TAD Range King schematic [traced]
- apollomusicservice
- Resistor Ronker
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The Tube Amp Doctor - Range King power booster
- Manfred
- Tube Twister
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I ran a simulation of this circuit and found the collector voltages as follows:fuzzbunny wrote:R1 & R2 are both 100k? Is that verified?
Thx.
Using R2 = 100kOhms : 1.8 Volts DC
Using R2 = 10kOhms: 7.7 Volts DC
A collector voltage of about 7 Volts is common in the known Rangemaster circuits.
IMO the Value of R2 must be 10kOhms.
- Manfred
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I made an an approximative PCB layout of the analog part for retracing the circuit.
The resistor which is labeled with the question mark is marked as R1 in the schematic.
At this point in the shot a resistor with following rings is shown:
yellow - violet - black - ? - braun.
The colour of the fourth ring looks like yellow.
Makes this sense because in this case the resistor would be 4.7 Megohms.
Which is the right colour?
The resistor which is labeled with the question mark is marked as R1 in the schematic.
At this point in the shot a resistor with following rings is shown:
yellow - violet - black - ? - braun.
The colour of the fourth ring looks like yellow.
Makes this sense because in this case the resistor would be 4.7 Megohms.
Which is the right colour?
- Manfred
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The symbol of the DC jack is wrong in the schematic, sleeve and tip have been mixed up.
Manfred wrote:I ran a simulation of this circuit and found the collector voltages as follows:fuzzbunny wrote:R1 & R2 are both 100k? Is that verified?
Thx.
Using R2 = 100kOhms : 1.8 Volts DC
Using R2 = 10kOhms: 7.7 Volts DC
A collector voltage of about 7 Volts is common in the known Rangemaster circuits.
IMO the Value of R2 must be 10kOhms.
I did a quick breadboard with Apollo's schematic values but subbed a 10K in the R1 position.
I used a variable resistor in the R3 position ( collector) and biased by ear.
The circuit sounded best with approx. 4.5v on the Collector, R3 around 50k.
The sound was ok but I think something is not quite right with the schematic/details as they are presented. I had a good look at the photos and it doesn't quite add up.
Don't get me wrong, I appreciate the great contributions Apollo makes to the forum! I just wanted to pass,on my findings for others to build on..
- Manfred
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Thanks for your work, I appreciate it very much.I did a quick breadboard with Apollo's schematic values but subbed a 10K in the R1 position.
I used a variable resistor in the R3 position ( collector) and biased by ear.
The circuit sounded best with approx. 4.5v on the Collector, R3 around 50k.
I ran a simulating using with R3 = 50k which confirms your results.
I think, to pass findings is one of the most important things here.Don't get me wrong, Don't get me wrong, I appreciate the great contributions Apollo makes to the forum! I just wanted to pass,on my findings for others to build on..! I just wanted to pass,on my findings for others to build on..
I appreciate the great contributions Apollo makes to the forum too.
- apollomusicservice
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There is nothing wrong with DC jack in my schematicManfred wrote:The symbol of the DC jack is wrong in the schematic, sleeve and tip have been mixed up.
- Manfred
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http://www.tubeampdoctor.com/en/shop_TA ... ooster_667
In the Specifications of the TAD Rangeking you can find;
- jack for external 9VDC power supply (tip: ground, sleeve: 9VDC)
In your schematic the sleeve is connected to ground and the tip to +9VDC
In the Specifications of the TAD Rangeking you can find;
- jack for external 9VDC power supply (tip: ground, sleeve: 9VDC)
In your schematic the sleeve is connected to ground and the tip to +9VDC
- apollomusicservice
- Resistor Ronker
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Still I don't understand, in my schematic Tip (or Pin) is on the ground.Manfred wrote:http://www.tubeampdoctor.com/en/shop_TA ... ooster_667
In the Specifications of the TAD Rangeking you can find;
- jack for external 9VDC power supply (tip: ground, sleeve: 9VDC)
In your schematic the sleeve is connected to ground and the tip to +9VDC
- Manfred
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Sorry, now I understand, you using an another drawing symbol for the DC-jack like I do, then the schematic is of course correct.
I use this drawing symbol, that was the point of confusion for me.
I use this drawing symbol, that was the point of confusion for me.
- Manfred
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I bought a Rangeking for a very favourable price yesterday.
I measured the passive components and some voltages too.
For a proper measure of R2 it was necessary to interrupt the conductor after its lead,
because I want not degoop the PCB.
I found:
R1 = 470 Kiloohms
R2 = 2.2 Megaohms
The calculation with the read values gives a DC-gain of about 430 for the transitor.
I measured the passive components and some voltages too.
For a proper measure of R2 it was necessary to interrupt the conductor after its lead,
because I want not degoop the PCB.
I found:
R1 = 470 Kiloohms
R2 = 2.2 Megaohms
The calculation with the read values gives a DC-gain of about 430 for the transitor.
- Manfred
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Indeed, I measured R1 with 470k an R2 with 2M2.rs wrote:From looking at the photos, R1 looks like 4M7 to me (yellow-violet-black-yellow-brown) but i could be wrong.
I ran a simulation with the new values which confirm the read voltage values.
- Manfred
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I ran the simulation with a BC548C transistor because a BC550C is not available, but both Types have nearly the same values.
Here a shot of the simulation.
Here a shot of the simulation.
- apollomusicservice
- Resistor Ronker
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Thanks Manfred but here is another one photo, R2 is still questionable. Unfortunately, the pedal is no longer with me.Manfred wrote:Indeed, I measured R1 with 470k an R2 with 2M2.rs wrote:From looking at the photos, R1 looks like 4M7 to me (yellow-violet-black-yellow-brown) but i could be wrong.
I ran a simulation with the new values which confirm the read voltage values.
- Manfred
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Thanks, for the another photo, I would say that the fourth ring is orange.