Dallas Rangemaster clone!

[Don]

I just "finished" building a Dallas Rangemaster clone using the instructions on the GEOFX website.

Everyone else is asleep so I only plugged it into a quiet (almost silent) amp to make sure that it works- and it does!!! I'll have to wait until morning to see how it sounds.

I built it on a terminal strip (to make it cheaper and easier, not more authentic), followed the original schematic (I might add caps and a switch to vary the boost range later) except for a DPDT foot switch and used an NOS OC44 from Small Bear.

Small Bear tested the transistor and provided the proper resistors to get almost exactly 7 volts at the collector. I was going to use trim pots and adjust it myself but I used their resistors and it came out right.

I've got the tranny in a socket for now but will cut the leads and solder it in (using a heat sink) later.

I'll paint and decal it later as well (that's why I said that I "finished" it).

I can't wait to hear it!

[Gris]

Was this from the Weber kit?

[Don]

It wasn't a kit. I pulled instructions from GEO and used parts from Mouser, Small Bear and my parts drawer.

I had Weber's Texas Cattle Drive but could never bias it correctly and get a decent sound of it. I've since stripped it of all of it's usable parts.

[Don]

The pedal sounds pretty cool! I won't get to hear it with a cranked tube amp until later, but even in a cheaper amp it sounds very cool.

Like my '69 Pedal, you can set it full up (it only has the one knob) and back of the guitar's volume or adjust picking dynamics to clean it up. It can get pretty dirty (nowhere near as much as a fuzz or overdrive pedal). It's not bright, spiky or harsh at all.

Later, I'll compare it to my '69 Pedal and Tone Bender MKII clone and follow the evolution of dirty sounds in the '60s.

I don't believe that op amps and clipping diodes improved the sound of dirt pedals!

[chuckocaster]

the obligatory TTIWWP post is in order, so i'm jumping on that grenade. all you es can thank me later.

[ziess]

Thanks man.

[Don]

Pics to follow.

[Gris]

UWP not WWP

[elicross]

Useless Without Pics, Worthless Without Pics, whatevuh. The point is, we'd like some gear porn!

Does a boost like the Rangemaster create any "dirt" itself, or does it just hit the front end of the amp with enough signal to produce clipping?

[Don]

It creates quite a bit of dirt on it's own, but it's on top of a dirty amp that it really shines.

This device is really a lot like an old, non-master amplifier. It has a volume that it needs to be set at to get it's sound. Your amp needs to be set at a certain volume as well. From what I've learned so far, these settings are LOUD!!!

It has a real, vocal, vowel like "honk" to it! It sounds great, but it will need some adjustment to be truly useful.

It's really nothing to look at.

The outside-

The inside (I will cut the leads on the tranny and solder it directly to the terminal strip)-

[Gris]

IIRC the pedal will short out (no sound) if the transistor hits the metal bottom, so you may need a piece of foam there (on the backside of the bottom) ...

[chuckocaster]

cool!

REMEMBER GRIS: i am a .

[Don]

For now I've been insulating between the tranny and the switch and letting the tranny contact the pedal cover with no problem.

The only problem that I had with this build was that the instructions assume that you know how to wire a DPDT bypass switch. I didn't. I had to jump online at midnight and look it up! Even then, it fired up correctly the first time!

[Gris]

Hmmmm, my Tonebender will NOT work at all if the bottom cover is reversed and the foam does not insulate the three G transistors form the cover...

[Strat Cat]

As long as the transistor's casing doesn't have continuity with the emitter, base or collector there's nothing to worry about. A lot of metal body type transistors have continuity between the case and the collector.

[Don]

Gris, Could it be that your Tonebender has a PNP tranny but is wired with a negative ground rather than positive ground so that you can use a regular power supply with it?

My Rangemaster clone has a PNP tranny and has a positive ground.

[Gris]

No cant use a reg neg tip with mine... just battery or funky doodle tip...

[Don]

This thing sounds great in front of my Express with the Express set in it's "Blues" mode (the Express has 4 modes with varying types and amounts of gain. "Blues" is the second lowest).

The sound has a nice crunchy texture, not too much gain, anf the notes fade into feedback if you like by raising the guitar's volume control as the notes fade.

[Franklin]

Awesome!

[Mandopicker]

Nice work.

I have been experimenting with that design for a while now with great results.

Though one thing really stumps me.

How is that the designs available are based on the original, yet current versions seem to use a 9 volt battery instead of the original 4.5 volt battery?

I realize that a 4.5 volt battery is unavailable without creativity, but I am positive that this makes a difference in the tonal capability and response of the pedal.

I still believe that 9 volts is too much voltage. I have even experimented with a 4.5 volt wall wart and the tone seems to be a lot less harsh and much better in my opinion. (Even used dying 9 volts measured close to 5-6 volts and it also sounded better.)

Am I wrong to assume that current pedals using a 9 volt battery will not sound exactly like the originals? This presumes that the resistor and cap values are equal to those found in a reversed enginered vintage pedal, and the only real change is the use of a larger battery.

I have photos of mine pedal, but I am having difficulty uploading for some reason. (I think you would find the design interesting. No terminal strips, just free floating point to point. Very stable and secure and looks real cool.) Photos show the use of an NTE Germanium Trans, but final version uses NOS OC44. (I'll keep trying to upload.

