Rangeblaster Build Question

[robotboy]

I'm about to build one of the many rangemaster variants. I'm considering building the rangeblaster, which can be found here.

http://fuzzcentral.tripod.com/rangemaster.html

My question is, can I use the rangemaster germanium transistors found at small bear for this project, or are they only for the rangemaster found at geofex?

[BD13UK]

Steve at Smallbear will supply you with a suitable transistor for your project if you contact him.

[Doug_H]

Looks like the biggest difference between the rangeBlaster and rangeMaster is the NPN xsistor. If you can get an NPN Ge from smallbear it should work.

Doug

[MartyMart]

I built a rangeblaster using an OC140 (CV7112) - which is NPN Ge, hfe
was around 140.
Works a treat, should be fine also with an AC127, also NPN.
I like Phillips "negative ground" versions, it makes it possible to power
them using a standard Boss type PSU i've had no problems this way,
trying this with PNP negative ground is a NO NO !!
Recommended 100% !!

Marty.

[Mojah63]

I also built Phillip's rangblaster. Steve at Small Bear had the npn ge transistor and his resistor values were spot on.

[robotboy]

I built a rangeblaster using an OC140 (CV7112) - which is NPN Ge, hfe
was around 140.
Works a treat, should be fine also with an AC127, also NPN.
I like Phillips "negative ground" versions, it makes it possible to power
them using a standard Boss type PSU i've had no problems this way,
trying this with PNP negative ground is a NO NO !!
Recommended 100% !!

Marty.

Cool. Where'd you get the OC140? I was under the impression that hfe was supposed to be 75-100, but I guess as long as it sounds good, it's all good, right? I'm building the negative ground version for the explicit purpose of being able to use a PSU. The pulldown resistors, polarity protection, and temperature stability are an added bonus as well though...  

[MartyMart]

I built a rangeblaster using an OC140 (CV7112) - which is NPN Ge, hfe
was around 140.
Works a treat, should be fine also with an AC127, also NPN.
I like Phillips "negative ground" versions, it makes it possible to power
them using a standard Boss type PSU i've had no problems this way,
trying this with PNP negative ground is a NO NO !!
Recommended 100% !!

Marty.

Cool. Where'd you get the OC140? I was under the impression that hfe was supposed to be 75-100, but I guess as long as it sounds good, it's all good, right? I'm building the negative ground version for the explicit purpose of being able to use a PSU. The pulldown resistors, polarity protection, and temperature stability are an added bonus as well though...  

I scored some  from Ebay last week !!
They were only 50cents each !!! :shock:
I can only presume that it was a mistake, as the seller has other similar
NOS Ge trannies for at least 10X that much......
They were "EX Military" stock  ?
It "crunches" quite nicely, probably need a lower gain one, but I like it :twisted:

Marty.

[formerMember1]

i am building  a dallas rangemaster clone according to geo fx(on terminal strip). i want to add a ge diode(reverse bias) to help with temp sesitivity.  i am confused about doing this and read it on the internet over and over again.  what lugs on the terminal strip do i solder the diode to? what ge diode works best? and also what is reverse bias, do they come like this?
or does it mean solder it iin backwards??
thanks to thoes who can help. i know i have a lot of questions but the main question is how to increase temp stability in the dallas rangemaster clone???

[formerMember1]

is it possible to solder in a transistor socket when building a dallas rangemaster clone according to geo fx? i never used them before(socket)?
if this is possible after i find the right transistor do i have to unsolder the socket and solder in transistor?

thanks

[formerMember1]

hey marty mart are those transitors you got off ebay the original ones used in dallas rangemaster's?

did you try other transistors?

are the ones you got off ebay european transitors,if they are do you know where i could get some?(online)
thanks....  :?:

[nelson]

is it possible to solder in a transistor socket when building a dallas rangemaster clone according to geo fx? i never used them before(socket)?
if this is possible after i find the right transistor do i have to unsolder the socket and solder in transistor?

thanks

Yes, think of a transistor socket jus like an IC socket. You dont have to desolder it to put the transistor in....

[MartyMart]

hey marty mart are those transitors you got off ebay the original ones used in dallas rangemaster's?

did you try other transistors?

are the ones you got off ebay european transitors,if they are do you know where i could get some?(online)
thanks....  :?:

formerMember1,
No, I built the "Range-blaster" which is the "NPN" version rather than "PNP"    http://fuzzcentral.tripod.com/rangemaster.html
The OC140's are similar to the original Mullard OC44's but are not "PNP"
It made it easier to have a version with a "normal" negative ground and
then you can power it from a "Boss" type PSU with no problems.
"Real" OC44's are impossible to find and will be at least 20 bucks a piece!!!!!
But "yes" they are European and "yes" they seem to sound great in all
the circuits that I've tried them in  
There's a thread somewhere about this and lots of folks were saying that
modern "Japanese" Ge's were very well made and stable ......... ?

Cheers,
Marty.

[spudulike]

I got the same transistors as MartyMart I think - OC140 (CV7112), they are ex-UK ministry of Defence, black, red spot, in original paper packets. I paid £3 for 20 from a guy called "6k8" - he has more available.

The hfe is consistent across the 60 I bought at 120 (+/- 20). They are (for germanium) very linear symmetrical switching transistors. I have used these in a dozen circuits now (some only breadboarded though). They have all performed well and are perfect for boosters and FFs.

The seller's shop is here http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=36332&item=7527094441&rd=1&ssPageName=WDVW - strongly recommended to ALL uk builders.

<Edit> He also has 2N696 trannies at 10 for £3  :wink:

[MartyMart]

Glad that you found him !!
I just ordered some more, with a few 1N34A's and some "mullard" valves
I've been popping those CV7112's into all kinds of circuits, with a slight
re-bias, they are sounding gorgeous ---- EVERY time !!!
Get 'em while there hot  

Marty.

[formerMember1]

MARTY MART
you mentioned that you can't find OC44 pnp ge for treble booster. small bear has them for 7.95$.
are they the "real" ones or something else. I emailed small bear and he said they work great and are what the original ragemaster's had.

On his site it says Mullard OC44

thanks man....    :?:

[cab42]

Spudulike,

Thanks for the tip. I had difficulties finding even one Germanium NPN, the only part I was missing for the rangeblaster, and think now I have ordered 20.

Hmm. what should I use the other 19 for? Any suggestions?

Regards

Carsten

[spudulike]

Erm, anytime a schem calls for a NPN lw-to-medium gain. Like I said Ive used them in all sorts of boards and once the bias is trimmed (by ear) they sound fantastic. Marty probably knows more about the biassing as he seems to have used them more than me. BUT ... try one as the input tranny on a Zakk Wylde OD ...

[formerMember1]

spudulike and cab42

is there any sound difference between a npn and pnp rangemaster?
thanks :?:

[spudulike]

Very subjective I think. I used AC128s in  "proper" rangemaster-clones, and I built Phillip's Rangeblasters with OC140s. Both excellent, the NPN was a little brighter, and the response was more even . The PNP had a definite "hump" - not midrange a la TS but at certain points on the neck there were "sweet" spots  :? . PNP was  little grainier, the NPN is smoother at low gains. The Rangeblasters biassed easier and were more consistent across transistors, the AC128s took ages to get sounding "right".

Maybe Marty could describe his experiences ? Probably make more sense than me  :oops:

At the moment I have a stacked 4558/5532 (a la Barber) and two OC140 in a TS808 clone-ish experiment on the breadboard. Mojo, mojo,mojo ....