Boost circuit completed- rangemaster type

[SILVERGUN]

Here's my first attempt at a pedal circuit.....and I cheated 
I bought the board and germ. from GuitarPCB.com    http://www.guitarpcb.com/apps/webstore/products/show/3436382
The build is called a P.U.R.P. --stands for Pump'd up Rangemaster Plus and I just ordered the suggested NOS 2n404  (rated 78hfe with .0mA leakage)
I biased it to -7.1 vdc per the excellent build instructions on his website,,,I have no experience with any other germs, so I have nothing to compare it to

It's Barry's take on the Dallas circuit with a tone switch that lets you choose from 3 different input caps .0068, .02, .047, so you can choose from a standard treble boost, or 2 other switchable positions that move the boost freq. lower into the mids, and then even lower to include the full freq. range...

For me, I prefer the stock .0068 position because I already have enough bass freq. response in my amp, and that position boosts the range that I need to accentuate the "sustain into feedback" trick that I have been attempting to master.
If I made one mistake it would be that I should've installed a TO-5 socket to be able to quickly swap trannies.....and for now, I left out the footswitch to just get it up and running and see if I was going to like it.....I DO, and I will be attempting to insert this into the front end of my latest amp build, because I don't like pedals and extra cables.....(actually I will put this circuit into a pedal, with a TO-5 socket, and keep it to experiment with germs,, and rebuild a stripped down version for my amp)
I'm going to rebuild the circuit with only the stock input cap value, on turrets, with shielded cable right into V1,,, and make the effect relay switched on the front end.......wish me luck

I also thought this might be a cool idea to just build into a guitar control cavity....it's that small

As always, I need to thank jojokeo for all of his help, input, and kindness in sharing....THANKS! 

 

[smackoj]

nice work senior gun. I built a NPN version of the RM using the General Guitar Gadgets PCB and my own parts on it. I agree with you that it is really nice if you can build it with the transistor socket so you can swap different trannies without heating the board up. I don't know if there is any difference in sound of the PNP orig. vs the NPN. I wouldn't think so other than the amount of difference we could hear between diff. trannies of the same ilk.

the only negative I have had is I'm having trouble with hi freq hiss which is the most common prob with RM's. I read thru the stuff on Barry's build page and got a few ideas on how to attack that problem. Once I have that figured out I should be a happy 'booster' camper.

smacko jack     

[SILVERGUN]

the only negative I have had is I'm having trouble with hi freq hiss which is the most common prob with RM's.

Thanks smacko 
YUP....I have the same problem, but haven't gotten back to it....

I built this quickly to see if i'd like it in front of my (already heavily OD'd amp) and I do,,,,and if I go ahead and use it, it'll be all higher quality components, and just hard wired right into my preamp, for just a slight effect

Man, does this thing make it sing.....hold a note, and right into harmonic....pretty cool

[Ed_Chambley]

The Dallas Rangemaster was the first pedal I ever built.  Don't even want to admit how long ago that was.  Way cool in front of a JTM 45.  I have not been building too many these days, but a friend of mine builds loads of pedals from old boss distortion pedals.  Says the pedals are cheaper than the parts and make a great platform for any pedal he wants to make.  I guess he is correct cause I see them sell all the time on ebay sell for around $15.  Talented folks build pedals. I need more room.

You are one of those talented folks.  I am just an old hack.  Gave up pedal building when I made a delay and took it to the store and compared it to a Wampler Faux Tape Echo.  Bought the wampler on the spot and now I only have xotic, keeley and wampler pedals.  I guess you only have so much time.

Have fun in the fuzzy underworld.

Joe and Geezer's pedals are beautiful.  Looks like you are following in their footsteps.

I just got finished making 3 new amp chassis 3 x 8.5 x 19.  I like my room.

[smackoj]

I guess people like Billy Gibbons, Eric and Brian May can't all be wrong with their like of the RM? RE: the high hiss. I have found two different explanations or I guess fixes reported on line. One which Barry lists in the 'build' notes on that guitarpcb.com website you linked to. He says the germanium transistor leaking juice out the collector is to blame and can be rectified with a low value non electrolytic cap. I tried one of those last night and did get a good amount of drop in the audible hissing.

Several other fellows I have read regarding the RM have stated that using a high quality brand of resistors with 5 percent or less of tolerance is the way to fix it. One such fellow recommends Vishay resistors. I haven't tried this fix yet because I don't have any 'specialty' type resistors and not quite sure where to buy them? I'm always apprehensive about buying small amounts of stuff to try it out because of the high cost to ship.

Good luck moving forward.  Jack   

[SILVERGUN]

Several other fellows I have read regarding the RM have stated that using a high quality brand of resistors with 5 percent or less of tolerance is the way to fix it. One such fellow recommends Vishay resistors. .

I have a bunch of the 1% 1/2 watters .....supposedly the metal film is less hissy   http://tubedepot.com/r-cmf60.html
They are a little too big to use on the pc board I got from Barry, but I always use them in my amps
If you tell me what values you need and PM me your address, I'll drop a few in an envelop for you and throw a stamp on it 

[smackoj]

Thanks Gun; I will have to look again later today at what R values. I'm gonna have to revise my statement about adding a cap to lower hiss. I just went to practice last night and couldn't use the RM because it was too hissy....bummer. I will try a few other small caps to see if I notice a difference though before I give up on the idea.

later, jacko     

[SILVERGUN]

couldn't use the RM because it was too hissy

I'm gonna work on that someday.....let me know if you stumble across anything

[smackoj]

I found another 'fix' proposed by some other stomp geek on the web. He believes that the bulk of the hiss is from leaky electrolytic caps. I checked my circuit at the output tip and found no stray DC so I'm thinking that's not this boxes problem?

later, jack   

[jojokeo]

Ola ladies and gents! I will use 100pf cap across the base-collector for taming things down. See if it helps in your cases? I will use the RM circuit for testing many germs & also in troubleshooting just to make sure I didn't just blow one up   But a word of advice on this is that these things have a broad array of interaction to each other. They can take on entirely different sound & character from one circuit to another or a position in a circuit. So the RM only goes so far for sampling. This has caused me to acquire quite the collection of those little devils.
You'll notice that this circuit really does favor single coils over humbuggies or HB's in parallel rather than series. It's a matter of preference but this circuit tends to "tone down" the sound into something rather nasally if you're not careful or use to it, and it also depends on the specific tranny and input cap too. But when using a strat for example, the in between positions will really get boosted even over the traditional 1,3, & 5 settings which is way different than normal. It makes those positions really shine. Same with HB's in parallel and/or with the toggle in the middle running both pup's in parallel. The increased capacitance lessens this character I'm sure you've seen? Just like with a woman, there's always some give & take and this is no exception.
The 2N404s are a good choice for this circuit. Careful on the sockets if you want to make it permanent. I wouldn't suggest it cause they can fall out easily and packing them into the enclosure makes for more of a challenge in fitting everything in there. Also, inside of an amp chassis - I highly recommend NOT doing this. If the little skinny legged creature does fall out - Murphy's Law says it's going right to one of your B+ areas!?  

[smackoj]

thanks JoJo for the good info. I have tried about six different NPN germs and found that I like the 2N440A best so far. I will try some better quality metal film resistors next with the goal of reducing hi freq hiss. Once I get that under control, I will really be able to 'listen' more carefully to the effect. It has been a fun learning experience and the parts don't cost much in comparison.