Rangemaster clone help?

[knives_on_static]

Hi guys  so i'm new to this site and building my own pedals. I decided to try with something extra simple, the Dallas Arbiter Rangemaster. I have most of the parts i need, however I was thinking of substituting a few because I found some possible alternatives that were easier to come by. Anyways, I was tinking of replacing the 100k pot with a 50k pot, the germanium transistors with silicon, the .033uf capacitors with .047uf capacitors, and .1uf capacitors with .01uf capacitors. I was wondering how this would affect the sound of the pedal and how it could possibly differ from the original?

[midwayfair]

Post a schematic. None of these values match anything in a rangemaster.

[knives_on_static]

Sorry for the mix up. I'm actually using the same parts pretty much as the BYOC Germanium boost, which is based on the Rangemaster and I'm trying to use them with the Rangemaster's NPN vero board layout. http://buildyourownclone.com/products/germaniumboost the schematic is somewhere inside the instructions. You can download them at the link i sent in the pdf file

[smallbearelec]

I decided to try with something extra simple, the Dallas Arbiter Rangemaster. I have most of the parts i need, however I was thinking of substituting a few because I found some possible alternatives that were easier to come by.

Don't solder before you have done some experimenting.

If you don't have a breadboard, do buy one, however simple.

http://smallbear-electronics.mybigcommerce.com/breadboards-and-accessories-1/

That tool will allow you to set up the circuit, make changes and see what you like and don't like. A silicon device won't give you the soft clipping with a tube amp that germanium does. The difference is subtle, but it's audible. Changes to coupling caps will affect how much low end gets through...more differences.

[knives_on_static]

Yeah, I'm starting to realize im making a few differences to the circuit. For all i know, it might as well be an original design. I would still want to know if anybody knows what changing the pot value would do and if the caps i might use are going to make the signal have more treble or low end?

[GibsonGM]

You'll have to post the schematic, knives...can't tell you what those changes will do unless we can see what it is you're talking about!  The arbiter RM doesn't HAVE a 100k pot, that I know of...it does have a 10k....got a schema?

[Ben Lyman]

I had a quick look at the link to GGG and it is really different from the original RM, it is kind of asking a lot to expect anyone else to follow that link and search for the schematic. There are a lot of knowledgable people here (I'm not one) and they can VERY quickly answer your questions if you post that schematic.
FWIW, INMHO, etc: I wouldn't mess with modding a modded GGG pedal. Also, breadboard it first no matter what. Also, if you want to make a very simple cheap silicon RM that sounds good, I have a schematic somewhere you can use. It is way less complex than the GGG.

[smallbearelec]

I was tinking of replacing the 100k pot with a 50k pot

You will want the greater resistance spread of the 100K pot to get the circuit biased correctly.

the .033uf capacitors with .047uf capacitors, and .1uf capacitors with .01uf capacitors. I was wondering how this would affect the sound of the pedal

The higher the value of the input cap, the more low end you allow in. The best reference on this subject is still R. G. Keen's article at GEOFEX. http://geofex.com/Article_Folders/Rangemaster/drm.htm

pedal and how it could possibly differ from the original?

The blocking cap in the original was .0047 mf., so you wind up with a fairly sharp cut to the low end. You might like more low-end, or not.

If you breadboard with a silicon device to start, you can use a cheap NPN device and avoid possible power supply issues.

[GibsonGM]

An LPB-2 would also give you good, "known" results using pretty much any standard Si NPN, similar parts count...just throwing that out there as a possible 2nd project for you! 

[Ben Lyman]

An LPB-2 would also give you good, "known" results using pretty much any standard Si NPN, similar parts count...just throwing that out there as a possible 2nd project for you!

Is it possible to build an Si LPB-1 with a .0022 input cap? or a .0047 input cap? or something like that, and would it basically be a treble booster? or maybe... a "trebley" booster? 

[GibsonGM]

Sure!    The input cap works with the input impedance (and capacitance...) of the <device> doing the amplifying.  "Fco" is the cutoff frequency.     

The formula is Fco= 1/(2pi)* R * C, for future experimentation.  R in Megohms, C in uFarads.   For right now, we don't need to make it that complicated, tho.

