Uh oh,.. Mark IIC+ help - no lead/gain

[exbest182]

Well, I was going to send in the IIC+ to Mike B. anyways...

Today, I fired up my IIC+.. and had no lead channel.. at all.. I almost never use the cleans... so I was surprised when I turned it on and I had clean tone... The only thing I noticed is my "Pull Lead" knob is actually cutting volume substantially... All the tubes look normal, though who knows how old those tubes are... cleans sound fine, and everything else seems normal, I just have no gain what so ever, everything is clean no matter what....

Any clues? Pre-Amp tube maybe? also I noticed when I power off the head I hear tube noises, like they're turning off... kind of like a little ting, hear and there for a few minutes while it's cooling down.. this happens regardless if i've been playing it 5 minutes, or 50 minutes... anywho.. anybody have an idea what could be the problem? I was planning to send it off to Mike B. anyways in a couple weeks for a cap job/once over, then planning on retubing.. maybe it's time to speed that up....

I'm going to assume it's V3.. but I don't have any spare tubes laying around... but please, let me hear thoughts and suggestions!

Thanks!

 

[zodiac272]

If you think it's V3 just rotate that tube to the other spots to see what's going on. or pull one from your MK V. 2 of the 3 Mark IIC+ I bought did not distort when I got them... like no gain. I sent them to mesa, I forget exactly what the problem was, maybe a bad LDR or something stupid in the lead circuit. It wasn't much to fix though. Is the tinging noise you hear the metal contracting as it cools inside the glass? maybe they are overheating, and ready to die? keep an eye on them. get some STR 415 and 416's for that baby.


good luck!

scott

 

[exbest182]

changing out V3 brought back my gain.. though I have a feeling it's time to retube the whole thing... the sound i'm hearing from the tubes are kind of like tapping on them..... it sounds like it's the metal contracting... but I'm going to retube it totally.. I don't know if I should retube before sending it to Mike B. or afterwards... or if i should just send the tubes with it... either way, it's up and running for now... i know that the amp hasn't been in to mesa since it was modded... God only knows how old those tubes are... I turned the amp off 5 minutes ago, and I'm still hearing that noise... also getting porcelain sockets put in when I send it in... sigh of relief for now...

Stupid question.. what would my C+ be classified as... Simul-Class, GEQ, no reverb, export tranny.. would it be DGX?

 

[Neptical]

the sound i'm hearing from the tubes are kind of like tapping on them..... it sounds like it's the metal contracting... but I'm going to retube it totally.. I don't know if I should retube before sending it to Mike B. or afterwards... or if i should just send the tubes with it.

Microphonic tube..no biggie. Just change it out for another tube..then I would re-tube it before you send it just for satisfaction and playability.

 

[zodiac272]

Yes your simul, GEQ, Export is a DGX. sweet.

Suspect tubes aren't worth using, maybe take out a resistor so you need to get it serviced. I'd say trash the tubes, but Mike B. will test out whatever tubes you send with it. After he services it, def have new reliable tubes waiting.

scott

 

[exbest182]

For tubes.. I was thinking going with the =C= set, and then using the dougstube pre-amp kit.. which I believe is..

V1 - Tung 12AX7
V2 - JJ ECC83
V3 - Penta 12AX7
V4 - Penta 12AX7

Anybody tried that set out in a IIC+?

I play like punk/thrash etc... Doug advised that set would probably be pretty good in a IIC+