Lee Jackson Metaltronix Amplifiers

[Doink]

So I walked into a local used shop a few weeks ago, looking for a saddle to one of my Floyds, and they happened to have a Stealth sitting there. Vaguely remembering them from the early 90's, and being in the market for a "budget" high gain tube head, I gave it a spin. WOW! Good amount of gain, Nice tone (smoother than a Marshall, and more gain) good clean channel... I ended up buying it right then and there, for $300, and played a show with it the next night.

After playing solid state for too long, I couldn't believe the noise coming out of my cab was actually me! So thick, so meaty, so "in your face"! I kept laughing every time I hit the distortion! I am definitely a tube convert now!

Soon after, I opened it up and saw that all the tubes were the original SLM branded tubes. I took to one of the local amp shops, Eurotubes, where they threw in some new JJ's. While the basic tone of the amp didn't change much, it does have more balls and grunt now, and I feel much more comfortable with new tubes.

The shop did mention that the original tubes were running very cold, because I guess there's a weird bias limit in the amp. They ended up putting in a set of 6V6's that tested at 35 ma, as these were the only ones suitable, and that was with the bias cranked all the way over. Is this common for this amp?

I do have a couple more questions:

-With the "Gain 1" and "Gain 2" thing, are these 2 separate, but identical gain stages? Or are they different switchable pots on the same stage? If the former is true, is it possible to wire the 2 together? I'm always after more gain.

-How would I go about adding in a standby switch? Is it as simple as locating the heater leads, and rewiring them to the on/off switch, while taking the other power supply leads from the power tubes and wiring them to the standby switch?

-Knowing that Lee is rooted in the JCM 800's, would any of the mods from http://www.schematicheaven.com/modifications.htm apply to the Stealth? Namely upping the resistor values from the plate resistors

-Is there a way to wire up a lead boost? I'd rather do this internally, and have it footswitchable, rather than deal with another mess of cables and a lead boost pedal in the effects loop.

Or are any of these covered in the Stealth DVD? I just ordered mine! And hopefully I'll be ordering the Bench Warrior and Marshall Mod ones too, if I decide to try to build my own modded JCM 800.

[ClassX]

Great find,,,

You ask,,

-With the "Gain 1" and "Gain 2" thing, are these 2 separate, but identical gain stages?

yes,,, they are identical ,, but you need a 2 button foot switch to use drive 2,,,, any basic 2 button switch should work,,, button 1 will switch channels of the amp,,, button 2 will switch from gain 1 ,.to gain 2 and back again.

Thus its like a 3 channel amp,,Clean,,Crunch,,and Hot,,,,

Keep on aRockin',,,,,,
_________________
!!!ATTENTION!!!,,,I am not a amp tech,,I was an employee at the SLM electronics plant,,that made Ampeg and Crate products,,for the last 3 years before they moved operations to China,,,

[Doink]

Howdy! Thank you for your reply!

I did round up a footswitch that works with the amp, and I am able to access Gain 2, but I was hoping that it would also be an increase in gain from Gain 1, which it is not.

So, I guess to rephrase this question, is this the same gain stage, or is gain 2 a duplicate, redundant stage that I could wire up in series with the first gain to get a ridiculous sound? I can't tell from the schematic, as I am not very good at deciphering anything more complex than a JCM 800 schematic.

[George]

I myself have often wondered about those very same questions you ask!
I still have not got hold of a foots-witch yet, to access gain 2!
Gain 1, seems strong enough for all the various hair metal stuff (when cranked)--but still needs something more for the most brutal kinds of metal.
I was hoping, that when I eventually got hold of a foots-witch, that gain 2 would be an heavier gain.
If you cannot wire the 2 gain channels up like you asked, I think some sort of lower gain pedal--in combination with the amp's gain, and dialed to work with each other---might be the ticket. Just something to overdrive the gain from the gain channel--enough to do the job!
Or, a pedal on the clean channel.
Yes, I too would hope someone knows the answer to your interesting question.
Not that I would have it done, but it would be great to know!
But I've decided to stick with the pedal option rather than modify the amp in any way.
Now should I ever find another, and it can be done--that's another story!
We would of course have to know if it's possible first, and exactly how to do it (step by step).
Is the gain not enough when cranked to the max, or is it not enough when you play with low volumes?

