everything is alright !

[LightSoundGeometry]

hello, I have built four rangemasters, two NPN and two PNP but there seems to be something wrong in my estimations.  I cannot get any boost from them. One of them, the NPN  red dot one gives a slight boost and a nice %^&*ed wah wah tone but the other three are not really doing anything..I can barely get unity gain from all four of them ..

I am using the resistors small bear provided me with, have change out all components in as many combinations or permutations thinkable and have tried to wire the out put several ways; I used a rheostat type connection to collector, used a potentiometer as the 10k in circuit and in the breadboard picture below I have the circuit layed out with the fixed 10k in circuit going to pot lug 1, 2 new output and 3 ground - inverse will reverse the volume output counter clockwise.  When I run the potentiometer instead of the fixed resistor it just turns the voltage on the collector like the rheostat type connection I had ..something aint right because I hear rangemasters are supposed to give tremendous boost and distortion.

what the heck am I doing wrong? !! help me! 

here is the 4th one still on breadboard with the standard components from the schematic that was sent with the transistor - this one is the Newmarket OC71 PNP

4.7n, 470K, 43K,3.9K,47N,220N and the 10K  plus the oc71

C=6.03dcv B=.63 E=.56





Just got the uglys book in class yesterday , so the physics/math is still beyond me ..we are in ohms law, chapter 3 ,  right now so i am unable to interpret the voltages and what they mean just yet but my suspicions says these rangemasters should sing like a bird and provide a significant gain boost.   I need the Forums sagacious eyes to see my error.

here is another BB shot :



here is one of the House NPN ones I got with offboard in an enclosure , after messing with components on BB endlessly :



The Other NPN was the Flat hat - it has a decent %^&*ed wah tone but is barely even unity gain and not much bass cut, I messed with it on the BB endlessly and just went with the values on the schematic and its right around 6 volts :

[peterg]

Please post the schematic you are using.

[LightSoundGeometry]

its in picture number two . I used the ones from small bear he sent me ..the PNP just has the 47mF polarity reversed with -9v

[LightSoundGeometry]

Please post the schematic you are using.

same schematic for all four builds , just reverse polarity for the PNP. are rangemaster supposed to give boost like the analogman beano boost or they just supposed to sound like a %^&*ed wah wah ..barely being unity gain is concerning to me. i swapped parts out on BB a bunch but nothing seemed to give me that boost.

[smallbearelec]

I hear rangemasters are supposed to give tremendous boost and distortion.

You''ll get this worked out. When you do, you will Not get tremendous distortion. The RM does not do that. It Will over drive a tube amp input in a pleasing way.

I notice that the schem you are working from is for an NPN device, so power is + 9. The OC71 is PNP, so power should be -9 volts, + to ground. If the device is not powered right, no surprise that you would not hear boost.

[LightSoundGeometry]

its wired -9v , I had the ground coming off the pot in picture in wrong spot, but its run to the positive rail, I think i was moving things around earlier experimenting.

this one has a nice wah wah tone, it sounds good but just not boosting the signal like I thought it would. I guess I am asking is, the rangemasters just boost/cut frequencies or they supposed to " wake like a jet engine" at like noon ?

just making sure I am not chasing my tail for something that is not there. My beano boost from analogman is so loud it almost blows my amp apart  but does not have anything near a wah wah tone..just making sure what these are supposed to sound like as I cannot afford a real one and all the youtube demos suck balls..the ones that are good have the rangemasters boosting the signal like crazy ..wondering if they are using the same sort of layout ?

[Gus]

It does not look like you are using the SB schematic after looking at the picture.

It looks like you have a fixed 10K at the collector then a cap to the volume control.  If the volume control is a 10K you are loading the output of the RM and reducing the output.

One of the things that makes a RM a little different is how the volume control is wired.

If you want a cap coupled output to a volume control use a 100K

[antonis]

Maybe LED resistor is shorted to IN-OUT jumper on the 3PDT switch...

Just ignore it.. It should only cause problem in Bypass mode..

