'Flabby/Muddy' Bass on the Lonestar? Want to change it?

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Wow djw, your description of the mod has made me even more thirsty and chomping at the bit to do the mod. Do you know any good Greek wines while I have the time? I'm still in limbo out here but any day now I'll be reunited and ready to do another experiment/upgrade to my LSC.

'Poop 2 Pop' was obviously my first choice for a name as well but a close second was 'Reeder Mid Mod.'

Also, thanks for the congrats. We named her Josephine.
 
THis is great. It's my first time posting. I'm going to do this mod next week. This is the only complaint I've had about my amp is the low is just too much.

Thanks!
 
'nu-tra' wrote:
"What are you using for jumper wire? Would resistor wire work?"

Hey 'nu-tra':

I used some old vintage type 'cloth-covered-wire...but I used it simply because I had it on hand.

I don't see any reason why 'resistor-wire' (without a resistor of course!HaHa!) wouldn't work as long as you keep the pieces short. Don't use any more wire than is needed to make the short 'jump' from the center contact to the empty contact on the right...or it might introduce some hum or RF interference.

I didn't find the need to use shielded wire...but rubber coated wire might guarantee that the wire doesn't 'ground-out' against the pot or chassis if you're careless when soldering.

Charles
 
Thanks Charles.

Do I need to to do both mods to this amp to fix the bass problem? I noticed there is another thread about changing out the mid pot on channel two. Is that a part of the mod that fixes the bass?
 
From 'nu-tra'

"Do I need to to do both mods to this amp to fix the bass problem? I noticed there is another thread about changing out the mid pot on channel two. Is that a part of the mod that fixes the bass?"

I have posted 2 mods for the Lonestar series of amps. Nether mod requires the purchase of ANY parts...merely some very minor soldering.

#1. Is the Channel-2 Mod. The primary purpose of this mod is to change the Channel-2 gain structure so that it sounds more like Channel-1. The mod increases the clarity and transparency of the tone. It does therefore as a 'side-effect' have some bearing on the bass sound too...but it is primarily a 'gain fix'.

This mod is accomplished very simply. It's a simple placement swap with NO PARTS TO BUY. The Channel-2 Gain Control Pot is detached and soldered into the place in the circuit where the Channel-2 Master Volume control pot is... Then... the Channel-2 Master Volume control pot is soldered into the place in the circuit where the Gain Control Pot was.

#2. Is the Midrange/Bass Mod. The primary purpose of this mod is to more precisely 'filter' the bass and midrange. It allows 'fine-tuning' of both these frequencies and helps to control and cut background 'boominess'.

This mod is extremely simple to do. It is done to the midrange pots on BOTH Channel-1 and Channel-2. One end of a piece of wire is soldered onto the middle terminal on the 'midrange' control...making certain NOT to disconnect the wire that is already there. The other end of the wire is soldered onto the 'EMPTY' terminal on the midrange control pot.(the terminal with no wire already attached).

Charles
 
I've just read all 20 pages of the Reeder Mod thread + the 4 of this thread. I'm finding the whole saga very interesting even tho I don't (yet) have a Lonestar.

I've got a Subway Blues - renowned for being dark sounding & I'm now wondering if this is the reason why.


Charles - the original quote from the Fender site said that the higher the value of the mid pot the more prominent the low-mids would be.


That might seem to stack up with the characteristic sounds of the following amps - info gleened from Schematic Heaven.


Amp Mid Pot

Blue Angel 25K
DC3 25K
Dual Rectifier 25K
Heartbreaker 25K
Lonestar 10K
Mark I 10K
Mark II C+ 10K
Mark III 10K
Mark IV 10K
Maverick 25K
Nomad 45 25K
Rectoverb 10K
Studio .22 10K
Subway Blues 25K
Subway Rocket 25K

As 10K Lin pots are readilly available - I'll stick one in the Subway & report back.
 
Charles, I did the Mid mod with the jumper wire, But I have a buzz now from the amp! Any ideas how I can get this buzz out? If I ground my guitar by using my hand to touch the strings, or any medal on the guitar the buzz is gone, I know its some kind of ground short, I didn't have this before the Mod,so what can I do to fix this!!
 
