#1
I've heard it's possible to make a 100 watt tube amp into a lower wattage amp by taking out tubes. The goal would be to make the amp distort sooner in smaller venues. Is there a way to do this and has anyone ever done it?

The reason I need to know is that my brother just bought a mesa dual rectifier and loves it when turned up. but of course it's ridiculously loud through his marshall 4x12. He can't afford an attenuator at the moment so i figured this method could be kind of like a cheap alternative til he can get one. We have a show this saturday so it'd be nice if the solution was inexpensive, if not free.

Please don't go into how he should've gotten a smaller amp in this case. He loves the tone and we knew this might come up. He found it used for something like $1200 USD so we jumped on it.

So can we take a pair of power tubes out or is there maybe another quick-fix?
dean edge one 5 string
Schecter studio-4
Samick fairlane-6
Ibanez sb900
Ibanez btb775
Fender p bass special deluxe

Dean Del Sol
Ibanez prestige rg2610

Peavey TKO 65
Peavey vb-2
Quote by the_perdestrian
listen to revelation, for he is wise in the way of bass-fu
#2
Wait, so what you are trying to do is make an amp that usually distorts at loud volumes distort at lower volumes? If that's the case, then just add a master volume pot to the end of the amp. Right before the signal goes into the speaker, put a volume control similar to a guitar's. Now you can use the original volume to control gain and volume and the new volume to control the volume.
Gear:
Schecter Hellraiser Deluxe
Boss DS-1
Crate GTD65

GAS List:
Mesa Boogie Dual Rectifier Roadster
#3
uh we're not tech's here. and the tubes are the end of the amp. an attenuator does exactly what you said but it has to involve a dummy load and other things to not damage the amp.

EDIT: actually the thing you describe sounds like how a SS amp works to me. You did realize we're talking about a tube amp right? Maybe i'm just missing something.
dean edge one 5 string
Schecter studio-4
Samick fairlane-6
Ibanez sb900
Ibanez btb775
Fender p bass special deluxe

Dean Del Sol
Ibanez prestige rg2610

Peavey TKO 65
Peavey vb-2
Quote by the_perdestrian
listen to revelation, for he is wise in the way of bass-fu
Last edited by Revelation at Oct 19, 2008,
#4
I'm not too sure about Mesa, but amps with 4 power tubes can have either the outer two or the inner two tubes removed to cut the wattage in half.
#5
any idea which it is,outer or inner, and wether we'd have to change the ohms for it? he has an cab that can do 8 or 4. and the head can do 16 8 and 4 i believe.

and yes there's 4 6L6's i believe.
dean edge one 5 string
Schecter studio-4
Samick fairlane-6
Ibanez sb900
Ibanez btb775
Fender p bass special deluxe

Dean Del Sol
Ibanez prestige rg2610

Peavey TKO 65
Peavey vb-2
Quote by the_perdestrian
listen to revelation, for he is wise in the way of bass-fu
#6
Quote by Revelation
uh we're not tech's here. and the tubes are the end of the amp. an attenuator does exactly what you said but it has to involve a dummy load and other things to not damage the amp.

EDIT: actually the thing you describe sounds like how a SS amp works to me. You did realize we're talking about a tube amp right? Maybe i'm just missing something.


Of course. It would seem to me, though, that this would be easily possible.
Gear:
Schecter Hellraiser Deluxe
Boss DS-1
Crate GTD65

GAS List:
Mesa Boogie Dual Rectifier Roadster
#8
i should say we don't have the gear or current knowhow to do the volume knob thing and projects on expensive stuff 5 days or so before a gig isn't a good idea when you don't know what ur doing.
dean edge one 5 string
Schecter studio-4
Samick fairlane-6
Ibanez sb900
Ibanez btb775
Fender p bass special deluxe

Dean Del Sol
Ibanez prestige rg2610

Peavey TKO 65
Peavey vb-2
Quote by the_perdestrian
listen to revelation, for he is wise in the way of bass-fu
#9
Quote by Øttər
Just saw it in half... right?


smartass



as far as on topic. ive heard that what you said is possible, but im not an expert. sorry
Just call me Bobby
Member of the official GB&C "Who to Listen to" list
Quote by mikeyElite
you build guitars worthy of sexual favors

Quote by Invader Jim
if this party gets any livelier a funeral is gonna break out.
#10
ok it actually has 4 6L6's and 2 EL34's i believe...which is odd. might be what rectifier means i dunno. any ideas ppl?
dean edge one 5 string
Schecter studio-4
Samick fairlane-6
Ibanez sb900
Ibanez btb775
Fender p bass special deluxe

Dean Del Sol
Ibanez prestige rg2610

Peavey TKO 65
Peavey vb-2
Quote by the_perdestrian
listen to revelation, for he is wise in the way of bass-fu
#12
Quote by guitarcam123
could you not just buy a distortion pedal?

This is a Mesa Recto. You don't buy a distortion pedal for this amp. You crank it until mothers are crying about the future of their unborn children.

To the TS, I think you might have better luck in GG&A.
#13
You can pull two of the power tubes. Pull the two inner ones so the heat dissipates better. It's not going to be much quieter, but you can decide if you like it and always put it back.
You also need to turn the impedance switch to the next highest setting- i.e. if it's on 8 right now, switch it to 16.

Also, regarding the tubes in your amp: there are four 6l6s and two GZ34s, which are rectifier tubes- there are no EL34s.

And do not listen to asfastasdark. You'll blow up your amp.
#14
Quote by end_citizen
This is a Mesa Recto. You don't buy a distortion pedal for this amp. You crank it until mothers are crying about the future of their unborn children.

To the TS, I think you might have better luck in GG&A.

