. My Mark III is extremely punchy, but I think it's lost a little bit of headroom compared to what it would have with new caps. I've seen people argue that a good cap, if used regularly, will be more reliable than a new cap. I've heard other arguments that its like an oil change - switch your caps before they blow and ruin other parts of your amp. It seems kinda financially based in my experience - TGPer's consistently suggest getting a cap job every 10 years, while my local tech said very few people want to pay to replace caps that are working.

[Helping Friendly]

Yea I've heard mixed opinions on cap changing.  My tech is old school and said I didn't need it. But some people on the boogie forum said a recap had great improvements on their tone. My caps have no visible leaking and the amp is pretty quiet but not dead quiet. So it will be interesting to see what the outcome will be. I do consider myself to have a great ear for subtle differences so I will report back when I'm finished.  I just ordered them tonight so expect a follow up in about a week or so
Thanks for the reply's

[IamWILSON]

Obviously, if you are planning on changing them yourself, you are educated in the dangers of tooling around inside your amp?  Serious voltage in those caps you're changing, so please take all precautions in properly draining the old ones and measuring to make sure there is no voltage running through them. 

From what I've heard, you may not hear much a difference if your current caps are measuring out fine.  I think the only reason most people hear a difference is because their caps did need replacing.  If you tech advises that they are fine, I'd just go with that.  And it's good to know that you do have a tech who is not in the business to just take advantage of you. 

[Heady Jam Fan]

Obviously, if you are planning on changing them yourself, you are educated in the dangers of tooling around inside your amp?  Serious voltage in those caps you're changing, so please take all precautions in properly draining the old ones and measuring to make sure there is no voltage running through them.  

From what I've heard, you may not hear much a difference if your current caps are measuring out fine.  I think the only reason most people hear a difference is because their caps did need replacing.  If you tech advises that they are fine, I'd just go with that.  And it's good to know that you do have a tech who is not in the business to just take advantage of you.  

Good points.

BillM has a video about draining caps before you even take the chassis out of the amp. I've never tested this approach with a multimeter, but I've used it and followed up with the more common approach (grounding to the chassis using something with some resistance).

Re, changes in the amp's sound... Even though my tech - who is a well-regarded amp builder - found my caps were within spec, it made a big difference in tone and feel on my DR. In my limited understanding, there are a two caveats to your point.

First, what is spec? I don't know about newer caps, but IIRC the old caps have a +/- 20% tolerance. That means a 20pf cap (using that number cuz its nice and round) will be "within spec'" if it measures anywhere from 16-24pf. Across 5 filter caps, that variability can make a difference.

Second, my understanding is that you can only do limited testing on a cap that is installed in an amp. So looking at the cap, listening to the amp and some limited measurements regarding whether it is functioning within spec will give you a good, but not 100%, idea whether they should be changed. On one hand, if the cap looks fine and the amp sounds fine, a lot of people would say not to worry (I probably agree). However, if you are worried enough to remove the cap from the amp and test it, your probably worried enough to replace it prophylactically. The problem here is that you might be throwing away a 'tried and true' cap for one that could be a lemon right out of the factory.

In the end, you won't know unless you do it. Just depends if its worth the price / effort. And like I said above, some people like the sound of the old caps, so its 6 and a half dozen whether a cap job is 'good' even if it does change the tone and feel.

Also, this kind of tech work leads you down a rabbit hole. If you do the filter caps, why not the bias cap? Then why not the cathode bias caps? Oh yeah, and those plate resistors are best when fresh, and don't forget about switching those 1w carbon comp voltage divider resistors to 2w heavy-duty, flame-proof, metal-oxide resistor for voltage dropping. Then you end up rebuilding an amp that was pretty much functioning correctly.

[Helping Friendly]

Caps should arrive Thursday! And yes I have great understanding and experience in tube amps. The caps are already drained as we speak and the boogie is ready for the freshies. I do plan on carefully de soldering the old caps in case the new caps sound worse. I don't think they will but if that's the case the originals will go back in and I will just eat the $50 I spent on the 7 F&T's. Stay tuned...

[Helping Friendly]

Ok well after recap I regret to say there is no difference.  I guess the old caps were good after all. Oh well. Peace of mind

[Buffered]

Ok well after recap I regret to say there is no difference.  I guess the old caps were good after all. Oh well. Peace of mind

And we're glad glad glad that you're alive!

[express50express]

Unless they show physical signs, do not replace. Mesa caps are high quality, and can outlast most amps. Mine are the original and show zero signs of failure. If you are that nervous replace every part in the chassis