Dallas Rangemaster Recommendations?

[motterpaul]

Okay - there are about 20 different versions of the Dallas rangemaster online if you Google it.



 I tried the one from this site but I had no luck (I assume the pot value is 10k although it could be 100k - it isn't marked). Some comments said to shoot for 4.5v with it but I was getting no sound any way.

I tried  troubleshooting for quite awhile, but never saw the problem. I felt my build was good, but I tore it apart now anyway. It could be my test box, maybe....

I was using an ac125 with a high Hfe (180). I just want something that works well pushing overdrives, or letting overdrives push IT over the top, I have AC125s with HFEs from 90 up to 200 to work with, although the leakage gets greater as the hFE goes up. So far, the EHX germ OverDrive sounds good, and the Crimson Drive.

I am thinking about the Keeley Java boost (I have two OC44s, but I really want to find something for the AC125s I have). I like the idea of positive effects (not -9v), its makes everything much simpler, although building inverters is not hard, just space and component intensive.

Recommends? I am thinking more along the lines of "boost" although fuzz is certainly cool, as long as it has some gain and nice tone to it. Oh, and I want it to use the Ge, not Si - just because I have them.

Thank you!!!!

[motterpaul]

According to this article: http://www.geofex.com/article_folders/rangemaster/atboost.pdf it appears I may have chosen a transistor with too much leakage.

To the people who have built these - did you stick to OC44s? Or other Ge trannies?

Did you set the bias using pots to replace the 68k and 3.9k resistors to actually dial in the right bias (and then replace with the closest-rated resistors?)

All I know is that I built this and I got less than unity gain, and no real overdrive-type sound or fuzz.

So, who has built a Dallas Rangemaster that you were happy with - and what did you use for Ge and resistors?

[kirshman]

travis posted a layout in contributions with an mp20a i think.  I built it and really like it.  I also used a 2n1307 in there that I really like.  For the dam red rooster build I did, which i like, I used a mp38.  That's only got a hfe of about 70, but 0 leakage, and it's sweet as well.  I also built the keeley java boost for a buddy, I think with a mp38 as well that he loves.  I use a trimpot on all of mine.  The trick with a lot of these treble boosters, from my understanding, is they're not really meant to be used as a standalone drive.  They're supposed to increase the awesomeness of an already driven amp.  So set your amp to just pre breakup, or have another drive going on there, and that's where they shine.  And those builds I mentioned all shine in this setting.

[motterpaul]

Thanks, I will take a look. I saw so many different layouts its pretty amazing, but a lot of them say you have to have the right transistor & bias or it just won't work.

EDIT: transistor

[Travis]

The layout I posted is for any PNP tranny. Doesn't have to be MP20A, I don't even necessarily recommend that (though it works well).

[motterpaul]

Hi Travis - I couldn't find the layout you posted, I searched rangemaster and dallas, separately.

I would appreciate a link. I saw one of your builds using a terminal strip. Is it on that?

[Travis]

I've never built one on terminal strip, so I don't know what you're looking at

I can't send links to pages on the forum for some reason. They always go to the forum home. It's on page 2 in the contributions section

My recommendation is just get the stock Rangemaster working before you worry about everything else. It's such an easy build, if you're having problems with it then you should really just sort that out first.

The stock Rangemaster is the best starting point anyway

[motterpaul]

Can't get links to work? all you have to do is paste them in and they become links.

I thought I saw a build of a fuzz (maybe rangemaster) in "show us your pedals" by someone who (I think) also said their wife was doing soldering, I guess it wasn't you.

Anyway - as I said in the top message here, I did build a rangemaster, and it was working but obviously not the right transistor because while I got treble, I got no boost. What I have read (Geofex, DIY) said you have to get the bias right - so now I am building a version with a trimpot (as suggested by Kirshman above). I am sure my build was right (it is so simple, it's pretty easy to verify), so I am pretty darn sure the bias was the problem.

I am really trying to find a good build for the AC125s I have, something that boosts mostly, but also has a decent fuzz sound on its own. I have found a few options, but the rangemaster is a "classic" so I want to see if I can make it work - with the AC125s.

