Mark 2b recap?

[Whitey]

Hi,
4 weeks ago I bought a 2b (childhood dream).
What I would like to do is to send it to Mike B. for a recap job. The problem is that I come from Germany and its to expensive to send it to Mesa.
What I don´t like: The sound is very compressed; with high gain the attack is louder than the tone itself. Is this a sign, to recap although the amp is very quiet? The amp was at the local repairman for service and all the tubes are new.
I´ve read often in this forum, that the 220 u caps are not the best quality. Also I often read that some of the resistors could go out of range. Who can tell me who are the typical suspect rs and cs?
Another person wrote there is no need to replace the cathode bypass-cs (22u, 25V) if they are younger than 40 years. Can you confirm this?
I wrote to Mesa an asked for the email of Mike B. No way.
I would be VERRY happy if you could help me in some way.
Thanks and excuse my bad english.
Whitey

 

[tonejam]

Can't help you, Whitey, but just want to say your English is extremely good!

 

[Whitey]

thanx

 

[daviedog]

Cathode bypass cap value affects the bass response of the tube circuit.
It's a popular mod but the 25mf has a 50year track record of good tone. Since the values Al electrolytic drift rapidly, the 40year statement you read is bogus. Check every 4years. Same for filter caps! I have been using F&Ts. German, good quality. Competitively priced.
Not sure about compressed / pick attack? How many Mesas' have you played? The versatility of mesa amps does add to the time of dialing in YOUR tone. Most people on this forum wouldn't have it any other way.
Welcome..

 

[McBarry]

I don't agree with the 40year suggestion.

Given it will be nigh on impossible to know exactly how much use it's had, and even then, I subscribe to the notion of replacing electro's every few decades (loosely speaking), if it were mine I'd be replacing the PSU caps, the bias caps, and yes, the cathode bypass caps at a MINIMUM.

Regarding resistors going off value, check those on the high voltage rails at a minimum.

You are lucky that a member here called MkIIBoogie is not far from you and can hopefully assist. But also hopefully your local repairman is familiar with valve amps and performs quality work?? If you were really lucky, he might be Gundolf Roy who made the Kitty Hawk amps in the 80's... hehe.. LOL

Personally, I only use F&T in my amps. Sprague are silly expensive Down Under, and I'm not gonna risk trying other brands. A possible exception is the nice beefy RIFA 100uf elecro's I've used in Fender bias supplies. Nice, well built and sturdy caps.

Hope this helps,
Dave

 

[Whitey]

Thanx for your statements.
I owned a mark 2c for more than 25 years, played 2 other 2bs in musicshops. I also tried to build a mark 2b preamp by myself (had an education for radio and tvs in the late 80s). I killed my 2c by soldering to much. This is why I will not touch any solderingpoint in my 2b!
I never like the clean sound of the 2c. Im much happyer withe the clean-tone of my 2b.
And now I have got a date, 2nd mai at a local repairman (he wrote on his homepage "boogie repair"). He told me on the phone (extremly friendly guy) that he repairs boogie since more than 25 years....and he uses F&T caps. I will report.
One question to McBarry: I could not find the user MKIIBoogie?
Whitey

 

[McBarry]

G'Day Whitey,
search mark2boogie..
Dave

 

[Whitey]

Hi to everyone!
Report:
First of all....now I am happy with my amp.
When he took the amp on the table, he switched it on without an instrument, just to listen to the noise. ..verry quiet.
When he opened it, he checked every electrolyt-c. All in verry good condition. There was no need to replace any filtercap.
Then he checked most of the resistors...all ok. He noticed, that there was some contact problems at the powertubes. He changed 2 cs: 0.1 uF Bass and 0,047 Middle and the V1. He took a chinese one. Also he checked every tube. He touched the powertubes to see if they have got all the same temperature.
That was all. I was impressed.
Thanx to Roger!

 

[McBarry]

Not to disagree with your tech, and it also must be said that two different folks will have 2 different opinions..

I replace said caps based on age alone.
I know there's stories about lifetime use, and only replace if bulging, replace if tone is off, replace if voltages aren't "right" etc etc etc. blah blah,.....

Best case is U keep them, lose a bit of tone, and all's well.
Worst case is caps dry up, fail, and range from exploding or shorting and conducting obscene voltages around the chassis/circuit...

To me it's asking for trouble to expect an item filled with a solution trying to keep two plates apart after 30-40years to stay wet and function optimally, or even correctly.

Yes, some parts in a vintage amp command great respects and adulation when aged and functioning well - transformers, preamp tubes, speakers to name a few.
But the rest suffer age-related fatigue, and if they fail the results will hardly be an improvement to your tone.

Like I said, not trying to cast doubt or disagree with your tech, but I think it's sensible to have pro's and con's for future readers..
Enjoy yr amp and the multitude of tones it's capeable of..
DB