Got my new Mark IV.....and questions.

[trickyrick]

Whats up everybody, bought my mkiv off e-bay, the pics weren't great, but it looked like it was in good shape. I opened the box and it looked brand new! The shop sending the amp forgot the power cord, I e-mailed them telling them how happy I was with the purchase, that the amp was way better then expected. He is sending out the cord, and went on to explain that the guy who traded it in had just bought it new a few weeks before, wasn't happy with it and traded it in. I mean the thing still has the made in usa sticker on it....home run.

here is my question now. The guy has GT 5881 power tubes in it with stock mesa preamp tubes. The tubes look brand new as well. I did a little research, and what I have found so far seems to explain that they are a very low watt ( 30w ) tube, and if they are directly replaced in a 6l6 socket, it could ment down the amp.

If this is true, I can only assume the guy used it in class A only, tweed, triode? Is any of this valid? Should I pop in some 6l6's to be safe? I am going to try and get a cord because I don't think I can wait anymore.

The amp smells new so it kind of helps with aromma theropy, but thats it.

I look forward to all of your expert advice and direction. Thanks.

 

[Pinweaver]

Check the Mark IV manual, it's in there.
5881's are replacements for 6L6's. No need to be careful with settings. They are slightly less powerful, that's all. It's EL34's you have to be careful with, only use them in the outer sockets.

 

[trickyrick]

Thanks pinweaver, could I expect a different tone using 6L6's as opposed to the 5881's? Do the 5881's breakup earlier like the EL34's, or is it just a matter of taste?

 

[Pinweaver]

Thanks pinweaver, could I expect a different tone using 6L6's as opposed to the 5881's? Do the 5881's breakup earlier like the EL34's, or is it just a matter of taste?

I've never used 5881's before so I'm just going to copy/paste the interesting part of the manual for you:

POWER TUBE SUBSTITUTION:

This procedure is in keeping with Mesa/Boogie’s quest for ultimate versatility. As you know, different tubes offer different sounds and playing characteristics and your new MARK IV offers four choices:
FIRST: the standard four 6L6’s which produce by far the best allaround performance. They deliver the most powerful clean sounds along with the richest distortion.
SECOND: Type 5881 is similar to the 6L6, but these tubes are just slightly less powerful. Although they will produce a somewhat rounder, more “vintage” tone.
THIRD: For those seeking the traditional British edge to their overdrive sounds, EL-34’s can replace the 6L6’s in the end two sockets (outerleft and outer-right). When running the amp in class A, only the two EL-34’s will be operating. In Simul-Class, a combination of two 6L6’s plus the EL-34’s produce a louder, fatter sound while retaining the British edge. (Expect the clean sound to suffer a bit whenever EL-34’s are used.) All combinations of Triode, Pentode, Tweed and Normal power can be used with this EL-34/6L6 combination.
FOURTH: Those of you who recall the great sounds of old Fender Deluxes will be delighted to know that four 6V6’s can also be used in the MARK IV...but, ONLY when TWEED and SIMUL-CLASS are selected. Also, to reduce tube wear when using 6V6’s, the 8 ohm speaker should be plugged into the 4 ohm jack. However, please note that Mesa/Boogie cannot accept responsibility for any blown 6V6’s incurred during such usage! Proper operation depends totally on the correct setting of the aforementioned switches and this will be impossible to verify for warranty tube coverage. So please exercise caution when using 6V6’s! Incorrect setting of the switches won’t usually cause immediate tube failure, but the strain caused is far in excess of recommended ratings.

 

[trickyrick]

Thats funny, I just went into and read the tube replacement section at mesa came back out and saw your post. Thanks for taking the time, that was kind of you. I think I am going to do a comparison. I am pretty much concerned with the amount of gain each tube offers, ie. rich distortion ( 6l6)as opposed to rounder (5881) distortion. Thanks again.

 

[trickyrick]

One more question, from what I understand boogie tubes are color coded. I assume each color represents a certain bias, one color is biased colder then another and so on. If I choose to purchse a set of boogie 6L6CG's how would I know what color to get. I know that sounds like a stupid question, but..... My nomad had green 6L6CG's in it, someone suggested these were cold. I thought they sounded warm. What color do you MKIV owners have? Would I need to have my amp rebiased, it's pretty much new. Should I just call Mesa and get there input? Thanks in advance.

