Just got my Mark IIC+ in today. A few problems...

[Soundstorm]

Well, for starters when I plugged it in the fan started making this buzzsaw type noise. I took the fan out (there is lots of dust inside this guy), and there was a splinter from the cab stuck inside. Took the splinter out, problem solved.

I noticed a slight distortion underneath my playing. Could be microphonics? I'll try switching V1. This guy put in a mix of preamp tubes for me, I think he has a Sylvania in V1.

The reverb or eq footswitch is NOT working. When REV switch is engaged, I get no sound with the Rev set on 10. Without the reverb switch plugged in, I still have no reverb.

The Rhythm channel overdrives a lot easier than I thought from reading reviews. I can get a good light overdrive with the Vol1 on 6-7, Master 1 on 2.

NOTE: I blew a fuse a little while ago...took the fuse out and it was a 1a, whereas the instructions on the back say I need a 2.5a. I just replaced the fuse, but haven't played the amp (and won't be able to play at a healthy volume until tommorow). Could the wrong fuse suck any tone?


I am in no way a metal player. I like classic rock sounds like AC/DC, Zeppelin, and "new classic rock" tones like Clutch and Queens of the Stoneage. I would like to use the rhythm as an acoustic-like clean, and lead channel for a good classic rock type overdrive. I'm looking for a FAT and MEATY sounding overdrive.

Can anyone suggest some tube recommendations, and SETTINGS most importantly. I had a Mark IV before this one, and I realize I'm going to have to spend much more than a few hours with it, but so far I am not very impressed.

 

[JOEY B.]

I am in no way a metal player. I like classic rock sounds like AC/DC, Zeppelin, and "new classic rock" tones like Clutch and Queens of the Stoneage. I would like to use the rhythm as an acoustic-like clean, and lead channel for a good classic rock type overdrive. I'm looking for a FAT and MEATY sounding overdrive.

Volume 1=8 , Master=5, then adjust the lead drive to get your amount of gain. Use the Lead Master to control overall volume. The push pull tone pots will vary with the guitar being used. I don't know if an acoustic-like clean and FAT and MEATY overdrive can co-exist on a C+without severe rolloff of guitar volume on the rhythm channel.

 

[clutch71]

Well, for starters when I plugged it in the fan started making this buzzsaw type noise. I took the fan out (there is lots of dust inside this guy), and there was a splinter from the cab stuck inside. Took the splinter out, problem solved.

I noticed a slight distortion underneath my playing. Could be microphonics? I'll try switching V1. This guy put in a mix of preamp tubes for me, I think he has a Sylvania in V1.

The reverb or eq footswitch is NOT working. When REV switch is engaged, I get no sound with the Rev set on 10. Without the reverb switch plugged in, I still have no reverb.

The Rhythm channel overdrives a lot easier than I thought from reading reviews. I can get a good light overdrive with the Vol1 on 6-7, Master 1 on 2.

NOTE: I blew a fuse a little while ago...took the fuse out and it was a 1a, whereas the instructions on the back say I need a 2.5a. I just replaced the fuse, but haven't played the amp (and won't be able to play at a healthy volume until tommorow). Could the wrong fuse suck any tone?


I am in no way a metal player. I like classic rock sounds like AC/DC, Zeppelin, and "new classic rock" tones like Clutch and Queens of the Stoneage. I would like to use the rhythm as an acoustic-like clean, and lead channel for a good classic rock type overdrive. I'm looking for a FAT and MEATY sounding overdrive.

Can anyone suggest some tube recommendations, and SETTINGS most importantly. I had a Mark IV before this one, and I realize I'm going to have to spend much more than a few hours with it, but so far I am not very impressed.

Sorry to here that MarkIIc+ is giving you some fits. If boogiebabies doesn't see this post send him a PM. Also contact Elpelotero as he is knowledgable as well.

How did you like the Mark IV for Clutch? What songs are you playing with it. I play Soapmakers and Burning Beard w/ my Rect-o-Verb combo and it sounds pretty good. Good luck with the IIc+.

 

[Soundstorm]

I replaced the fuse, and switched the V1 tube for a Mesa 12ax7a, and there was a somewhat noticeable difference in tone and response at low volumes.

As to the poster above....Vol 8, and Master 5? Man, that's freakin' ear bleeding loud, isn't it? Hell, I'll give it a shot.


As for Clutch, the Burning Beard intro riff rocks on the Mark IV R2 channel! I can get a punchier version of R2 on the C+ on the rhythm channel with the vol 1 cranked.

I spent another couple of hours with the C+, and I think i'm starting to get into the ballpark of getting the hang of this guy If it's anything like the Mark IV, the tone will get better and better the more I spend time with it, I know that. I was a little panicked in my first post, but all is well, I think. I'll get a chance to crank it up with my current settings tommorow and see how they go.

