need more headroom...

[jdurso]

ok so lately ive noticed a huge lack of headroom in my roadster. i've begun to wonder whether its the difference between switching my power tubes to kt77s, whether i need new preamp tubes, whether i should invest in an open back cab, whether i should look at different pups for my guitar or whether its my settings?? i really cant pin-point it yet but i played an express 5:50 a couple weeks ago and was floored by the headroom on the clean channel. i'm pretty confident i can get that headroom out of the roadster but dont know if its the 6l6s or the fact that its an openback cab design or whether its just the differences in the preamp design? any thoughts?

 

[coppa]

Isnt the roadking 100W?.
How loud are you playing?.
how hot are your pickups?. try the neck pup for cleans, and roll off the volume a bit.

other than that put channel volume all the way up ang gain very low then ballance out your dirty channels to match the volume of the clean.

too much trebble on the clean channels acts like a trebble booster which=distortion

 

[nitrous2400]

ok so lately ive noticed a huge lack of headroom in my roadster. i've begun to wonder whether its the difference between switching my power tubes to kt77s, whether i need new preamp tubes, whether i should invest in an open back cab, whether i should look at different pups for my guitar or whether its my settings?? i really cant pin-point it yet but i played an express 5:50 a couple weeks ago and was floored by the headroom on the clean channel. i'm pretty confident i can get that headroom out of the roadster but dont know if its the 6l6s or the fact that its an openback cab design or whether its just the differences in the preamp design? any thoughts?

add sum presence and highs... if your at the max already try a sonic maximizer if you have acces to one, when not abused they can add a good deal of headroom. otherwise try an eq in the loop and boost upper mids and highs....

worse comes to worse buy a triple recto tons of clean headroom wiht 150watts :lol:

 

[phyrexia]

Your settings. Show them to me.

 

[jdurso]

Isnt the roadking 100W?.
How loud are you playing?.
how hot are your pickups?. try the neck pup for cleans, and roll off the volume a bit.

other than that put channel volume all the way up ang gain very low then ballance out your dirty channels to match the volume of the clean.

too much trebble on the clean channels acts like a trebble booster which=distortion

roadster is 100 watts which is what i have my clean set to. my ec1000 has emg 81s and my fernandes ravelle have a sd jb. yes i do use both pickups and do roll off the volumes for get a super clean but headroom is still lacking especially compared to the express 5:50.

ok as for settings:

channel 1: 100 watts, diodes, clean
gain 10
volume 12
treble 12
mids 11
bass 12
presence 2

channel 2: 50 watts, rectifiers, fat
gain 11
volume 11
treble 1
mids 1
bass 11:30
presence 10

channel 3: 100 watts, diodes, vintage
gain 10:30
volume 9:30
treble 1
mids 2
bass 1
presence 12

channel 4: 100 watts, diodes, modern
gain 1
volume 9
treble 1
mids 11
bass 12
presence 1

i also have an eq in the loop which i basically use as follows: (all relative to flat)
100 - up 25%
200 - down 10%
400 - down 25%
800 - up 30%
1.6k - up 25%
3.2k - flat

again, i just switched from 6l6s to kt77s due to the 6l6s dying and the kt77s being the only spares i have. when i siwtched tubes i also had to change my settings. i'm beginning to think its not the amp but rather the tubes and the pups in my guitars. i was playing a prs mira when i played the express so that could have something to do with it.

 

[jdurso]

also forgot to mention... i use the output and solo knobs as my global volumes. i use the output for the dirty channels and the solo for my cleans. i cant get the channels totally balanced since the cleans are always a little lower, so i set the solo knob a little higher than the output and using the rg-16 make sure the solo is switched on when i go to channels 1 and 2.

 

[155]

are you getting break-up sooner then you want ? Try something with a single coil, I have an lp and the 85 in the neck is really wound up and pushes the preamp too. so mabye its the pups more then anything, there may be a way to get less gain with different preamps, I dont know what they are . I play the same setting with a strat and a single coil and all that goes away. Just back off your gain a little more mabye. oh, also lower your first 2 levels on your eq some

 

[jdurso]

are you getting break-up sooner then you want ? Try something with a single coil, I have an lp and the 85 in the neck is really wound up and pushes the preamp too. so mabye its the pups more then anything, there may be a way to get less gain with different preamps, I dont know what they are . I play the same setting with a strat and a single coil and all that goes away. Just back off your gain a little more mabye. oh, also lower your first 2 levels on your eq some

first two meaning 100 and 200?

i tried my buddies srv strat and basically im hearing the same results. the best way i can describe it is that i'm not getting that airy/chimey clean i thought i had going and which i found in the express. what i'm going to do is play the express with a guitar loaded with emgs and see if its the express' voicing i like or the prs mira. also i'll play the mira through a roadster and see if its the prs' pickups that created the tone im after.

 

[155]

yes the 100 and 200, mabye the different voicing but I can get a ton of headroom of out my roadster with the same setting and an emg 85 I just back off the gain and the master vol, also the bass and it works good. I know there are ways to tame the preamp gain with the 12ax7s you can change them to somthing like a 12au7 or 12at7, dont know what it will do with the other channels though.

 

[jdurso]

i changed the strings on my guitar and adjusted my pickup height and it helped a little. i also dropped 200 a little and it brought out a little more clarity but i have a feeling it might be the kt77s. i think i'll switch back to 6l6s and maybe look into some different preamp tubes and see how it goes. still wondering if an open back cab instead of the basson would do the trick.

