LSC/LSS owners; are you happy with channel2?Want to fix it?

[remocity]

Those setting would only be relative to way that you have your ch 1 setup as far as making a match. Plus in the stock config you don't have the ability to interplay different levels of Drive, Gain, and Master on ch 2 to get the different tones that we are getting.

Rubbish. Pots are pots!!!! All they do is let signal through. They may vary in taper (how much you need to turn them)but they allow zero signal or full signal - nothing else - unless we are talking some sort of mythical stardust going on here.

Try the mod and then go stick your head in the sand in embarassment!

 

[jonp]

Try the mod and then go stick your head in the sand in embarassment!

As I say. All the pots do is let signal though. They DO NOT AFFECT TONE. You can set the pots to any position between zero and full. The different pots just achieve it at different places. If you need a lesson on how to turn pots..............

 

[ja22y]

Those setting would only be relative to way that you have your ch 1 setup as far as making a match. Plus in the stock config you don't have the ability to interplay different levels of Drive, Gain, and Master on ch 2 to get the different tones that we are getting.

Rubbish. Pots are pots!!!! All they do is let signal through. They may vary in taper (how much you need to turn them)but they allow zero signal or full signal - nothing else - unless we are talking some sort of mythical stardust going on here.

Correction: Pots allow zero singnal or full signal AND all resistance values in between.
I think what jonp was saying is for example if gain on ch1 is at 10, then to get the same ch2 would have to be at 6. We know that the pot cutoff around 6 1/2 so it's not possible for ch2 to get this tone without the mod.
Shouldn't be an issue at higher gain setting though.

 

[remocity]

JonP is really missing out on a substantial change in sound for the better to channel 2 in all positions.
It's like night and day.
After the mod you will not be able to make channel 2 sound anything like it used to.....thank God!

 

[jonp]

JonP is really missing out on a substantial change in sound for the better to channel 2 in all positions.
It's like night and day.
After the mod you will not be able to make channel 2 sound anything like it used to.....thank God!

As I say. Hold the pot between thumb and index finger and turn in a circular motion!!!!!!!!!!!!

 

[remocity]

I can't wait for you to wake up and take 20 minutes out of your day to try the mod.
Your reaction and all your retractions of needless uninformed posts will be make for some precious reading.

 

[thirstypirate]

Rubbish. Pots are pots!!!! All they do is let signal through. They may vary in taper (how much you need to turn them) but they allow zero signal or full signal - nothing else - unless we are talking some sort of mythical stardust going on here.

If by mythical stardust you mean varying levels of resistance then, ok.

Pots can have any number of frequency centers and there by affecting a different range of freqs. The two in question obviously do.

It's not as if I was too stupid to try and find the tone on my amp with the knobs before I opened it up and pulled out the soldering iron. The sounds I get now were not there before.

 

[jonp]

I can't wait for you to wake up and take 20 minutes out of your day to try the mod.
Your reaction and all your retractions of needless uninformed posts will be make for some precious reading.

Ouch!!!

Even if our opinions on "the mod" differ, we both have a great amp!!! Enjoy.

 

[remocity]

Agreed!........Although mines better than yours now..........

 

[cb101]

I posted sometime back and I just wanted to share something with any non-mechanic types trying this mod. Be very careful with the caps. When I took mine to a tech to do the mod he showed me how much voltage can be stored, he actually got the caps to arch a little bit with the chassis, after he had drained the killer voltage from them, to demonstrate to me how deadly they can be. Please be careful.

 

[creekhed]

So...how do we discharge them as to NOT DIE?

If I play a chord and unplug the amp will the voltage drop to safe levels or is there an ADDITIONAL step?

Thanks...I just don't wanna die! lol
I HAVE done some soldering but not in this context and I do want to be safe here, know what I mean?

 

[djw]

So...how do we discharge them as to NOT DIE?

If I play a chord and unplug the amp will the voltage drop to safe levels or is there an ADDITIONAL step?

The additional step: don't touch the caps, period. (Jesus, we might be talking about serious liability here. All disclaimers apply. It should be understood that people do this at their own risk. I am NOT an electrician, so what I give you is not advice; it's an anecdotal account of my limited experience.)

