Myths, Legends and the Mojo of the Dallas Rangemaster

[Lucifer]

Nice build.

Plenty of room in there, Dr N.

Does that help to give it a nice 'airy' sound ?

[DrNomis]

Nice build.

Plenty of room in there, Dr N.

Does that help to give it a nice 'airy' sound ?

Lol.....usually my builds take up quite a bit of space in the enclosures I use, when I had finished building the pedal, I thought I had missed a few essential parts, so here I was looking at the insides of my finished Rangemaster pedal, and scratching my head, cause I was so used to working on complicated builds, it threw me for a few seconds.....

[Scruffie]

Bit off topic but I just measured the Black Glass Mullard OC44 I had earmarked for this, stuck it in, 50mA leakage, 207hFe, biases to 7.1v with stock rangemaster values, perfect!

But... when pulling it out the breadboard, the bottom of it cracked almost round the entire body!

Does anyone have a good suggestion of what to use to hold it together as it still works but I don't trust it to last forever in a pedal now and the 130hFe/161mA Mullard OC71 I have just doesn't sound as good or break up as nicely.

[Seiche]

pre-war hide glue. civil war that is.

[Scruffie]

pre-war hide glue. civil war that is.

I was thinking more a modern filler, preferably black in colour and available in the U.K

[mictester]

pre-war hide glue. civil war that is.

I was thinking more a modern filler, preferably black in colour and available in the U.K

A dollop of Araldite! When it sets, you can shape it (carefully) with a craft knife and paint it black with a drop of acrylic paint. Nobody will know the difference!

[lowbrow]

I'm thinking water thin superglue is your best bet. Carefully applied it will be a strong repair and not very visible.

[Scruffie]

pre-war hide glue. civil war that is.

I was thinking more a modern filler, preferably black in colour and available in the U.K

A dollop of Araldite! When it sets, you can shape it (carefully) with a craft knife and paint it black with a drop of acrylic paint. Nobody will know the difference!

Ah! Perfect, got a pack of that I never used.

I'm thinking water thin superglue is your best bet. Carefully applied it will be a strong repair and not very visible.

I thought about super glue but wasn't sure how good an idea it would be having it get filled with (admittedly quick drying) liquid as I think the crack goes quite deep in.

[astrobass]

I built one with a P416B Russian germanium. Hfe was measured in the high 90s. Used the tagboard effects layout as a starting point, but did it point to point on regular perfboard.

Used a 25 turn trimpot to dial in the bias, got it to give a perfect decay with no sputter, no fizzle. Went from "okay, pretty neat" to "I will never play guitar without it".

The biasing seems to be critical to getting it right.

I also don't see the point in playing with the input cap. If you grab an average 10% 4n7 at random, its actual capacitance will vary between 4n23 and 5n17. The original used 20% tolerance caps, right? A random 20% 5n will vary between 4n and 6n. So, not much point in stressing over the difference there, as I doubt they were measuring components to make sure the 5n caps were exactly 5n. Your 10% 4n7 will fall within the range of values actually found in every single original model. For what it's worth, I used a ceramic cap for everything except the larger values where electrolytics were necessary.

[astrobass]

Oh, also worth noting: I didn't use my DMM to bias. I biased by ear. Time consuming, but worthwhile.

[Liquitone]

I have been using OC45's lately, as the supplier I get them from has black glass CV7003/OC44's only from hfe of 130 and above, but has OC45's in the 70-100 range. I am not sure which brand they are. All 3 builds I used them on had the collector voltage at -7V without needing to bias, and they all sound great, unlike the one I build where I used a long-metal-can AC128, that one sounded really harsh and unpleasant.
I was wondering about the importance of Transition frequency. I am assuming it doesn't matter for guitar effects as the frequency lies in the MHz range, way above the KHz range of the guitar. This is the only major difference I could find between an OC44 (8MHz) and an OC45 (4MHz).

[DrNomis]

I just tried one of the Russian GT308A Transistors I bought on eBay in my Rangemaster build, it seems to work fine, the Transistor I used has an Hfe of 75, zero leakage and biases up with -7.21V on it's collector so I might try reducing the emitter resistor from 4k7 to 3k9 to get the collector voltage back down to 6.8V like it was before....