Real Mullard OC44's

[Easywider]

Just scored & wondered if these were the real deal Yellow Sleeved Mullard OC44's & if they'd work well in a Rangemaster or Fuzzface with these gains......! Was told they were taken out of old 60's , early 70's test equipment , quote from him : 
Here are four pieces of Mullard OC44 glass encapsulated germanium PNP transistors with the distinctive yellow sleeves

As you can see in the photograph, they have been carefully recovered without the use of a soldering iron, from a 1960's / early 1970's piece of test equipment

Thet are marked Mullard and Great Britain and have the codes GW and VS

I have checked them for gain and were measured with gains of 45, 52, 173 and 220 at an Ic of 2.5mA


Thanks ,

Chris

[rockgardenlove]

I honestly wouldn't use them at all...I'd sell them for some outrageous amount of cash, and build 10 pedals with the profit.  (Well, maybe not 10, but you get the drift.)

[markm]

I honestly wouldn't use them at all...I'd sell them for some outrageous amount of cash, and build 10 pedals with the profit.  (Well, maybe not 10, but you get the drift.)

[R O Tiree]

IIRC, you need a gain of about 180 for a good RangeMaster. The ones at 45 and 52 are useless to you.

[Fret Wire]

 75-100 hfe is Usually recommended for the Rangemaster, and in practice does give good results. That 45/52 hfe pair will make a fine sounding fuzz if you bias it right. I've made quite a few with pairs that run 40-60 hfe and they sound just fine. If your 45/52 pair has low leakage, and are stable, use around 50/51k on Q1's collector and the standard 8.2k on Q2's collector and it should sound just fine.

[R O Tiree]

Clearly, I didn't remember correctly... 

[rasco22862]

Talking about rangemasters:P. Can i make one with an Ac188k?, What hFE should i look for?

PD: Wich DIY projects are there for a good booster?

[petemoore]

  Transistor? the one..that beats the other ones..lol, they all fall somewhere in your picture, they might need put in to size them for leakage and gain in your picture, generally low leakage is better and the GEO guidlines on the Austin Treble Blaster article are worth a look for selecting candidates..
  Booster...any and all.
  I'm using Omega alot, that or the Mosfet transistor I biased.
  Jfet's are cool and sound..Jfet-ey,
 

[tcobretti]

Talking about rangemasters:P. Can i make one with an Ac188k?, What hFE should i look for?

PD: Wich DIY projects are there for a good booster?

Do a search for boosters and you'll get several options.  The two boosters based on Ge transistors that I can think of are the Rangemaster and the Rangepig. If you use larger input and output caps you can make the Rangemaster a full range booster instead of a treble booster.

[Easywider]

Thanks to All.....Just searched around & Very confused on testing for leakage , is there anyone or place on or offline that offers this service , testing transistors ? Just seems too confusing for me ! 

[tcobretti]

I'd say don't worry about it.  Just build the circuits and see which transistors work best.  It's not like these are real complicated circuits, so even if not a single transistor is usable you haven't wasted a ton of money.  I bet at least one of them will be good, if not more.

[calculating_infinity]

Thanks to All.....Just searched around & Very confused on testing for leakage , is there anyone or place on or offline that offers this service , testing transistors ? Just seems too confusing for me ! 

No, but you can buy pre-tested Germ trannies from smallbear which may make your life easier.

[Easywider]

I'd say don't worry about it.  Just build the circuits and see which transistors work best.  It's not like these are real complicated circuits, so even if not a single transistor is usable you haven't wasted a ton of money.  I bet at least one of them will be good, if not more.

Thanks Travis , Feel better about it now.....Think thats what i'll do......Just put them in & see what i get  !

[petemoore]

  There are ways to reduce and increase gain, these techniques have their 'add' and dis-advantages.
  Too much gain and the RM might clip funny, too little gain and it might not distort much, every one of those Ge eggs will have a different gain and frequency response, often quite noticable.

[Easywider]

What ways could be used to increase/decrease the gain , resistors of a certain value , or a trimpot ? what would be the advantages / disadvantages of doing this in circuits such as the Rangemaster & fuzzface ? Also , Is there any other circuits where a high gain GE ( say 170 - 220 hfe ) would be to an advantage ?

Thanks ,

Chris 

[analogmike]

Those seem to be the real deal, here is the one I have :



Like someone said, they are valuable for restoration so you should probably sell a few on ebay or something, as they are real ones, not the black "mullards" the other guys are using and selling.

Good score, have fun!

[jaytee]

Are the black ones not made by Mullard?

[markm]

Those seem to be the real deal, here is the one I have :



Like someone said, they are valuable for restoration so you should probably sell a few on ebay or something, as they are real ones, not the black "mullards" the other guys are using and selling.

Good score, have fun!

To outsiders of this forum and hobby, I bet it seems strange that we would collect old components and cherish them!
We are really the only people that would understand!
Nice one Mike!!