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Re: Earthquaker Talons

Posted: 24 Feb 2015, 18:14
by zedsnotdead
OFF-TOPIC

@darmstat
Could you tell me where do you host your images? Tks!

Edit: oh Forget about it, I think I found the answer ("Upload attachment" below....)

Re: Earthquaker Talons

Posted: 24 Feb 2015, 19:24
by thesmokingman
if you look closely, those LEDs are in a traditional feedback diode arrangement with 100p in parallel to them. traces on the other side back that up

Re: Earthquaker Talons

Posted: 24 Feb 2015, 19:39
by Nocentelli
thesmokingman wrote:if you look closely, those LEDs are in a traditional feedback diode arrangement with 100p in parallel to them. traces on the other side back that up
?
That's what the schematic shows.

Re: Earthquaker Talons

Posted: 24 Feb 2015, 19:40
by zedsnotdead
Guys, need some help.

This is what I have so far. I named the componentes to make it easier to follow:
talons%20%20%204.jpg
Talons_schem.jpg
Now, I just haven't figured out where C12 is connected, although positive side of C10 gives me connected to 500k pot (drive) lug 3 :scratch:
Don't know if it's correct....

what do you think of this?

Re: Earthquaker Talons

Posted: 24 Feb 2015, 19:45
by thesmokingman
talons 7(the last one I saw on here) showed them in series

Re: Earthquaker Talons

Posted: 24 Feb 2015, 19:58
by darmstat
Looks better then what i came up with....lol :D

Re: Earthquaker Talons

Posted: 24 Feb 2015, 20:31
by Nocentelli
thesmokingman wrote:talons 7(the last one I saw on here) showed them in series
Yeah, my bad.

Re: Earthquaker Talons

Posted: 24 Feb 2015, 20:34
by thesmokingman
zed, the missing presence control will come off the first feedback loop just like the zendrive with a 1k in series with a 5k pot with a 3n3 to ground. low pass filter with corners from 8042.2 Hz to 48253.2 Hz

Re: Earthquaker Talons

Posted: 24 Feb 2015, 21:04
by darmstat
So...The presence is something like this ? ?

Re: Earthquaker Talons

Posted: 24 Feb 2015, 21:26
by thesmokingman
looks like lug 1 runs to the cap and 3 is tied to 2 and they run over to the resistor. and I dunno why I said the cap runs to ground ...

Re: Earthquaker Talons

Posted: 24 Feb 2015, 23:36
by Nocentelli
darmstat wrote:So...The presence is something like this ? ?
I really like the three band baxandall EQ on this, but i'm getting very little dirt with just a 3n3 cap on the presence control.

Re: Earthquaker Talons

Posted: 25 Feb 2015, 01:47
by thesmokingman
Yep ... Your comment fixed that for me ... So throw out the stuff about the presence control. The traces didn't follow like I thought when I blew up the pics plus it doesn't follow the logic. Whole purpose of that filter is to set the frequency of what doesn't clip. Hooray for failure!

Re: Earthquaker Talons

Posted: 25 Feb 2015, 02:15
by zedsnotdead
Ok, I forgot the filter (presence) part.

here's how it looks like for what I could trace/verufy till now:
ScanImage001.jpg
Im pretty sure C4 is grounded.

Re: Earthquaker Talons

Posted: 25 Feb 2015, 02:52
by darmstat
Hi Zedsnot dead. Cam e you confirm if the 10uf capacitor is at the vref ( resistor 93 and resistor 92)? I also think that at the end of the gain pot (500k) there maybe a 10k resistor and 1uf capacitor, then then the capacitor is connected to ground or vref?

Re: Earthquaker Talons

Posted: 25 Feb 2015, 03:39
by thesmokingman
Looks like 1u into 1k.

Re: Earthquaker Talons

Posted: 25 Feb 2015, 16:14
by thesmokingman
stared at it some more. zed's labeling has pin2 of op amp connected to c11 going to r12 to vref. corner frequency of high pass is 159.2Hz. presence is drawn correctly.
c12 goes from r93 to ground best I can tell.
also, you can just eliminate the question mark between pin3 of presence and c10.

Re: Earthquaker Talons

Posted: 25 Feb 2015, 19:50
by zedsnotdead
Sorry guys, haven't had any time today.
I have to return the pedal tomorrow, so I'll try to check what's left as soon as possible. I think I will shoot again some new photos of the PCB, more detailed ones I hope ...

Re: Earthquaker Talons

Posted: 25 Feb 2015, 19:55
by thesmokingman
what else are you missing?

Re: Earthquaker Talons

Posted: 25 Feb 2015, 21:49
by darmstat
I think the 3 components i have circled. I am guessing that they go to the 500k pot for the gain?? Please look over.

Re: Earthquaker Talons

Posted: 25 Feb 2015, 22:06
by zedsnotdead
hmmm.... I think that 500ka pot (gain) right lug (3?) is connected to a cap + resist that goes to the tone stack instead of Vref, much like the guvnor scheme.

Like this:
marshallguvnor.gif
marshallguvnor.gif (6.82 KiB) Viewed 2258 times
But let me check that when I get my hands on the pedal later tonight.