[LightSoundGeometry]

It does not look like you are using the SB schematic after looking at the picture.

It looks like you have a fixed 10K at the collector then a cap to the volume control.  If the volume control is a 10K you are loading the output of the RM and reducing the output.

One of the things that makes a RM a little different is how the volume control is wired.

If you want a cap coupled output to a volume control use a 100K

Gus this is where I am getting messed up at..when I use a 10K pot/rheo in place of the fixed 10k it just changes the current to the collector and pretty much gates/chokes the sound or shuts it off ..sound only comes out around a small part of she sweep..so i went back to the fixed 10k and then wired the output like i learned to do from tagboard effects

I have spent a 6-8 weeks on this now and cant get it ..if someone would be kind enough to teach/show me how to make this type of connection I would be grateful

[induction]

Look at the schematic again. The volume control is a voltage divider with the wiper feeding the output cap, not a variable resistor. The transistor bias won't change with the pot setting because there's always 10k between the collector and the rail.

[LightSoundGeometry]

alright induction, going to give it a go here soon and will post a picture and stuff with my results. See if you can look it over again for me. I am guessing the power filter is non factor ? and in one of them, I took some of the diy forums advice and stuck that 1m after input cap to ground which made me believe the power filter cap was optional.

I am going to use a 10K pot as my voltage divider , output to the 220n,  then to output jack  see if I can get the fat hlf cranked wah wah tone to blow my speakers lol

[induction]

I am guessing the power filter is non factor ? and in one of them, I took some of the diy forums advice and stuck that 1m after input cap to ground which made me believe the power filter cap was optional.

Power filtering and polarity protection are always good ideas. Because of the way this circuit is biased, it will amplify noise on the power rail. So much so that simple power filtering may not be enough. In addition to onboard power filtering, I'd use a regulated adapter or a battery on this one.

And, yes, pulldowns on both the input and the output are another good idea if you plan on switching it on and off. The originals didn't have stomp switches, so the pulldowns won't be in many schematics, but they will prevent switch pops, and won't cause any problems if they're high enough in value.

[LightSoundGeometry]

HOLY *&^% - she is a boosting now ..bout lost an eardrum 

as you can tell by my breadboard, we are finishing up chapter 2 and starting 3.. not voltage dividers but how a circuits open/close with switches and introduction to resistance like this in the form of a rheo or a pot etc ..I had to think of the volume control like my little LED experiment and it finally come to life lol !!

she is sitting just under 7 volts or so



thanks for taking a look and giving me some help. Later on tonigth I can transfer this to a vero strip and box it up !  Going to take my other ones apart and redo them

[Ben Lyman]

This has been a great thread for me to read as well, thanks guys! I totally understand the desire (fixation? Obsession?) with building these things with cool, old, and/or correct parts, I wish I had the time and resources to do all that extra mojo stuff. Anyway, I wanted to share something that I found online and has worked really well for me using a 2n3904 and this seems like as good a place as any. Talk about a Wocked Cah that will blow your speakers! headroom to spare! I like the 4.7uF as C3 but I also had a very nice result when running a 10uF parallel to the 4.7uF, it gave me a cool balance of mid+bass boost and made my little tweed Princeton sound like a wall of Marshall stacks 

[Gus]

Looks like it is still wired wrong the output wiper (black wire)looks like it is going to the collector of the transistor.
One side of the potentiometer goes to the supply and the other side to the collector  the wiper goes to the output cap

[LightSoundGeometry]

GUS, I switched it around the way youre talking about and played til my fingers bled ..I havent played so much guitar in one day I bet in over 8 years. 

my finger calluses hurt lol  - no rig should go without an RM

[mth5044]

Beware of that current limiting resistor touching the bypass jumper on the switch.

[LightSoundGeometry]

 SHE IS A BEAUTY !! 

[Ben Lyman]

"CAP"tain America... badump-bump-pshhhhh!
sorry, couldn't "resist" 

[hymenoptera]

lol, yeah the 6800pF cap (blue grey red?) caught my eye too. I've never seen one that value before