Removing tubes question

[lex666]

Hey guys,

Amp GAS has got me wondering... If I'm thinking about getting a 100 watt Marshall amp, but I'm thinking 100 watts may be too much for my setting... Can I just remove 2 of the 4 power tubes and reduce the power to 50 watts? Is it that simple? Will this affect the tone, reliability, or anything? Do I have to remove any pre-amp tubes too? Will it need to be re-biased?

Just wondering if removing tubes is a safe alternative to getting a lower powered amp. I'm thinking about the new 100 watt JVM combo...


Thanks!

 

[Empty Pockets]

Re: Removing tubes question

So you want a 100 watt marshall but you want to cut it's power to 50 watts?

Y'know they make 50 watt marshalls too...

but i'm pretty sure the rule of thumb is that it has to be the outer pair or inner pair of power tubes. It can't be the two in the middle. I don't know if it's different on the JVM's or not -- i'm sure somebody who does will be around soon tho.

 

[lex666]

Re: Removing tubes question

So you want a 100 watt marshall but you want to cut it's power to 50 watts?

Y'know they make 50 watt marshalls too...

Yeah I know, but I'm GAS'ing for the JVM combo, and it only comes in a 100 watt version.

 

[Empty Pockets]

Re: Removing tubes question

Yeah I know, but I'm GAS'ing for the JVM combo, and it only comes in a 100 watt version.

heh yeah i was just givin you a hard time mang. Those are the new ones with the really complex circuits and KT66 tubes right? That's the only reason I'm hesitant to recommend pulling tubes as of yet.

 

[The Golden Boy]

Re: Removing tubes question

It's pulling either the outer pair and inner pair and halving the impedance.

So if you're running a 16 ohm 4x12, pull a pair of tubes- and change your impedance selector to 8.


HOWEVER...

You probably won't notice a bit of difference. Halving your power will get yourself somewhere around 12% less volume.

 

[sosomething]

Re: Removing tubes question

You probably won't notice a bit of difference. Halving your power will get yourself somewhere around 12% less volume.

12% less volume but 50 watts less headroom, which I think is the desired effect.

 

[lex666]

Re: Removing tubes question

heh yeah i was just givin you a hard time mang. Those are the new ones with the really complex circuits and KT66 tubes right? That's the only reason I'm hesitant to recommend pulling tubes as of yet.

You must be thinking of the Vintage Moderns. Those are loaded with KT66 tubes...
http://www.music123.com/Marshall-Vintage-Modern-2266-Tube-Combo-Amp-480772-i1172834.Music123

I'm talking about the JVM series loaded with EL34's... Not sure why this description says 2 EL34's... I'm pretty sure its got 4...
http://www.music123.com/Marshall-JVM410C-Tube-Combo-Amp-480775-i1172835.Music123