 

[eltrain858]

One more question, from what I understand boogie tubes are color coded. I assume each color represents a certain bias, one color is biased colder then another and so on. If I choose to purchse a set of boogie 6L6CG's how would I know what color to get. I know that sounds like a stupid question, but..... My nomad had green 6L6CG's in it, someone suggested these were cold. I thought they sounded warm. What color do you MKIV owners have? Would I need to have my amp rebiased, it's pretty much new. Should I just call Mesa and get there input? Thanks in advance.

they'll most likely tell you that the color coding is just for matching purposes and there is no method to the madness..

and you don't bias a Mesa

From the MkIV manual:
"Time to change tubes? Just plug our tubes into any one of our amps and you're DONE. No tech needed. NO bills and no BS about biasing. And most important: The bias is RIGHT because it can't change!"

 

[guitardude05]

^but doesnt it say somewhere that technichally, it can be changed but is highly NOT reccomended? im trying to figure out if my amp has been 'biased' just so i know, but idk how to check it. pprobly not, but i'd still like to know.

 

[eltrain858]

^but doesnt it say somewhere that technichally, it can be changed but is highly NOT reccomended? im trying to figure out if my amp has been 'biased' just so i know, but idk how to check it. pprobly not, but i'd still like to know.

yeah, but it would involve a soldering iron rather than a screwdriver... (would have to be modded)

 

[trickyrick]

OK, I have had a chance to spend a couple of hours with the Mark IV and my first impressions are not so good. To me, the amp sounds very thin and when I thicken it up with either the EQ/bass/lower treb/lower pres, it gets flubby.
It is a wide body with a C-90, and I understand it's open back, but it seems really, really thin to me. I don't know if it's the tubes or not, they are groove tube GT6L6C's, it also says aka KT66/5881 on the tubes. When I first posted they were 5881's that was all I saw because I hadn't pulled them from the sockets, just peered in.

I have tried the settings in the mesa manual, and checked out the settings on grail tone also but I can't get anything resembling a Petrucci tone. Again I understand I am not playing through 6 4x12 closed back cabs, but I was expecting something in the same timezone.

I am not giving up, I understand this amp needs to be tweeked to find the sweet spot. I love the clean tones I get out of R1, it seems you can spin the knobs anywhere and still have a nice sound on that channel, but I have it dialed in just the way I like it. R2 is an interesting channel, I can easily dial in a different clean tone to a nice lead tone/chunky ryth tone, but the lead chan has me confused.

I think I will start by changing the tubes and go from there.

I tried a processor through the front of the amp, havn't even tried the loop yet, and it sounds great on C1 without using the processors preamp or anything like that, just the delays and mod effects.

I know this is not a recto, but I was expecting a little more focused distortion. I was playing through a roadster last week, and I just couldn't stop. I loved the distortion on that amp and I thought the clean was great too.

Keep in mind, I owned a MKII for a long time, and that amps distortion was beautiful. I was kind of expecting something close to that. That amp had an evm12, could that be it? The nomad I owned had a C-90 and that speaker handled a lot of heavy gain without getting flubby.

I tried all the different power amp switches as well as the preamp switches and I just can't find it yet. I am by no means ready to give up after only a few hours, but I am still kind of bummed.

I really went over the amp with a fine tooth comb as they say, and it really looks brand new, New like nothing is even broken in yet. Newer then an amp sitting in a showroom. Could that have something to do with it?

As always, comments and questions are welcomed and appreciated. Thanks.

 

[Pinweaver]

Keep experimenting. It took me well over a couple of months to find a tone I was really happy with, and I still tweak the amp almost every day.

And there's nothing wrong with trying different preamp tubes either.

 

[guitardude05]

hahaha, i felt the same way man. i was pretty disappointed the first week or two, but after that time i learned alot about the amp from this site and messing around with it for that time. now i love the amp hahah.

it might have to do with your pickups if they're still stock too, my gibson has hotter pickups than my ibanez which has stock pups so it sounds very good. hang in there. :wink:

edit: think of it this way, instant gratification is only fun for a short time. when you take a long time to dial in the tone you like it's soooo much sweeter.

