Charles Reeder's original thread is here:
'Flabby/Muddy' Bass on the Lonestar? Want to change it?
Lots of additional information and theorizing throughout the original thread, some further mod ideas, and one or two diagrams.
BASIC MOD DESCRIPTION: Add a short jumper connection between the middle and left left terminals (or wiper and high side) of each channel's Midrange potentiometer. Optionally, you can insert switches in the middle of this (these) connection(s), though you'd then have to decide where to drill a hole in your chassis or repurpose an existing one.
EFFECT: Reduces flubby bass response, especially at higher volumes; allows more precise control of bass and midrange, with more than enough low-end still available.
NOTE: Several users (self included) have reverted Channel 1 back to its un-jumpered stock configuration. The benefits of this modification seem to be more pronounced on Channel 2, and have been deemed as less effective or desirable on Ch1. Some feel that higher-volume muddiness is improved on both channels, but there may be a sacrifice of some of Channel 1's "mojo" at less-than-super-loud levels.
YOU MIGHT TRY THIS MOD IF: You feel your Lone Star's low-end response is muddy and has less definition than it seems like it could, especially at higher volumes.
YOU SHOULD NOT DO THIS IF: You are perfectly happy with the performance of your Lone Star as-is.
HOW THE MOD WORKS
Charles discovered this possibility when looking at a site for modifying Fender Hot Rod Deluxes, which, apparently, share the same symptoms in the ears of some of its enthusiastic user base. Here's an excerpt from the post Charles quoted:
Again, I have to confess my inability to make much sense out of this, other than to say that this does seem to give the Mid and Bass effect more independent control of their parts of the tone range. My own amp tech claims this should have no effect on the tone, though there's agreement here that the effect, subtle as it is, is audible.If you look at most of the older (Fender) designs with a midrange control (such as a vintage Twin Reverb), the Mid control is wired with the wiper tied to the high side of the pot, just like the bass control. This effectively turns the potentiometer into a variable resistor (a variable resistor is a 2-terminal device, whereas a potentiometer is a 3-terminal device that is used as a voltage divider, as in a volume control). On these amps, you can turn the volume all the way off by turning all the tone controls to 0. This then allows you to more precisely balance the lows and highs coming through the tone circuit.
SKILLS/MATERIALS NEEDED: Basic soldering competency; ability to take great care while tinkering in close proximity to high-voltage capacitors.
Also, have onhand a short bit of insulated wire -- literally a half an inch will suffice. A light gauge is fine.
HOW TO DO THE MOD
SAFETY NOTE: If you are at all uncomfortable with electronics, soldering, or taking care around extremely hazardous electronic components, DO NOT DO THIS. Please take the time to understand the safety requirements when opening and working with the insides of tube amps. Especially: Do not touch the blue cylindrical capacitors. Even when the amp is unplugged, they likely will contain enough static charge to cause you serious, deadly harm if touched and allowed to dump all that energy into you.
The instructions below assume:
- You understand the important safety precautions.
- You know about the LS' 5th screw, threaded up through the underside of the amp, which is for grounding and vibration dampening.
- You know how to remove the amp chassis from the cabinet, taking care to place it on a steady and well-lit work surface; and you have done this.
1. Use a small flathead screwdriver to loosen and remove the knob and plastic washer from the Mid control on Channel 1. Loosen and remove the short hex nut around the threaded collar in front of the pot. The pot should now be sitting in its hole in the chassis, loosely.
2. Push the Mid pot for Channel 1 back into the amp, still connected but out of the way. You need to do this in order to access the Mid pot for Channel 2.
3. Look down at the Mid pot for Channel 2 as it sits in the chassis. Notice that the pot has 3 terminals, only two of which are connected to any wires (the RIGHT and CENTER, as seen from the front).
4. Leaving the existing connections as-is, solder a short bit of insulated wire between the ends of the LEFT and CENTER terminals on Channel 2's Mid control. Be careful not to drip any solder onto the PCB.
5. Re-affix the Mid pot for Channel 1 and decide if you want to try this with Ch1 or not. Current consensus is probably: Not all that worth it, Channel 1 is pretty perfect as-is. But it's an easy mod to reverse (just unsolder or clip the added connection), so gauge your own needs.
6. Reattach knobs, reassemble amp + cab, and don't forget your AC and speaker connections.
Thanks to plan-x, thirstypirate, loudguitars, Chrissmoth, and all you crazy modders out there.Well, after this weekend, I would have to say that the midrange "reeder" mod is a success. I didn't tell the soundman or my drummer (who uses in-ears) what I did to the amp. After the 1st night I asked, "How does the amp sound?" The soundman said, " I had to turn you up a little and the guitar (Telecaster) sounds really clear tonight." He said that the LSC sounded more vintage than before. The drummer said that the guitar sounded less muddy. I would have to say that I did turn the mids up a little more than before the mod. I used to run them about 9 O'clock, now about 11 to 12 O'clock. I used channel two alot more for the Country stuff and just used my volume pedal position up and down for solos and louder parts of the songs. This mod is probably not for Metal guys, as the area of mids that seem reduced are in the 400 to 800 Hz range. But, the bass control now seems more active above 1 and between 3 O'Clock. I could reach back and dial in all the thump that I needed for and Classic Rock stuff. But, for Country and Blues music and if you have a Gibson guitar I would recommend it! My vintage 335 sounds very "Carltonesque" with this mod.
First impressions are that the difference is subtle at the levels I can play at home, though I can hear it. It does seem to focus the ranges that the controls affect, which is nice. So far I don't miss anything about the response I had before; I was concerned I might be unhappy at lower levels, but I can turn the bass up a lot more than before and it's fine.
This mod... goes the rest of the way by drying out the gain a little more. It removes the background murkiness, that low-end mud that the gain signature seemed to literally be standing in a pool of: everything above a certain point was nice and clear, but below that point it was submerged in muck that blurred the lower harmonics. Now it's like you can hear everything, and those harmonics have been set free. The gain is crisp, from top to bottom. Ch1 and Ch2 both benefit from this.
Couple of other things: I never really gave the Thicker setting much attention before; a while back after spending some time with the Thick setting I decided that I liked the Normal gain setting best, as it seemed the most open and uncolored. The other two seemed to cloud and flatten the tone too much for me. Now however, the other two settings seem to really step up and -- with the Strat at least* -- the Thicker setting really sings. It's actually amazing how transparent it remains, while somehow managing to really juice the gain with some real muscle. I may have to make it a practice to flip that switch when I use the Strat.
And I may be tripping, but it seems like I can get good harmonic feedback more easily now. Maybe it's all a result of the 2 mods together that I've allowed my gain & drive controls to creep a little higher... but I don't remember such voluntary feedback like this before. It's pretty awesome.
It stands out the most on ch2 with the drive on and a nice gritty tone, but I also was getting a clearer more pronouced low freq response on the clean channel with all the other wonderful harmonics unchanged ala Jerry Garcia. (awesome!)
And once again: A big thanks to (Doctor) Charles Reeder for his ridiculously productive tinkering! ("Honey, what are you doing down there??")