Another Rangemaster, But.......

[Mick Bailey]

I'm really pleased with my Rangemaster build that occupied most of my time over the weekend, so I thought I'd post a couple of pics. I wanted to get closer to the original, rather than adding to my Hammond stompbox collection. The case is bent up out of aluminium sheet in a home-made bending machine. The front panel is actually light grey and is lettered using fired-on Lazertran (as is the battery cover, not pictured). Inside is the usual tag strip, with carbon comp resistors to get as close to the original as possible. It does sound spot-on.

There appears to be two panel variations of the original Rangemaster and I wonder if anyone knows why there is a difference? One uses Gill Sans as the typeface and the other uses something that approximates quite closely to Arial Baltic bold. Interestingly, when you examine the battery cover lettering it's all over the place on the originals, with highly variable spacing between words and letters which goes against the accuracy of computer graphics and requires some 'fiddling' to look right.

Pics are in 640x480 so the detail is a bit obscured and the colours are slightly off......

Front;
http://www.avwz35.dsl.pipex.com/rangemaster.jpg

Inside battery compartment;
http://www.avwz35.dsl.pipex.com/rangemaster battery.jpg

[jacobyjd]

wow, that's a lovely build. Nice execution! 

[jrod]

Nice job!!! That looks very good!

[Toney]

just lovely!

[Curly]

impressive!

[rousejeremy]

You forgot the ledger line on that A note!

[Solidhex]

Yo

  That looks really great.

--Brad

[SpencerPedals]

Top notch DIY stuff for sure...that is outstanding

[Jim Jones]

Wow, that looks fantastic!  Great job!

Jim

[Mick Bailey]

Here's a bit better shot of the front......

http://www.avwz35.dsl.pipex.com/rangemaster2.jpg

[Laumschoon]

Wow, great build. Love it. You forgot 2 screws. Above and under that knob.

[Mick Bailey]

Did wonder about the screws, but decided to wait until I got the correct pot so I got the holes in the right place. Could be a long wait, though......

[noelgrassy]

Mick, your build is so too much! It's really something to see all the effort you put into this to make a solitary unit. You didn't mention the xistor you used. Was it an OC44 or the CV7003? Did you get to use the stock resistor values or use trim pots to bring it under submission? I ask because I'm working on a Rangemaster but more akin to the Keeley Java do-dad. I'm using positive ground just
because I'm assuming the Keeley couldn't really sound correct operating a PNP xistor in a way it wasn't designed.


What's next on your F/X build list?

[Mick Bailey]

Transistor is currently a Mullard OC71 (Hfe 98) due to my OC44 being defective.  Apparently Rangemasters were fitted with either, but the OC44 was more common. I'm ordering a few OC44s and will pick the best and replace the OC71.

I used the stock resistor values and the collector voltage measures 7.4v. All of the photos of original pedals that I've seen use the stock resistors, so given the huge variation in OC44s (My Mullard book from 1961-62 shows them having a range of 40-225) there must have been a fair difference in sound between each unit. That is, unless they matched the transistors to the stock resistor values.

[Mick Bailey]

BTW,

Next build will probably be a Univibe with the original size and style of case and panel layout. Just collecting the bits. I also want to build another Rangemaster, but with a steel case and hammer-finish paint to get closer to the original.

[Electric Warrior]

I have some photos of Rangemasters with 4k7 and 3k7 resistors instead of the usual  3k9.
The ones with OC71s all seem to have a black or brown Hunts capacitor at the input, a 0.0082µF Siemens styroflex at the output and mostly 50µF electrolytics. The OC44 units on the other hand seem have tubular ceramic caps of the usual values and mostly 25µF electrolytics (some seem to have a 25µF on top of the terminal strip and a 50µF at the bottom).

Hfe doesn't seem to make too big a difference when biasing these. I have a yellow jacket OC44 with an hfe of 200 and a black glass one with an hfe of 90. The collector voltages are just 0,3 volts apart when I put them into the same circuit.

[Mick Bailey]

Thanks for the info - any chance of posting some links to the pics?

[Electric Warrior]

I think I found most of them on ebay. PM me your email adress and I'll send them to you. Nearly 22 MB of pictures - I hope your inbox can handle that much.

[Mick Bailey]

Got them!

Absolutely fascinating. Now I will have to make another.

Thank you very much for the info.

[cat]

Absolutely fantastic, well done. Might have to follow your lead with my build.

Cat