Fuzz Face on the fritz

[CJ]

gonna try a 2N4402 version, low gain PNP silicon,

here is my co-worker working out on the Vox Long tom, supposedly used on Zep 1>

https://www.youtube.com/watch?v=27KcfQSOD4M

https://www.youtube.com/watch?v=fXqZhb8NBV8

 

[Wildfara]

I forgot to get back to this thread...I did build a FF into a Strat style guitar and I love it. Flip of a switch and its fuzz lead or rhythm time. I stuck the battery in the trem pocket and made a new face plate out of steel. I'll post up some pics later...Its really pretty fun. The controls are extremely responsive to where the guitar volume is set and i have all three knobs right there at fingertips. I deleted the other two Strat style controls...so the way its set up is. Your selected pickup into volume into on/on dip switch and out to amp or selected pickup into volume  pot into dip switch to fuzzface and out. Its not that complex but freaks people out haha

 

[Wildfara]

I also bought a Peak DCA 55 transistor tester which is indespensible for testing random pulls. I think another generation came out recently that has tracing software so you can plug it into your computer.  It takes all the guesswork out of leakage and gain etc. not to mention pinouts and bad transistors.

 

[CJ]

built a 2N4402 PNP version , sounds great!  gain a little high , q1 hfe = 220 and q2 = 180 according to the computer programs  linked upstream on pg 2.


the most important resistor is the emitter resistor on q2, had to use 1.5 K to get V-c up to 4.7 volts,

wish somebody would write a program where that resistor value is the unsolved variable.

used a fixed value for the emitter resistor and no feedback cap.

you can vary the cap value to give more treble, but it sounds pretty raspy, the rolled off fuzz face sound is the way to go.

got a little above unity gain so it does not blast out the house PA.

going to order some 2N2222 like Gus uses and see what it sounds like with the lower hfe.

thanks to everybody for all the cool replies! 

SG ready to rock, battery low after a miscue, >

 

[Whoops]

what are your favorite transistors for this box?

lots of Germanium cans on evilbay, don't know which ones are fake, looks like some good stuff from USSR,

I like selected AC128, OC types, the Japanese 2SAxxx or 2SBxxx types are also quite good and very stable, Russion GE can also be nice and are quite cheap.

I never seen an NKT275, all the original FF pedals I've seen had AC128, AnalogMan started the trend for the NKT275, his website  stated that the NKT275 was the original transistor in the FF , blablabla, and the best sounding one and the one they were putting in AnalogMan pedals, people followed.
The reality is this circuit sounds really good with most selected pair of germanium transistors, with the right Bias, and I also like it with the capacitance of the non-alkaline batteries.
I've built a lot of FF pedals and A/B most of the online myths, the 3 guidelines above I find them to be helpful.
I always use it as the first pedal in the chain and the guitar has passive pickups

CJ if you want some Germanium transistors I can send you some selected  pairs of different types, I have a nice stock

 

[Wildfara]

I second the 2SA and 2SB varietys...Best luck with those and i seem to find them in tons of stuff.

 

[PRR]

> wish somebody would write a program where that resistor value is the unsolved variable.

This interacts with the Q1 hFE and its base resistor. And if you are Ge/Si anbidexterous, Ge or Si Vbe.

In a simple analysis, Q1 has huge hFE, its base resistor is tiny. Then Q2 Re will come up to Q1 Vbe, and a half-bias point can be solved trivially.

But Q1 Rb can't be tiny, it would tone-suck. Also the Venerated Values come from days when transistor hFE varied all over the place, low-hFE cheaper.

"Measuring hFE" is a problem because Q1 runs at a low current; also different depending what Rc you use for Q1 (and some slop from Q2 hFE). Vbe is likewise uncertain until a bias point is found.

So it really is a 3-pipe problem. Or 30 seconds with a handful of resistors.

 

[abbey road d enfer]

But Q1 Rb can't be tiny, it would tone-suck.

Simulation says input Z about 500 ohms @ 1kHz. Even if pessimistic, the actual Z cannot more than 2k, which is enough to "suck tone". I believe it's part of the mystique. Combined with the typical inductance of a pick-up, the end result is distinctively fuzzy low notes, but up the neck the tone is not too dirty.
I believe there's no rule when it comes to overdrive/fuzz/distortion pedals, they're the result of rolling components and listening, unless the miracle of pure serendipity happens.