Right now I use Rhythm channel as a clean, then throw my TS808 clone as a boost for mid gain rhythm. Then I'll use the Lead channel for heavy Tool sort of riffs. My problem with the Mark IV was that I couldn't find a happy mid gain ground between R2 and Lead in the same song. It seems that the voicing of the two channels on the C+ are a little more similiar, so that I can transition between them for rhythms in the same song without any sort of awkward voicing transitions.

I'm still clueless as to what's wrong with the reverb. I'd like to avoid sending it to Boogie, because I know it could take a long while to fix. On the other hand, it would be nice to give it a tuneup. Hmm...(awaits replies from the C+ gurus)

 

[JOEY B.]

I replaced the fuse, and switched the V1 tube for a Mesa 12ax7a, and there was a somewhat noticeable difference in tone and response at low volumes.

As to the poster above....Vol 8, and Master 5? Man, that's freakin' ear bleeding loud, isn't it? Hell, I'll give it a shot.

I'm still clueless as to what's wrong with the reverb. I'd like to avoid sending it to Boogie, because I know it could take a long while to fix. On the other hand, it would be nice to give it a tuneup. Hmm...(awaits replies from the C+ gurus)

The rhythm channel volume will be insane without guitar volume rolloff. Use the Lead master to control lead channel volume.

 

[Elpelotero]

are the reverb cables plugged in correctly on the underside of the chassis? try switching them...


I generally like to put medium-hot tubes in there...this way you don't have to crank the volume as much. I put the Volume1 at whatever level I can. For recording type stuff, I would do what JoeyB suggested...you crank the Volume1 to 8 or 9 and put the channel masters around 4-5. However, as noted, this may not give you a pristine clean sound. So turn the Volume1 down to about 5 and put the Rhythm knob to around 2-3. This should be a decent volume to play/jam and the clean won't break up. Single coils work very, very well, btw. You crank the Lead Drive as high as you want to get your sound (I go up to like 9) and then put the Lead Master to a comfortable listening level for you.

You had a Mark4 before, so I assume you are putting similar settings with mids, bass, etc

 

[Soundstorm]

Yes, I'm doing something similiar to my Mark IV settings. I'm using a '78 LP custom, and the pickups must be really hot because I always have a really low drive setting on whatever I play, but I still manage to get a light palm mute chunk if I want, and plenty of overdrive. This is what I'm working with right now:

Vol 1: 7.5 pulled
Treb: 8.5 pulled
Bass: 3 pulled
Mid: 7
Master 1: 1-2 pulled
Lead Drive: 3
Lead Master: 7.5 pushed
Presence: 7.5

Graphic EQ: W shape, with 240 and 2200 at the center line, 750 half way to the top line, 80 at the top line, 6600 slightly below the top line.

Try those and tell me what you think. Sounds good at the lower volume I'm playing at right now.

I'm using a Mesa vertical 2x12 with a 12GH30 and a Vintage 30.

 

[jvk]

Could the wrong fuse suck any tone?
Nope.

I noticed a slight distortion underneath my playing. Could be microphonics? I'll try switching V1.
That can be either ghost notes from dodgy filter caps or the preamp tubes going micro-funky. When they're on their way out, tubes can become sensitive to the speaker vibrations picked up by the chassis. Stick in some tubes that are known to be good and try it.

The reverb or eq footswitch is NOT working. When REV switch is engaged, I get no sound with the Rev set on 10. Without the reverb switch plugged in, I still have no reverb.
If you lose the signal with the reverb engaged, like Elpeletero said it'll be the connections to the tank, make sure they're plugged in tightly, try swapping them around (there's 2 wires coming from the tank with phono plugs at the ends). If there's any rust or oxidation on the plugs or sockets, clean them with a metal brush or contact cleaner and try again.

The EQ footswitch is not working.
Are you sure? If you can switch to lead it means that the switching circuit supply is alright, so if there isn't anything wrong with the jack/cable/footswitch, it can be a dodgy LDR, but I doubt it.

Did your amp have these problems before the fuse blew?

 

[Soundstorm]

Yes, they had these same problems before the fuse blew.

I tried radical EQ settings to make sure my ears weren't playing tricks on me, but it isn't working. BTW- there are two 1/4" jacks on the underside of the chassis...what's the difference between the two?

I'll try swapping around the plugs on the reverb tank.

 

[jvk]

If I remember correctly, looking from the back the jack on the left is for the Lead/Rhythm and the one on the right is a stereo one for the the EQ and reverb.

- corrected

 

[jvk]

By the way, if you want a quick analysis of your amps "pretty bits", open her up and take some high-res shots of the inside of the chassis, showing all the circuit boards, and post them here. Some of us will have a field day, and you'll probably get some interesting feedback

 

[Soundstorm]

Ok, I just need to find a digicam first.

About the footswitch inputs....I have a two button footswitch for REV and EQ, but with one 1/4" output. So I'm a bit confused about there being two jacks on the underside.

 

[Soundstorm]

Do I need a TRS cable for the dual footswitch? I already tried it, just curious for future reference.



I tried the reverb again with nothing plugged into the jack, just tweaking the knob. All it does is lower and slightly add overdrive to the signal.