 

[siggy14]

You have to remember, this amp was designed in the late 80's and revisioned in the early 90's, with that being said the amp will not sound like a modern amp. It can get close, but if you are comparing to other modern amps with gobs of bottem end, then you will be disappointed.

I just got my Mark IVA and i am loving it for Rock tone and 80's and early 90's metal/grundge. However i do not expect this amp to get into any of my recto area's.

As this amp does not need a screamer in front, it does benafit from it by adding more gain and tightning up the already tight bottem end.

OK, I have had a chance to spend a couple of hours with the Mark IV and my first impressions are not so good. To me, the amp sounds very thin and when I thicken it up with either the EQ/bass/lower treb/lower pres, it gets flubby.
It is a wide body with a C-90, and I understand it's open back, but it seems really, really thin to me. I don't know if it's the tubes or not, they are groove tube GT6L6C's, it also says aka KT66/5881 on the tubes. When I first posted they were 5881's that was all I saw because I hadn't pulled them from the sockets, just peered in.

I have tried the settings in the mesa manual, and checked out the settings on grail tone also but I can't get anything resembling a Petrucci tone. Again I understand I am not playing through 6 4x12 closed back cabs, but I was expecting something in the same timezone.

I am not giving up, I understand this amp needs to be tweeked to find the sweet spot. I love the clean tones I get out of R1, it seems you can spin the knobs anywhere and still have a nice sound on that channel, but I have it dialed in just the way I like it. R2 is an interesting channel, I can easily dial in a different clean tone to a nice lead tone/chunky ryth tone, but the lead chan has me confused.

I think I will start by changing the tubes and go from there.

I tried a processor through the front of the amp, havn't even tried the loop yet, and it sounds great on C1 without using the processors preamp or anything like that, just the delays and mod effects.

I know this is not a recto, but I was expecting a little more focused distortion. I was playing through a roadster last week, and I just couldn't stop. I loved the distortion on that amp and I thought the clean was great too.

Keep in mind, I owned a MKII for a long time, and that amps distortion was beautiful. I was kind of expecting something close to that. That amp had an evm12, could that be it? The nomad I owned had a C-90 and that speaker handled a lot of heavy gain without getting flubby.

I tried all the different power amp switches as well as the preamp switches and I just can't find it yet. I am by no means ready to give up after only a few hours, but I am still kind of bummed.

I really went over the amp with a fine tooth comb as they say, and it really looks brand new, New like nothing is even broken in yet. Newer then an amp sitting in a showroom. Could that have something to do with it?

As always, comments and questions are welcomed and appreciated. Thanks.

 

[eltrain858]

where do you have the bass knob set on the lead channel? if it's above 2, try turning it down.

also, cabs make a huge difference to tone. what were you playing the roadster through? as a related but slightly aside comment, man i wish they made widebody thieles...

 

[trickyrick]

OK, instead of addressing all of the great replies separately, I will address them as best I can in one post. I have tried several axes, some with hotter pickups. I have an S520WNF with stock PU's because I like the dark tone. It sounds great clean. I have an RG570 with a Duncan TB9? It's basicaly the Lynch pickup and it's lower output but with the basswood body it's pretty hot. I have a vintage G&L S500 with ash body and that axe sounds good through anything.

I have played with the bass controls and yes it does make a difference. It is certainly not like other amps. However, I have really been playing with the EQ today and found playing with the 80 slider is a great way to get low end. I also found maxing out the 6600 slider causes a bit of microphonics, is this normal? It is in any channel.

I spoke with mesa to find out when the amp was built, (Chris said 03 by the way, the amp must have been in a store for a while, because I still can't beleive how mint it is) I asked him about the color codes on the tubes, he said that is how they match the sets and has nothing to do with bias. greens, greys, reds blues, whatever there just a matched set.

I have a boss GT6 which I love, I used to run it in the front of my last amp. I tried it in the effects loop and it works great. Better then expected. All of the modulation effects sound fat and round and there is no noise what so ever. In fact the amp is quite on all channels. I was fooling around with some of my heavy presets on the clean chan and was blown away by how it sounded. I needed to adjust some of the preamp settings on the GT6 but it was way cool. Then I tried some lite TS9 type of boosts on the lead channel and boom there it was the sound I was hoping for. So I play for half an hour on this one setting and I am really getting into it. So I switch the loop off to just the amp drive and I think, hey this sounds pretty good without effects. WTF more confussion.

