Mark IV clean channel is dirty

[ajtooke]

Well, it was. I turned it off and back on and now it's fine. I turned the gain down to about 2 and it was still distorted. The thing is, I'm not entirely sure it was the amp - I just bought a lightly used C-7 Hellraiser with active EMG pickups, and I'm not sure if a dying battery can cause that kind of sound. Anyone have any experience with that? I doubt the battery is dead after only two months, it looks barely played too so it can't have that much playing time on it.

The more likely explanation is that it really was the amp's fault. What exactly happened? And why did it go away when I turned the amp off and back on?

It's a very old head, early 90's and I just had it fixed because a redplated power tube blew a fuse.

edit: And while I'm here I might as well ask about getting a good sound. Every clip I hear has either an amazing rhythm tone, or amazing lead tone, but I can't seem to dial something like that in. I've looked at the settings posted here countless times, and currently have it set like this:

Lead channel
Treble - 7
Mid - 4.5 - 5.5
Bass - 2-3.5
Presence - 2 pulled
Gain - 8 pulled
Drive - 7 pushed
Harmonics, Class A, Triode, Tweed power
Running through a Mesa 3/4 back 1x12 with 4 new 6L6's and 12Ax7's from JJ tubes. My guitar is either an Ibanez RG with Dimarzios or Schecter C-7 Hellraiser with 7-string EMG85's.

I just can't get that smooth lead tone, it's always kind of harsh and rhythm is "flubby" and not very heavy even with the bridge EMG85 and gain settings as above. It stays flubby even with bass at 0. Do you guys think it's the cabinet? I can't help but think that closed back would work better. But I also have a suspicion that something is up with the amp - is it possible for two Boogies of the same model to sound different?

Sorry for the long post, it's been frustrating me for a while though. So much in fact that I've been considering trying to sell my mark IV and get a newer one, but I have more to try first. I'm just surprised that my settings here can't make sounds like I hear in videos and clips, with similar guitars.

 

[dmcguitar]

dying batteries on active pickups can cause distortion, or a weak signal. if the guitar was left with a cable plugged in, even when not playing, the batter will drain. if you wanted to rule that out just try a different guitar, or a different amp (of course you'd need to have another amp, maybe a small practice one?)

 

[Axis39]

Try swapping out the preamp tubes. I had a similar problem and swapped out V1. Good as gold now.

Might be the batteries in your guitar too. But if new battery don't fix it, try new a preamp tube or two.

 

[ajtooke]

I don't leave the guitar plugged in, and I already said that the problem went away. Sorry, guess that wasn't clear - it made the distorted sound on the clean channel, and I turned the amp off and back on and it was fine. I was just wondering if it was cause for concern. My main thing is getting it to sound good - tweaking non-stop over the past few months and I just can't.

And to Rabies, yes he did replace a couple of resistors along with a long list of repairs that I've been meaning to do.

My tubes are pretty new by the way, I've got different ones in there between a month and two months old. Thanks for the replies, much appreciated!

 

[mrd]

First thing first: you aren't gonna get too good of a rhythm tone from a 1x12 cab. Hook it up to at least a 2x12, but more is better. I usually run my Mark into a 3/4 stack (4x12 + 2x12). I have a 1x12 cab too and when I play my MarkIV through it, it sounds very weak compared to how I usually run it. Sometimes I use the 1x12 for a good lead sound cuz I can crank the amp way up and it's not as loud as 6 speakers driving heh.

As for settings, I don't know what kind of sound you're going for... but try setting your power section differently, namely: full power, pentode, simul-class.

Try these settings on the lead channel:

Gain 7-8 pulled
Treble 7-8
Mid 1-3
Bass 0 (I only use bass in the lead channel when I run the gain/drive VERY VERY low and use the lead channel for an alternate, singing clean channel, and even then I only set the bass knob to about 2 or 3)
Drive 7-8 pulled
Presence 7 pushed

From here, you wanna set up your EQ. If you're just jamming by yourself, you can go more extreme with the EQ cuz you don't have to sound good in any sort of mix, cuz all you can hear is yourself.

A good classic V sounds fine, but with a 1x12 you won't be able to hear much bass thump on the 80hz slider. The way I run my EQ is pretty plain right now, I basically just run everything at unity gain (IE: I don't use them) except I scoop out the 750hz slider to about a cm above the bottom line.

Try it out, see how you like it.