 

[Bo Deadly]

I believe there's no rule when it comes to overdrive/fuzz/distortion pedals, they're the result of rolling components and listening, unless the miracle of pure serendipity happens.

Agreed. I built a trio of fuzzes at the same time once partly just to see if they sounded different. To that end I made two units with the same transistors with very similar gains and leakage. Those two pedals did indeed sound identical. The third sounded different.

Regarding tone sucking from the low impedance input, the FF generates a lot of harsh high frequency buzz. So removing that at each step is important I think. That cab be with low Z input (and tweaked by rolling back the volume on the guitar), limited bandwidth transistor (older Germaniums), and ultimately the high cut of older guitar speakers like the extremely common Jensen P12Q commonly found in Fender amps of that era which crushes everything above 5kHz. If you run a FF direct into a power amp and then a P12Q (no git amp), it actually sounds pretty good. But if you pipe it into a studio monitor or otherwise full range driver, there are nasty high frequencies.

 

[abbey road d enfer]

and ultimately the high cut of older guitar speakers like the extremely common Jensen P12Q commonly found in Fender amps of that era which crushes everything above 5kHz. If you run a FF direct into a power amp and then a P12Q (no git amp), it actually sounds pretty good. But if you pipe it into a studio monitor or otherwise full range driver, there are nasty high frequencies.

Indeed, speaker roll-off is a very important factor in making a nasty square-wave tolerable.
A terrible example is in some Nashville recordings where the engineers did fuzz by DI'ing the guitar directly in the console. I think they believed the fuzz sound would be more "HiFi" that way! And I guess the other musicians, band leader and contractor did not want to have that sound in the studio.

 

[rackmonkey]

Indeed, speaker roll-off is a very important factor in making a nasty square-wave tolerable.
A terrible example is in some Nashville recordings where the engineers did fuzz by DI'ing the guitar directly in the console. I think they believed the fuzz sound would be more "HiFi" that way! And I guess the other musicians, band leader and contractor did not want to have that sound in the studio.

Brings up another angle on the fuzz thing, Abby.

No doubt a lot of folks are anti-direct. But i’ll remind you that direct-into-console fuzziness is the key part of some iconic guitar sounds: “Revolution”/Beatles, “Black Dog”/Zep, several of Neil Young’s Crazy Horse-era riffs, Robert Fripp’s guitar sound on Bowie’s “Heroes”, much of Nile Rodgers’ funkiness in Chic and with Bowie,  Roger McGuinn’s Rick 12 on “Eight Miles High”, etc.

Given the differing views on direct guitar fuzz/distortion, you’ll probably either love or hate this:

JHS Pedals Colour Box. Neve 1073 channel in a pedal (or such was the goal of the designer):

http://tonereport.com/reviews/jhs-colour-box
https://tapeop.com/reviews/gear/107/colour-box-preampeq-pedal/

CJ, I played with one of these in a shop a few weeks ago. I’ll be danged if the blocking distortion+fuzz I could dial in on this thing wasn’t a dead ringer for that Spirit in the Sky Sound.

Makes me want to plug in to a channel and get out the scope and signal tracer and see what can be learned.

I’ve built a lot of fuzzes and can’t add a lot beyond what’s been said, but i’ll offer up something that’s been indispensable to me in identifying potentially suitable Ge’s for the purpose (I far prefer the limited bandwidth Ge’s over what I perceive to be the harsher sound of Si). If you don’t already have a copy of Towers Transistor Substitution Handbook, here’s the link to a PDF copy on my Google Drive:

https://drive.google.com/open?id=0B__Vr0ik2GcgcDI1OV9qcEtFTEE

Just can’t get to these posts in time to join in on the fun.  Making a living is interfering with living.

BT

 

[abbey road d enfer]

No doubt a lot of folks are anti-direct. But i’ll remind you that direct-into-console fuzziness is the key part of some iconic guitar sounds: “Revolution”/Beatles, “Black Dog”/Zep, several of Neil Young’s Crazy Horse-era riffs, Robert Fripp’s guitar sound on Bowie’s “Heroes”, much of Nile Rodgers’ funkiness in Chic and with Bowie,  Roger McGuinn’s Rick 12 on “Eight Miles High”, etc.

