Removing two tubes to reduce power,60/100 watt switch,attenu

[Tmuggie]

Hello
I finally got a mesa boogie after many years of wanting one. I traded a guitar for the f100 212 combo. I like the amp ok but am a little dissappointed with the overdrive channel. I like the tone of it but it sounds muddy...not much definition. What I am wondering is if you crank it really loud will it tighten up any? I can't play it loud for anytime at all because I will end up divorced , the neighboors will hate me and I will end up completely deaf...(half deaf already).
I don't know how old the amp is. It has mesa tubes in it, I don't know if they were ever replaced, if they need replaced, or what ever.
Part of it could be my guitar....it is a Mexican strat with a humbucker and two single coils.....probably stock pick ups and dont know the specs. I am really starting to hate that guitar but that is another story....but anyway back to the amp. Can old tubes have that big of effect on the definition of the sound? I read a few reviews on the f100 combo that stated similar issues with the muddiness of this amp.....so I am not really sure what to think. I have noticed that when I do crank it it sounds much better but I cant enjoy it because its way too f'n loud. I don't gig anymore, I play just for my own enjoyment. I know it's way too much amp but I am going to live with it. Also... the style of music I play is rockin bluesy metal.
Another thing I was wondering about is taking two of the tubes out,outer or inner (does it matter?) and plugging the speakers into the 4 ohm socket. Will that damage something? Also....the 60/100 watt switch on the front....what exactly is going on there?(electronically)
Could I theoretically have a thirty watt amp if I took two tubes out, put it on 60 watts and plugged the speaker in to the 4 ohm slot?
IF that were ok then I am thinking about putting a attenuator on it....50 watt model would be ok wouldn't it?
Any advice appreciated.

 

[94Tremoverb]

The half power switch shuts off two of the power tubes, so you wouldn't gain anything by pulling two - depending on which pair you pull, you'll either get no difference or silence.

Bad, old or worn tubes (preamp tubes especially) can muddy the tone. If it's from one of the times Mesa were using Russian tubes, they (along with most of the Sovteks) are just muddy anyway, as are JJs, in my experience. If you don't want to spend money on NOS types, at least make sure there are fairly fresh power tubes in it, and Chinese preamp tubes (easy to identify by the bright chrome twin strips on each side of the plate structure). You might also want to try some different types (not just brands) of tubes, in particular a 12AT7 in the phase inverter position which will give more clarity. The Lead channel is voiced pretty dark anyway though, you may just not like it.

No, a 50W rated attenuator is not enough if you're going to crank it. Even in 60W mode the amp will put out more than 50W clean, and even more driven into distortion, if you're going to. 100W is the minimum.

 

[Tmuggie]

Thanks for the info. Is there any way to tell who made the tubes?
I will get some numbers of of them and post them later this evening.
Thanks!

 

[RectoStudioGuy]

As far as pulling two tubes out this is the general consensus on that:

"Then there are those folks that have the great idea of pulling two tubes out of their 100 watt amp to turn it into a 50 watt amp. To put it bluntly
and get a lot of argument, this is a stupid idea. A great amp is made up of many components. Power transformers, output transformers, capacitors,
and other parts, make up the design. If one takes a Marshall 100 watt Super Lead, and pulls two of the tubes, and properly sets the impedance
selector, turning the amp into a 50 watt amp, what actually happens? Well, we have a 100 watt power supply, that is now even less taxed than
before. The "50 watt" Marshall will now have less dynamics, less feel, less touch sensitivity. It will be a nice, clean, 50 watt amp. Its 100 watt
power supply will never reach saturation. Its output transformer will never be pushed. It will actually be cleaner than it was as a 100 watt amp at
most settings and have greatly reduced touch dynamics. The only distortion you will get is when the output tubes are at their limit, and this will be
an unbalanced sound, although some might think this is just to their own tastes."

 

[MrMarkIII]

The 60/100 switch is there so you don't need to remove two tubes.
Also, when it comes to mud, the manual is your friend:
"Too much Bass will cause a flabby unfocused sound that can’t be
dialed out because excessive Bass has been introduced to the
pre-amp in the early stages.
Try setting the BASS control to (7:00) for clean sounds in the
CLEAN Mode and (4:00) or below when dialing up High Gain
overdriven sounds in this Mode. In the Channel 2 / CONTOUR
Mode, try setting the BASS somewhere between (10:00 through
2:00). These settings will depend upon the amount of Gain and
Treble that you have dialed up."
Manuals can be downloaded at the website.
Hope this helps

 

[Tmuggie]

I looked at the tubes in it and the power tubes, 6L6 gc str 430 on the outside, green.
454's, gray on the inside.
12ax7a Russian 2 in all the pre amp.
Is it standard practice to mix the power tubes like this?
I also noticed that the outer two power tubes are brighter than the inner ones and one of them sometimes has a blueish glow to it.
They all appear to be on when the 60 watt switch is flipped.
Is this normal? Sorry for all the questions and thanks for your paitience.
I am new to tube amps and just trying to figure out what is normal.