 

[ajtooke]

Hey mrd, first of all thank you for the detailed reply. I've been trying some of the things you said in the past few hours. I started off with your front panel settings, which are pretty close to mine, and ended up almost back where I started (bass and mid a bit lower and presence pushed). As for the power settings, it's pretty tough to get a good tone with pentode or simul-class because I can't crank it until next band practice, and it sounds much better at lower wattage settings at my volume levels, which already piss people off in my apartment complex - I will try different power settings next practice though. Full power definitely made it tighter and a bit louder, but not necessarily better.

I think you might be right about the cab - it is a 3/4 back, so I lose some bass response. But while I was back there playing with power settings I noticed that no matter what I have set (my old power / tone settings, or yours) I like the sound that comes from the back of the cabinet way better :? Bass response is tighter and there's none of the normal "flab," and leads sing rather than make my ear drums bleed with harsh high end. I also like my C-7 Hellraiser's tone much more than the RG.

I think I might have to try some 2x12 closed back cabs..

 

[JOEY B.]

If you can find one, try out an EV loaded 1x12 MESA thiele cab. There is a reason that they bring as much money as most 2x12's.

 

[stokes]

The flubby tone could be caused by old,weak filter caps.Your amp is about 15 years old,I can guarantee that fresh caps will tighten things up a whole lot.In fact the intermitent distorted sound could also be caused by a cap that is about to go south.A different cab will help with the tone issues,but not if your caps are weak,and after ten years or so,they get weak and cause the symptoms you describe.If you do change the caps be sure to tell whoever does it to use good quality caps,not the asian variety.I use only F&T's and Spragues,dont let anyone tell you it doesnt matter,it does,and my "guarantee" only applies to those caps.

 

[ajtooke]

If you can find one, try out an EV loaded 1x12 MESA thiele cab. There is a reason that they bring as much money as most 2x12's.

Yeah I've looked into that one, but that would mean trading my medium head in for a short one. Almost gauranteed to lose me money that I don't have with the age of this thing.

The flubby tone could be caused by old,weak filter caps.Your amp is about 15 years old,I can guarantee that fresh caps will tighten things up a whole lot.In fact the intermitent distorted sound could also be caused by a cap that is about to go south.A different cab will help with the tone issues,but not if your caps are weak,and after ten years or so,they get weak and cause the symptoms you describe.If you do change the caps be sure to tell whoever does it to use good quality caps,not the asian variety.I use only F&T's and Spragues,dont let anyone tell you it doesnt matter,it does,and my "guarantee" only applies to those caps.

Awesome, thanks so much for the info. I will definitely look into that. So fresh caps will mainly serve to tighten it up? Will they help with taming harsh leads? Any other components that could have wear on them that I should look out for?

Thanks again!

 

[stokes]

What happens with caps is that they deteriorate very slowly.Most people dont even notice the change in the amps response until it becomes severe,they kind of just acclamate to the change as it goes along.I have changed caps for people who thought they were fine...until they heard the amp with fresh ones.The power supply is the heart and soul of an amp,and filter caps are the backbone of the power supply.New caps can help with taming harsh leads,but I've found a bigger contributor to harsh sounding leads in Boogies is the power tubes.Specifically the way they are biased.But I can tell you that nothing in the amp will work "right" with a sub-par power supply,so to me,biasing an amp with weak caps is futile.Pretty much the only other compnents to be concerned with are the tubes.Power tubes tend to wear out rather quickly,especially current production tubes,its true that "they just dont make them like they used to".Preamp tubes can last a very long time,especially NOS pre's.I have an Ampeg from the '60's with the original preamp tubes still in there going strong.High gain amps like Mesa's will wear preamp tubes a little faster than an older Fender type,but they still should last a lot longer than the power tubes.I strongly suggest new filter caps before you go dropping big $$$ on speakers.Not that I am minimizing the effect of good speakers,but it is better to get the amp up to par so you can really evaluate the worth of a speaker.

 

[6L6C]

Awesome, thanks so much for the info. I will definitely look into that. So fresh caps will mainly serve to tighten it up? Will they help with taming harsh leads?

Had my caps done last year on a 1993 Mark IV, nothing wrong with the amp. Just did some reading on the subject and decided I wanted to do a PM (preventive maintenance). Bottom line the amp sounds so much better but the feel is a bit different also, especially the clean channel just responds so much better as far as dynamics. The caps are F&T's and Spragues.