 

[jvk]

Do I need a TRS cable for the dual footswitch? I already tried it, just curious for future reference.

Yes, a stereo cable is required (TRS=tip-ring-sleeve).

I tried the reverb again with nothing plugged into the jack, just tweaking the knob. All it does is lower and slightly add overdrive to the signal.

Makes sense. The reverb tank is not working properly, either the springs are damaged, or it's the cables/connection.

There are two leads coming from the tank. The grey one should be plugged in between the two jacks, and the white one should connect to the other socket.

 

[clutch71]

...I tried the reverb again with nothing plugged into the jack, just tweaking the knob. All it does is lower and slightly add overdrive to the signal.

I have seen a mod where they mod the reverb pot as a second volume. Not sure what series it was for but I'm wondering if that was done on this amp. I have a very very limited experience with this amp but I do know to get that great saturation you really had to crank it! You can switch to the class a setting but the simul-class cranked sounded much better.

Definately get some pictures of the guts posted. Your liable to burn up your screen with the replies but it will be worth your time.

Best of luck!

 

[jvk]

It's not a mod, it's broke :lol:

When the grid on V3A isn't connected to anything (i.e. reverb tank no workey, or not connected) it just amplifies noise (the grid isn't grounded) which's injected back into the signal chain. The way the reverb pot is wired in parallel with a 4.7k resistor means that turning it up increases the effect of V3a at the same time as increasing the resistance to ground a little bit. Hence adds more fizzle and drops the output volume. The drop is hardly noticeable with the reverb working.

 

[Boogiebabies]

When the reverb loses ground to the tank is has no path to complete the circuit. It hangs just above ground and interferes with the signal or dips in and out.

Lets start with the basics.

I would do the 1 wire mod first. It sounds very typical of the problem.
Solder 1 wire to both outer sleeves of your reverb cables on the chassis end. This can happen at any time regardless of the condition of the amp.
The washers on the reverb jacks corrode. I have not seen a clean one yet. Since there is no way to replace the washer under the board, the wire shares the ground with the other jack. I shoot the death out of the washer with De-Oxit and clean the reverb cable ends and the tanks outer
RCA connectors. In most cases the mod will work without the cleaning.

The dual footswitch it the right jack behind the power tubes

Make sure a tube is not touching the speaker and run a patch cable through your effects loop jack to see if you have a dirty connection.

If the reverb comes back and you still have the buzz, you may need to check the filament ground resistors below the speaker taps. They can cause a buzz as the tubes struggle to find ground references through the two 100ohm resistors. Generally only one blows. Check all IIC+'s for blown screen grid resistors and the amp needs a general spring cleaning.
As mentioned, preamp tubes, pots,loose and dirty sockets can all cause issues. I spend 2-3 days on an amp before I even plug it in.

Lets get some pics up and look her over. The less the delirium tremors, the better.

 

[Elpelotero]

Yes, I'm doing something similiar to my Mark IV settings. I'm using a '78 LP custom, and the pickups must be really hot because I always have a really low drive setting on whatever I play, but I still manage to get a light palm mute chunk if I want, and plenty of overdrive. This is what I'm working with right now:

Vol 1: 7.5 pulled
Treb: 8.5 pulled
Bass: 3 pulled
Mid: 7
Master 1: 1-2 pulled
Lead Drive: 3
Lead Master: 7.5 pushed
Presence: 7.5

Graphic EQ: W shape, with 240 and 2200 at the center line, 750 half way to the top line, 80 at the top line, 6600 slightly below the top line.

Try those and tell me what you think. Sounds good at the lower volume I'm playing at right now.

I'm using a Mesa vertical 2x12 with a 12GH30 and a Vintage 30.

Try these settings on the Lead channel to get a nice classic Mark2C+ sound....these can get kind of metal, which I know is not your thing, but it may help you to think of the knobs in a new way you didn't see before...
Volume1: same as you have, 7.5; NO pull
Treble: 8 PULL
Bass: 2 NO pull
Middle: 4
Master1: 2 PULL
Lead Drive: 6 PULL
Lead Master: as high as you can; NO pull
Presence: adjust to taste
Graphic EQ: keep the W shape, but bring the 750 down below its neighbors

If you're going for that classic rock Marshall sound, you definitely have to up the mids and highs and kill some of the bass on the graphic eq.

 

[Restless Rocks]

When the reverb loses ground to the tank is has no path to complete the circuit. It hangs just above ground and interferes with the signal or dips in and out.

If soldering is not your cup of tea you might try replacing the reverb cables with a standard dual RCA to RCA cable from your stereo system. This will ground and sheild both the send and return signals to the reverb tank.

 

[Soundstorm]

Thanks for the input, everyone.

BoogieBabies...before I solder, do you think the problem with the EQ could have something to do with the reverb not coming on as well?

EQ works, I just can't footswitch it. Tried again today with a TRS cable in the correct socket and neither the EQ or the REV switch did anything.