Myths, Legends and the Mojo of the Dallas Rangemaster

Discussion regarding early stompbox technology: 1960-1975 Please keep discussion focused and contribute what info you have...
User avatar
polarbearfx
Resistor Ronker
Information
Posts: 310
Joined: 27 Sep 2007, 11:14
Has thanked: 3 times
Been thanked: 2 times

Post by polarbearfx »

can you guys give me a rundown of the transistors that sound good in this circuit and what kind of hfe I should track down?

I tried an ac188 and it was ok, I had a cv7 and it just sounded a bit too ratty.

the colourboost has an nkt275, is it a rebadged new version or authentic?

User avatar
polarbearfx
Resistor Ronker
Information
Posts: 310
Joined: 27 Sep 2007, 11:14
Has thanked: 3 times
Been thanked: 2 times

Post by polarbearfx »

also i noticed that when I don't use a battery but an adaptor the thing sounds just not right. Much better with battery, I also think because of this it also sounds better without LED. Maybe I am having a placebo moment. I know this to be true with fuzzes, but on a RM?

User avatar
JHS
Cap Cooler
Information
Posts: 483
Joined: 14 Jul 2007, 11:20
Been thanked: 5 times

Post by JHS »

OC44, OC75/76/81, NKT275, AC125, AC155.

HFE should be app. 80-100.

My fav. is the AC125, sounds like a OC75 but is way less noisy.

I don't recommend to use AC188/128, excellent in a Fuzzface but compared to the other types they sound flat and liveless in a RM . Often they have to much hFE and some R-values must be altered to get a useful sound out of the RM with a AC128.

JHS

User avatar
DougH
Transistor Tuner
Information
Posts: 1087
Joined: 18 Aug 2007, 04:53
Has thanked: 4 times
Been thanked: 23 times

Post by DougH »

polarbearfx wrote:also i noticed that when I don't use a battery but an adaptor the thing sounds just not right. Much better with battery, I also think because of this it also sounds better without LED. Maybe I am having a placebo moment. I know this to be true with fuzzes, but on a RM?
Check your adapter voltage. It's probably putting out more than 9v.

User avatar
polarbearfx
Resistor Ronker
Information
Posts: 310
Joined: 27 Sep 2007, 11:14
Has thanked: 3 times
Been thanked: 2 times

Post by polarbearfx »

DougH wrote: But in all honesty, for a simple booster I prefer Gus Smalley's NPN Boost. I can set it as fat or thin as I want and it is much more consistent with different amps and etc. All it lacks is the soft little compression/attack thing that the Ge transistors do in the Rangemaster. And you can get that effect with an alnico speaker and the right amp (don't necessarily even need a pedal). Otherwise it can sound/behave almost identical to the RM.

And there's no mojo- you can get the parts at Radio Shack. Who'd a thunk it?
I have played around with this circuit, its not bad. Any suggestions on tweaks? what tranny do you use? thank you

User avatar
celadine
Solder Soldier
Information
Posts: 201
Joined: 22 Aug 2007, 06:12
Has thanked: 16 times
Been thanked: 19 times

Post by celadine »

Why not just use a germanium in Gus's boost? Could switch polarities, maybe screw with the bias.

User avatar
markm
Diode Debunker
Information
Posts: 787
Joined: 26 Jun 2007, 14:41
Location: U.S.A.
Been thanked: 10 times

Post by markm »

celadine wrote:Why not just use a germanium in Gus's boost? Could switch polarities, maybe screw with the bias.
I've done that too.....
It was okay and I think I have a layout I did for that too.....somewhere. :roll:
Join together with the "Banned"!

User avatar
DougH
Transistor Tuner
Information
Posts: 1087
Joined: 18 Aug 2007, 04:53
Has thanked: 4 times
Been thanked: 23 times

Post by DougH »

I used a 2n2222 in the NPN Boost, but I've also used 2n5089's etc. Pick which one you like. The NPN Boost is a really good circuit, and you can add a control to the emitter circuit to adjust the passband to thicken the sound or make it sound pretty much like a Rangemaster.

The Rangemaster is good too, I like it more than I used to with the tweaks I just did.

User avatar
markm
Diode Debunker
Information
Posts: 787
Joined: 26 Jun 2007, 14:41
Location: U.S.A.
Been thanked: 10 times

Post by markm »

DougH wrote:I used a 2n2222 in the NPN Boost, but I've also used 2n5089's etc. Pick which one you like. The NPN Boost is a really good circuit, and you can add a control to the emitter circuit to adjust the passband to thicken the sound or make it sound pretty much like a Rangemaster.

The Rangemaster is good too, I like it more than I used to with the tweaks I just did.
I messed around quite a bit with the Gus Booster and I must say it is quite underrated in my opinion.....just a very versatile and good sounding circuit!
Join together with the "Banned"!

User avatar
polarbearfx
Resistor Ronker
Information
Posts: 310
Joined: 27 Sep 2007, 11:14
Has thanked: 3 times
Been thanked: 2 times

Post by polarbearfx »

him interesting, so i can add a mini trimpot doug? where would you add this exactly and how?