Looking forward to thoughts.

Again, beautiful job!

[Don]

The 4.5v battery would have to make a difference. The transistor wants to see about 7 volts at the collector though. I don't know how it was done considering that the schematic is supposedly the same.

I suppose they were just originally run on very low voltage.

I just added a switch to change input capacitors on mine last night (I only work on it late at night). It adds a very useful, fatter tone.

I can't get over how great this pedal sounds!

BTW, the transistor in mine is a CV7003 which I'm told is the military version of the OC44.

[Gris]

I have some extra OC44 if anyone wants to make me one... :-)

[Mandopicker]

Given that the original voltage was only 4.5 volts, I think that 7 volts on the collector...in modern versions...might just be more than the designer intended. I think the idea of getting the right tone is starving the collector of voltage a bit more than to give it 7 volts. Never would have been possible with the original design and the use of a smaller battery by half.

Try using an old 9 volt battery with anywhere from 4.5 to 6 volts and listen to the difference. (Even 1x 1.5 volt and 1 x 3 volt watch battery put together.)

IMO: If you like the tone with a 9 volt battery, you'll really love it with less (4.5 to 6 volts)

Also, I installed the switch to go from .001 or .01 cap and the combination of available tones is really good. Also added high value resistors (2.2M) to ground at the input and output to alleviate the switch pop.

They are great pedals and figuring them out is a lot of fun.

Anyway, thanks for letting me chime in.

[Don]

I stopped by Radio Shack today to get a DPDT switch so I could switch from the stock .005uF input cap to .012uF and .020uF. While I was there I grabbed a 3xAAA battery box so I can try it at 4.5 volts.

I read that it's warmer with less gain at lower voltages.

Even though an OC44 is supposed to see about 7v at the collector doesn't mean that they used it that way in this design.

[Gris]

There was an ancient by now thread years ago on Weber board re differing voltages, etc, etc...

[Mandopicker]

It certainly seems to sound warmer with less voltage and there would also be the perception of less gain, but frankly there is already quite a bit available. Check it out and let us know the results.

Here is another tip...the pedal works best through a cranked amp...not getting the full thrust at bedroom levels. Just wait until the neighbors are out and your wife's at Yoga class and let it rip. That's what I do.

I'd love to find that tread, Gris.

Thanks.

[Don]

Here is another tip...the pedal works best through a cranked amp...not getting the full thrust at bedroom levels. Just wait until the neighbors are out and your wife's at Yoga class and let it rip. That's what I do.

I tried it that way and like it. I actually don't care for it at all in front of a clean amp. It's really cool in front of my Mesa/Boogie amp in it's "Blues" mode where there's a moderate amount of gain.

It's a loud device that likes to be placed in front of a loud amp.

[Mandopicker]

Happy Thanksgiving fellows...

I owed you guys a few photos of my Rangemaster Clone. Since these were taken I have added an OC44 and water decal graphics similar to those found on original Rangemasters. I will try to upload a few shots of the final version. Hopefully this gives you a good idea. Tried to keep it real simple.

It does have a internal plug for a 9 volt and functions as expected, but I usually play it plugged into a 4.5 volt wall wart.

Enjoy.

[Don]

Very cool! I like the point to point wiring. Very neat work!

I might add an LED to mine later. My goal was to start close to the original and add what I think I need as I go.

I've started working on a decal for mine. I don't know what I want to call it yet!

[Don]

I just tried this at 4.5v (4.82v, actually- 3 AAA batteries) and about 6v.

I liked it a lot at 4.5v. There was less gain and is was less bright, more balanced. It almost made the input cap switch redundant.

My case is too small for the 3 x AAA pack. I wonder what their life expectancy would be in this pedal?

Can I safely use a 5v voltage regulator to drop the power down to 5v?

[chuckocaster]

don, you got a pedal power2? if so you can sag an output. if not, why not run a resistor on your 9v input jack? put it on a switch, or maybe pot a pot in there to adjust the bias? i've seen that on several pedals.

[Gris]

Yeah, yeah, I like the pot idea.

[Don]

No Pedal Power- no jack on this pedal either. I use a daisy chained power supply. I wouldn't work with the PNP tranny.

I suppose I could measure the bias with the 4.5v battery pack connected and use a trim pot to set it at the same voltage with a 9v battery connected. I could put it on the side of the case and change it on the fly.

I have spare 5v regulators. The nice thing about them is that it's always 5v no matter what the current draw is.

[chuckocaster]

gotcha, maybe the 5v is the best way to go then. i still think the pot would be cool though.

[Strat Cat]

If you can fit a 9V battery inside you could add a simple voltage divider circuit with a pair of 10K resistors. That would give you your 4.5V

[Mandopicker]

Great idea Strat Cat...

Thought about it, but never did try to implement that feature.

[Don]

Yes! I'll run down to my laboratory and give that a try tonight. I could put it on a switch.

[chuckocaster]

just thinking out loud here, but couldn't you just clip and reverse one of the power plugs on your daisy chain?

[Don]

just thinking out loud here, but couldn't you just clip and reverse one of the power plugs on your daisy chain?

No. They have to be isolated to do that.

[chuckocaster]

well, there ya go.