 

[MrMarkIII]

I looked at the tubes in it and the power tubes, 6L6 gc str 430 on the outside, green.
454's, gray on the inside.
12ax7a Russian 2 in all the pre amp.
Is it standard practice to mix the power tubes like this?
I also noticed that the outer two power tubes are brighter than the inner ones and one of them sometimes has a blueish glow to it.
They all appear to be on when the 60 watt switch is flipped.
Is this normal? Sorry for all the questions and thanks for your paitience.
I am new to tube amps and just trying to figure out what is normal.

Hey, welcome to the club!
I wouldn't say it's "standard", but it's not unusual to mix tubes to get different sounds. It's more common to find variations in the pre-amp tubes. The STR-454s, by the way, are great tubes. Hang on to those!
The "glow" within any tube really doesn't mean much, and certainly doesn't indicate imminent failure or excessive wear, etc. It's just an indication of trace amounts of gas in the tube.
All the power tubes remain lit, even in 60 watt mode. The unused pair is in standby.
Hope this helps

 

[Tmuggie]

Hey, thanks glad to be here and glad to have finally gotten a boogie!....it just needs a little tweeking.
The 454's look newer than the 430's, I don't know if they are or not but they look it.
I will eventually get around to replacing everything in it but I think I will concentrate on the preamp tubes right now. I have read several threads talking about the tubes in the v1 and the v4 slot. I am wanting more definition in the low end on the drive channel. Any suggestions?
I am also going to get another guitar. I have a Taylor I am wanting to trade for a Carvin, a dc 200 or 400 hardtail to be specific. I used to have a dc-200, loved that guitar but it got swiped.I think that would do wonders for the amp.

 

[94Tremoverb]

Mixing power tubes is OK as long as all four bias in the right range at the same time - which they should do if they're all Mesa tubes. There's some evidence that running slightly mismatched pairs gives a more complex, richer tone too. I wouldn't worry about it yet, anyway. The 60W switch turns off the cathode connections to the tubes, so they are shut down from a signal current point of view, but the filaments remain on so they still glow orange (but not blue). The difference in filament glow doesn't make any difference, tubes just vary in this. The blue glow is almost never anything to worry about either, contrary to the very widespread popular myth - usually it just indicates the tube is working and healthy. (There are a very few cases where a blue glow is bad, but it's a different type of blue from the normal one and you can tell, if you know what to look for.) It may be worth swapping the inner and outer pairs round to see which (if either) sound better in the 60W mode. If you were actually only ever going to run the amp in 60W mode, it would in fact be better to remove the unused tubes, since there is some evidence that running them for extremely long periods with the filaments on but no current flowing can reduce their performance.

You are right to concentrate on the preamp tubes initially. If it has all Russian 2's in the preamp it will certainly sound muddier than it can. You could change just V1 and V4, but V2 is also very important to the tone of the distortion channel - maybe even more than V1, and even V3 makes a difference - so considering the cost of them, I would replace them all. Mesa's Chinese preamp tubes are fine if you don't want to start experimenting with more specialised ones just yet. Keep the Russians as spares since they are at least fairly reliable.

 

[Tmuggie]

Thanks for all the info and knowledge guys . I will try some of those suggestipns.
I had an old tube that came out of an pos crate that I still have. It was an 12ax7a "hot rods" made in china.... Put in the v4 slot. Seems like it sounds worse so I'll try it out somewhere else. I used to have some kind of 12ax7 that I used on the crate in place of that one... Tore the house apart the past few days, can't fond the m f'r anywhere. I got it from my dad years ago. He had a bunch of old tubes in a cardboard box. I'm gonna call him an see if he's still got that box... No tellin what he may have in there.
There is a place here in lexington called " pops resale" . I go in there pretty regularly. Well.... He had a big box of tubes in there for the longest time... Always there... sitting in the same spot, I never needed them before. I went in there the other day ( big smile on my face) and wouldn't you know it, some guy had come in there a few days before and bought the whole damn box. I was pretty bent outta frame to say the least!!

 

[YellowJacket]

As far as pulling two tubes out this is the general consensus on that:

"Then there are those folks that have the great idea of pulling two tubes out of their 100 watt amp to turn it into a 50 watt amp. To put it bluntly
and get a lot of argument, this is a stupid idea. A great amp is made up of many components. Power transformers, output transformers, capacitors,
and other parts, make up the design. If one takes a Marshall 100 watt Super Lead, and pulls two of the tubes, and properly sets the impedance
selector, turning the amp into a 50 watt amp, what actually happens? Well, we have a 100 watt power supply, that is now even less taxed than
before. The "50 watt" Marshall will now have less dynamics, less feel, less touch sensitivity. It will be a nice, clean, 50 watt amp. Its 100 watt
power supply will never reach saturation. Its output transformer will never be pushed. It will actually be cleaner than it was as a 100 watt amp at
most settings and have greatly reduced touch dynamics. The only distortion you will get is when the output tubes are at their limit, and this will be
an unbalanced sound, although some might think this is just to their own tastes."

Of course there will be a lot of argument =-o

This hasn't been my experience at all with my Dual but a Recto isn't a Marshall and I can yank out a rectifier tube to adjust the power supply to work correctly with tubes. I also run my Dual with two Yellow Jackets and two empty tube slots and I have done so for quite some time. The amp is still very responsive and clips like crazy. The clean is incredibly warm and the gain is thick with a lot of clarity. The plus side is that with the lower power and lower bass provided by EL-84s, the amp tracks much faster and doesn't have the same 'flubbiness' as it does running at 100watts.
I would postulate that the "less dynamics, less feel, less touch sensitivity" is simply a product of less power which means a 240watt 4 x 12 with stiff speakers (v30s) is simply too much power handling capability for 15watts to deal with. The same effect is produced with 50watts, but to less extent. Everyone knows a Triple has more oomph than a Dual or a Single. Swap to a 100watt or a 60watt cab and the lower power situation can easily hold its own.

 

[RectoStudioGuy]

Great! Though I would think that it's the early break up of the lower wattage EL-84's that attribute to a good portion of that gain rather than the reduction of tubes. I use a deep mod 20/20 for some gig's and pratice of course and always enjoy that chiminess that comes in with it's early break up. (Though I can't say that the 20/20 always play's well with others :wink: )

 

[94Tremoverb]

Running Yellowjackets isn't the same as just pulling power tubes though - it changes the amp to cathode-biased (NOT Class A), which will alter the dynamics, feel, harmonic overtones when overdriven - and running EL84s also produces an impedance mismatch (unless you compensate for this by connecting the cab to a different output) which will change the tone as well. It changes far more than just reducing the maximum power output, which is what pulling two tubes does.

I sort-of agree with the comments in that quote, but I disagree that it's necessarily a bad thing. Pulling two power tubes *does* make the amp cleaner and have a sharper transition into overdrive, and less subject to sag exactly because the power supply is working further away from its capacity, but that doesn't mean that the amp will sound bad. It's absolutely no different from turning down the master volume to the same power level with all four tubes in - the sag is dependent only on the power output, and it doesn't matter whether that's via two tubes or four, the power supply doesn't "know". In an amp where you're pushing the power stage to get the distortion, it will reduce the touch sensitivity, but not in an amp where the distortion is coming from the preamp.

 

[RectoStudioGuy]

Running Yellowjackets isn't the same as just pulling power tubes though - it changes the amp to cathode-biased (NOT Class A), which will alter the dynamics, feel, harmonic overtones when overdriven - and running EL84s also produces an impedance mismatch (unless you compensate for this by connecting the cab to a different output) which will change the tone as well. It changes far more than just reducing the maximum power output, which is what pulling two tubes does.

I sort-of agree with the comments in that quote, but I disagree that it's necessarily a bad thing. Pulling two power tubes *does* make the amp cleaner and have a sharper transition into overdrive, and less subject to sag exactly because the power supply is working further away from its capacity, but that doesn't mean that the amp will sound bad. It's absolutely no different from turning down the master volume to the same power level with all four tubes in - the sag is dependent only on the power output, and it doesn't matter whether that's via two tubes or four, the power supply doesn't "know". In an amp where you're pushing the power stage to get the distortion, it will reduce the touch sensitivity, but not in an amp where the distortion is coming from the preamp.

Agreed. And perhaps I'm thinking others are like me in that when playing (clean or overdriven) the tone I'm seeking is that full power tube saturation. To me it's the sort of sound that preamp distortion, while it can be really great, cannot match that of the power amp tube.