Dallas rangemaster treble booster schematic

As a result of that the bias point of the pedal will change from one unit to another, to fix that and try to make the best sound out of the pedal we have two options:. It is commonly agreed that the ideal bias point for the Dallas Rangemaster Treble Booster is to have Q1 collector voltage at The bias point has a direct effect over the output waveform shape and the sound of the Rangemaster. In the image below you can see the output signal with different Vb values when the Volume knob is maxed out:.

But part of the character and mojo of this pedal remains on its biasing. The simplicity of the circuit makes builders experiment adding some extra features so players can have some more knobs and switches to play with.

The Dallas Rangemaster Input Cap modification is the most popular one. By simply changing the C1 input cap we can transform the frequency response making it more limited or wide. This modification is not as popular as the Input Cap Mod and for a reason.

Although it has to be admitted that 10nF is a low value for an output cap many pedals use caps in the nF to 47uF range for this. You can get more info about this is the Bias Section. Thanks for reading, all feedback is appreciated: info electrosmash. Skip to content. These vintage resistors could bring more organic sound but also are blamed to bring the noise.

For other vintage effects like the Fuzz Face that noisy by definition , carbon comp resistors are a great choice adding a bit more noise to a high gain fuzz wont hurt anyone. On the other hand, for a booster like the Rangemaster maybe carbon comp technology is not a good idea you want to keep all as clean as possible , so modern film resistors are a better choice.

The potentiometer: The original Dallas Rangemaster uses a UK Welwyn 10k ohm sometimes 20k unit with two mounting screws. The potentiometer body was made of bakelite and isolated from the chassis, but this feature does not add any benefit for the pedal. The original Germanium transistor was the Mullard OC44, long time ago discontinued. They are claimed to sound good with a soft clipping knee but also noisy, microphonic, temperature dependent and gain variable.

Capacitors: There is not much magic involved on the caps, they are just common available technologies: 47uF is aluminum electrolytic, de 5nF and 10nF are films. Dallas Rangemaster Treble Booster Schematic. The circuit is beautifully simple, a single stage Common Emitter PNP amplifier: C1: Is the series 5nF input cap, it will remove any DC level from the input signal and also create a high-pass filter together with R1, R2 and the input impedance of the Q1 transistor.

This cap is crucial for the pedal equalization. You can read about this filter in the Frequency Response section and also in the Mods part. They provide the required bias voltage to the base of the transistor and define the operating point of the pedal. RV: Is an audio logarithmic 10K potentiometer.

The simplicity of the circuit makes builders experiment adding some extra features so players can have some more knobs and switches to play with. There are 4 ways to ground the Rangemaster circuit:. The Dallas Rangemaster Input Cap modification is the most popular one. By simply changing the C1 input cap we can transform the frequency response making it more limited or wide.

This modification is not as popular as the Input Cap Mod and for a reason. Although it has to be admitted that 10nF is a low value for an output cap many pedals use caps in the nF to 47uF range for this. Users have different setups or "loads" so the result is variable.

You can get more info about this is the Bias Section. My sincere appreciation to J. Blake Arnold for your help with this analysis. Thanks for reading, all feedback is appreciated: This email address is being protected from spambots. You need JavaScript enabled to view it. Some Rights Reserved , you are free to copy, share, remix and use all material. Trademarks, brand names and logos are the property of their respective owners. Table of Contents. These vintage resistors could bring more organic sound but also are blamed to bring the noise.

For other vintage effects like the Fuzz Face that noisy by definition , carbon comp resistors are a great choice adding a bit more noise to a high gain fuzz wont hurt anyone. On the other hand, for a booster like the Rangemaster maybe carbon comp technology is not a good idea you want to keep all as clean as possible , so modern film resistors are a better choice. The potentiometer: The original Dallas Rangemaster uses a UK Welwyn 10k ohm sometimes 20k unit with two mounting screws.

The potentiometer body was made of bakelite and isolated from the chassis, but this feature does not add any benefit for the pedal. The original Germanium transistor was the Mullard OC44, long time ago discontinued. They are claimed to sound good with a soft clipping knee but also noisy, microphonic, temperature dependent and gain variable. Capacitors: There is not much magic involved on the caps, they are just common available technologies: 47uF is aluminum electrolytic, de 5nF and 10nF are films.

The circuit is beautifully simple, a single stage Common Emitter PNP amplifier: C1: Is the series 5nF input cap, it will remove any DC level from the input signal and also create a high-pass filter together with R1, R2 and the input impedance of the Q1 transistor. This cap is crucial for the pedal equalization. You can read about this filter in the Frequency Response section and also in the Mods part. They provide the required bias voltage to the base of the transistor and define the operating point of the pedal.

RV: Is an audio logarithmic 10K potentiometer. It will control the amount of volume of gain applied to the input signal, check the Voltage Gain section for more info. R3: is a 3.

C3: 47uF electrolytic cap, makes the guitar signal to bypass the R3 resistor. This makes the signal to get higher gain despite the bias point established by R3. C2: it is the 10nF output series capacitor. Its task is to clean any DC for the output signal. Diagram below shows a setup that allows switching between 5nF, 10nF and 15nF capacitors for a wide range of sounds.

As always, I used transistor socket to allow playing with different types of transistors and tried pretty much everything I had unfortunately, no OC The one I liked the most was GTV that came out of the bin labeled hfe and gives a perfect collector voltage of -7V with stock biasing resistors.

I am making a tagboard range master and want to do the input cap switch slightly simpler on-on between a 5 and 10nf and was wondering — do I need to run a ground wire from the switch?

Or will it be okay as your image suggests — just wires running from and to the board? LED and bypass switch are not shown, they are standard true-bypass circuit together with the LED current-limiting resistor.

Not an afterthought, LED is part of the bypass circuit that is not shown on the schematic for simplicity. Why have you included a second 47mf cap with a 1meg resistor, when my treble booster kit only has one? I cannot possibly know why your kit has one. The second one filters input DC voltage when using a 9V adapter. If you use batteries you might not need it. Does it matter if the max voltage is much higher than that, e.

Thanks for this awesome project. Yeah, any will do. Hi Bancika! Thanks for the comment, Guido. Thank you. You are very welcome. This site stands as my thanks to the online community that has taught me everything I know. If this not possible, can you tell me where I need to solder the black cable of the battery. Hello, First let me tell you that is a really good job!

And by the way I wanted to see if I can remove the 9volts battery of the system and at the output directly solder a Jack cable that directly going to the amp and if that gonna be function. Nice but, did you have a sound sample to hear what it sounds like? And I found a oc44n does it will works? Hi with those old transistors you really have to try and see as they are all over the place with the specs.

Gain and leakage may or may not be good enough. Ideally, try a handful of transistors and pick the one you like. Nut I searched on internet for schematic but yours is very different from all others that I found. Name required.

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