just got a IIC+

[alistair]

I just managed to snare a IIC+ in pretty good condition for a good price. It's a bare bones model (export, 60w, reverb) but in Australia, any IIC+ is rare.

Just a few little questions- the reverb seems to be affecting the gain significantly. Eg., the higher I turn up the reverb, the more gain.

However, the two gain controls on the front seem to be having little effect in the lead channel (lead drive and lead master). The amp won't get much beyond a bluesy breakup. Still sounds great though.

Any idea what it could be? It's a single owner amp (up until now) and he swears there have been no mods etc. I'm gonna replace the shitty sovtek pre tubes tonight and see if that helps. Power tubes are USA fenders. Are these ok tubes? they sound pretty decent.

 

[Aart]

Lead master isn't a gain control as far as i know. Volume I is a gain knob if i'm right, together with the lead drive.

And the treble has to be past 6.

 

[dodger916]

Maybe a dumb question: You're pulling the Lead Drive knob, right?

Yes Aart, Volume 1 has significant influence over the gain structure of the lead channel

V3 & 4 control both Reverb and Lead Drive together. Looking from the back of the amp, these are the two preamp tubes on the far left. Might be a good place to start.

You can download the manual off the Mesa website:

http://www.mesaboogie.com/manuals/Mark II-C Manual - Maintenance & Repair.pdf


Oh yeah, congrats on the C+! I have a fully-loaded 60 watt export IIC that I love.

 

[alistair]

thanks for the replies guys.

Yeah with both volume 1 and lead drive on 10 (and lead drive pulled) its still a light overdrive at best. Reverb is definitely affecting it though.

I'll change the tubes out tomorrow and let you guys know what happens.

 

[tony777]

if you're searching for metal tones, you'll need an eq in the FX loop.
I use a boss GEQ7, but there is other brands out there.
I have a 60 w C+ (bare bones) and a Simul C+ fully loaded, both export models.
But dialing the reverb shouldn't affect the gain, so that makes me wonder a bit.

Anyway, try this:
volume 1 at max 7
treble above 7, pulled
bass about 2 pull (if you like) depends on cab and gtr.
treble 4 and up
master as high as you like, but please don't kill yourself. and pull deep
Lead drive high......10 if you like (pull for distortion, laughs)
Lead master: the lower the more scooped tone. and pull if you like.
And it should definitely be enough gain.
Prescence (located with the reverb button) higher than 4 (but dial to taste)

let us know

Tony

 

[alistair]

Thanks for the reply.

Yeah, I'm not even looking for metal tones, just putting the amp through its paces. I really wanted it for it's amazing clean channel, so it's not even a big deal for me, but something is funny. Tube change didn't seem to help, but I'm thinking a ground has come loose somewhere in the reverb circuit...

 

[lesterpaul]

how does she sound with reverb on 0?

 

[Boogiebabies]

You need to do the one wire reverb cable mod. The ground on the reverb is causing it to float above ground reference and is basically making your reverb a mini 1 watt tube amp.

 

[Mulemasta]

Hey man, are you sure it's a IIC+ or a IIC? Any IIC in Australia is rare, but if it's the one that just sold recently on ebay then there is a good possibility of it not being a IIC+ which explains the lack of gain. My IIC is not over the top in the way of gain, but make sure the Vol 1 is at least 7 or above. Pull the bright switches. Anyway it's a good score all the same, congrats, check the serial no and do a loop test and you'll know for sure.

 

[alistair]

Clean Channel sounds normal with reverb on 0, dirty is still lacking balls though. I think i've got the info for that reverb one wire thing somewhere on my computer, so I might give it a good clean and if thats not making it happy try that out.

Also, no its the one off ebay. That was definitely a standard 2C. This is serial numbers in the 13's so there is no question. RP11A circuit board (with the initials RS on it which is kinda fun), + on the back, passes loop test.

I've got a IIC as well, once I know the IIC+ a bit better I'm gonna post a comparison of the two models.

 

[adrenaline junkie]

When I got one of my IIC(+)'s it didn't have anywhere near the amount of gain it should have, and it turned out to be a Bad LDR. Gain level was about like a cranked up Super Lead.

 

[alistair]

well i mucked around with some tubes- a new set of JJ's actually made the amp a lot noisier! it was silent before!

Cleaned up the reverb connections and that has fixed the reverb which is cool, makes a big difference.

now the reverb is sorted, I've been able to figure out whats going on.

The lead drive has no effect on the sound whatsoever. The lead master works, but the lead drive adds no gain, whether its set on zero or 10 it sounds identical.

I'm guessing it's not a tube problem now, so options are either the pot itself or maybe the effects loop? Surely if plugging in to the loop and not hearing a difference on the lead drive can be a IIC+ test, there is some relation between the loop and gain pot?

 

[jerseydrew]

I think it's time to take the amp to a tech. I recently bought a MKIIC+ and when I took it home, I didn't think it sounded too good. I brought it to a tech and when I got it home there was a HUGE difference.

 

[Boogiebabies]

When I got one of my IIC(+)'s it didn't have anywhere near the amount of gain it should have, and it turned out to be a Bad LDR. Gain level was about like a cranked up Super Lead.

Yes, LDR 3 if bad would negate the lead drive.

 

[alistair]

how can I check if LDR 3 is bad? Can I visually check on the board or use a multimeter to get a reading?

 

[LEVEL4]

Congrats! Well, how is it? Is the Mark IIC+ everything it's cracked up to be? Did it meet or exceed your gain and distortion expectations?

 

[dodger916]

Congrats! Well, how is it? Is the Mark IIC+ everything it's cracked up to be? Did it meet or exceed your gain and distortion expectations?

I'd say "not yet determined", as he has no Lead Drive!

 

[LEVEL4]

I'd say "not yet determined", as he has no Lead Drive!

Oh. Duh! That's what I get for not reading the entire post!

 

[dodger916]

I'd say "not yet determined", as he has no Lead Drive!

Oh. Duh! That's what I get for not reading the entire post!

I almost razzed you for that, but my "better judgment" got the best of me! Look Mom, I finally grow'd up!

 

[alistair]

does anybody know the value of the LDR's in the IIC+? The schem merely says LDR2 or LDR4 etc.