#1
I'll apologise now for asking a question that may have been answered elsewhere, but I'm fairly new to valve-amps and I know very little about the intricacies, I simply know I prefer the sound of valve than solid-state

I've had my Marshall JCM900 (4100 model, 100watt) for about 6 months now, and I'm wondering what sound qualities different valve types have. Mine is fitted with 5881s, which I believe are meant to have a bit more gain to them. I've read in a few places that EL34s are preferable but I've not been able to find an explanation of why, or not in layman's terms at least.

Is it possible to briefly outline the benefits of either valve type?

If it helps, I don't tend to use the natural overdrive of the valves. I love the warmth of the clean tone and how it reacts to distortion, but I like to have the clean channel as clean without the crunch so I get that from a pedal. I went for the 100watt mostly so that I have enough headroom to get the volume I need but without getting the overdrive that I don't necessarily want all the time (you can add it with a pedal but can't take it away..)

So, can anyone help?
PRS SE Chris Robertson
PRS SE EG
PRS SE Angelus Custom
Yamaha SF1000 (Both of 'em)

Laney L20H Lionheart
Marshall 1936 w/ Eminence

Rather large pedalboard..
#2
The differences in the circuit of the amp are much more important. Switching the power tubes will not have a dramatic effect in most cases, especially if you aren't overdriving the power tubes.

Also, I'm pretty sure EL34s draw more current than 5881/6l6 tubes so they aren't necessarily a direct swap in a lot of cases. I don't know if you can put EL34s in that amp without modification, so you'd need to research into that before popping them in your amp.
I don't give a shit if you listen to me or not
#3
Quote by Kevin Saale
The differences in the circuit of the amp are much more important. Switching the power tubes will not have a dramatic effect in most cases, especially if you aren't overdriving the power tubes.

Also, I'm pretty sure EL34s draw more current than 5881/6l6 tubes so they aren't necessarily a direct swap in a lot of cases. I don't know if you can put EL34s in that amp without modification, so you'd need to research into that before popping them in your amp.


I know that much, but that's something I'd pay a qualified technician to do, I'm more concerned about selecting the right ones if I'm going to change them at all. The amp will be due for a service in another 6 months so might as well take that chance to have it switched up a little and experiment
PRS SE Chris Robertson
PRS SE EG
PRS SE Angelus Custom
Yamaha SF1000 (Both of 'em)

Laney L20H Lionheart
Marshall 1936 w/ Eminence

Rather large pedalboard..
#4
Quote by makutoid
I know that much, but that's something I'd pay a qualified technician to do, I'm more concerned about selecting the right ones if I'm going to change them at all. The amp will be due for a service in another 6 months so might as well take that chance to have it switched up a little and experiment

I've got the 2100, they're both JCM900's, I'm a fan of the JJ E34L's, they've got a tad more bottom end focus apparently, might be nice if you're looking for a little boom in your stick.
Quote by R45VT
Bastards.