My friend the amp tech does this for a living, and he said doing the above will drop the voltage down to a level that might zap you a little, but won't stop your heart from beating or probably even hurt you at all. He does this stuff every day, so I trusted his advice to me with the understanding that I took my own risk. He did say it would arc a little if you were to touch one, and in some cases might even leave a sooty black mark in the amp. In any case I took that to mean just don't f*cking touch the caps. In the end, this was not a problem for me. I was just really careful. Normal precautions like: not getting drunk beforehand, wearing rubber-soled shoes, making sure I had good light, etc.

How do you remove the chassis? I mean what set of screw do you need to remove first so the chassis don't fall of when you undo the last one. I see that there're 4 screws from the top where the handle is and a 'ground' screw that goes from the bottom of the chassis and into the top of the cabinet. So 5 screws and is that it?

Actually, it was easier than that. There are 4 screws on top of the amp. Unscrew them, and pull the amp out the back of the cabinet. End of story. (Actually, you have to unscrew the back panel thingy first, but that's pretty obvious.) The 4 screws are threaded into these square nuts that are bracketed into place on the underside of each corner of the chassis. They don't go anywhere. It's a very smart design. The only hitch I encountered was that the amp is narrower than the cabinet, so I had to jury-rig that joist setup with the back panel so I could just flip it up and out; regular old Fenders usually fill the width of the cabinet so it's a straight match.

That ground screw didn't even come into play when I did it. Which maybe means I "screwed" something up, but so far so good.

 

[creekhed]

Thank You Thank You Thank You!

 

[cb101]

He used a sort of jumper that connected to the caps. Almost like you would drain a tub of water. I didn't watch the whole process. Maybe someone could chime in that knows what they are doing on the technical side.

 

[djw]

I posted sometime back and I just wanted to share something with any non-mechanic types trying this mod. Be very careful with the caps. When I took mine to a tech to do the mod he showed me how much voltage can be stored, he actually got the caps to arch a little bit with the chassis, after he had drained the killer voltage from them, to demonstrate to me how deadly they can be. Please be careful.

Yes. Be careful, be smart. To recap, as it were:

Don't touch the caps;

Don't touch the caps;

Don't f*cking touch the f*cking caps.

 

[sbalderrama]

some more info on draining caps:

http://studentweb.eku.edu/justin_holton/caps_p.html

I find this paragraph particularly interesting:

"This means touching the chassis with one hand, and touching anywhere that's wired to the cap's positive plate with your other hand, will make your body a path for the caps to drain. Immediately it will discharge several hundred volts which will pass through your heart. If you live then consider yourself lucky. The ground you're standing on may be at the same electrical "potential" as the chassis—especially if you're in the basement or outside. So you could still be electrocuted even if only one hand is working inside the amp! Remember: what makes working on power supplies so dangerous is that you don't even have to come close to the filter caps to be killed. "


more fun conversations:

http://www.tdpri.com/forum/amp-central-station/102679-draining-amp-mod.html

Personally, I woudn't even think about working in there without checking with a mulitmeter that whatever method you used worked, and I'd probably do the "resister and alligator clip" thing and leave it hooked up. "Being Careful" on it's own is not useful... too many things can happen, you can slip, graze the circuit board, etc.

 

[ja22y]

So the 'killer caps' are the 6 blue capacitors, 2 large, 4 medium, and 2 small from the pics?
would latex glove provide insulation?

 

[thirstypirate]

Definite NO on the latex gloves. In the Navy we use thick Rubber electrical safety gloves for working inside of an energized circuit.

 

[djw]

So the 'killer caps' are the 6 blue capacitors, 2 large, 4 medium, and 2 small from the pics?
would latex glove provide insulation?

Not for the voltages in question, no. That amount of electricity would go right through them. You'd need gloves that are heavy enough that they'd be too unwieldy to do what you're trying to do.

 

[cb101]

It only cost me $40.00 to have my tech do the switch and for me it was well worth it (as it turns out, I switched back but that's just a matter of personal taste). The other thing is that, as mentioned in a previous post, Mesa will not void the warrenty if a good soldering job is done, something I can't do.