Help with identifyiing capacitors in P.U.R.P rangemaster build kit please.

[Anonymous]

Hi,
I’m having some issues Identifying the values of the caps in the PURP’D treble booster kit V3 and where to stick which to where on the pcb.
I would just like to double check rather than remove them after guessing and getting it wrong. I have tried the guide for identifying them but the numbers just seem out to me.
The numbers printed on the caps are ; 382J63, 473J100 & 223J100 (I may have the last one sussed but….)
I am new to this pcb malarkey. O r….. how do I test them
TIA, Doc.

[Barry]

Go to the Guides Page for anything you are not familiar with.

The GUIDES PAGE – Mandatory Reading for all!

There is a Capacitor Code chart for you.

[Cybercow]

Doc . . . .

382J63 = 3.8nF (3n8F or 0.0038µF) @ 63v (I think you may have a typo – 3.9 is the more common value rather than 3.8. And the PURP does NOT have a 3,9nF or 3.8nF cap – I believe you meant to type 682J63 which is 6.8nF and IS used in the PURP.)

473J100 = 47nF (0.047µF) @ 100v

223J100 = 22nF (0.022µF) @ 100v

And as Barry points out, there is a LOT of information on the Guides Page.

[Anonymous]

Thanks guys. I appreciate the assistance.
I did have a look at the guides. Like I said, I’m new to this and I had trouble reading it compared to what I have in front of my ‘passed their use by date’ eye balls. Full steam ahead I say!

[Anonymous]

The guides are a wealth of info I must say and have helped me heaps. And now for the next question.
In the Q1 pinout which is the emitter, inboard or outboard? I have a PNP germanium transistor with a painted dot over the emitter pin and that’s what I must go by. Yet again I can’t find the correct search terms. My apologies if I’m being a pain.

[Cybercow]

Doc – here’s the pinout configuration for the PCB . . . .

If you have the PNP germanium transistor from the kit, this should make things simple. If you’re using a different BJT for Q1, we’d need to know what the type (number) it is. What is the type of transistor you’re using?

[Anonymous]

Cybercow. Thank you! You have answered my question perfectly!
Marks (Should that be Marx?) /numbers on the transistor are (2 cyrillic letters, a sideways figure 8 and a capital n, 4028807. It looks like a W.W.1 tin hat with 3 legs.
The kit that I bought doesn’t come with any transistors. I bought the V3 P.U.R.P from Pedalparts Australia. Link –
PPA
The story goes, I bought another RM kit from a different local site some months ago, complete with Russian Germanium transistor, the thing didn’t function. I thought I’d ‘blown’ something. I bought another, same outcome. Cut my losses, went elsewhere and found what I assume is a better kit and here we are!
Thanks again Cybercow.

[Anonymous]

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you may want to pick up a capacitance tester for added “security” … dirt cheap and easy to use … note that many multimeters can test for capacitance but a dedicated tester has a much larger range it can test … multimeters start to want when you enter the pico values…

[Anonymous]

The HoldPeak HP-36D looks identical to the one I have … if it is … it works great but the battery door is a nightmare … less that $20 … can test to low value picos

[Anonymous]

hi Cybercow, what silicon PNP transistor would work for the PURP?  Any recommendations?  Been scanning datasheets but would like to see what has worked for others …

[Barry]

Germanium Transistors measured for PURP project here:

*Germanium Transistor N.O.S. PNP for P.U.R.P. Rangemaster Project

[Cybercow]

Jeremy – “hi Cybercow, what silicon PNP transistor would work for the PURP?  Any recommendations?  Been scanning datasheets but would like to see what has worked for others …”

I’ve experimented with several different PNP BJTs with the PURP build and they all tend to work to one degree or another. Bias adjustments were needed when changing most of them. I go the best results out of the ones Barry has in stock, cheap Russian MP20B, AC188, NKT275, AC125, AC125, OC44, OC71 and so forth. Most importantly the gain needs to be between 45 and 150 with as low of a leakage as you can find. I even used some silicon PNP BJTs with fair success. The ones Barry has are a slam-dunk.

[Anonymous]

Thanks for the recs … I picked ip the recommended germanium transistor and will socket it.  I’ll experiment with others, including the ones you noted, and will see what happens  … thanks again folks

[Anonymous]

Hey Barry, is there a reason that there’s no cart in my end of the germanium transistor site that you sell?

[Barry]

I am not able to replicate an issue. Let me know if anyone else is having an issue.

Let me know if I am missing the issue. see images below.

[Barry]

Don’t forget to purchase or clear your cart afterwards.

[Anonymous]

Here’s a screenshot Barry. Off topic but……….I think it may be because I’m in Oz?

[Author]

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