fuzzface germanium transistor

[josh_homme]

the original fuzzface germanium transistor version does not have a led indicator. can i put a led in the circuit board without it affecting the sound?
i am planning building it myself, dont know much about it..

[drewl]

Sure, I didn't bother because believe me, you'll know it's on.
Anyway, is yours true bypass? you can get another footswitch with extra lugs and wire the LED to that.

[josh_homme]

i havent made it yet, i ve ordered the parts, they should arrive in a day or two. the parts list is from this site Original Fuzz Face | Arbiter Fuzz Face | Dallas-Arbiter Fuzz Face | Hendrix Modification ,
so is the schematic.. some other schematics with germanium transistors that also have led indicators are a bit different than the "original" schematic. one like that :

http://www.generalguitargadgets.com/...ff5_sc_pnp.pdf

[josh_homme]

i really dont know almost anything about it.. where do i put the led? between the 1k resistor and switch ?

[loudthud]

The LED is D4 on the General Guitar Gadgets schematic. Both schematics are really the same except the second adds a true bypass switch and a power supply jack. If the LED is too bright you can increase the 1K (R11) to 4.7K or 10K. That will increase battery life since the LED uses more 10 times more juice than the Fuzz Face circuit.

[josh_homme]

i get it now! thanks for the help!!

[josh_homme]

I have completed the fuzz (using this schematic Smallbox Effects Projects : Fuzz Face ) .
it works, but there are still some problems, when the fuzz pot is turned all the way there is a noise ( lilke motorboating), and when i turn the tone pots on the guitar (treble or bass pickup) way down to 0, there is even a wierder sound. and i have put a led, bud when i connetct the cables it stops working.
quite a few problems..

[Mark Hammer]

Although addition of a status LED is, in theory, a simple affair, there are a few things to be mindful of.

1) You have to be able to see it, and you have to be able to continue seeing after you've looked at it (i.e., not go blind). This means adjusting the resistor in series with the LED to provide the optimum visibility.

2) The amount of current drawn by the LED can't be so substantial that a) it drains the battery, and b) produces an audible pop when you engage the effect.

LEDs vary in how much brightness they produce for a given amount of current provided to them. This rating is in millicandles (mcd). Most of the standard indicator LEDs are going to be somewhere in the neighbourhood of 300-1000 mcd, and will produce acceptable brightness when a resistor around 1.8k-3.3k is placed in series with them.

Other LEDs fall into the category of "superbright". These will usually have ratings of 2000-6000mcd, and are VERY intense. Intense enough that they need "taming". In many cases, you can stick resistors in the range of 10k-15k in series with them, to restrict how much current you feed them.

The nice thing about superbrights is that, because they do not need as much current to be visible, they don't drain the battery as quickly. As well, another benefit of low-current superbright LEDs is that when you step on the stompswitch, they do not produce a "pop" when suddenly drawing a noticeable amount of current from the battery.

[thumbs]

Assuming your transistors are good, there could be a couple of things going on. They may be mismatched. (Fulltone uses an intentionally mismatched pair of silicon transistors in their '70 fuzz to give it more sputter and fizz.) You may also have a bias problem. A lot of builders swap out the 8.2k resistor with a 20k trim pot so they can adjust the bias. Around 4.5v seems to be the sweet spot for most people. Another good idea would be to use sockets for the transistors. You could experiment with different types without soldering and risking damage from heat. Best of luck with your build. Let us know how it comes out.

[Robert M. Martinelli]

Hi Gareth, and welcome!
May I suggest you to start another thread instead of "hijacking" an existing one?

It's just a matter of good "housekeeping", and it will help people who will have similar problems in the future to take advantage of all the info available here by simplifying their search.

Starting a new thread also gives your problem a better visibility, so it will be easier for you to get all the help you need.

There are a lot of kind and knowledgeable people here (Mark, Loudthud, RG and many others), help them to help you!

Hope this helps

Best regards

Bob