Earthquaker Devices - Monarch revision 2 - 2011 [gut shot]

General documentation, gut shot, schematic links, ongoing circuit tracing, deep thoughts ... all about boutique stompboxes.
Didi&Stulle
Information
Posts: 17
Joined: 06 May 2010, 07:55
Has thanked: 3 times
Been thanked: 11 times

Post by Didi&Stulle »

seems like Earhquaker changed to multilayered pcbs lately :?

I found a lot of seemingly non-collected pads (I marked these blue), which seem to be connected on a non-visible layer, so I guess it wont make sense to put more effort into tracing my friend's board, right?
any ideas are welcome.
Attachments
monarch traced.jpg
monarch traced missing connections.png

marshmellow
Cap Cooler
Information
Posts: 470
Joined: 16 Aug 2007, 07:31
Location: Germany
Has thanked: 16 times
Been thanked: 119 times

Post by marshmellow »

To me it looks like they are all connected to the top layer which is probably ground.

User avatar
Intripped
Cap Cooler
Information
Posts: 564
Joined: 25 Aug 2009, 01:03
Location: Italy
Has thanked: 700 times
Been thanked: 220 times

Post by Intripped »

not all of them:
there are some other traces on the top-layer of the PCB - i can see two running under the upper row of components
and the upper-left diode is not connected to the top layer... maybe it's really a 3 layers board

...what about taking some other pics from different angles, and one of the other side too? :)

pietro_moog
Breadboard Brother
Information
Posts: 108
Joined: 03 Jun 2010, 19:00
Has thanked: 8 times
Been thanked: 45 times

Post by pietro_moog »

even if it's a 3 layers board, i don't think it's gonna be too hard now. the first stage (a mosfet, cool idea) is basically traced, the eq part is pretty much understandable and for the rest of the circuit we almost have it. a rough schematic can help to visualize everything.

pietro_moog
Breadboard Brother
Information
Posts: 108
Joined: 03 Jun 2010, 19:00
Has thanked: 8 times
Been thanked: 45 times

Post by pietro_moog »

so, basically, this is a mosfet input stage, eq, a jfet mu-amp and then a jfet buffer with 2 resistors and caps to cut the high end. cool.
what is that wire on the side of B-? i have some doubts on the part between the volume pot and the mu amp but the rest is pretty much figured out.

btw, i don't think this is a 3 layers board at all. the traces that we miss are on the top layer and under the components. the vastly majority of the top layer is ground.

Didi&Stulle
Information
Posts: 17
Joined: 06 May 2010, 07:55
Has thanked: 3 times
Been thanked: 11 times

Post by Didi&Stulle »

what is that wire on the side of B-?
you are right: the wire "B-" goes to the dc jack battery connection ... right next to the "B-" is a ground pad (G) that goes to the input jack.

johnk
Resistor Ronker
Information
Posts: 277
Joined: 05 Apr 2010, 07:33
Has thanked: 32 times
Been thanked: 273 times

Post by johnk »

pietro_moog wrote:so, basically, this is a mosfet input stage, eq, a jfet mu-amp and then a jfet buffer with 2 resistors and caps to cut the high end. cool.
what is that wire on the side of B-? i have some doubts on the part between the volume pot and the mu amp but the rest is pretty much figured out.

btw, i don't think this is a 3 layers board at all. the traces that we miss are on the top layer and under the components. the vastly majority of the top layer is ground.

I agree that it's most likely a 2 layer board. got any shots of the bottom of it?

pietro_moog
Breadboard Brother
Information
Posts: 108
Joined: 03 Jun 2010, 19:00
Has thanked: 8 times
Been thanked: 45 times

Post by pietro_moog »

this is a first schematic. maybe someone can work it in a software.
myself, i'm not sure of a few values, like the ones on the bs170, but the schematic should be this.
Attachments
Scansione 1.jpeg

pietro_moog
Breadboard Brother
Information
Posts: 108
Joined: 03 Jun 2010, 19:00
Has thanked: 8 times
Been thanked: 45 times

Post by pietro_moog »

i have some doubts on the 12k resistor before the eq, it looks like a strange value. can you measure it with a DMM?
and the 1k / 10k resistor from the bs170 leg is probably a 330Ω

User avatar
Intripped
Cap Cooler
Information
Posts: 564
Joined: 25 Aug 2009, 01:03
Location: Italy
Has thanked: 700 times
Been thanked: 220 times

Post by Intripped »

this is my RE:
something to verify
please read the notes within the images
Attachments
the arrows indicate the connections to verify
the arrows indicate the connections to verify
components names match the schematic
components names match the schematic
marked in BLUE some traces that should be on the top layer, please verify that.<br />Also: all the YELLOW pads should be connected to ground - please verify this with the tester
marked in BLUE some traces that should be on the top layer, please verify that.
Also: all the YELLOW pads should be connected to ground - please verify this with the tester

User avatar
Intripped
Cap Cooler
Information
Posts: 564
Joined: 25 Aug 2009, 01:03
Location: Italy
Has thanked: 700 times
Been thanked: 220 times

Post by Intripped »

... Didi&Stulle?

