C+ reconstructive surgery

[Platypus]

My fully loaded simul C+ is finally back to life. First off I would like to thank Boogiebabies for his support and advice during this process, it would not have been possible without him.

When I received this amp it looked like an absolute murder scene...

1) Someone had sent this back to Mesa in 1990 to have the outer simul sockets wired for 6L6's.. replacing the 220k resistors with 22ks and changing the bias resistor to a 22k instead of 33k.

2) Missing pins galore in the power tube sockets

3) Brightness reduction mods

4) Looks like the inside of a hoover vacuum... I didn't even think it was possible to look that bad.


Before:

This doesn't even begin to define how filthy this amp was... look in the directory for the big shots of how it looked.

I spent 4 days cleaning the amplifier with qtips and DeOxIT cleaner. I went through over 200 qtips; their tips were pure black afterwords. I cleaned everything aside from the GEQ board as that one tends to be sensitive apparently. All the pots and jacks were crusty and rusted out before, now they are smooth.

The tone alone before replacing the components was drastically better after the cleaning.

This is the result of the deep clean:

After this, all the components were replaced to be back to their normal stock configs and the pin1/8 mod was done on the outer EL34 sockets.

The result is 110% better than what I started with I am happy to report.. although interestingly enough, my other c+ (60-100) has brighter and more punchy tone thus far. The simul is much smoother and rounded and also much louder.

So I end with one question.. what are you C+ guys using for preamp tubes? What would you recommend aside from super expensive NOS tubes for good tone? The previous owner also put 2 SPAX7s in V1 and V2 (which are supposed to be super quiet and have more gain but I've read conflicting reports of this?) and I'm still not 100% blown away by the amp yet. Furthermore, the reverb knob is essentially useless up until 8 on the dial.. preamp issue?

The tone is great now but it feels restrained compared to my other C+.

 

[Platypus]

For what it's worth, the amp came with a Bugle Boy (?) ECC83/12ax7 in the spare 12ax7 holder so I am definitely going to try that in V1.. but I'd like to replace the whole lot as they appear to be mutt assortment of different Mesa tubes. I know for sure I want different V1 and V2 tubes.. and possibly the reverb tube as it seems to be completely weak/nonexistant on this. 8 on the dial here is about 3 on my other C+ as far as reverb.

V1 is closest to the simul/class A power switch correct? Furthest away from the 105 tranny?

 

[STUART]

Great cleanup job !! 8)

I have a recently accquired C+ also that needs this treatment ,what type of DEOXIT formula spray did you use to remove the years of grime ?

My current C+preamp tube selection :

V1 RFT ECC83
V2 TUNGSRAM ECC83
V3 RFT ECC83
V4 TUNGSRAM ECC83
V5 BRIMAR 12AX7

 

[Platypus]

Great cleanup job !! 8)

I have a recently accquired C+ also that needs this treatment ,what type of DEOXIT formula spray did you use to remove the years of grime ?

My current C+preamp tube selection :

V1 RFT ECC83
V2 TUNGSRAM ECC83
V3 RFT ECC83
V4 TUNGSRAM ECC83
V5 BRIMAR 12AX7

Grab the Caig DeOxIT spray, they sell it at guitar center.. if you plan on using it to clean the pots, grab the Caig Fader Lube as well so you can apply that after the DeOxIT in the pots only. Don't use it on the GEQ

 

[ketiov]

I have V1-V5 in my Mark IV loaded with Tung Sol 12ax7's. I got them after quite a few people recommended them. I haven't tried any other tubes, except a set of Mesa 12ax7's, but I like the sound I'm getting. The Tung Sols apparently last a pretty long time and are reliable.

If you're a tone Nazi though, I'd go with something less basic, since there's probably better (and more expensive) tubes out there.

 

[Nomad]

The Best stuff in the business.

For Cleaning Everything except pots.

http://www.grainger.com/Grainger/items/1D262




For any kind of Pots or sliders. Anything that requires lubrication.

http://www.grainger.com/Grainger/items/1D261

 

[dodger916]

For what it's worth, the amp came with a Bugle Boy (?) ECC83/12ax7 in the spare 12ax7 holder so I am definitely going to try that in V1.. but I'd like to replace the whole lot as they appear to be mutt assortment of different Mesa tubes. I know for sure I want different V1 and V2 tubes.. and possibly the reverb tube as it seems to be completely weak/nonexistant on this. 8 on the dial here is about 3 on my other C+ as far as reverb.

V1 is closest to the simul/class A power switch correct? Furthest away from the 105 tranny?

I'm having great results with NOS Raytheon long black plates and NOS Herleen, Holland tubes (Amperex, Bugle Boy, etc.) in V1. I've been able to score some good ones for <$30 with shipping. I find the Herleen tubes to be on the bright side, and good compliments to the smoothness of NOS Mullards. But I really like the Raytheons in V1/V2.

I also had good results with a new balanced Mullard 12AT7WA in the PI in my Simul C+. It seemed to remove some unwanted courseness.

 

[Platypus]

Thanks George

I might experiment with changing the placement of the cords for the reverb, there are two cords on mine and I am pretty sure they are in the right jacks but I'll double check it.

Any verdict on these SPAX7s? Should I bother keeping them in?