Thanks for your input.

[motterpaul]

For the links - try right clicking the URL so it all gets highlighted, hit right-click >> copy

paste here: http://guitar-fx-layouts.42897.x6.nabble.com/Axial-Rangemaster-with-inverter-and-input-blend-td20089.html

ADDED: I am doing this one which is close to yours in concept - different values. If this (below) doesn't work I will try yours:

[rocket88]

the rangemaster is not a fuzz, it is a boost. get your terminology right, so you know what to expect as far as sound from specific effects. there is an article on Geofex that explains how the rangemaster works. i would find it and read it.

the only thing i'm going to say to you is, it's not about the type of transistor with Ge, it's about hfe and leakage. every transistor will sound different and may or may not sound better to YOU, but not someone else. you're measuring of hfe for your batch is way off. i have about 300 of the same brand and same model, in fact another 150 just showed up as i'm writing this, and the gains are not as high as you are getting. check your math and that you're measuring it properly.

if you are that interested in Ge i would read through the pinned thread i started about Ge transistors and diodes. there is a wealth of information about hfe ranges to expect and descriptions of how they sound in certain effects. in fact i have posted the gains to expect from these with the number of transistors in each gain range.

also, the one you posted is nothing like the one travis has posted. the one travis posted has a pot to control the input cap making it not just a treble boost, but a boost for different frequencies.

[kirshman]

Someone just posted that the park fuzz rocket posted in contributions uses an ac125. You could also try a fuzz face.  I know they're not necessarily boosts but pretty great circuits.

http://tagboardeffects.blogspot.com/2010/03/few-veros.html?m=1

You'd need a small daugterboard to make negative ground but there are several on here as well.

[motterpaul]

Sorry - late edit: this post is reference to this statement:

"get your terminology right, so you know what to expect as far as sound from specific effects. there is an article on Geofex that explains how the rangemaster works. i would find it and read it."


I wrote:

"I did build a rangemaster, and it was working but obviously not the right transistor because while I got treble, I got no boost. What I have read (at Geofex and FSB) said you have to get the bias right - so now I am building a version with a trimpot (as suggested by Kirshman above). I am sure my build was right (it is so simple, it's pretty easy to verify), so I am pretty darn sure the bias was the problem.

"I am really trying to find a good build for the AC125s I have, something that  boosts  mostly, but also has a decent fuzz sound on its own.

There, I am obviously referring to a different circuit - not the rangemaster.

"I have found a few options<, but the rangemaster is a "classic" so I want to see if I can make it work - with the AC125s."

I write the word boost twice in reference to the rangemaster, and I clearly said I had another circuit that has a nice fuzz sound. Then I said "I want to see if I can make the rangemaster WORK, I never said I want to make it into a fuzz.

As far as any reference to fuzz goes, here, is what I referring to; I was reading the Geofex article and it distinctly talks about a type of distortion you can achieve with the rangemaster:

"The magic in the effect is all buried in the details of the biasing, the transistor characteristics, and what it does to a following tube amplifier. It’s not widely understood, but all transistor gain decreases at low collector currents. Normally transistors are biased as close to the middle of their linear swing area as possible to get the biggest possible non-distorted signal out. (But) If you bias a bipolar transistor near cutoff, the gain of the transistor is heavily dependent on the instantaneous signal in a way that compresses the signal more the closer to cutoff it gets. Even for signals that do not fully cut the transistor off, the signal is softly compressed more on one side than the other, which amounts to asymmetric distortion of the waveform since the compression is instantaneous. This asymmetric distortion adds a sweet, liquid quality that gets more noticeable as notes are hit harder. Hit a note hard enough (or just use a high output pickup) and you can actually drive the transistor fully into cutoff, and get a changeover into harder distortion"

Now, since I am discussing different transistors, and biasing, and have high output pickups, and since I have not yet heard what I might achieve, I don't know how the "harder distortion" might sound. But since we are talking about Germaniums, it seems pretty logical that the aforementioned "distortion" will sound  more like "fuzz" than a mere boost - otherwise it wouldn't be talking about clipping and distortion (are those features of a boost? no.)

