Should a 77 Mk I be recapped?

[jakeddy]

I know this is common to do to other "vintage" amps. How about Boogies?

 

[RussB]

I would.

Caps are good for 15 years or so...after that, you're running on borrowed time.

 

[Boogiebabies]

Right on the money. I would start by taking a look at them and looking for leakage or bulging. Boogie caps drain to ground pretty quick so they last very long, but it is often risky after such a long period. I also look for attack response and low end frequency loss (MUSH). They can also start to produce a bad hum when they are on there way out. After that they can leak or just plain over heat and explode. I have seen this. It looks like an AK47 taking out a pumkin. Carbon and guts all over.

I would send it to Russ.


Take a look here an you will see the before and after power cap job.
Notice the neat soldering with flux and the blue silicone and how it is perfectly applied.


http://www.acplink.com/chassis/display.aspx?curpage=165

 

[jakeddy]

Who's Russ?

 

[RussB]

I don't think that "Russ" guy is into shipping amps around the country, though :wink:

 

[Boogiebabies]

Sorry, Russ is out of business.

 

[jakeddy]

Oh, hello Russ. :lol: :?

 

[MarkPurney]

If the amp is used regularly, but not heavily, then you should probably get away with changing them every 15 years. Filter caps can actually go bad more quickly if the amp hasn't been used for a long time.

If you do it yourself, be safe and bleed off any residual voltages which might exist.

 

[jakeddy]

Well now it's off to see Mike B at Boogie for a recap and any tweeks he can do to make it sweeter. As he is doing them, I don't see them as mods or detracting from it's value. Do you?

 

[Tuna141]

IMO, a cap job will not decrease the value - it is preventative maintenance on a 20 year old amp.

Also, IMO, having the legendary Mark series guru Mike B. tweek an amp, should not decrease the value (possibly increase the value if anything). The exception to this would be some serious or custom/personalized modding.

 

[jakeddy]

Would it be appropriate to say "great minds think alike"? :wink:

Having Mike B tweek the amp really isn't a mod, he's Boogie's master amp tech. I'd still consider the amp to be "stock". He is going to pull the PC's and install the caps with the leads under the board, the same method as in 77.

To me, a plus to the value.

 

[RussB]

What Mods are you considering?

What weaknesses in the amp are you trying to fix?

 

[jakeddy]

The pull gain tones are farty and the reverb is lacking. On the subject of reverbs, Mike B told me to check the springs in the tank, as time goes by the old ones have some foam in them that falls apart and gets in the springs (makes them dead) and mine is that way. I'll have to get the model number of the tank and see if I can get a new one. I might just put new springs in but a tank switch would only cost about $20.00.

Can you substitute a 3 spring tank for a 2 spring used on these older amps?

 

[908ssp]

I replaced a two spring accutronics reverb tank for a three spring accutronics and it worked fine. But there is a bunch of different tanks so I don't know if they are all compatible or do you have to stay in some small group. I might just give it a try. I'll let you know what I find.

 

[Boogiewan Kenobi]

I have a '77 Mark I and I sent it to Mike B for a once over and he didn't need to touch a thing CAP wise. If they are fine, I leave well enough alone. If you love the tone of it, why mess with it? If you are getting crackles, hums then go for it, won't hurt the value a bit.

BWK