Yeah, but he doesn't want a loud amplifier, the TS wants it quite but with distortion. So he can buy a distortion pedal and then turn the amp down...
Is that not possible?
#15
It is possible, but whats the point of having a great hi gain amp if you run a distortion box before it? It wouldnt sound the same.
#16
Quote by guitarcam123
could you not just buy a distortion pedal?



yea, just buy a pedal or a GNX 1, 2 or 3 workstation ($100 used). cooking tubes just to make distortion is stupid and wont last long. your tubes will get replaced more than enough time$ to buy a few pedals on ebay.

also, i was playing with a VOX battery powered amp ($130) and it had great sound with all the built in sound effects.

good luck
Last edited by BR0THERALEX at Oct 20, 2008,
#17
Quote by BR0THERALEX
yea, just buy a pedal or a GNX 1, 2 or 3 workstation ($100 used). cooking tubes just to make distortion is stupid and wont last long. your tubes will get replaced more than enough time$ to buy a few pedals on ebay.

also, i was playing with a VOX battery powered amp ($130) and it had great sound with all the built in sound effects.

good luck



Somebody please track this guy down and torture him until he dies of blood loss? I have too much self respect to do it myself.
Then there's this band called Slice The Cake...

Bunch of faggots putting random riffs together and calling it "progressive" deathcore.
Stupid name.
Probably picked "for teh lulz"

Mod in UG's Official Gain Whores
#18
so i would pull out the two middle EL34's? and since he plugs into the cabinet's 4 ohm plug i would plug the other end into the amp's 8 ohm send.

Also, we should leave both the GZ34's in right?

I would like to note that there are times we can crank it. outdoor gigs and the like so i'm just looking for a cheap thing to do for indoor gigs. apparently our gig is in a hall so we may or may not be able to crank it. depends how big the hall is.
dean edge one 5 string
Schecter studio-4
Samick fairlane-6
Ibanez sb900
Ibanez btb775
Fender p bass special deluxe

Dean Del Sol
Ibanez prestige rg2610

Peavey TKO 65
Peavey vb-2
Quote by the_perdestrian
listen to revelation, for he is wise in the way of bass-fu
Last edited by Revelation at Oct 20, 2008,
#20
Quote by Shinozoku


Somebody please track this guy down and torture him until he dies of blood loss? I have too much self respect to do it myself.


I'll do it...

It would benefit humanity as a whole.
Enjoi <--- Friend me
Quote by Scowmoo
Otter, you're my new god.
#21
Quote by asfastasdark
Wait, so what you are trying to do is make an amp that usually distorts at loud volumes distort at lower volumes? If that's the case, then just add a master volume pot to the end of the amp. Right before the signal goes into the speaker, put a volume control similar to a guitar's. Now you can use the original volume to control gain and volume and the new volume to control the volume.

Not be be rude but that is totally wrong and would never work.

You need to look at some tube schematics. MV controls lie at the end of the pre-amp before the phase inverter not after the power stage.
#22
ok now that website says to set it to half the ohms. he can run the cab at 16 into an 8 ohm send on the amp. who's right here? i don't want to be responsible for blowing anything up.

Also i'd like to add that it's not truely the volume i'm trying to change but i'm trying to achieve less clean headroom. while the amp may not seem quieter at the same level on the volume knob i believe it would distort sooner. So he'd have to turn up less to get the same distortion...right?

and again also the above link says that it can put your bias off. since mesa's can't be rebiased(without a lot of hassle) this solutions sounds like it's not for us really. hmmm. guess i'll just have to talk him into buying an attenuator. Thanks for your help. It's been a real learning experience for me.
dean edge one 5 string
Schecter studio-4
Samick fairlane-6
Ibanez sb900
Ibanez btb775
Fender p bass special deluxe

Dean Del Sol
Ibanez prestige rg2610

Peavey TKO 65
Peavey vb-2
Quote by the_perdestrian
listen to revelation, for he is wise in the way of bass-fu
Last edited by Revelation at Oct 20, 2008,
#23
i think theres a thread about making an attenuator somewhere on here.
Quote by asfastasdark
+1. This man knows his ****.


Walker Rose.
#24
Quote by Revelation
ok now that website says to set it to half the ohms. he can run the cab at 16 into an 8 ohm send on the amp. who's right here? i don't want to be responsible for blowing anything up.
whatever impedance setting on the amp, you want the cabinet's impedance to be double that. 16 ohms cabinet connected to the 8 ohm output will be fine.

Quote by Revelation
Also i'd like to add that it's not truely the volume i'm trying to change but i'm trying to achieve less clean headroom. while the amp may not seem quieter at the same level on the volume knob i believe it would distort sooner. So he'd have to turn up less to get the same distortion...right?
wrong. the amp will be quieter at the same settings. But it won't be much quieter.

Half power =/= half volume

you're only getting a 3dB decrease by running half power. noticeable, but not half.
to get half as loud, you need a 10dB decrease or 1/10 power.

Quote by Revelation
and again also the above link says that it can put your bias off. since mesa's can't be rebiased(without a lot of hassle)
don't worry about the bias. the dual rectifier has a bias supply for the grids. you'll still have the same idle current through each tube that you had before. the problem would be with an amp that had cathode bias and shared cathode resistors. that kind of amp would run colder if you pulled tubes.

Quote by Revelation
this solutions sounds like it's not for us really. hmmm. guess i'll just have to talk him into buying an attenuator. Thanks for your help. It's been a real learning experience for me.
attenuators are okay, but they change the tone a bit. Power scaling by modifying the power supply is better, but more complex.

if you want to keep it simple, an attenuator would probably be your best choice.
Meadows
Quote by Jackal58
I release my inner liberal every morning when I take a shit.
Quote by SK8RDUDE411
I wont be like those jerks who dedicate their beliefs to logic and reaosn.