tube choice

[shaunsmusic]

hi guys,I'm new to the 18 watt world.A friend built me an 18 watt marshall clone,which i love,but the tone at high volumes is very crunchy.Are there tubes that produce more/less crunch so that I can vary the tones at high volume?thanks.....shaunsmusic

[kleuck]

12AY7 will lower the gain, used in the V1 position.

[zaphod_phil]

....but the tone at high volumes is very crunchy....

Congratulations. That's exactly what a Marshall 18W is meant to do! It is a Marshall after all. A 5751 in the PI will take some of that gain down, but why ruin a good amp? Or maybe a Vox AC30 would suit you better.....

[Brewmaster]

....but the tone at high volumes is very crunchy....

Congratulations. That's exactly what a Marshall 18W is meant to do! It is a Marshall after all. A 5751 in the PI will take some of that gain down, but why ruin a good amp? Or maybe a Vox AC30 would suit you better.....

+1 on all points.

[kleuck]

It's a matter of taste, i don't think every guitarist in the world likes the same amount of drive, or uses a guitar exhibiting the same ouptut level as all others.
If the DNA of the 18 watts only derives from its gain, well you can open here a topic about Marshall Guv'nor...
With a tube amp you can just with tube substitution find your own sound, and drive.
So why not ?

[zaphod_phil]

I do agree with you that tastes are different, and that's what keeps this world from becoming really boring. However, if he wants a mainly clean amp, then a Marshall 18W probably isn't the right choice. IMO the Marshall 18W's "raison d'etre" is its unique crunchy/creamy distortion tone (sorry I don't have a French keyboard).

[kleuck]

I agree, but in the distortion range is wide, one can adjust this amp to his taste, a 5751 is not that much different from a 12AX7.

[marshman]

Maybe I misunderstand the goal, but wouldn't it be easier to use guitars for that? I mean, a set of 6-ish K ohm single-coil p'ups would give you pretty good headroom, while something with a nasty 12K humbucker would see some grind a lot earlier...and a lot easier to do than swapping preamp tubes, at least in a gig situation.

[jimipage33]

I prefer subbing 270k's for the 470k's in the PI. Lowers the crunch and lends to a little more clean headroom, but retains the sparkle/chime that we love in a good pair of EL84's.

[zaphod_phil]

Maybe I misunderstand the goal, but wouldn't it be easier to use guitars for that?

I usually just roll back the guitar's volume control Actually, I was going to mention that before, and I'm not sure why I didn't. To me it seems that I get nicer tones with an 18W amp's volume turned higher up, and the guitar volume rolled back, then with amp's volume low and the guitar volume maxed.

[tubelovin]

I agree, all of my amps have a better clean tone when the amp is cranked and the guitar is backed off.

What are you using for guitars? Unless your pickups are too hot you should be able to get some geat sounds by backing off a bit.

[marshman]

A few years ago, before I'd laid eyes/ears on an 18 watter and was using a nice channel-switching Rivera, I bypassed my guitar tone pots and seriously considered bypassing the vol, as well. Now that I'm getting used to using my vol pot to control things, I realize I'm gonna hafta go in and rewire the guitar with fresh tone controls. There really are a world of great tones hiding in there once you start using those knobs.

And while the practicality in an 18 watter is debateable, the 12AY7 is still worth a look/listen...

[StarGeezers]

We tried a 5751 in the PI of the 18W Ab Min... sounds really nice, and not that much less gain...
We've been doing like ZP and using the guitar V to adjust the sound... works great on the gig... EASY too !!!

[drake]

There really are a world of great tones hiding in there once you start using those knobs..

+1, yeah, that´s why they´ve been there since the dawn of guitar amplification

Robben Ford bypasses the vol/tone controls on his guitar too; and uses an Ernie Ball volume pedal instead; and he goes from clean to dirty pretty nicely... maybe you can try that

drake

[dotfret]

Well, I don't like the modern 12AX7 in my 18watt style amp (front end is similar, but 6L6 output stage). The thing crunches too much for me, and I prefer to use NOS 12AX7, which gives a more rounded sound.

Yes, a 12AY7 in V1 will take it down, and a 5751 in V3 will also give a smoother sound, as noted above.
My suggestion, for tube rollers, is to try a 12AZ7 in V1. Less of a drop than a 12AY7, a smooth NOS sound, and a really cheap answer.
Also, I am told, the 12AZ7 is a useful sub in the trem channel if you can't find out why it spontaneously oscillates!

It does depend on what guitar you are using - the 18 watt is flexible with Fenders and overdrives too easily with Gibsons, to my mind. I am using a Nashville Telecaster mostly, and it is easy to "kick" for solos by using one of the humbucking settings, when using a single coil for rhythm.
As Phil said, you can turn the volume down ...

[grndluxe]

i tried a 12AZ7 in 2 different amps. didn't like it in either one. used a Sylvania NOS 5965 and it was closer to a 12AY7 than the 12AZ7 was. shaun wants clean and i was creamier. i have a set of NOS General Rohren EL84s that i think cause my amp to be too clean. try a set of them or email me about buying the set i have. they are only about 2 mos old and played very little. i'm looking for a better affordable set on ebay.

[dotfret]

General - there was an Italian selling those on eBay - if you got them from him, they are probably Russian, although up to about a year ago they were East German. He does test them very carefully, and matches them well.

[marshman]

Also curious now if maybe a more effecient speaker (though we have no idea what the OPs playing through) might give him greater volume before distortion sets in.