question on tubes and marshalls

[FALKEN]

turning the treble down helps but I think that the offensive frequency is more narrow than the high shelf eq...

I have found that different tubes can make a night and day difference but I have always just told an amp tech what sound I was going for and let them decide....only I haven't had a tech in a few years so I don't know.....

ok for now I will assume it is the preamp tubes and see what I can do about that... am I correct in assuming the third tube is a rectifier tube and I should probably leave that one as is?

 

[Farview]

The tube next to the power tubes is the inverter tube.

 

[Outlaws]

am I correct in assuming the third tube is a rectifier tube and I should probably leave that one as is?

Well if the tubes are almost dead then they will be a night and day difference.

The recifier tube is generally fatter than the other tubes and almost as big or bigger than the powertubes. The thing is though that your amp doesn't have a recifier tube.
Again, back to the 'bite'.....you are aware of the routing you can do with this amp right? You have hi and low inputs with bright and normal inputs for each of those. You can use a jumper cable between them so you can mix the inputs. http://www.guitar.com.au/amplifiers/electric/marshall/vintage/1987xinputs.html

 

[mx_mx]

I would take it back and get something more appropriate for what you are trying to do. Getting the 100 watt and/or changing the tubes won't turn it into a good clean amp. Marshalls just don't do clean (not the tube ones anyway)

Are you saying my mg100hdfx does good clean?

 

[Farview]

Are you saying my mg100hdfx does good clean?

I haven't had a chance to play every variation of Marshall that has come out. There have been a couple that did clean up well, but I don't know which models they were. (or if they are still made)

 

[FALKEN]

thanks, outlaws.

that's weird that it has 3 preamp tubes then...

its not like there is a reverb...i don't get it?

yeah about the jumper cable... that's what i've been doing on the 30-watter but on the 1987x it has enough top end that I've just been playing the "normal" channel....

 

[e-dog]

It could just be that you don't like the frequency curve on one of the tubes...

JJ/Telsa EL34s sound good, kinda midrangy/bright though, you could try different brands and see what works.. In the pre stage the new "Mullard" GT-12AX7-M is pretty cool, very, um swirly, i guess, in the upper midrange, but to get rid of highs/bite usually a 12AT7 is recommended (from what I've seen), Phillips JAN 12AT7s are pretty dark, if that's what you're after.

And, I BELEIVE the ECC803S is just a premium version of the ECC83, which is the same as the 12AX7.

You could swap out either of those and see if that helps.

Also, maybe a 12AY7 for the pre, lower gain, might help with a "clean" sound.. of course, the gain stage might try to make up for it.


.

 

[Farview]

The ecc803 is a tesla 12ax7 with the old long ribbed plate design. The 3rd tube is the inverter tube, not a preamp tube.

 

[FALKEN]

weird, never heard of an inverter tube before...

what amp is this modeled after, farview? is this the one in like '75 or something when then went to a ss rectifier?

 

[Outlaws]

thanks, outlaws.

that's weird that it has 3 preamp tubes then...

its not like there is a reverb...i don't get it?

yeah about the jumper cable... that's what i've been doing on the 30-watter but on the 1987x it has enough top end that I've just been playing the "normal" channel....

A lot of amps have 3 preamp tubes. Some even have like 5...just look at those Mesa Recs.

 

[Farview]

The inverter tube is part of the phase splitter and is technically part of the power amp. I just looked at a bunch of marshall scematics, none of them had tube rectifiers except the really really old jtm45's. The Plexi's had a SS rectifier.