User avatar
Nocentelli
Tube Twister
Information
Posts: 2165
Joined: 09 Apr 2009, 07:06
Location: Leeds, UK
Has thanked: 871 times
Been thanked: 796 times

Post by Nocentelli »

as yet unverified, sounds good on the breadboard:
monarch_nocentelli.gif
brownwhopping wrote:How can I learn by reading threads an making circuits, when some day I can see a lawsuit or somebody beat me in the face for that?

johnk
Resistor Ronker
Information
Posts: 277
Joined: 05 Apr 2010, 07:33
Has thanked: 32 times
Been thanked: 273 times

Post by johnk »

does you breadboard version sound like the original?
I also drew up a vero for it.

User avatar
Nocentelli
Tube Twister
Information
Posts: 2165
Joined: 09 Apr 2009, 07:06
Location: Leeds, UK
Has thanked: 871 times
Been thanked: 796 times

Post by Nocentelli »

No, and i'd advise holding fire until the schem has been looked at a bit more closely. Last night through headphones it sounded great, but after a longer play through a few amps at volume it doesn't seem right (to my ears). I've only got linear pots, but even taking that into account i have to crank the bass and roll the treble almost off or it is way too thin and harsh. I'll check over my breadboard layout carefully, but i wouldn't build the vero i posted as is.
brownwhopping wrote:How can I learn by reading threads an making circuits, when some day I can see a lawsuit or somebody beat me in the face for that?

pietro_moog
Breadboard Brother
Information
Posts: 108
Joined: 03 Jun 2010, 19:00
Has thanked: 8 times
Been thanked: 45 times

Post by pietro_moog »

well, the schematic structure seems pretty reasonable now. the values too. log pots on the eq are pretty much important, you can see by yourself on the duncan simulator. btw, on the bass pot, 2.2nf and 22nd should be switched, 2.2 is between lug 3 and 2. that's a big reason because it doesn't sound right. and the 470pf treble bleeding cap on the gain is more harmful than useless. i cut those even in amps. the last 2 caps, 220pf and 100pf they could be chosen by preference. even the eq could be modeled after personal taste.
anyhow, this pedal looks cool, but it's just a mosfet boost cascading in a fet mu amp with an orange eq in between.

johnk
Resistor Ronker
Information
Posts: 277
Joined: 05 Apr 2010, 07:33
Has thanked: 32 times
Been thanked: 273 times

Post by johnk »

thanks!
looking at the gut shots, it appears that on your layout, the two 100K resistors on the lugs 2&3 of the bass pot should be 10K's. maybe that would give it more low end.

deafbutpicky
Information
Posts: 49
Joined: 03 Jun 2011, 10:07
Location: germany
Has thanked: 27 times
Been thanked: 19 times

Post by deafbutpicky »

pietro_moog wrote: anyhow, this pedal looks cool, but it's just a mosfet boost cascading in a fet mu amp with an orange eq in between.
...there's still a chance to do it with three diodes and an opamp :P
I'm using capacitors to replace my guitar effects and give more clarity to the sound.

User avatar
Intripped
Cap Cooler
Information
Posts: 564
Joined: 25 Aug 2009, 01:03
Location: Italy
Has thanked: 700 times
Been thanked: 220 times

Post by Intripped »

looking at this pic of another previous version there's a 100E resistor near Q3 and Q4 (on the right in the image)

so probably this is the source resistor of the mu-amp (R17 referring to my schematic)


Image

johnk
Resistor Ronker
Information
Posts: 277
Joined: 05 Apr 2010, 07:33
Has thanked: 32 times
Been thanked: 273 times

Post by johnk »

yep. that looks like a 100 ohm to me too.

I wish the op would've taken some pics on different angles of his REV2 so we could see some of the resistor and cap value markings better.

johnk
Resistor Ronker
Information
Posts: 277
Joined: 05 Apr 2010, 07:33
Has thanked: 32 times
Been thanked: 273 times

Post by johnk »

I built up my vero of it and it sounds great. the only thing is, is that it seems to have less gain than the video demos that I've seen. otherwise it's awesome.
if I can find a way to up the drive/dirt, it'll be perfect.

Post Reply