If you're using a cap a couple of orders of magnitude smaller than the original, you will be moving the Fco several times higher.  If you have a few different caps, just try them.   .002 would be quite tinny, I'm sure!!  But, changing a .1u to .05u or something - you'll definitely have some nice treble boost and that might be what you want.   

Don't forget, you can put them in parallel and they will add!  Series makes them smaller.  IE, .05 in parallel with .05 will be .1u...etc.

[PRR]

> schematic is somewhere inside the instructions



It really saves time to have the plan in FRONT of everybody's eyes.

Now that I see it, I see a mod of a mod of a mod.....

The original was positive ground, someone turned it on its head to work with common-negative supplies.

The flip-over is rudimentary, meaning poor supply-crap rejection (and the mod adds no supply filtering to what would have been a battery-power original).

The bias is clearly for a Germanium part. Silicon will need different VR1 R2 ratio.

Germanium was more common in PNP; Silicon is mostly produced NPN (tho today NPN and PNP are the same price). Using NPN makes it work-out nice with common-negative power supplies.

Overall, I think you may get where you want to be by stealing studying about any other plan. I _do_ agree with studying ALL the plans you can find.... but part of that study is seeing what works naturally and what is just clumsy.

[anotherjim]

Several things not to like about that Ge boost - in addition to Paul's comments...

Output cap C5 will probably cause switching pop when effect engaged - needs a pull-down resistor on the output side for the same reason the design has R1 on the input as an anti-pop resistor.

Bias pot goes to zero, which is pointless as a low value of VR1 will just hold the Transistor switched off. Using a 50k pot instead is reasonable BUT with 47k or 56k resistor in series so the bias can't go fully off. Those values are probably moot if you switch to silicon for Q1.

Input cap selector Sw2 will cause switching pop. C2 & C3 would need high value resistors across each one. These need to be large (4.7Meg - 10Meg) metal film type but will serve as anti-pop without affecting the bias much.

[knives_on_static]

Hey guys, sorry i've been away for a while. Very helpful replies thanks. Sorry if i was unable to post a pic of the byoc schematic. Had trouble figuring that out since im new to the site. So, if i was to use the original rangemaster, but replace several parts with those from the BYOC pedal, im guessing it would still function as a treble booster and cut the low end? I'm going to have to use 100k pots as i guess they're better than using 50k and i may still want to use the silicon transistors i have since i have tons. Will it still cut down the low end and cause a boost?

[GibsonGM]

If you want to just pop a Si transistor where a Ge is called for...no, sorry man!  It may not work at all...like PRR was saying, you'd have to re-bias the thing, dunno if you have the experience for that.  Might just get you pee'd off, and make you quit this awesome hobby!!!   A treble boost is just...a boost...that allows more treble to be amplified than bass frequencies, so....

If you have the Si transistors, and some R's and C's, you really COULD just make an LPB-1 or-2 and use smaller input/output caps, to get a good-sounding treble boost.  I'm sure there is an ACTUAL Si treble booster on here somewhere, if you look, tho!!

http://www.muzique.com/schem/multi.htm

[anotherjim]

Funny how you often think only the day after posting, but...
De-popping the cap switch - probably better if the cap-switch order was reversed -  that is the switch common facing the input and the 2 extra caps facing Q1 base. Then the de-pop resistors go from each switch/cap connection to ground..

If you just want to get on and build a Si based Rangemaster, just make this...


...other than this, it seems to me there isn't a great deal of interest in silicon Rangemasters. Thing is, since there's only one transistor and it's gain isn't that critical, it's fairly painless to source a suitable PNP Ge transistor if you only want one for yourself.
Then have the satisfaction of boasting germanium mojo.

[knives_on_static]

Thanks for that vero layout i just wanted to use silicons cuz they're easier and cheaper to find. I wanted to build at least 5 treble boosters. 1 for myself and the rest as gifts for my friends. Also, i think i read somewhere that PNP circuits cant use standard boss 9v power adapters? However i could've misunderstood that. I'll definitely be looking into building other boosters, and hopefully build a Roger Mayer Classic Fuzz next

[Ben Lyman]

Here's the super cheap'n easy Si treble booster I made for my brother and it sounds great, he loves it. You can change the input cap to something like .0047uF if you want less treble boost.
It's one of the very first pedals I made, foolproof in design, it's a great way to get yourself acquainted with the circuit for just a couple bucks.