Woody wrote:

"Charles, I did the Mid mod with the jumper wire, But I have a buzz now from the amp! Any ideas how I can get this buzz out? If I ground my guitar by using my hand to touch the strings, or any medal on the guitar the buzz is gone, I know its some kind of ground short, I didn't have this before the Mod,so what can I do to fix this!!"

This is the first case of 'hum' that I know of so I'm really not sure...but it sounds as if:
(A) you have one of the wires going to ground. Possibly on the chassis or the body of one of the pots. Also, if you used too much solder...you could possibly have grounded-out the connection with a solder drip creating a 'bridge'. Or a solder 'buildup' on the connections from the channel-2 mid pot could be grounding against the underside of the channel-1 mid pot.
(B) If you used bare wire...if the piece is too long it could pick up hum or RF interference.
(C) If ANY one of your wire connections is not making good contact with the terminal...it could easily cause this as well. It would be much the same as having a guitar cable plugged in without a guitar.

I used some old vintage style cloth-covered wire (just cause I had it on hand)...but just about any wire should work out OK if the lengths are kept really short. If using longer lengths to mount toggle-switches etc....then some shielded wire might be called for. I think (but am not sure) that bare wire would be OK in really short lengths.

It almost has to be a connection somewhere. If in doubt...get some shielded wire and redo it all carefully.

Hope you get it fixed with minimum bother! Charles
_________________
 
from 'Chrissmoth':

"I've just read all 20 pages of the Reeder Mod thread + the 4 of this thread. I'm finding the whole saga very interesting even tho I don't (yet) have a Lonestar.

I've got a Subway Blues - renowned for being dark sounding & I'm now wondering if this is the reason why.


Charles - the original quote from the Fender site said that the higher the value of the mid pot the more prominent the low-mids would be.


That might seem to stack up with the characteristic sounds of the following amps - info gleened from Schematic Heaven.


Amp Mid Pot

Blue Angel 25K
DC3 25K
Dual Rectifier 25K
Heartbreaker 25K
Lonestar 10K
Mark I 10K
Mark II C+ 10K
Mark III 10K
Mark IV 10K
Maverick 25K
Nomad 45 25K
Rectoverb 10K
Studio .22 10K
Subway Blues 25K
Subway Rocket 25K

As 10K Lin pots are readilly available - I'll stick one in the Subway & report back."

To 'Chrismoth':
I definitely think you're onto something! It has become apparent to me...that the values and taper of pots have a POWERFUL EFFECT on tone...and a few simple little 'tweaks' can yield some dramatic results!

Do let us know what you discover with your 'Subway Blues'. It could help out a bunch of different folks with different amps.

Regards: Charles
 
woody said:
Charles, I did the Mid mod with the jumper wire, But I have a buzz now from the amp! Any ideas how I can get this buzz out? If I ground my guitar by using my hand to touch the strings, or any medal on the guitar the buzz is gone, I know its some kind of ground short, I didn't have this before the Mod,so what can I do to fix this!!

Wow! What a drag. I would expect what charles said. You might have pushed the wire to far and it's touching the pot casing. I had to watch out for that, so I trimmed my wire down. Also my wire was about 1 1/2" long. Very short. You got to get back in there and figure it out.
 
Charles, after I noticed to buzzing I opened up the amp and took the jumpers off, -----I still have a buzzing going on!! ---I'm Going to pull the chasse back out tonight and re check the wires that are on the mid Pots, -------One thing I did notice, -----when I have the drive switch off theirs no buzzing coming from the amp, ----As soon I engage the drive switch this is when I get the buzzing!! ----Would you say it's on the 2 channel mid Pot??? --I just want to state that this amp was quiet before this.. I hope I can get this fixed, It really sucks having this niose!!
 
Woody wrote:

"Charles, after I noticed to buzzing I opened up the amp and took the jumpers off, -----I still have a buzzing going on!! ---I'm Going to pull the chasse back out tonight and re check the wires that are on the mid Pots, -------One thing I did notice, -----when I have the drive switch off theirs no buzzing coming from the amp, ----As soon I engage the drive switch this is when I get the buzzing!! ----Would you say it's on the 2 channel mid Pot??? --I just want to state that this amp was quiet before this.. I hope I can get this fixed, It really sucks having this niose!!"

To Woofy:

Man you're having a bad day! This kinda stuff can be so frustrating!

But, before doing ANYTHING else to the pots and the wiring:

IMPORTANT! Did you re-tighten the chassis 'mystery-screw/bolt'?

There is a 'sticky' thread about it at the top of the 'Modern Era Amps' page entitled 'LSS Chassis Bolt'. It pertains to this common bolt found on many (if not all) Mesa amps.
This bolt seems to serve the dual purpose of helping to prevent chassis vibration AND grounding the chassis to the 'foil-shielding' on the underside of the top of the combo/head shell.
I left it loose once after working on a DC-5 and had a very bothersome hum and high-frequency static. I was sure that I had messed something up...until I began to 'break the amp down' again and noticed that the bolt was loose. I tightened it...problem solved.
The more gain you use...the more noticeable would be the hum. Using channel-2 with the 'drive' engaged would really cause the hum to be loud (if this is the problem).
So, go check that before going any further.

If that doesn't fix it...you COULD have a bad V1 tube (this is the tube which works the 'drive' circuit on channel-2). Does that seem like too much of a coincidence...that V1 would go bad...just as you are doing some mods? Well...I've found that the 'gremlins' are always 'lurking' around just waiting to 'trip us up' by staging coincidences that will befuddle us! So, as unlikely as it seems...your V1 could have gone bad just about the time you did the mod!

Also, you could have left a bad connection on your middle terminal on the channel-2 mid pot when you removed the wire 'jumper'. Check that out.

You could have allowed some solder to drip down inside the pot.That would cause problems! Careful dis-assembly of the pot, cleaning and re-assembly would be called for. I hope that's not the problem!

Putting too much heat on the pot for too long, when either soldering on the 'jumper' wire (or unsoldering it) could have messed up the pot. That's the 'worse-case-scenario'!

A bit of advise. And I know it's hard to follow...but...take a 'breather' and 'cool down' for a while! It's very frustrating to have something like this occur...but while you are 'on-edge' like you doubtless are right now...you could make a serious mistake...and either 'foul' something up...or even brush against a capacitor and hurt yourself!

Come back and approach the problem later...when you are calm...and you will be more likely to discover your mistake and fix it.

Regards: Charles
 
thirstypirate said:
Wow djw, your description of the mod has made me even more thirsty and chomping at the bit to do the mod. Do you know any good Greek wines while I have the time? ...
Also, thanks for the congrats. We named her Josephine.

Hey hey, Josephine! Thirsty, I'm probably too late, but I couldn't really help you with Greek wine. If you were in France or Italy, I'd be all over it; but where you are, or were, (get ready) it's all Greek to me!

Ha! Ha! Ahem.

Okay so I had a chance to open 'er up a little last night with my Strat, and here are some more impressions.

My comfort zone with the bass has moved up probably 2-3 clicks. As we all know this makes a huge difference in a Boogie, and pre-mod this would have rendered the tone basically pooped out. Now I feel like I have the same weight in the low end, but again it's much more defined and you can actually hear the bottom of it.

Back to the pool-of-muck analogy: where before the tone's lower limits could blur below the muck into indefinite mush, now you can clearly hear where it stops. It's like you can actually draw a line around the whole thing. You still get the same magical harmonic richness that the amp delivered before, but the textures seem much clearer at the edges.

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.

Finally, I may get a bug up my butt soon and figure out a switching solution for this, if purely out of curiosity to a/b the mod -- it is pretty subtle. However, though I was worried I might lose something without the switch, at this point I see no compelling need to do it. As-is, at any volume, the amp remains improved and amazing. The "loudness" thing, with the beef at low volume, was pretty cool, and maybe if I did a lot of low-volume jazz gigs it might be more useful**... but if I had to choose, I'd take what I have now in a heartbeat.

