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Pfoooh

Dirk,

what do you reckon is up with this 505 cap?

That should be 5uF, but that doesnt make sense?

Maybe it's a 50 pf and the second 5 is a tolerance marking? Or maybe an S? Can you see any other markings on it?

That's what I'm assuming, but it's not consistent with the other one (101).

Wow, same happened to my fallout character when i maxed his social marketing bullshit instead of soldering.

So I traced the circuit and it's pretty much what we already know. The only differences are thus:

- the input cap is 22n on both sides
- instead of 1s1588, this uses 1n914
- output cap of the high-gain red side has an "H" painted on it, but is the same value 105 as on the yellow side. The IC also has an H painted on and the chip markings are sanded off.
- the feedback loop cap on the yellow side ist a weird value. 505? The red side has the usual 101=100pF.
- On the high-gain red side the gain resistor is 100k, on the yellow side it is 1k.

I think the last part is news, as this resistor was always assumed to be 10k and the gain pot changed for high-gain on DIY projects.

Seiche wrote:So I traced the circuit and it's pretty much what we already know. The only differences are thus:

- On the high-gain red side the gain resistor is 100k, on the yellow side it is 1k.

I think the last part is news, as this resistor was always assumed to be 10k and the gain pot changed for high-gain on DIY projects.

Are you sure? From the picture, they are all 10K, and there is no difference.

pretty sure, yes, which pictures are you referring to and which resistors?

I think they were brown-black-red (1k) and brown-black-yellow (100k), but it's not entirely clear on my pictures and I already flipped the pedal.

Those magical diodes can be found again and my big question is do they really make a difference in this thing? I made a clone of this and still need to figure out the best settings with those dip switches LOL

Seiche wrote:pretty sure, yes, which pictures are you referring to and which resistors?

I think they were brown-black-red (1k) and brown-black-yellow (100k), but it's not entirely clear on my pictures and I already flipped the pedal.

The picture is not clear, the color ring reading looks more like brown - black - orange (10k)

that resistor is 10k, but it is not the resistor that Seiche is talking about.
the correct one is behind the 1uF capacitor (square, marked with "H")

Intripped wrote:that resistor is 10k, but it is not the resistor that Seiche is talking about.
the correct one is behind the 1uF capacitor (square, marked with "H")

Correct. The 10k carbon comp is R6 in my schematic. Feedback resistors R5 are not in the direct audio path and thus not carbon comp (but rather carbon film). One of the resistors is behind the cap, which is why I can't find a clear picture of it (I took a few pictures at the time). These are the best pictures I have of them:

jalmonsalmon wrote:Those magical diodes can be found again and my big question is do they really make a difference in this thing?

which diodes are you referring to? The Ma856s? Because the 1s1588 were changed to 1n914s by Analogman himself.

I built my clone with Ma858s and 1s1588 but socketed them, but haven't gotten around to actually A/Bing them myself with common replacements.

Seiche wrote: which diodes are you referring to? The Ma856s? Because the 1s1588 were changed to 1n914s by Analogman himself.

I built my clone with Ma858s and 1s1588 but socketed them, but haven't gotten around to actually A/Bing them myself with common replacements.

From pedalhackers site, and I cannot say if those are real MA856s or MA858s
They are pricey too!

oh did you buy all of them?

I did not have the chance to try the original. but if the schematic is correct, then the clone sound and behaviour should be equal to the original, RIGHT???
Judging by that, i did the clone and the pedal sound great. However, there is not one PRO musician who tried it and remained visibly disappointed in the nature of the sound of this device.
I made it very well .. i even inserted the original diodes MA856 & 1S1588:

.., bla bla.. and nothing spectacular.

Perhaps the only advantage is that it does not color the sound ... but .. overdrive/distortion with such a neutral tone...

I don't understand the hype at all about this device!

BTW. i made only wooden enclosures:

However, there is not one PRO musician who tried it and remained visibly disappointed in the nature of the sound of this device.

don't you mean "didn't remain visibly disappointed"? As in they were disappointed because they expected more?

I also wasn't that fond of it, especially the pairing of playing both sides at the same time. It felt difficult to get a good sound in my opinion. I would prefer a prince of tone kind of deal that only had one of the sides and use a boost in front of it. I could only use them alternating both channels, not at the same time.

Seiche wrote:

However, there is not one PRO musician who tried it and remained visibly disappointed in the nature of the sound of this device.

don't you mean "didn't remain visibly disappointed"? As in they were disappointed because they expected more?

I also wasn't that fond of it, especially the pairing of playing both sides at the same time. It felt difficult to get a good sound in my opinion. I would prefer a prince of tone kind of deal that only had one of the sides and use a boost in front of it. I could only use them alternating both channels, not at the same time.

My bad english, of course, they expected much more from this pedal. Fact is that we have better sounding devices which are 4x cheaper that this hyped pedal.

I traced the 1S1588 and the MA858 diodes pn-junction curves and searched for suitable curves.
The MA588 is a good replacement for the MA856 the curves are very similar.
I found that the 1N914 is a good replacement for the 1S1588.
The shape of the MA858 curve is similar to base-emitter and base-collector curve of BJTs the values are close each other.
I will continue to search for the suitable BJT.

I have tried various transitors the MPSA18 base-emitter diode gave the best match with the MA858 Diode.
So can the MA856 replaced by the MPSA18 base-emitter diode.