Express mod question

[Subjecttochange]

I know this may be a bit of a heretical post but I was wondering if I could get some help.

I love the responsiveness of my clone, and the singing controlled feedback kind of thing, but my LP is a bit loose in the low end when it comes time for rhythm type stuff... which leaves me two options...

A. Become a better lead player and just stick with that... someday...

B. The more realistic option- to change the circuit a bit. I am thinking that the power tubes are just getting slammed and causing it to be muddy.

Any suggestions? I know there are a lot of guys that move to lower output pickups... but the LP sounds great with other amps.

[Jana]

Let me take a guess, no slamming/flaming intended.

You set up the amp, tone controls, etc. so that you get a nice fat lead sound, probably on the bridge pickup. Then when you go to play chords and rhythm it is all muddy.

Maybe try this: go to the neck pickup, set the tone controls for a good rhythm sound. Then switch to the bridge pickup and see if you can get the crunchy sound. It will probably be ice pick treble for a lead sound at this point, not to worry though, there are tone controls on the guitar, roll them back a bit and there is the warm lead sound.

My rule of thumb is to set the amp so the guitar has a nice chimey rhythm sound and then roll off guitar tone controls to warm up the leads.

[rooster]

Yeah, what Jana said pretty much. And actually I have altered mine a bit for the end you seek but not many here have so I won't present this. When I was looking for a solution for this issue, everybody suggested swapping pickups. Sure, there is a lot to this so don't rule this out.

But I have to ask about your speaker box/speakers, too. What is going on here? KF really built his amps around particular speakers you know. I think it was one of those 'why waste your time with crap tone?' kinda things on his part. I mean, he sure DID NOT plug into a box of contemporary Greenbacks and call it good.

Any, I would suggest you investigate this a bit, too. Really, the main thing is that you are focusing on a really BIG issue concerning humbuckers. Many famous people have figured it out, BTW, and you can, too. When you do, you will be rollin', amen! Good luck.

[M Fowler]

I don't know I use a Les Paul and the express had a lot of treble so I actually changed just changes a couple of caps to roll off that treble icepicker.

I am used to using a very clean amp and kick in the gain with a pedal so the Express and Asteroid are new creatures for me to learn volume knob control.

Mark

[Structo]

Yeah, I never was much of a guitar volume control rider.
I am used to stepping on a switch for a volume boost for lead or different tones.
This new amp I built from the Hammond organ which turned into more of a plexi more than anything is the first amp that really cleaned up well when I rolled the volume control down.
Totally different animal.

I think it pushes me to be a better guitarist in reality.

[Robbie]

I know this may be a bit of a heretical post but I was wondering if I could get some help.

I love the responsiveness of my clone, and the singing controlled feedback kind of thing, but my LP is a bit loose in the low end when it comes time for rhythm type stuff...

You are not alone. I have run into this exact same low end response. I have tried different 6V6's and EL34s along with various speakers. The amp almost wants more pre low cut to get rid of the flabbiness. After reading several threads here, there is one set up that has helped me out thanks to Glenn. Set the Brite switch to the up positions (max) then use a loooong guitar cord or tap in 2000 to 4000pf across the input jack of the amp. This adds a nice upper mid resonant boost which adds focus and counteracts the briteness. It also helps clean up the guitar when the volume is rolled back.

Good Luck,

Robbie

[jjman]

You could try changing a preamp cathode bypass cap from ~25u to ~1u. And there's no need to go online since Radio Shack often has them in stock. (I'm not concerned with heresy on preamp electrolytic cathode bypass caps. ) Or you could reduce the PI input cap by a factor of 10 or more. I used the cathode cap approach on my homebrew tweed champ. (Another circuit that is supposes to be bright but came out the opposite in my setup.)

When you consider all the variables in an amp there’s no reason to think that every value has to end up being the "gospel" one. Experiment and use the ones that work best for you.

[Buschman]

How loud are you playing? If you have the amp cranked way up the bottom will flab a bit. Turn the bass pot down and the mids halfway. If you are playing at lower volumes the bass will be cleaner and you can get away with the bass pot turned up more. It's not as tight as JMP but tighter than a tweed bassman.

[Subjecttochange]

Thanks guys.

Buschman- I am usually playing about 11-1 o'clock. It gets pretty flabby after that and I really have no need for that much overdrive. Especially with my LP, my strat usually gets a little more juice though.

jjman- I think I may try that. I have an 18watt that I did that to and it really tightened up the bass- or really just makes it more usable.

I'll keep experimenting at my practice sessions when I can really crank it for settings. I have looked into getting new Humbuckers for it (Nice PAFs or something) but honestly, I don't have all that much experience with PU swapping/types/etc. Currently, I have Burstbuckers in my LP standard if that helps anyone.

Thanks again

[Buschman]

It seems I changed R7 to a lower value to reduce gain a bit. Some people have used a 250k pot here. It would be a place to experiment. Changing the bypass cap to a 1 or even a .68 will definately tighten things up.