User avatar
DougH
Transistor Tuner
Information
Posts: 1087
Joined: 18 Aug 2007, 04:53
Has thanked: 4 times
Been thanked: 23 times

Post by DougH »


User avatar
polarbearfx
Resistor Ronker
Information
Posts: 310
Joined: 27 Sep 2007, 11:14
Has thanked: 3 times
Been thanked: 2 times

Post by polarbearfx »

thats a cool idea. I am going to have to try that out. thank you

User avatar
polarbearfx
Resistor Ronker
Information
Posts: 310
Joined: 27 Sep 2007, 11:14
Has thanked: 3 times
Been thanked: 2 times

Post by polarbearfx »

hey doug which cap did you find worked the best with the rangepot mod?

User avatar
DougH
Transistor Tuner
Information
Posts: 1087
Joined: 18 Aug 2007, 04:53
Has thanked: 4 times
Been thanked: 23 times

Post by DougH »

I used a 1uf. .68u -> 1u was actually a pretty useful variation for me.

User avatar
modman
a d m i n
Information
Posts: 4890
Joined: 19 Jun 2007, 16:57
Has thanked: 4394 times
Been thanked: 2131 times

Post by modman »

If nobody is offended by this, I split off the discussion about mojo components: special resistors, caps or others, into a separate thread:

Big Mojo Components Debunking - thread
Please, support freestompboxes.org on Patreon for just 1 pcb per year! Or donate directly through PayPal

User avatar
sosodef
Solder Soldier
Information
Posts: 162
Joined: 26 Oct 2007, 04:14

Post by sosodef »

I wonder could that range control work on a fet based boost?

Anyone find any success with silicone in the rangemaster?

User avatar
snail
Solder Soldier
Information
Posts: 202
Joined: 30 Aug 2007, 00:41
Been thanked: 2 times

Post by snail »

Nice sound clip DougH!
Thanks for sharing. cool feedback moment!

snail

User avatar
modman
a d m i n
Information
Posts: 4890
Joined: 19 Jun 2007, 16:57
Has thanked: 4394 times
Been thanked: 2131 times

Post by modman »

sosodef wrote:I wonder could that range control work on a fet based boost?

Anyone find any success with silicone in the rangemaster?
My dad always told me and again last week: just act normal. But I can't. I was going to build a nice GE FUzz and GE Rangemaster to check out the mojo. Couldn't stick to that plan anymore once I read Brett's Piggybacking thread at diystbxes. I built a piggyback Fuzz and a piggyback Rangemaster

I couldn't believe that he thread died out on a 'oh we found some low gain si so we stopped experimenting.' This was the ticket to building a fuzz almost two random couples of cheapo transistors. Strange boutiquers haven't picked this up yet...

1. Take two identical random silicon transistors (for more mojo: your fav fuzz silicons
2. Tie the BASES together,
3. Cut off one COLLECTOR
4. connect a 3k to 6k resistor between the EMITTER of the collectorless devicr and the EMITTER of the other transistor.

By varying the resistance, you can dial in the gain you want...

Read more here:
https://www.diystompboxes.com/smfforum/ ... ic=49543.0

or try Brett suggestion of low gain SI for your Rangemaster?
Quote from: brett on 20-09-2006, 05:27:28
After word got out about the qualities of the 2N2369A (hFE about 70), I mostly lost interest.
allow me to quote from the above thread. Maybe I should do some clips with my piggybacked Rangemaster tomorrow....
RG wrote:« Reply #7 on: 20-09-2006, 22:30:54 »
It's only a suspicion, but I'll bet that the gain reduction does not remain constant across a range of values of base current.

Since the active base has an effective Shockley resistance and the passive one does not, it would be moderately amazing if the gain reduction was linear.

This is probably a Good Thing, in that it is even more asymmetrical than a transistor all by itself. It may be more Fuzz Face-y than a realy germanium FF.

It's worth some more testing.
Please, support freestompboxes.org on Patreon for just 1 pcb per year! Or donate directly through PayPal

User avatar
analogguru
Old Solderhand
Information
Posts: 3238
Joined: 26 Jun 2007, 13:58
Been thanked: 124 times
Contact:

Post by analogguru »

Dallas Arbiter Rangemaster Treble Boost

Original Rangemaster with three modern modifications
1. In and out sockets,
2. Footswitch for on/off,
3. Battery terminals changed to suit modern battery (pp3)
Have a look at this ugly "blasphemy":

http://cgi.ebay.co.uk/Dallas-Arbiter-Ra ... dZViewItem

analogguru
There´s a sucker born every minute - and too many of them end up in the bootweak pedal biz.

User avatar
JofZ
Information
Posts: 20
Joined: 08 Jan 2008, 20:51

Post by JofZ »

JHS wrote:A lot of European guitar players used the Rangemaster with succes and RM equipped with OC75, NKT275 or OC44 can sound quite different.

I would never use an original RM today, you can't expect a good sound after 40 years from a RM, but a vintage Strat, an old AC15/30, WEM or 18W Marshall and a good RM-clone generate an excellent tone.

Eric said, he used an OC75 equipped RM, a borrowd LP Std. and a JTM45 with KT66 tubes, normal input, for most of the recordings and IMHO it sounds very good on the Beano album, concidering it was 1965 and compared to the crappy sound on Beatles record from this time.

JHS
Clapton was a drunk and drug user during those years. This is really important to take into consideration as his memory is almost gone. If you read his new book he talks all about the Beano album, his gear and his lack of hearing today. He also clearly states he has no real clue what he did between the Bluesbreakers and Derek as he was literally trashed the entire time.

The book states a guitar into the amp, no pedals at all!

Post Reply