Pharaoh Coupling Caps

[zedsnotdead]

I have both a original and king tut. I'll will check those caps and also try to record a soundclip of both so we can check the differences.
One thing I know for sure: those Ge diodes on king tut are Vf=~0,5v 1n34A, so it wont sound the same on that Ge mode - I am planning to substitute those for some other Ge diode I have that got the correct Vf of ~0.30v

[luks999]

cool man, that would be awesome!
so the original one, uses different germanium diodes than the 1n34a. do you know which ones?

germanium diodes with 0,3V are for example those two:
http://www.musikding.de/Germanium-Diode-OA1182_1
http://www.musikding.de/Germanium-Diode-1N949_1

the demo of the king tut sounds very nice! but im still not sure with with specs i should build it. the orginal sounds great too.
what differences do you hear? is the original more aggressive and dark?

[zedsnotdead]

The original one I think they are 1n34a with vf=~0,3 (that im sure). But my stock of 1n34a were vf=~0,50 so I built King tut with those. (they are probably fake 1n34a, but they sure look like the real ones, DO7 and all...)

regarding the difference in sound/tone, like I said Ill try to record a sounclip for comparision purposes, as soon as possible, and i'll post it here.

[luks999]

ok thanks! looking forward to it!
ordered some via ebay, dont know which vf they have.
on musikding for the 1n34a there is: Vf = 0,7-0,8V

[zedsnotdead]

Well here are some given values for 1n34a:
http://www.reuk.co.uk/Germanium-Diodes.htm

http://www.madbeanpedals.com/forum/index.php?topic=8161.0 - (midwayfair's post)

I mean, you must know what are the Vf test conditions. For example, this graph gives 0,35 @ 1mA:
http://www.mtmscientific.com/1n34a.html

[zedsnotdead]

Hi!

so I just opened my original Pharaoh and guess what...









.... so there are 6x 470nF

Now I did some sound testing and using 47nF instead the sound is not so scooped, it has a nice mid hump. I like it!
I could probably record some soundclips for comparision purposes, may I have the time...

HINT: 1N60P for Ge diode sounds like a beast! 

[luks999]

Thanks man!
so the original uses 1N60P? will try to get some

what you mean with scooped?
so you like the 47nF better?

love to hear some demos

[zedsnotdead]

Thanks man!
so the original uses 1N60P? will try to get some

No, it seems like 1N34A Ge diodes for sure, but I also tried out some 1N60P. Killer sound, better than 1n34's imho.

what you mean with scooped?
so you like the 47nF better?

I mean that King Tut with 47nF have pronounced mid-range compared with the original's 470nF. I firstly thought that it could be some differences on the resist/cap values in the tone stack components, but that's not the case. So I just assume that this 47/470 cap difference could be responsible for that tone change.
One thing I also noticed is that, even though king Tut's pots value are the same as the original, the later have a noticeable less output.

love to hear some demos

I will try to record some sounclips asap. Don't know when but i'll try.

[Hexjibber]

Just thought I would add my findings on this..

I replaced all the 47n caps with 470nf and for my taste at least it has made a noticeable improvement. I've yet to try it through my proper rig but it seems to have changed the responsiveness of the tone controls dramatically, perhaps the combination of more lows being allowed through in some sections (C4, C7 & C12) but being also cut in others (C6 & C9) as a result of the bigger caps has given the overall tone a bit of extra oomph but also some highs in there too which make it seem more aggressive.

To me anyway it now sounds like the sort of sound I was looking for when I built the pedal, pretty dark but lots of wallop and the ability to add cut into the sound so it's not just a wall of mud!

The difference seems night and day to me I'll be honest, but of course these things are subjective! I'm no technical expert, just using my ears and my ears like it!

Cheers,
Graham

[zedsnotdead]

yes, that description is accurate with the differences I hear between king tut's 47nf and the original 470nf.

I really need to record that sound clip...  sorry, didn't have the time to do it yet. Think maybe this xmas holyday will give me some spare time to do it.

[luks999]

yes! i built this thing recently too.

ive found out that the King tut is basically a rams head clone like on the big muff page
http://www.bigmuffpage.com/Big_Muff_Pi_versions_schematics_part4.html
exact same values as in the TUT

i liked the sound of the Blackarts on youtube and ive built it with 470nF as well
the sound is great, although i dont have a comparison, but great to hear you guys like it more

whats kinda awkard at the beginning, is the volume boost on SI and no clipping selection

[zerkalo]

Hey guys,

I built the pharaoh using the schematic from Big Muff Page, this one : http://www.bigmuffpage.com/images/schematics/Pharaoh%20Big%20Muff%20Clone%20Schematic.jpg

I changed the caps values from 47nf to 470nf, but something is wrong when I switch to the 39k resistor (the high setup) :
it's like the caps are charging or something, I play big chords and the volume is crashing then comeback.
It only work a bit when I roll down the volume from my lp.

It's only my third built so I don't really know what's wrong. I have double checked values and polarity but nothing on this side.
All the schematics I found does not mention a change of values apart from the 470nf 47nf dilemma.

Someone have an idea as to where this problem could be coming from ?

(hey first message here, glad to be part of such a great community  )

[JackSkellington]

I don't expect this issue changing those caps. Maybe you wrong something. What board are you using? PCB, stripboard...
Check the caps are in the right spot and, if it's possible, if they are well connected.
In case try to come back to the 47nF and test it again.

[zerkalo]

I'm using a kind of "all Muff purpose" pcb from Coda Effect, a really nice guy from France.
Check this out : https://www.coda-effects.com/2016/01/big-muff-pcb-available.html ; https://www.coda-effects.com/2016/04/black-arts-toneworks-pharaoh-fuzz-clone.html

All ready did an Green Russian clone with the same pcb, work like a charm.

Yeah I will try to replace the 470nf but first I really want to understand why this don't work.
And it's always a pain in the ass to de-solder components.

Anyway thanks for the respond Jack, and happy halloween, halloween, halloween; in advance 

[JackSkellington]

Thanks!

I figured out that you made some mistake after the caps changing, 'cause before it worked fine, right? If it is so check around them.
Or try to check around the resistors switch.