I hope I can get a chance to fire it up with the Gold Top soon and see where this takes me.

*I know Mesa recommends the Thicker setting for leads on single-coils, and now it really makes sense.
**To be clear, as Charles says there is still plenty of bass on-hand; what's changed is before there was a less-tangible low-level oomph that was more pleasing at low volume, but muddy at higher levels. But I don't really miss it.
 
That pretty much covers it. The amp before the mid mod was pleasing for a bedroom situation with no band. Big and full of sub harmonics. But live, I had to watch it, stepping into my bass player's territory, he would complain. Now the bottom doesn't get near as muddy when the bass player and I compete in those frequencies.
 
OK - I’ve been trying to work out how this second Reeder mod works – but I can’t really explain it.

So I’m just going to try it out & see what happens.

My friend Bear has come up with the wiring diagram for this such that it is switchable and a further mod which allows the 25K mid pot to be switched down to a 10K pot.

This involves wiring a 10k resistor in series with a 6.8K resistor (16.8K in total) These two resistors are then soldered between the two outer connectors of the mid pot.

This is a vague attempt to describe what's going on with the second Reeder mod

midpot1.jpg


And this is the mod I'm proposing to make such that bothe the second Reeder mod & the er... 'Bear-Mod" are both incorporated & switchable.

midpot2.jpg


Right I'm off to buy the bits - will report back later.
 
Hey Chrissmoth:

Looks like someone has been really busy!

Just to clear things up...as some of the other readers might be a bit confused by what you are proposing here....

This is a midrange-pot mod which you are doing to your 'Subway Blues'
...is that correct?

I believe you posted that the Lonestar midrange pot is 10K (incidentally the same as many of the 'classic' Fender amps)...and the Subway blues has a 25K pot midrange.

So, (correct me if I'm wrong) the purpose of the resistors which were added to the 25K pot in your diagram is to bring the 'value' of the 'Subway Blues' midrange pot down to approximately 10K (like the Lonestar and older Fenders)...and you and 'Bear' collaborated to combine that change with a 'switchable' version of the midrange-pot-mod outlined in this thread. It would seem that this combination of mods should get you a pretty convincing 'Fender-like' response from your mids and bass.

Well...I'm excited! I eagerly await your 'test results'. If this works out (as I anticipate it will)...no amp is going 'to be safe' anymore from our grubby, 'mod-hungry' little fingers! People are going to be 'custom-shaping' their EQ response to suit their needs. There is another thread already running on the board about some 'pot-swapping' mods done to a Roadster.

Let us know as soon as you have something to report: Charles
 
Yep - your summary is bang on

I'm going to town to get the bits right now

In the meantime I found this which should be of interest to anyone reading this thread

http://www.duncanamps.com/tsc/

Use the Fender model - same as a Boogie tonestack

Interestingly making C3 larger in value drops the frequency of the 'mid dip' could be of use for sorting the upper bass / lower mid problems

Have fun - see you on the other side
 
For those who are interested in some more involved mods with some added versatility thrown in...

...take a close look at what 'Chrissmoth' is doing to the midrange pot on his Subway Blues.

Those of you who have some familiarity with Rivera amps...are no doubt aware of one of the 'standout' features of the Rivera tone control setup...the 'Push/Pull-Mid-Shift' pot...which allows you to choose between a 200hz and a 400hz 'center-point' for your midrange frequencies. This is Rivera's way of allowing you to choose 'Blackface' or 'Tweed' voicing for the 'American' channel'

By using the 25K pot with a 16K resister in parallel (switchable) Chrissmoth can shift his midrange just as is done in the Rivera amps. I believe in his case (correct me if wrong) he is using the original pot with an external switch to bring the 16K resister into the circuit when desired. But by using a 25k Push/Pull pot with the 16K resister engaged when the pot was pulled...you could pretty effectively increase the versatility of your 'Lonestar' (or whatever).

Definitely worthy of consideration!

Charles
 

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