[Doink]

Hey George! Gains 1 and 2 sound identical to me. I guess for a lot of players, this would allow them to set up one gain as a crunch/rhythm, and set the other one for full gain as a lead/solo booster.

I don't do a lot of "crunch" style, so I just crank all the gains and pre's. It's enough gain for me, but I wouldn't mind having a bit more on tap. If it is possible to run gains 1 and 2 in series, then I would like to mod it to do such.

[ClassX]

Geeez I cant imagine running both gain 1 and gain 2 in series ,,,

Well actually I can imagine it ,, ,, can you say over the top gain,,,

I have a 5 button GK footswitch somewhere that uses the standard 1/4 stereo plug,, that just may do that ,, I'll see if i can dig it out and give it a try ,,would be neat if the right combination would give you a stacked gain 1 & 2 preamp sound,,,,

Come to think about it I have an old rack mount pre amp that has 4 12ax7s in it ,, 4 distinct levels of gain ,,ch 1,,clean,,crunch,, ch 2,,lead,,hot,,all foot switchable,,,,

Keep on aRockin',,,,,
_________________
!!!ATTENTION!!!,,,I am not a amp tech,,I was an employee at the SLM electronics plant,,that made Ampeg and Crate products,,for the last 3 years before they moved operations to China,,,

[George]

Hello Doink!
and ClassX!

Just a reminder, not to blow up our amps/speakers, in this quest for even more gain!
I've yet to even get the footswitch that allows access to gain 2.

I cranked her up today, with the gain all the way up, with the preamp at five, and gain 1 at ten;
so loud, at just two on the master volume!
and yes! yes! yes! --what a great gain this amp has already!

But, if the gain from both gain 1 & 2 can be used together,
then all I can say is WOW! and WOW, A-GAIN!

What you say might work ClassX, but please be careful!

[Doink]

Is there some kind of trick to getting this damn DVD to play right? I've tried 2 different DVD drives, and 7 different programs. The very first time I popped it in, it sort of worked. It got about 3 minutes in, on the VLC player, before everything just stopped working.

Now VLC crashes when I go to play it. It says "Microsoft Visual C++ Runtime Library.
Assertion failed!
Program D:\ProgramFilesFromC\VLC\vlc.exe
File vm.c
Line 1483"

The stock Windows DVD player plays it really really really slow and reacts really really really slow.

Ants DVD player says "Access violation at address 1000BB81 in module 'player.dll'. Read of address 00000000."

Blah blah blah blah.... Do I really need to list what the other ones say or do when they crash?

[Doink]

A couple of updates here:

A) I finally got the DVD working, since switching over to a different computer. Lot's of useful info here, but nothing on any mods.

B) Upon further review of the schematic, I've determined that the Gains 1 and 2 are just 2 different controls for a shared circuit. That's ok because...

C) ...GET NEW PRE AMP TUBES! I noticed my amp was getting noticably quieter over the last couple of weeks, so I took it down to my local tube shop. They tested it all out, and my pre amp tubes proved be very worn out, so they threw in a set of hot JJ's. OH MOMMA! Now we're talkin! I'll put this up against any Marshall, Peavey, Mesa.... About the only amp I still like more is the Bogner Uberschall. No need for an additional gain circuit here.

I'm fortunate enough that one of the worlds foremost tube supply shops, Eurotubes, is just a 20 minute drive from my house. They really know their stuff, and they are very thorough in their testing and matching. They mainly supply JJ tubes, which sound frickin great in my amp! Give them a visit at www.eurotubes.com !

[George]

Glad you got your DVD working!
Little things like that can drive a person mad.

How can you not be Proud?!!
It's rather hard to believe when you come to think about it. But then you realize, that this "Crate" was designed by Lee, and you smile a rather large smile!
And the clean channel takes very well to distortion pedals.
The more I play this amp, and this is strange---I seem to be leaning more to Hair Metal--which I could never play well,---rather than the most Heavy Doom metal---which I play well enough indeed.
She's forcing me to play Hair Metal! and she is making it easy for me to do it!

Coagulations!