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General => Open Discussion => Topic started by: Thewintersoldier on May 22, 2021, 10:06:54 PM

Title: Mythos Golden Fleece
Post by: Thewintersoldier on May 22, 2021, 10:06:54 PM
If you didn't know, the golden fleece fuzz is a clone of the Alan Yee Fuzzy nuts which in turn is a modified Electra+. I built the golden fleece on a fuzzdog Electra board. The Mythos high road is a joey landreth edition of the fleece with Bat41 diodes in both spots. It's a good sounding variant if your looking for a simple build. I used a100k for the volume pot, mythos uses a linear pot.
(https://uploads.tapatalk-cdn.com/20210522/aece80f06b6e13bcb1e7f6368fda9146.jpg)

Sent from my Pixel 5 using Tapatalk

Title: Re: Mythos Golden Fleece
Post by: jjjimi84 on May 22, 2021, 11:14:19 PM
Very cool! I am going to put this on the breadboard and hear what the hype is all about.
Title: Re: Mythos Golden Fleece
Post by: Thewintersoldier on May 22, 2021, 11:26:03 PM
Try the alternate diodes, or even a higher gain tranny. Might be a good candidate for a ptp build!
Title: Re: Mythos Golden Fleece
Post by: dan.schumaker on May 22, 2021, 11:55:21 PM
If you want to try something cool, put R3 on a switch to change the bias of the transistor.  You can get have it really cook, or have it be more of a dirty boost.  I did the same thing on my Breaker pedal.
Title: Re: Mythos Golden Fleece
Post by: juniorknebel on July 07, 2021, 03:27:55 PM
4.7k resistor in input?
Title: Re: Mythos Golden Fleece
Post by: Thewintersoldier on July 07, 2021, 05:24:18 PM
Quote from: juniorknebel on July 07, 2021, 03:27:55 PM
4.7k resistor in input?
47k, sorry I realize now it looks like there is a period there.
Title: Re: Mythos Golden Fleece
Post by: Aleph Null on July 07, 2021, 05:43:14 PM
I've built a few versions of the Electra, it's amazing how much component choice can effect the voicing in simple circuits like this. I've found that diode selection and output cap value make the biggest differences. I also prefer the EQD "Speaker Cranker" style bias control to a master volume.
Title: Re: Mythos Golden Fleece
Post by: Zerro on July 07, 2021, 06:50:28 PM
Here is very interesting, that before diodes is not any resistor - so, those diodes are affecting gain of transistor. See this schematic - author is describing this effect too.
Title: Re: Mythos Golden Fleece
Post by: Jmilla on July 10, 2021, 04:56:21 PM
Does anyone know where to find a 1590a Electra PCB in the us?
Title: Re: Mythos Golden Fleece
Post by: Aleph Null on July 12, 2021, 06:15:07 PM
Quote from: Jmilla on July 10, 2021, 04:56:21 PM
Does anyone know where to find a 1590a Electra PCB in the us?

Effects Layouts has the Cranky Speaker (http://effectslayouts.com/product/crankyspeaker/). It's also pretty easy to build on vero.
Title: Re: Mythos Golden Fleece
Post by: rob_f on September 05, 2022, 01:36:17 PM
Sorry for resurrecting such an old thread - thinking of giving this one a go, but just wanted to confirm the values please because the picture doesn't come out great on my laptop. Thanks all!

R1 - 47K ??
R2 - 2M2
R3 - 4.7K ??
R4 - 680
R5 - jumped
C1 - 47nF
C2 - 33nF
C3 - 47uF
C4 - 47uF
D1 - 1N4148
D2 - any Ge ??
Title: Re: Mythos Golden Fleece
Post by: Aleph Null on September 06, 2022, 05:49:20 PM
Quote from: rob_f on September 05, 2022, 01:36:17 PM
Sorry for resurrecting such an old thread - thinking of giving this one a go, but just wanted to confirm the values please because the picture doesn't come out great on my laptop. Thanks all!

R1 - 47K ??
R2 - 2M2
R3 - 4.7K ??
R4 - 680
R5 - jumped
C1 - 47nF
C2 - 33nF
C3 - 47uF
C4 - 47uF
D1 - 1N4148
D2 - any Ge ??