 

[HalfDeaf]

+1 on getting the caps replaced. I've been told that this should be done about every ten years or so.

I've had a similar experience to Axis39 - swapping preamp tubes can really help, and they're pretty cheap. Buy one or two new 12AX7s (or NOS if you've got the $$$) and experiment.

Tweaking a mesa amp at "apartment" sound volumes can be maddening. Don't get too discouraged, though. All the little tweaks to the preamp stage tend to become insignificant when you play at full band volume. I also use class A/tweed power in my apartment, but I set my tone up at the rehearsal studio for full power/simulclass/pentode. I find that the optimal lead channel gain and drive settings are WAY below what I dial in at low volume. Its not uncommon for me to run lead gain at around 5-6 and drive at 3-4...seriously. At apartment volumes, I tend to go around 8 with both. I think you'll find that the natural power tube distortion you get with full power/simulclass/pentode played as loud as you can will give you the smooth tightness you're looking for. Another tweak you can do is use EL34s in the outside sockets. They tend to tighten things up and sound MUCH better at apartment volume with class A/tweed/(triode or pentode).

 

[fpoon]

Haven't read all the replies yet but just know that I too have a Schecter C-7 Hellraiser with EMG's and I'm getting awesome smooth lead and clean tones out of my Mark IV.

 

[ajtooke]

cool, lots of people for changing caps. I will have to get that done, once I build up a little cash- just spent it all on the C-7

Anyway, it really does sound a lot better with a little volume. I took it to practice last night and played through my drummer's Crate 4x12 and it sounded awesome. That's with full power, triode, and Class A with lead at 2, master at 3, and all other masters set to match lead volume - same settings as I've been using. Even at lower volume when we were playing after 12AM it sounded a good bit better than my 3/4 back.

I've heard that the 1x12 Thiele has a very directional feel to it, so unless I combine that with my 3/4 back, which I probably can't afford to do, I think the Recto 2x12 or similar will be a better choice. Plus I can't fit a medium head on the Thiele. First thing is the caps though, which unfortunately probably won't be for a few months, depending on how much it costs (estimates anybody)? I can live with it now that I know I'm not just out of my mind and there CAN be fixable variations between two of the same amps. At least it sounds good at practice.. :?

 

[JOEY B.]

I've heard that the 1x12 Thiele has a very directional feel to it, so unless I combine that with my 3/4 back, which I probably can't afford to do, I think the Recto 2x12 or similar will be a better choice. Plus I can't fit a medium head on the Thiele. :?

The Thiele is no more directional than any other closed back cab, per speaker. Step to the side or in front of the 4x12 and you'll see what I mean. The 1x12 requires a further distance to disperse the sound over a 2x12 or 4x12 closed back cab, that's all. Earcandy and Genz Benz make a nice ported 2x12 from what I've seen. Those would be plenty wide enough for a medium head. As far as variance in loud tone vs. bedroom tone goes, CRANK THAT ****!

 

[ajtooke]

I've heard that the 1x12 Thiele has a very directional feel to it, so unless I combine that with my 3/4 back, which I probably can't afford to do, I think the Recto 2x12 or similar will be a better choice. Plus I can't fit a medium head on the Thiele. :?

The Thiele is no more directional than any other closed back cab, per speaker. Step to the side or in front of the 4x12 and you'll see what I mean. The 1x12 requires a further distance to disperse the sound over a 2x12 or 4x12 closed back cab, that's all. Earcandy and Genz Benz make a nice ported 2x12 from what I've seen. Those would be plenty wide enough for a medium head. As far as variance in loud tone vs. bedroom tone goes, CRANK THAT sh!t!

Alright, I will keep those cabs in mind when I look for another one. I figure I might as well keep the 3/4 back because I won't make much off of it and it should help "disperse" the sound more, since you say all closed backs are relatively directional.

I'll also keep your 'turn it up' advice in mind next time I want the cops called on me :lol:

 

[JOEY B.]

I'll also keep your 'turn it up' advice in mind next time I want the cops called on me :lol:

Just live in an area where most of your neighbors don't want the cops on their street (for some reason or another :roll: :roll: :roll: ) Then put alarms on everything you own, aquire a pit bulldog and a Dirty Harry .44 magnum. You are now free to let the Boogies do the talkin' . It's worked for me for the last 15 years . When there were two Rottweilers in my household I made the comment, "You might break in with a crowbar, but you'll need a shotgun to get out." :lol: