The Mark IV thread....!!

[Zorshelter]

With the Mark IV really like The EVM12L, I tried V30 and they are really too harsh for me, I also tried C90 which are still too harsh for me even if we kinda get used to their sound....I tried it on a 4x12 Marshall JCM900 Lead and the sound is not so bad (even if I thought V30 were in it...)

There are a lot of good speakers out there but so far for me the EVM12L is the answer

 

[boogietone]

I have EV12L's in a 2X12 recto cab and they sound awesome.

 

[boogietone]

Is this a screen resistor?

No. On most Mesa amps (and all the Mark series) the screen resistors are mounted directly to the power tube sockets. They span from pin 4 on the socket to the terminal strips mounted between the power tubes.

That resistor in your pic is a Dale .6W unit, the only Mesa amp I know of that uses those for the screens...and places them on the PCB...is the Heartbreaker, and it uses two of them in parallel for each tube.

I suspect one of your power tubes has arced from the heater to the plate. Look at the bases of all of them, you're looking for a carbon track probably between pins 2 and 3.

Anyone no where I can a .6W Dale resistor?

 

[AdmiralB]

I have them in a few values, I can't see your pic anymore - do you know what value you need?

Mouser is where I get them, they're Dale CCF60 series...just search on "CCF60" at mouser.com.

 

[UsrName]

I have EV12L's in a 2X12 recto cab and they sound awesome.

I like this idea. Pretty much the bottom half of a halfback 4x12, no?

 

[TheSandman]

Sorry for my laziness, plus it's a lot of pages to read through, but what do people mean when they say that have a Mark IV green or Mark IV red? Does it have something to do with the a and b versions?

 

[boogietone]

Green or red usually refers to the MKIII's. I've never heard of red or green associated with MKIV's but I could be mistaken. MKIII's revisions had different color stripes above the power cord. A no stripe or black stripe was the first iteration of the MKIII series followed by purple, red, blue and green. Green being the final version of the MKIII's. Each having subtle differences in the preamp and or power amp and reshaping of the voicings here and there...I think. Here's a link that is very informative:
http://homepage.mac.com/mesaboogie/dot.html

 

[UsrName]

Update to my 2x12 issue:

I changed some of my normal settings, and this seemed to help quite a bit. Especially the gain and eq settings. I also tried two EL34s and I'm really digging the sound now.

Next on the list is a head cab for better portability.

Thanks for the help guys and Happy New Year!!

 

[mdortona]

Hi All!

Here's the story:

I recently popped in 4 6V6 tubes in my Mark IVA to tame things a bit volume wise and get a more Fender Deluxe-ish clean. I am following the customary instructions (i.e. Tweed power , Simulclass, plugging into the 4 ohm jack etc.). However, according to Markus at MB, running two 8 ohm cabs in parallel (in this case a MB EV-Theile and a MB open back cab) into the 4 ohm jacks with the 6v6s, isn't recommended. He suggested that I buy a series load box so that the amp "will see" a different, safer load. I'm still not clear why it should make a difference, since reportedly you can run a pair of 8 ohm cabs in parallel into the 4 ohm slots with the 6L6s without any issues. What am I missing or misunderstanding? Thanks in advance for the help and enlightenment!

Matt

 

[MrMarkIII]

'Cause running an 8 ohm speaker from the 4 ohm jack (or 16 ohms from the 8 ohm jack) creates a mismatch that is easier on the tubes.
The "normal" load of 8 ohms or 4 ohms (two 8 ohm speakers into each of the 4 ohm jacks equals 4 ohms total) will not be so normal with the 6V6s.

 

[mdortona]

Thanks for the enlightenment Mr. MarkIII! That makes much more sense now

Matt

 

[diaz]

Mark 4 has so many different settings, its mind boggling. My buddy spent a whole afternoon dialing a rhythm tone. Once he found something he really liked, he had to screw with the settings before writing them down and now he lost that sound, maybe forever lol...

-D

 

[EirikBrandal]

I have some problems with my Mark IV. The Lead Channel sound like it's designed for playing blues. I've copied almost every setting I've come over, but still it doesn't sound good at all! My 15w marshall transistor amp sounds better! I bought it new, and it came yesterday, so I don't think it's anything wrong with the tubes.

Another problem is the Tweed Power. Even though I have the volume and master volume at 10, it doesn't produce any high volumes at all!

I've considered taking it to a tech, but since I've only had it in two days, I want to find out if the problem solves itselves.

Any help appreciated

 

[Shep]

If it's new take it back.. but it sounds like Tube's something not connected right..

 

[EirikBrandal]

The problem is that I ordered it in Germany, so I can't just drop by. I live in Norway..

But are you talking about the power tubes or preamp tubes? I've seen that only 3 of the 4 power tubes have this blue glow that all mesa 6l6's have. And the one that's not glowing blue aren't very hot either. None of the preamp tubes glow whatsoever.

But thanks anyway

 

[Shep]

something sounds abit funny.. I would take it to a tech and get him to look at it.. it could be tubes, can't be sure with out looking at the amp..

 

[EirikBrandal]

I hope there's enough competence around here then. Don't really think so. But first of all I'll talk to the boogiers at my school and see if they know anything. I think almost all of the teachers got one.

thanks

 

[bryan_kilco]

I am new here...first post. Hello all!

I bought my Mark IV used, off of Ebay, about 2 years ago.

when it arrived, all 4 power tubes were broken (dumbass shipped it with tubes in their sockets =/)
but thankfully he shipped extra, used, Mesa tubes...which I ran for a while.

The amp has problems - the Lead Channel Low-Mid-High doesnt work at all. I constantly have to use the 5-band for any eqing.

I retubed her over the summer with Sovtek pre and GT powers.
sounded good. now, she's getting noisy again.
a few shows ago, the master volume started dropping from stage volume down to barely aduiable volume. bugged the heck out of me, and I had someone tell me it was probably a bad Master Volume pot.

but, after practicing and another show, it was fine.

does anyone elses Mark IV get WAY too loud? Like, Im talking....independant volumes on about 3, Master at like 2 and its VERY loud.....anyone?

also...Im thinking about shipping her to Mesa in Cali. Last time I took her to a local "tech", they charged me $100 and only swapped my tubes around into their incorrect spots (i.e. EL34, 6L6, EL34, 6L6)....wtf?!?! =/

 

[jerseydrew]

You obviously have to ship it to a reputable tech.

 

[bryan_kilco]

You obviously have to ship it to a reputable tech.

which is my problem.

I dont know any good techs around here.

Can Guitar Centers work on Mesas? cause....all the shops ive been to around here NEVER carry Mesa gear.

I'm in a band that plays out a few times a month on average, and I dont currently have a working backup amp.

On the backburner I have a Peavey Transtube Supreme and an old 5150, both need repair....but I need a tech! Im thinking....Ill repair the SS Peavey first, cause they sound decent for what they are....and once that is repaired Ill ship out the MkIV.