Those values look correct, except for R1, which appears to be labeled 4.7k. You can probably get away without that resistor if you wire the switch so that the input is grounded in bypass. If you do opt to use a pull-down resistor, you a larger value like 1M is a more common choice. 4.7k is very low and will cause high-end loss.
Title: Re: Mythos Golden Fleece
Post by: rob_f on September 06, 2022, 10:31:02 PM
Quote from: Aleph Null on September 06, 2022, 05:49:20 PM
Quote from: rob_f on September 05, 2022, 01:36:17 PM
Sorry for resurrecting such an old thread - thinking of giving this one a go, but just wanted to confirm the values please because the picture doesn't come out great on my laptop. Thanks all!

R1 - 47K ??
R2 - 2M2
R3 - 4.7K ??
R4 - 680
R5 - jumped
C1 - 47nF
C2 - 33nF
C3 - 47uF
C4 - 47uF
D1 - 1N4148
D2 - any Ge ??

Those values look correct, except for R1, which appears to be labeled 4.7k. You can probably get away without that resistor if you wire the switch so that the input is grounded in bypass. If you do opt to use a pull-down resistor, you a larger value like 1M is a more common choice. 4.7k is very low and will cause high-end loss.

Thanks, that's good advice! 1M isn't surprising given that all variations of the electra PCB that photo above is based on all also use 1M. I might order a couple of different values and see what effect it has though - am I right in thinking R1 is what determines your input impedance? I wonder if perhaps R1 is deliberately low on this circuit to more closely match the pickup impedance? (More like classic fuzz than a distortion?)
Title: Re: Mythos Golden Fleece
Post by: Aleph Null on September 07, 2022, 08:18:39 PM
Quote from: rob_f on September 06, 2022, 10:31:02 PM
Thanks, that's good advice! 1M isn't surprising given that all variations of the electra PCB that photo above is based on all also use 1M. I might order a couple of different values and see what effect it has though - am I right in thinking R1 is what determines your input impedance? I wonder if perhaps R1 is deliberately low on this circuit to more closely match the pickup impedance? (More like classic fuzz than a distortion?)

Yes, R1 determines the input impedance. Low impedance usually results in a loss of high frequencies, which may or may not be a good thing. R1 also forms a high-pass filter with C1, so it could also mean a loss of lows; 4.7K with 47nF give a cut off frequency of 720Hz. The circuit as drawn is basically a silicon treble booster with clipping diodes.
Title: Re: Mythos Golden Fleece
Post by: rob_f on September 07, 2022, 09:24:30 PM
Thanks, that's really helpful. I hadn't really twigged the RC circuit going on at the input. Will have a play with the values and see what happens!
Title: Re: Mythos Golden Fleece
Post by: davepotnoodle on July 31, 2023, 03:17:46 PM
Hi all, sorry for reviving an old thread again. I'm new to breadboarding/ schematics and really struggling to wrap my head around how everything is laid out. Does anyone happen to have a photo of a breadboarded version?
Title: Re: Mythos Golden Fleece
Post by: jwin615 on August 01, 2023, 05:53:02 AM
Quote from: davepotnoodle on July 31, 2023, 03:17:46 PM
Hi all, sorry for reviving an old thread again. I'm new to breadboarding/ schematics and really struggling to wrap my head around how everything is laid out. Does anyone happen to have a photo of a breadboarded version?
Dirtbox has a stripboard layout
Any line on the stripboard that is unbroken(red square) is a common node to other parts attached. Once the strip is broken, it becomes a separate node. I.e. a new row on your breadboard.
Links attach uncommon strips to a singular node, just like your breadboard. So row A, H and the right half of G are all on a common node.
Hope this helps you sort through it.

http://dirtboxlayouts.blogspot.com/2023/03/mythos-pedals-golden-fleece.html?m=1
Title: Re: Mythos Golden Fleece
Post by: davepotnoodle on August 06, 2023, 10:50:50 PM
Quote from: jwin615 on August 01, 2023, 05:53:02 AM
Quote from: davepotnoodle on July 31, 2023, 03:17:46 PM
Hi all, sorry for reviving an old thread again. I'm new to breadboarding/ schematics and really struggling to wrap my head around how everything is laid out. Does anyone happen to have a photo of a breadboarded version?
Dirtbox has a stripboard layout
Any line on the stripboard that is unbroken(red square) is a common not to other parts attached. Once the strip is broken, it becomes a separate node. I.e. a new row on your breadboard.
Links attach uncommon strips to a singular node, just like your breadboard. So row A, H and the right half of G are all on a common node.
Hope this helps you sort through it.

http://dirtboxlayouts.blogspot.com/2023/03/mythos-pedals-golden-fleece.html?m=1
That's perfect! Thankyou so much!