However, I never EVER said, I hope the rangemaster makes a great fuzz.


I did write:

"I thought I saw a fuzz (possibly a Rangemaster) built by [Travis] ...."

There is an implied "or" in that sentence. Had I meant to include rangemasters in the fuzz category, I would have used commas, but then again, that is just me. I tested through Freshman English at the university level so I know how to read and write. But obviously I can't expect everyone to read at the level I tend to write. So, that is that.

As far as my HFE's -

Here is the picture of my tester: http://s1304.photobucket.com/user/Paul_Motter/media/Pedal%20Builds/Ge%20Tester_zpswf84kouw.jpg.html

Here I am using it: http://s1304.photobucket.com/user/Paul_Motter/media/Pedal%20Builds/1st%20reading_zpskthvhirb.jpg.html
http://s1304.photobucket.com/user/Paul_Motter/media/Pedal%20Builds/2nd%20reading_zpsyx0dabpg.jpg.html

The momentary switch is all I added, otherwise the tester is just like the one offered at this site.

My tester also brings up many AC125s in the 80 to 110 range, which I heard ( from this guy on Youtube) say is normal for the batches labeled as "VI" (6) range of AC125s, the highest average hFEs of the Ac125 series. My memory of that video says 90 to 150 is normal for the VI range, meaning some will be above and some below. Just because I mention using the higher HFE ones doesn't mean that is all I have. I have been picking some of the higher ones to see what they do. Yes, I know sometimes lower is better (so, far, I tend to like higher in the circuits I have built).

I am getting the numbers and plugging them into Mirosol's excel spreadsheet and it tells me what the hFE is. It also tells me the leakage. I looked around to see if the standard when quoting AC125 hFE is to subtract the leakage - Mirosol's spreadsheet does not do that, which is what I was relying upon.

Now, I did just read a forum at FSB that gives a formula for subtracting leakage:

2. Measure the nominal Hfe: connect the 2.2m resistor and, when you're happy the transistor has stabilized, note down the reading you now get and multiply this by 100. E.g. 1.89v = 189 Hfe.

3. Now the correct Hfe: subtract the reading for leakage from the reading for nominal hfe and multiply the result by 100. E.g. 1.89v - 0.115v = 1.775. 1.775 x 100 = 177.5 Hfe.

If that is what you do I will stand corrected. It looks like on average that would reduce my HFEs by about 8% (just based on the example above).

Now, as far as your thread - please drop me a link and I will be happy to read it, and I hope I gain much valuable information. Thanks for offering.

[motterpaul]

Okay - now the rest of the post (which is on a far more civil tone).

the rangemaster is not a fuzz, it is a boost. get your terminology right, so you know what to expect as far as sound from specific effects. there is an article on Geofex that explains how the rangemaster works. i would find it and read it.

I said above that I had already read that article - that was what I was referring to when I mentioned the overdrive on a rangemaster.

the only thing i'm going to say to you is, it's not about the type of transistor with Ge, it's about hfe and leakage. every transistor will sound different and may or may not sound better to YOU, but not someone else.

I know this - obviously. Not sure what your point is - My goal is to find a use for AC125, not to build the perfect rangemaster. That was what I said.


if you are that interested in Ge i would read through the pinned thread i started about Ge transistors and diodes. there is a wealth of information about hfe ranges to expect and descriptions of how they sound in certain effects. in fact i have posted the gains to expect from these with the number of transistors in each gain range.

I am very interested, thank you.

also, the one you posted is nothing like the one travis has posted. the one travis posted has a pot to control the input cap making it not just a treble boost, but a boost for different frequencies.

The truth is, I was busy building, so I just gave a quick answer to acknowledge that I would look at Travis's circuit when I was finished with the one I was working on.

[Travis]

motterpaul wrote

Can't get links to work? all you have to do is paste them in and they become links.

I thought I saw a build of a fuzz (maybe rangemaster) in "show us your pedals" by someone who (I think) also said their wife was doing soldering, I guess it wasn't you.

