Fuzz face schematic. Arbiter Fuzz Face


The Fuzz Legend
Thanks for visiting a. The Dallas-Arbiter Fuzz Face has been available since 1966, also it shows no indications of dying in the near future. Through this design’s past you will find all sorts of different variations within the fundamental original circuit, from PNP Germanium to NPN Plastic, along with a numerous quantity of fuzz pedals that derive from it. Probably the most notable Fuzz Face-based distortion pedals is the most popular. the Sola Seem ToneBender MKII. The Fuzz Face continues to be performed by nearly every famous guitarist which has ever resided, which trend will likely go on for a really lengthy time.

What’s Inside. The Germanium Years
I believe this pedal’s durability arrives partly to the quite simple design. You will find four resistors, three capacitors, two potentiometers, and 2 transistors. there you have it. The initial resistors were 1/2-watt carbon-composition having a tolerance of 10%. The input capacitor would be a 2.2F electrolytic axial lead. The capacitor in the wiper lug from the fuzz pot to ground would be a 20F electrolytic with axial leads. The .01F capacitor that attached to the third lug from the volume pot was metallized polyester. The initial versions from the Fuzz Face were outfitted with PNP Germanium transistors. There have been a minimum of three types used: NKT275, AC128, and SFT363E. These 3 transistors are very tricky to find nowadays. Watch out for modern-day reproductions from the AC128 and NKT275. When it comes to SFT363E. I have never even seen one! The circuit board below has NKT275 transistors.

Fuzz face schematic

Here is a schematic from the original Germanium transistor form of the Dallas-Arbiter Fuzz Face:

Fuzz face schematic

What’s Inside. The Plastic Years
As time used on, Germanium transistors were gradually being eliminated in support of the greater stable and consistent Plastic versions. Consequently, Dallas-Arbiter started equipping the Fuzz Face pedals using these new transistors with differing results. They are doing seem not the same as the initial Germanium versions, usually having a more harsh and aggressive clipping instead of the “soft” clipping characteristics of Germanium. There is just one part which was altered within the circuit apart from the transistors. The 470-ohm resistor was substituted for a 330-ohm. Also, check out the image from the Plastic Fuzz Face circuit board below. Observe that the positioning of the 33K and also the 330 resistors are complete opposite of what they’re within the Germanium version. The 470 is at the middle in the last version, however it’s gone to live in the outdoors near the 20F capacitor. The transistors that were utilized in these versions incorporated: BC108C, BC183L, BC109, BC109C, and BC209C. Most, if not completely, of those transistors continue to be created and can easily be bought. Some time back I purchased some BC108 and BC109C from Futurlec, however i don’t recommend them like a supplier due to their shateringly slow shipping. The circuit board below has BC183L transistors, that have the B-C-E pinout. The rest of the transistors which were used possess the more standard C-B-E pinout, if you stumble upon a Fuzz Face with something apart from the BC183L, the bottom and collector leads is going to be twisted around to operate correctly.

Fuzz face schematic

Here is a schematic of all of the the initial Dallas-Arbiter Fuzz Faces, the NPN Plastic:

Fuzz face schematic

The Brand New Fuzz Faces. Arbiter Reissues
Recently there’s been an enormous resurgence of great interest within the original Arbiter Fuzz Faces, most likely fueled through the very mediocre sounding Dunlop Fuzz Faces. A few years back, the Arbiter company designed a limited run of reissue Fuzz Faces, filled with AC128 transistors. Should you check out the circuit board picture and also the schematic below, you’ll notice that it isn’t exactly a reissue, but a better form of the initial. However, all of the reissue circuits aren’t exactly the same from unit to unit. you will find a number of variations within the circuit. mostly using the two collector resistors around the two AC128 Germanium transistors and also the output capacitor. Underneath the circuit board picture you will see the schematics of two different variations from the reissue circuit. but there are other!

Fuzz face schematic

Here’s the schematics of a few of the variations from the Arbiter Fuzz Face Reissue, with changes highlighted in red:

Fuzz face schematicFuzz face schematic

What Is the decision?
You can’t really draw a conclusion regarding which version is “better” compared to other, because many people such as the Plastic versions, and a few individuals don’t. It’s reliable advice, however, the Plastic versions will clearly be free from one significant problem that plagued the Germanium Fuzz Faces. temperature instability. It has been noted many occasions over when they extreme heat. they’ll cease working. It had been also much simpler to create more consistent sounds from unit to unit using the Plastic versions (whether individuals “sounds” were good or otherwise remained for that purchaser of pedal to determine). An issue with Plastic transistors that does not appear to exist with Germanium is they might have an excessive amount of gain. An excessive amount of gain may cause a Fuzz Face to seem horrid. With Plastic it might be tough to stick to the Q1 hfe of 70 and Q2 hfe of 120, since most Plastic transistors are excess of 120 to start with. Someone in Aron’s Stompbox Forum stated that putting a 100pF capacitor over the Collector-Base junction from the transistors inside a Plastic Fuzz Face clone is needed control the gain and oscillation, so if you choose to build this version, remember that.

How about PNP Negative Ground Wiring?
Personally, i don’t even think that wiring up PNP transistors (Plastic or Germanium) as negative ground is among the best ideas. The PNP transistors are merely not designed to function having a negative ground and osciallation and “motorboating” sounds are typical outcomes of wiring a Fuzz Face with PNP transistors as a result. Here’s more information from R.G. Keen (GEOFEX):

During theory, the negative ground conversion for FF along with other PNP circuits must work each time, there’s a significant quantity of occasions where it causes oscillation, motorboating, etc. Sometimes you are able to clean this up by placing a big freaking capacitor over the power leads, sometimes you also require a low-impedance .1F ceramic, too, and often you’ll need divine intervention. Check it out if you would like, but remember that you will find conditions and layouts that won’t be hassle free should you switch power and ground.

So, for me, I’d always leave PNP transistor-outfitted circuits as positive ground. A circuit such as the Fuzz Face uses such a tiny bit of current that the battery can last a really lengthy time, despite heavy use. as lengthy as there isn’t an Brought to improve current draw. If you are absolutely determined to utilize a negative ground Fuzz Face, I recommend that you simply feel the extra trouble of having some NPN Germanium transistors that will work correctly having a positive power and negative ground. Small Bear Electronics has NPN Germanium transistors.

My Clone
There’s been lots of debate about the need for using carbon composition resistors inside a circuit when you are attempting to clone the seem of the vintage effect pedal. However for my Fuzz Face clone, I have made the decision to construct it as being precisely as you possibly can, meaning using as numerous NOS parts when i can get hold of, so when they are unavailable, using new production parts that may reproduce the from the originals. The FirOr2-watt carbon comp. resistors can be found from Mouser, although they are 5% tolerance rather from the 10% the original circuit used, however this only denotes that the need for the resistors is going to be nearer to the preferred resistance. I additionally had a significant time finding 20F axial lead electrolytics, but after searching with the Mouser catalog, I came across they do indeed stock 20F/25V Sprague Atom capacitors, which is perfect. For that .01uF capacitor I will be utilizing an original-type flat, metallized polyester film with axial leads. Choosing the right transistors with this circuit may also end up being an issue, but fortunately I’ve some SK-series Germanium transistors which are perfect. I additionally soldered a 2M2 input pulldown resistor towards the bottom from the circuit board to avoid it from popping with true bypass.

Project Files
Note: These files are NOT for use inside a pedal that you’re building to make money. The PCB file is copyrighted artwork and it is susceptible to a licensing fee.

FACE THE FUZZ – Germanium PNP Fuzz Face Guitar Pedal Demo

  • ehafh: some nice sounds and playing