Definitive "Live at Pompei Echoes" fuzz face clone

[traktop]

I know there has been a couple of threads talking about Gilmour/Pink Floyd guitar tone, but they always seemed to end talking about Muffs.
There are some silicon fuzz face clones around here that sound great in the demos, (meathead, etc..), but some of them are like refined versions of the original pedal, (sunface bc108 looks good).
I´m looking for something that nails the Gilmour Live at Pompeii Echoes fuzz sound to build inside my strat, so it has to clean up very nice as well.
I know that such a little circuit will probably require some trial and error, so transistor kind/gain combinations advices are welcome.
Cheers Gilberto.

[Muadzin]

Live at Pompeii is my favorite Pink Floyd album/vid. I do love the Muff in all its incarnations but that tone in Echoes beats Dave's later Muff tones IMHO. So I fully endorse this thread. I take it you have read the relevant pages on Gilmourish regarding this tone?

Live at Pompeii effects and amps:
http://www.gilmourish.com/?page_id=14

Dallas Arbiter Fuzz Face:
http://www.gilmourish.com/?page_id=73

The problem with the Live at Pompeii tone is that it uses a BC108 equipped Fuzz Face, tamed by a volume pedal in front of it, into the 3 famous Hiwatt amps, into the WEM cabs and possibly 2 HH Electronic IC-100 100W solid state heads with rotary speakers as well. Methinks the Fuzz Face itself is the easiest part to reproduce of that signal chain.

[traktop]

Muadzin wrote

The problem with the Live at Pompeii tone is that it uses a BC108 equipped Fuzz Face, tamed by a volume pedal in front of it, into the 3 famous Hiwatt amps, into the WEM cabs and possibly 2 HH Electronic IC-100 100W solid state heads with rotary speakers as well. Methinks the Fuzz Face itself is the easiest part to reproduce of that signal chain.

Well, I´ve already got the hiwatt head and the strat... Only the fuzz face and Gilmour´s left fingers
Months ago I built a rams head violet muff and is really great doing its thing. It sits on my pedalboard between buffers, etc... with no complaint. Given that a fuzz face must be first on the signal chain I want to do it inside my guitar, so I´ve got a music tool ready to rock at any time, anywhere.  
I named the sunface before cause that´s the only ff clone around here that specifies the BC108 transistor, and the demos seemed to sound great.
I was wondering if maybe there is any "Pompei Gilmour sound" freak around which made experiments with a ff layout and nailed the thing, so he could share some wisdom and advice.
Cheers,Gilberto.

[Travis]

There's nothing different about the BC108 Fuzz Face except for the transistors, so you could build any stock NPN Fuzz Face layout and use BC108.

Keep in mind there are lots of different BC108 out there. Maybe get a few different types to try, or try to find the same brand that was used in the original if you're really adamant about accuracy.

I would not add any mods except a pregain pot to simulate the volume pedal that Ciaran mentioned. Bonus points for using the same value pot as the volume pedal David used. The volume pot on your Strat will do the same thing, but the impedance will be different with the volume pedal in play, which will have an effect on the overall sound (even if it's subtle with the pot maxed)

Maybe bias trimmers to fine tune the attack/decay and cleanup, but you should be able to get a good sound with the stock values as David did

[Muadzin]

I'd go with this layout from Harold Sabro, because it has a biasing trimpot. Although you'd probably need a trimpot for the gain as well. Or set it with a fixed resistor as David seems to have it set maxed all the time. The only outside controls would be the FF volume and the pre-gain pots. Personally I would use a push/pull pot as 500K push/pull pots seem to be easy to find. Plus I already got one lying about.

I'm thinking of doing this myself as well. I already have a guitar that is heavily influenced by David. It has the hot Seymour Duncan bridge pickup (which he didn't have yet at the time of Live in Pompeii though) and a built in wah board to create the Echoes seagull screams. It also has a boost circuit which I don't really like and was looking for something else to replace with. This could just be it.

[traktop]

Yeah, I thought about Sabro layout as well, or even the eric johnson layout around here since it has the Q2 pf cap and a trimmer as well.
I´ve got a set of suhr v60lp  coming to replace my shitty scn noiseless pickups.
I already have 2 x 250k push-pull tone pots waiting for me to come out with something, (may be a diy ssc noiseless system  and a fuzz). My intention is making it as a one volume knob fuzz, (500k trimmer),  and attach it anywhere inside the back plate with velcro.
The "seagull" strat idea sounds so cool!!!

[traktop]

Travis wrote

Maybe bias trimmers to fine tune the attack/decay and cleanup, but you should be able to get a good sound with the stock values as David did

The cleanup would be important here. I remember I tried a plum crazy efx polecat once, (fuzzy lady with a Si/Ge switch), and loved how it completely changed the character from fuzz to od just touching the guitar volume knob...

[alltrax74]

Listen to the samples of my Pink Face, I'll send you the layout if you like it
It cleans up very well as you can ear on the "pink face strat take 1" sample

[traktop]

Sounds great!
It really nails that  "shine on..." lead sound.
The thing is that I didn´t get into germanium transistors yet, (got loads of silicon tough), but I will do it sooner or later, so if you share your layout and tell me about what kind of Ge transistors I should try, it would be an excellent excuse.
I finally made the sabro layout with pretty much everything shocketed. I boxed inside a 1590a "prototype" enclosure, but didn´t try it yet.
Will share my progress

[alltrax74]

Here is my layout 

[Muadzin]

I built the Sabro layout, I used some BC-108's and I rocked it before boxing. It worked and I biased it to a sound of my liking. I used a 1K trimpot to control the fuzz settings and used a 500K push/pull pot for volume and to act as a circuit bypass. When I installed it in my guitar however the circuit no longer rocked but instead.... sounded like a clean guitar should, but not like a fuzzed up guitar should. I recorded a phrase into a looper using the same guitar, then used an audio probe to insert the signal into the fuzz face at its input and loo and behold, there be fuzz. But when using the direct signal from the guitar, clean guitar again.

Weird shit. I've built three guitars with fuzz factory circuits inside them and they behave as they should, but not this circuit. The finicky nature of the fuzz face at work again? Maybe some weird kind of impedance or grounding thing going on?