Rangemaster vs. LPB1

[javacody]

Other than the in and out cap differences, resistor value resistances, and transistor type differences, these two circuits are basically the same. Where they differ the most is the method of getting the output. How do the two methods effect the sound?

[Lonehdrider]

From a technical standpoint I'm not in a position to comment, sonically, the LPB1 I built was very much more a treble booster, the rangemaster seems more of a clean gain sort of boost to my ears. Granted with slight substitions perhaps they're more similar than different, but the LPB1 I built had my strat sounding more like a tele, whereas the rangemaster (until its maxed out that is) is more of a clean gain without coloring the guitar quite as much. Granted the LPB1 I built used a SIL tran, the rangemaster clone I built has a GE tran and I did have to fudge on some of the caps on the LPB1 because its what I had or could find easily (which could easily explain the shrill nature of the one I built). My RM clone maxed volume wise gets just this side of being a full blown distortion to my ears anyway. Now I just leave the RM on and set max volume I want for leads and then just roll off the guitar volume where it cleans up nicely for chords/rythmn work (ok I'm cheap too, I didn't have to buy a DPDT switch that way haha) . For such a simple circuit I like it a lot.

Regards,

Lone

[petemoore]

1.   GEO Technology of the Dallas Rangemaster...read
 LPB: Silicon transistor
 D.R.: Ge Transistor.
 Silicon transistors are easier to get to hold bias,
 For a Ge Booster like Rangemaster....Use alot of trimpots and sockets, or a breadboard, then hunt down your reputed to be The Right One transistor's[s?]...or do like I did 'till I finally did ^that, which is build one after the other with inconsistant or un-re-affirmed results.
 Look at the Rangepig at Marco's-Munkys site, for a  Si booster with Some "Rangemasterey" character.

[javacody]

pete, which components should be replaced with trimmers for biasing?

[petemoore]

What I'm suggesting there is a [dedicated Rangemaster] protoboard' in other words Everything is either socketted or trimpotted.
 That way you can 'diddle' with all the resistor and cap values.
 You could probably leave the Emitter resistor alone...but what the heck.
 I just used trimpots [or regular] that are at least as big as the resistors on the schematic, or socketted them,
 Just get it somehow that most all the variables can fairly easily be messed with, and use your ears and DMM to get a bias on the tranny you'll like.
 On mine I use a quite cold basement room, get bias set, then I grab the transistor for 20-30 seconds and reset the bias...if I can get a 'reasonable' range without gating or other wierdness...that's the bias setting I'll go for...having it hold a decent bias at different temps I think is a good 'bad scenario' to use for setting bias.
 Someone typed something like  this and I 'heeded', now I type: I've been really liking the VOX Treble Booster. It has lower value Base biasing resistors...I'm liking the performance!!!
 My VOX has a 5k pot trimmed down to something smaller [with resistor across lugs 1 and 3] and that sets bias on collector...everything else is probably very near same as schematic except maybe the input cap [of the two versions on the page only the incap looked different to me].

[javacody]

Pete, have you tried the ge diode trick on your ge transistors to make them less temperature sensitive?

[petemoore]

LPB questions are elaborately answered by takin the less than 10 dollars worth of parts and building one on about a 1 inch piece of perf...that should take about 20 min. [for a ..lol.. certified builder]
 No really, these LPB's 'throw' togather as easily as any schematic I've seen that has an active...and sound great.
 I've used them for different applications too.
 One into the other for overdrive/Boost sounds, to bring output level like UP^, to spice up a 'meduim burn' circuit...the latter is one of my favorites...take your basic OD tone, then kik on the LPB for the lead section...
  IMO if you build Efkts, you will have need for an LPB [or fet etc work'alike'] booster.

[saros141]

What I'm suggesting there is a [dedicated Rangemaster] protoboard' in other words Everything is either socketted or trimpotted.
 That way you can 'diddle' with all the resistor and cap values.
 You could probably leave the Emitter resistor alone...but what the heck.
 I just used trimpots [or regular] that are at least as big as the resistors on the schematic, or socketted them,
 Just get it somehow that most all the variables can fairly easily be messed with, and use your ears and DMM to get a bias on the tranny you'll like.
 .

+1.  I built a Rangemaster "testbed" circuit, with socketed tranny, I/O caps, and series trimpots for the 68k (33k resistor plus 50k pot) and 3k9 (2k7 resistor plus 2k5 pot).  I find that I don't really need to adjust the emitter trim very much.  The travel of that 50k pot plus changing batteries makes it relatively easy to get a good sound with most trannies that test decent.  The cap swapping option is something I highly recommend, you can really get a sense of not just how the value of the cap has an effect on the sound, but also its construction (mylar vs polystyrene vs paper-in-oil vs mica, etc.).