I have been running some simulations of JFETs in order to study a bit about how to bias JFETs properly and also to teach myself along the way. I'm having problem with some of my calculations though. I am currently able to accurately calculate the operating point of a simple JFET circuit so long as it only has a source resistor. However, I've noticed that as soon as the drain resistor gets large enough to limit the current to be lower than the expected current draw for some source...
I want to add a flashing LED to a tremolo using a simple 2N2222A switching arrangement as in the attached diagram (the 330K is connected to the LFO output).
It needs a 4u7 from the base to filter LFO feedthrough (ticking), and I'm thinking - should I be worried about leakage discharging through the base-emitter from that cap and damaging the transistor. Is that ever going to happen? I could add a small current limiting resistor from the emitter...
Anyone have the slightest clue what these two chips are? I've tried to figure out what they are, but nothing has come up so far...
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I've been doing some cleaning up at home, and rediscovered my grandmother's old AM radio - an AWA Radiola (Model B29 = Radiola Eight, I think; 1955-1960s based on the ARTS&P license sticker.)
What caught my eye was the transistor complement label inside the back flap, listing eight germanium transistors and one germanium diode. :-)
The listed types are: AWV 2N374/2N1636, AWV 2N373/2N1634 (x2), AWV 2N406 (x2), AWV 2N408 and AWV 2N217S (x2); the diode is an Anodeon 1N295.
I can see that...
Whilst I've built plenty of stompboxes in my time, my dabblings with germanium have been few and far between. I've built a fuzz factory and it's good BUT I'm now wanting to do a 'traditional', properly biased germanium fuzz face and also to play with low-gain transistors / a few different values to do a Sun Face clone (my understanding is that low gain transistors are used there? Can anyone confirm please?).
I keep seeing general comments that 'modern' germanium transistors just do...
Seems like a noob like question, and it is. :mrgreen:
but basically what I'm asking is, what changes what and how can I learn to bias a transistor to be clean, for say a clean boost, or output stage. Or, how could I bias one for fuzz, or overdrive? I've learnt basic things from building my own circuits, and see the differences in the biasing, but my question is basically what changes what?
I have a number of old RCA germaniums and they always have some sort of code on them, a combination of letters and numbers I can make no sense of. Was there some sort of date code they put on these? Anyone know how to read it?
Hiya - is there any difference between these. Looking to build a Formula No. 5 and I have some 2n5484 lying around, but parts list asks for 2n5457. Cheers
Since I haven't found U406 or LSU406 at sensible cost I'm trying to replace them with something else. U406 is a dual FET. Can I just replace it wit two single FETs? Like J201 or some other single FET?
I'm making this preamp
So I get the theory behind Darlington pairs, and successfully bread boarded a few schematics, but I really want to understand the proper math behind the resistors for a Darlington pair. Right now all I can find are suggested resistor values, and I'd really like to be able to calculate these values on my own.
Hi,
i know that many topics were about Dr boogie transistor's ,but i had to open a new topic
My problem is that in my country (Croatia) the j201 is very rare and vvvvvvvvveeeeeeeeeeeerrrrrry expensive
I found the alternative in a form of a 2N5458 which costs much much less
So the question is what kind of sound will the 2N5458 produce,and which elements do i have to change on the pcb(source resistor,etc.....)
Also those with the expirience of experimetnig with other alternatives I ask of yout...
Hey all:
I just bit the bullet and ordered a couple of GT313s from mother Russia. 3 will go into a Toecutter, and I think 3 more have Buzzaround written all over it. They're specified at 20-200hFE.
For those of you with GT313 experience, do they follow any trends gain-wise, or are they completely random, as most Ge transistors are?
I only bought 10, so I want to make the most out of what I've got. Thanks!
Notice I put idiots plural - not idiot's ... as I hope I'm not alone :block: But I don't think there is a correct simplistic explanation of how to do this here or elsewhere? So I thought it might help others if I put one up - it would have helped me. Here's the infamous article kindly provided by RG Keen But it's a bit obfuscatory to the average homebrew tinkerer I think. Really I'm just spelling out what KindaFuzzy has already said ...but I don't think that's a bad thing (if the mods do - feel...
Hey guys, it's near to impossible to find a J201 in Italy and I need those for runoffgroove projects. Can they be replaced, or do I need to search better?
Hey fellas!
Let's say we have a simple buffer like here:
schemo.png
It's probably totally nooby question, but would it be hard to switch it into a booster? I mean - changing or adding some components with a flip of a switch, so we have some additional gain at the output? Or it would just be better to stick a LPB in there and switch between two pot values?
Forgot to mention - it's going to be a part of a wah circuit. I've heard that boosters cause distortion problems in wahs. :scratch:
Hi All - bit of a newbie to all of this, but I'm getting the bug for building (instead of circuit-bending) pedals. I've currently got a Colorsound One Knob Fuzz that's got two transistors in it (a 2N222 and a BC548 in place of BC 108 and 109) and I'm wondering about lowering the noise in the circuit (I know, it's a fuzz pedal, but I want a clean fuzz).
Does anyone have any recommendations for this - it's the Dragonfly (Andrew Carrell) circuit by the way.
I'm about to launch a fuzz face build (Joe Bonamassa fuzz replica) thanks to turretboard.org's layout and schematic. However I'm stumped by one simple thing. The layout provided by the website shows two resistors without a value but with a voltage indication: 0.5V on Q1's collector and 4.5V on Q2's collector. SO my question is simple: how in the hell do I manage to get these voltages there? Does it mean that I have to use trimpots there? How do I do,...
Just got me this great compressor and curios as I am...so I've tried to find which
fet is used at the input.
But no luck yet so therefore I ask U people here ; smt with marking GS g
Does anybody know what that is ?
First of all sorry about my english, i'm spanish and, well, i'm sure that eventually i'll write something hard to understand :lol:
I have a question about Fuzz Face that maybe it's kind of noob.
I'm a newbie and i'm about making my frist build. I was thinking to make a LPB-1 or something similar, but I love fuzz pedals, and everyone seems to agree that a FF is a good starting point, as it doesn't require lots of parts and is easy to build.
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