So in summary, I realize to satisfy my heavy recto jones, I just need to add a little boost. Hey no big deal right, I am certain 90% of us do. As far as the clean channel goes, I dig it more and more each time I play it. Add a little chorus and delay and I can pick chords all day. I still need to figure out what I want to do with channel 2, I am not trying to overload my brain man, I just want to play. I am a tweeking fool and I am ok with that. I feel like I am cheating using OD effects, but tube tone and sustain with some tastful effects make Richie a happy boy. I am sure a couple of weeks I will start posting settings on grail tone.

I am certain of one thing, I am going to try and get an EVM and build a widebody thiele cabinet. My original inteniton was to gut the combo and put it into a custom made imbuya cab and then build a matching thiele. But this cab is so clean, I can't bring myself to do it. I will build an extension and try to match the tolex the best I can, I have loads of 3/4" baltic birch in the shop, maybe I'll spray it in a textured black finish. Sounds like a winter project to me. I will post pictures and dimensions when I do, maybe I'll just try and design my own ported cab to the wide body size. Thanks for all the help guy's, My Rg is calling, gotta go.

 

[guitardude05]

You have to remember, this amp was designed in the late 80's and revisioned in the early 90's, with that being said the amp will not sound like a modern amp. It can get close, but if you are comparing to other modern amps with gobs of bottem end, then you will be disappointed.

I just got my Mark IVA and i am loving it for Rock tone and 80's and early 90's metal/grundge. However i do not expect this amp to get into any of my recto area's.

so basically what you're saying is this amp cant really be pushed into the modern metal tones of today by itself? ex: gojira, chimaira, etc.

 

[eltrain858]

so basically what you're saying is this amp cant really be pushed into the modern metal tones of today by itself? ex: gojira, chimaira, etc.

forgive my non-metalhead ignorance, but does LOG not use modern metal tones?

 

[eltrain858]

I am certain of one thing, I am going to try and get an EVM and build a widebody thiele cabinet. My original inteniton was to gut the combo and put it into a custom made imbuya cab and then build a matching thiele. But this cab is so clean, I can't bring myself to do it. I will build an extension and try to match the tolex the best I can, I have loads of 3/4" baltic birch in the shop, maybe I'll spray it in a textured black finish. Sounds like a winter project to me. I will post pictures and dimensions when I do, maybe I'll just try and design my own ported cab to the wide body size.

my solution for this (hopefully soon) will be to swap out my chassis into a head and match that with a metal-grill vert 2x12 w/ c90 top and EVM bottom. it's not the same as a thiele and combo, but its closed-back and ported on the bottom so it should achieve a similar effect. plus it will be a lot easier to carry a head than a combo, and the 2x12 will have casters (i keep them off the combo cause i stack it on the 1x12 ext). i'm gonna hold onto my wide 1x12 ext, that way i can match the head with either a fatty 2x12 for bigger gigs or with the 1x12 for bedroom jams and little gigs.

 

[trickyrick]

I am just playing through a 1 12 open back combo, I would love to experiment with a closed back 4 12 cab. Systematic Chaos sounds pretty freakin heavy to me.

 

[Rufuss Sewell]

DUDE!!! Get those 5881's out of there NOW!!!

I had my Mark IV for about a year with 5881's in it (the previous owner installed them.) I was never too happy with the tone. I like a modern metal sound or even a Metallica 80's sound, but it did neither. It just sounded like a decent rock amp. Being kind of ignorant at the time I didn't think different tubes would do much. But I finally replaced them with 6L6's and the thing came to life!!! It's been totally stunning sounding ever since. I've tried a bunch of the settings on this site and found the ones I like best.

Unfortunately I couldn't get both a lead AND rhythm that I liked at the same time so I picked up a Triple Rec for rhythm. I loved the Mark IV rhythm, but I like it's lead tone way better than the Triple rec so that's that. Now I have a huge tone palette... but I mostly love the Mark IV.

Get those shitty tubes outta there!!!