Anyway - as I said in the top message here, I did build a rangemaster, and it was working but obviously not the right transistor because while I got treble, I got no boost. What I have read (Geofex, DIY) said you have to get the bias right - so now I am building a version with a trimpot (as suggested by Kirshman above). I am sure my build was right (it is so simple, it's pretty easy to verify), so I am pretty darn sure the bias was the problem.

I am really trying to find a good build for the AC125s I have, something that boosts mostly, but also has a decent fuzz sound on its own. I have found a few options, but the rangemaster is a "classic" so I want to see if I can make it work - with the AC125s.

Thanks for your input.

For some reason when I've done the links in the past they just direct to the forum home

Anyways. That was a tagboard, not terminal strip. Also it was a silicon fuzz face, not a Rangemaster, so I didn't see the connection there

Did you try any different transistors in your original build? The Rangemaster isn't very picky about transistors so the fact that it wasn't boosting at all suggests another problem in your build to me

You can use the AC125s for just about any Ge build. I don't think it's fair to say rocket was somehow being a jerk by not pointing out that the park fuzz "reissue" uses them. That transistor is one of the cheapest around, and is very commonly used.

But I have a neat suggestion for you. Try the Buzzaround. Start with the stock one or ARC B3 (which has a built in voltage inverter. This is a good project for the ac125 and the sound sits somewhere between a buzzy vintage fuzz and a modern distortion. It's a great pedal.

Try q1 hfe ~ 75
Q2 hfe ~ 90
Q3 hfe ~ 135

Leakage is fine in this circuit. Actually you need leakage for Q3 to bias properly. The park fuzz is a similar circuit but the Buzzaround is a very popular project

[motterpaul]

I am replying to myself because, Rocket, when you say things like this

"the only thing i'm going to say to you is, it's not about the type of transistor with Ge, it's about hfe and leakage. every transistor will sound different and may or may not sound better to YOU, but not someone else. "

1. That just sounds like something you would say because you think I don't know it.

2.  But you were not clear in saying "within the realm of AC125s" - which only shows that you could also write better.

FYI: I tried AC25s with low HFE (closer to 100) and got the same result. What I need is a bias trimpot. maybe two (one to replace the other resistor).

Here is an idea - let's stop assuming things. You obviously think I am far more stupid about these circuits than I am. I spent my first year focused on FET circuits and overdrives, not fuzzes, so Ges are new to me, but I have a pretty good understand of their basics so far. Give me a little time before you start getting so critical with me.

And please stop talking down to me. I know what a boost is, I know all of the related terms of which you speak. If you tried to read me like I do know what I am talking about, instead of taking things out of context and assuming I am just saying stupid things, then you wouldn't think I was so uninformed.

That has been the basis of our arguments since day one. You read something I say, and take it out of context because you don't understand my frame of reference. If you don't understand something I say, ask me if to clarify, don't just start ragging on me for what you think I don't know.

Thank you. I hope THAT is clear.

[motterpaul]

Travis...

Thanks - I saw your tagboard build, but that was not the one I was referencing that I thought I saw you had built a terminal strip pedal - so just never mind on the terminal strip.

Your tagboard I will get to soon, I just built two different Ge circuits I need to try out including a rangemaster with a trim.

I tried lower HFE AC125s in the basic rangemaster, but got the same results. They have said rangemasters need very low leakage. But I am about to try the one I just built with the trimpot and I will try different AC125s.

Right now, finding a use for the AC125 in general is my main goal. This guy on YouTube
https://www.youtube.com/channel/UCGhzS1GbX-yxyBrUJtnUMoA
thinks AC125s are great, and he says he uses them in almost everything.

[motterpaul]

[quote] But I have a neat suggestion for you. Try the Buzzaround. Start with the stock one or ARC B3 (which has a built in voltage inverter. This is a good project for the ac125 and the sound sits somewhere between a buzzy vintage fuzz and a modern distortion. It's a great pedal.

Try q1 hfe ~ 75
Q2 hfe ~ 90
Q3 hfe ~ 135

Leakage is fine in this circuit. Actually you need leakage for Q3 to bias properly. The park fuzz is a similar circuit but the Buzzaround is a very popular project[/quote]

Sounds cool - thanks, I will try it.