Furthermore, the 6L6s in mine are Mesa 5881s which apparently suck highs out a bit. I was talking to Elpelotero about this last night and he said he ran into a similar issue. I can't quite get the treble bite out of this that my 60/100 has and increasing the presence or treble begins to make it harsh past where I have it now. I can say I definitely like the drive characteristics of the 60/100 more but I prefer the cleans on the simul. They are definitely both different, a lot different than I thought they would be before having played both.

I am going to put some of my GT6L6GE's in the inner sockets and see if I can get some sparkle back to this pup. I guess I really don't mind the reverb being subtle because I can get the tone I want out of it.. however once I turn the dial past 7 I start to get some hum (quiet, but there) so I'd rather just have it back to normal.

 

[STUART]

Hi there Geo !!

Yes it still needs a good cleaning but you should have seen it before it got to it's current level of "clean" having been blown/ cleaned out with an "air gun"!!

For sure that chassis had a good bale or two of fluff surrounding it, we could have spun the fluff and knitted a jersey
Wonderfull job George with the air gun still due you for all the help chum buddy..

Appreciated Platy for the cleaning agents advice too, got a couple of cans on order now

 

[Platypus]

Hi there Geo !!

Yes it still needs a good cleaning but you should have seen it before it got to it's current level of "clean" having been blown/ cleaned out with an "air gun"!!

For sure that chassis had a good bale or two of fluff surrounding it, we could have spun the fluff and knitted a jersey
Wonderfull job George with the air gun still due you for all the help chum buddy..

Appreciated Platy for the cleaning agents advice too, got a couple of cans on order now

Here's some general tips..

Number one.. I would get yourself a shop mask and cover your nose/face with it all times.

The DeOxIT comes with a spray tip and a cap, it's much better to spray the solution into the cap and then dip cotton swabs into it than it is to just spray it everywhere. The tip is useful for getting into the pots themselves.

Pots: Spray a bit into the back of the pot, you will see the slot you need to spray into. Be careful when spraying as it comes out fast and you don't need a lot. Once you spray inside the pot turn it back and forth all the way about 10 times then give it a few minutes. Apply one more exact cleaning and after the wait this time apply the Fader Lubricant and do the same thing except just give it one coating.

Jacks: The jacks tend to get really rusty both on the receiving metal end as well as the tube itself. Cotton swabs dipped in the DeOxIT are fantastic for this, simply swirl the swab inside the jack all around as well as the receiving tip. Make sure you do the input and footswitch jacks as well as the loop jacks. Especially focus on the speaker jacks as those are tone suckers for sure if they're oxidized.

Sockets: Spray with the tip into the sockets on top and then get some pipe cleaners and work them around in there when it's nice and wet. They will come out BLACK if they've not been cleaned in awhile. Then quickly flip the chassis over to expose the amp itself and wipe the residual spray it; it will leak onto the other side so catch it there (won't hurt anything).

Power/Preamp board: Again, cotton swabs will do the job of getting inbetween all the components. Clean all the connects with the components where they connect to the boards. AVOID the GEQ board if you have one mounted on the inner side. This area is very fragile apparently.

Avoid getting any cleaner of any kind into the GEQ sliders themselves.

Then I would give it half a day or so to try out before testing anything.

If you need more specific help shoot me a PM, I'd be glad to walk you through what I did.

 

[Platypus]

George, did it look anything like this?

:lol: :lol: :lol:

 

[Platypus]

lol look at the difference on the preamp board alone in the 'after' shot and the latest one I posted, it's so ridiculously filthy :lol:

 

[blacklight_uk]

Maybe you could start a new topic: dirty amp porn :lol: :lol: :lol:

 

[Platypus]

Maybe you could start a new topic: dirty amp porn :lol: :lol: :lol:

LOL :lol:

You're a filthy little amplifier!

 

[Stonge]

v1 - amprex 12ax7a (best tested)
v2 - fisher ecc83 (tested good)
v3 - amprex (tested good)
v4 - fisher (best tested)
v5 - an old mesa sp12ax7 (if that's possible)

I like my tone like I like my women..warm and smooth.

 

[Nomad]

My Mark III looked like that when I got it. It was trashed inside out. I cleaned it from one end to the other and when I got done it looked mint. A lot of dirt goes a long way to making an amp appear trashed. After I got mine cleaned up I was blown away at the difference. I purchased it off Flebay and the guy posted pics that made it appear in good condition, it wasnt.

It had a number of things that didnt work. Oh well it all works now and I love it too.


Someone mentioned not cleaning the sliding faders? What gives? I had to clean mine when I got it and had to clean them many times before I got em working again. Now they all work fine. You must use Lubricated Cleaner but its OK to clean em.

BTW dont ever clean a Pot or Fader with non Lubricated Cleaner. It will kill em deader than heck.

 

[camsna]

I knew about 'not' cleaning the grease off faders...

But good ol' DeoxIT won't do for pots?

 

[Platypus]

I knew about 'not' cleaning the grease off faders...

But good ol' DeoxIT won't do for pots?

It will but you must follow up with the Fader Lubricant I mentioned in my cleaning post.

 

[camsna]

????

 

[Platypus]

:lol:

http://store.caig.com/s.nl/sc.2/category.293/.f