 

[mikey383]

I'm not too familiar with the Roadster, having never played one, but from looking at your settings I can try to recommend something. Maybe try turning the gain and the channel volume down some, and turn the master up.

I find that when I turn the gain up past 9 oclock and the channel volume up past 11 on my Dual, it tends to break up sooner. I end up having to turn my channel volumes down and the master up to get a consistent level.


Also, changing the preamp tubes to something like a 12au7 or a 12at7 would probably work somewhat, but you'll change the overall tone of the amp. The distortion channels won't have as much gain with either of those tubes.

 

[jdurso]

I'm not too familiar with the Roadster, having never played one, but from looking at your settings I can try to recommend something. Maybe try turning the gain and the channel volume down some, and turn the master up.

I find that when I turn the gain up past 9 oclock and the channel volume up past 11 on my Dual, it tends to break up sooner. I end up having to turn my channel volumes down and the master up to get a consistent level.


Also, changing the preamp tubes to something like a 12au7 or a 12at7 would probably work somewhat, but you'll change the overall tone of the amp. The distortion channels won't have as much gain with either of those tubes.

i'll try that

 

[coppa]

Im pretty sure its your setting 10oclock gain on the clean channel and emgs is bound to break up some, but if it were not:

some tubes start to sound a little scratchy as they are just about to die

someone already said above use the master volume of your amp to get your cleans loud enough. 100watts is plenty of headroom and if its not maybe you really do need a triple rec

 

[Rocky]

KT77's are a type of EL34. Granted t hey are cleaner and bigger than most EL34's but they are still 'an EL34' A 6L6 is going to give you a more scooped tone and headroom.

There is NO reason for that amp not to give you thunderous headroom. I would suggest that if you cant get enough you are playing WAY too loud.

 

[jdurso]

KT77's are a type of EL34. Granted t hey are cleaner and bigger than most EL34's but they are still 'an EL34' A 6L6 is going to give you a more scooped tone and headroom.

There is NO reason for that amp not to give you thunderous headroom. I would suggest that if you cant get enough you are playing WAY too loud.

yeah thats what i was thinking. by any chance do you know what characteristics in a amp/tube/guitar/cab/pickup or any combo of those lend them selves to more or less headroom? i would imagine a higher wattage amp with an open back cabinet with a very wide sounding speaker with lower output pups would lend itself to more headroom but i could be wrong. does anyone know the science around it?

BTW Thanks Rocky for the reply

 

[JW123]

I was reading on eurotubes web site about power tubes. A KT77 is the equivalent of a 6550 power tube, which is one of the most powerful made. A more powerful tube should give you more headroom.

Go over to the euro site and read up about their tuneup packages for mesa. Theres some interesting info over there.

On my Roadster combo I run the clean master dimed and the gain around 9-11 oclcock. I then adjust my other channels with less and less master to get a uniform level between channels. Ch 1 Clean, Ch 2 Brit, Ch 3 VIntage, Ch 4 Modern, The modern master is of course the lowest around 9-10 oclock. Mine seems to have plenty of gain, maybe your power tubes are crapping out on you. If you had some spares you might try that. Some tubes die slowly and some go all at once.

Good Luck

 

[MrMarkIII]

Yeah, speakers might be the ticket. The Roadster has two Vintage 30s, right? Those are only 60 watts. The Express has the C90, a 90 watter. Vintage 30s break up sooner than the Boogie C90.
Or try a Celestion GT12-100. More highs, lows, power handling than either of the aforementioned.
Also, take out some of the "honk" in the mid-mids and add some presence.

 

[Juancito12]

Headroom in a tube amp can be affected by:
Preamp gain stages
Plate voltage
Filter Caps
Efficiency of the speaker
Efficiency of the output transformer
Type of rectifier.
The strength of your pickups
How hot the preamp and power tubes are biased.

Your case seems to point to power tube bias. Those KT77's may be designed to break up sooner which would throw your bias out of wack. Do they run overly hot compared to your 6L6's? I mean hot enough to head the chassis to the point its scary? That's a sign your bias is off. Your headroom issue might be one bias resistor away from being solved.

 

[giantstepjoe]

On my Roadster combo I run the clean master dimed and the gain around 9-11 oclcock. I then adjust my other channels with less and less master to get a uniform level between channels. Ch 1 Clean, Ch 2 Brit, Ch 3 VIntage, Ch 4 Modern, The modern master is of course the lowest around 9-10 oclock. Mine seems to have plenty of gain, maybe your power tubes are crapping out on you. If you had some spares you might try that. Some tubes die slowly and some go all at once.

Good Luck

I am doing the same as this on my Roadster head. Also I am using higher wattage speakers which give me a ton of clean headroom. I am currently using 2 mesa 1x12 cabs EVM-12l loaded ( 200 watts power handling each); one a halfback and one a thiele.

 

[jdurso]

Headroom in a tube amp can be affected by:
Preamp gain stages
Plate voltage
Filter Caps
Efficiency of the speaker
Efficiency of the output transformer
Type of rectifier.
The strength of your pickups
How hot the preamp and power tubes are biased.

Your case seems to point to power tube bias. Those KT77's may be designed to break up sooner which would throw your bias out of wack. Do they run overly hot compared to your 6L6's? I mean hot enough to head the chassis to the point its scary? That's a sign your bias is off. Your headroom issue might be one bias resistor away from being solved.

the kt77s might run a little hot but theyre from eurotubes and are preselected to a bias that would match the el34 setting on the roadster. i think its coming down to my tubes although i think an openback with a c90 will also help.