Throbak - Strangmaster  [traced]

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Manfred
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Post by Manfred »

In the shot you can see well the Germanium transistor typ 2SD96.
Who knows the applied Silicon transistor type on?
ThrobakStrangmasterShot.jpg

dv8r601
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Post by dv8r601 »

Dont get upset if I'm wrong but I think it was a bc108b in mine or maybe a 2n2222. I had it a while back and never messed with it because it sounded pretty good as it was.

Manfred
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Post by Manfred »

Thanks for your the answer.
In view of the current gain the 2N2222 is more likely.
Do you know the values of the other components too?

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Post by dv8r601 »

I didn't take time to write anything down when I had it, now thinking about it I'm almost certain it was an 2n2222a. Plus, They use them in alotta other pedals they make, so I'm pretty sure that is it. I'll see if the new owner can take some board shots and get back to me. I wanna make one myself, because it was a killer od pedal.

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Post by bc108 »

For sure, it seems that they use 2n2222: maybe due the low hfe (like the Ge's one's).
For reference, take a look to the Catalinbread Naga Viper; Rangemaster NPN version, some add's and use a 2N2222 transistor.

Manfred
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Post by Manfred »

I bought an used Strangmaster several months ago, I sold it in the meantime.
I made some shots and traced the PCB.
Furthermore, a made some measurements.
Here are the results:
ThrobakShot1.jpg
ThrobakShot2.jpg
ThrobakShot3.jpg
StrangMasterSchematic.jpg
Read transistor values:
NPN Silicon BJT 2N2222A:
hFE=258 at Ic=5,02mA
Vbe=0,752V at Ib=5,00mA
VceSat=0,018V at Ic=5,0mA and Ib=1,00mA
IcLeak=0.000mA

NPN Germanium BJT 2SD30:
hFE=119 at Ic=5,01mA
Vbe=0,298V at Ib=5,00mA
VceSat=0,017V at Ic=5,0mA and Ib=1,00mA
IcLeak=0,176mA

I made output traces using different input signal voltages at different bias pot settings.
I measured the frequency response too.
You can find the readings in the following ZIP-file.
All diagrams were labeled.
StrangMasterMeasurements.zip
(297.56 KiB) Downloaded 92 times

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jalmonsalmon
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Post by jalmonsalmon »

I am kind of wondering what effect that 220p cap has on the input to ground :scratch:

Manfred
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Post by Manfred »

jalmonsalmon wrote:I am kind of wondering what effect that 220p cap has on the input to ground :scratch:
The capacitor serves to supress radio frequencies.

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Post by RSWRecording »

jalmonsalmon wrote:I am kind of wondering what effect that 220p cap has on the input to ground :scratch:
Same thing I was wondering.

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Post by modman »

I didn't mean to lock this topic, just happened because it was put on solved in the wrong folder.
Keep on necrobumpin' that shit ;-)
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