These are certainly not my fave examples of fuzz, except Heroes.
However, they are acceptable, but really, my gripe was about some country recordings where I can feel the producer thinking "fuzz is hip, let's do that" and they end up with a turd. I don't have an example now from my head, but I'll check my country music compilations.
BTW, my fave Beatles fuzz sound is "And your bird can see".
True I'm an half-assed anti-DI. Let me explain: I favor it for bass, because it's much easier and gives better results on an average basis, and on acoustic in live situations, because it's the only way to be heard, but I generally hate it on electric guitar.
That said, one day I had a guitar player in my studio that said he didn't want to play through an amp and insisted on plugging his Vox Tonelab direct; I must say he managed to get a more than decent sound. That's the mark of an excellent musician.

Given the differing views on direct guitar fuzz/distortion, you’ll probably either love or hate this:

JHS Pedals Colour Box. Neve 1073 channel in a pedal (or such was the goal of the designer):

The surveys on this have not convinced me, particularly in view of the stiff price.
As you may have figured out, I'm not a fan of fuzz; I was a teenager when fuzz came out, and it was often used as a bad cover for poor playing ability. It left an indelible mark on my judgment, I guess.

 

[Bo Deadly]

Here's an interesting description of grown vs alloy junction Germanium transistors and how they were made:

TI Transistor Circuit Design: Chapter 1: Fundamental Considerations: 1963

I stole this from my father's pile of old books (he worked at Bell Labs for many years). It's so old, it burns my hands when I touch it.

Otherwise this book is nearly useless as transistors were just starting to replace tubes and it is largely about germanium transistors even though germanium only dominated the market for a relatively brief window of time. From the text:

"Most of the work in epitaxial films to date has consisted of depositing a layer of semiconductor material on a substrate of the same material - germanium on germanium or silicon on silicon."

That sort of gives you an idea of the moment in time when this book was published. By the time it hit the market it was probably obsolete.

UPDATE:

Here's a really good description of how Germanium transistors were manufactured:

http://www.thevalvepage.com/trans/manufac/manufac1.htm

So it seems the transistors that have low-bandwidth are not the grown variety as I have been claiming - they are all alloy-junction. It is the width of the base region that limits bandwidth. So certain transistors had wider base regions and thus limited bandwidth for whatever reason. And of course a high gain circuit (like the Fuzz Face) will also result in limited bandwidth.

 

[Wildfara]

"No doubt a lot of folks are anti-direct. But i’ll remind you that direct-into-console fuzziness is the key part of some iconic guitar sounds: “Revolution”/Beatles, “Black Dog”/Zep, several of Neil Young’s Crazy Horse-era riffs, Robert Fripp’s guitar sound on Bowie’s “Heroes”, much of Nile Rodgers’ funkiness in Chic and with Bowie,  Roger McGuinn’s Rick 12 on “Eight Miles High”, etc. "

I recently acquired an old Traynor 4200 mixer amp and a guitar into it with the channel cranked is an awesome SS fuzz tone. Fiddling with the 5 way EQ and built in reverb can really dial in some nasty tones. I dig it.

 

[CJ]

there is technically only one sine wave, but thee seem to be infinite of distortion.

And Your Bird Can Sing 

 

[abbey road d enfer]

And Your Bird Can Sing

Indeed, but mine can really swing.  ;D

 

[MagnetoSound]

'And your bird can swing' is another line in the song.

(Or 'swong'! )

 

[CJ]

well that song swung both ways, as it was on Revolver and Yesterday and Today.

Coral blue strat me thinks.

 

[abbey road d enfer]

Coral blue strat me thinks.

All litt seems to point at Epiphone Casino, played by George and Paul.
http://www.beatlesebooks.com/and-your-bird-can-sing
http://www.songfacts.com/detail.php?id=3877

 

[CJ]

strat vs casino>

https://www.youtube.com/watch?v=aiyBkxiZzoA

https://www.youtube.com/watch?v=Wxf9IZmtDYE