[Travis]

motterpaul wrote

Travis...

Thanks - I saw your tagboard build, but that was not the one I was referencing that I thought I saw you had built a terminal strip pedal - so just never mind on the terminal strip.

Your tagboard I will get to soon, I just built two different Ge circuits I need to try out including a rangemaster with a trim.

I tried lower HFE AC125s in the basic rangemaster, but got the same results. They have said rangemasters need very low leakage. But I am about to try the one I just built with the trimpot and I will try different AC125s.

Right now, finding a use for the AC125 in general is my main goal. This guy on YouTube
https://www.youtube.com/channel/UCGhzS1GbX-yxyBrUJtnUMoA
thinks AC125s are great, and he says he uses them in almost everything.

People almost always say that everything needs low leakage. You can't really rely on internet info as solid fact. The fact is, these circuits were made back in the day with the Ge transistors that were commonly available. I would say that it is very unusual for a vintage Ge transistor circuit to not work with leakage. Everybody knew about leakage when they were designing the effects, and it doesn't make much sense to design something that doesn't work with the commonly available parts

I guess what I'm saying is that this will work just fine unless you have a very very high amount of leakage.

Keep in mind that transistors with higher leakage are less temperature stable. The hfe and leakage will fluctuate greatly with temp changes, and will shift the bias point

[motterpaul]

Guys - I do appreciate your help.

Rocket, I am sorry I get hot under the collar - but it just seems like you misread me a lot. And then you recommend I read something I have already read thoroughly. This is a good example since I say I had read GeoFex article way up in Post #2 above... (You missed that).

But the point is that I appreciate your help - and I know you are trying to be helpful. I think I just need you to understand I am not nearly as clueless as you seem to think. I make mistakes like everyone, but I do read and I do comprehend and I do try my best.

Travis - good input.

Once again, I just built a second power inverter and it just heats up. This is the one I just built: and yes I do see the chip is oriented upside down.

[Travis]

motterpaul wrote

I am replying to myself because, Rocket, when you say things like this

"the only thing i'm going to say to you is, it's not about the type of transistor with Ge, it's about hfe and leakage. every transistor will sound different and may or may not sound better to YOU, but not someone else. "

1. That just sounds like something you would say because you think I don't know it.

2.  But you were not clear in saying "within the realm of AC125s" - which only shows that you could also write better.

FYI: I tried AC25s with low HFE (closer to 100) and got the same result. What I need is a bias trimpot. maybe two (one to replace the other resistor).

Here is an idea - let's stop assuming things. You obviously think I am far more stupid about these circuits than I am. I spent my first year focused on FET circuits and overdrives, not fuzzes, so Ges are new to me, but I have a pretty good understand of their basics so far. Give me a little time before you start getting so critical with me.

And please stop talking down to me. I know what a boost is, I know all of the related terms of which you speak. If you tried to read me like I do know what I am talking about, instead of taking things out of context and assuming I am just saying stupid things, then you wouldn't think I was so uninformed.

That has been the basis of our arguments since day one. You read something I say, and take it out of context because you don't understand my frame of reference. If you don't understand something I say, ask me if to clarify, don't just start ragging on me for what you think I don't know.

Thank you. I hope THAT is clear.

Regarding this, I can kinda see both sides of the argument.

In rocket's defense, it makes perfect sense to assume that you don't know anything about Ge transistors. In your thread here you say that you can't get a Rangemaster working, which for most of us is a 5 or 10 minute project (not including boxing). Not to mention your thread about the EHX germanium overdrive, where you were clearly pretty confused

He may be running out of patience, because it's annoying for somebody to work hard to understand the way things work, and then see you assume that you already know a lot on this subject with such limited experience. Rocket can see exactly where you are in your knowledge on Ge transistors, because he's already been there. That's hard to understand from your perspective.

In your defense, you just feel like you're being attacked. And that's perfectly reasonable and understandable. I apologize if you feel that I've attacked you as well. I don't think anybody really wants to argue at all here