Help identify this Distortion pcb?

[Psychophonic]

First post. Lifelong musician here, but new to the diy side of pedals.

Rogue Distortion. Trying to determine what this may be a copy of. For example, the Rogue Overdrive ODV-5 pcb is actually a PSK ODV-3, which is a SD-1 copy. Determining this allows me, a diy mod noob, to know which mods to research and attempt.

Was thinking this distortion unit would be a DS-1 copy but it does not look similar to me other than the tone, level, and gain controls. Any ideas?

Note, this pedal has a “True Bypass” sticker on the bottom plate.

[vigilante397]

Welcome to the forum

Chances are they didn't copy the PCB layout of whatever they cloned, so just staring at the PCB won't give us many hints outside of op-amp type and pot values. The manufacturer's description makes it sound like it could be a Rat, but the pot values and extra transistors bring that into question. A schematic would most likely be needed to know exactly what it is.

Short answer: no idea

[Fancy Lime]

Welcome to the nut house!

One opamp, three Transistors and those pot values smell of a Boss DS-1.

Andy

EDIT: Had a closer look at the tone control section around the 20k pot and now I'm pretty sure it is aDS-1 type of deal. The switching circuit seems converted to true bypass but they left the buffers in.

[Psychophonic]

Thanks guys. I'm really diving into this stuff and loving it. I haven't read so much since I was a kid in high school. Glad this site exists.

If this Rogue is indeed based on a DS-1, but the pcb layout differs drastically, it will be a challenge for me (noob) to identify which components line up with a real DS-1, making it difficult to know which parts to upgrade/mod.

[slashandburn]

I googled the DST-565 and stumbled upon this. One with a board of the same name, but they say there's no opamps.

There's a picture on page two, looks really similar to your board but with the model number DST-525 Rev. A.  This board is apparently a ModTone Speedbox, which I know nothing about. Looks very similar and the pot values are the same but no lm358.

https://www.harmonycentral.com/forums/topic/1544105-anyone-recognize-this-distortion-pedal-circuitboard/page/2/#comments


Edit: oh, and welcome!

[Psychophonic]

Thanks. I see the ModTone pcb. Hard to know what’s underneath those pots. Love the mfr’s description of the Speedbox. They managed to fit the words distortion, overdrive, and fuzzbox all in there, in a TS9 green housing to boot. I took a screenshot of the pcb that was shown.



Although I don’t see Belcat Co. on my Rogue pcb, the model number and board look similar enough to make me wonder. Still sheds no light on the question at hand, but it’s interesting.

Here’s Belcat: http://m.en.belcat.com/#

[Fancy Lime]

To come back to your original question on how to figure out how to mod this thing:

You have probably figured out already that the DS-1 is one of the most popular modding platforms. A search for "boss ds-1 mods" returns a confusing plethora of results. The easiest mod is to change the clipping diodes. There are only two diodes in this PCB, so no mystery which might be the right ones. They are the orange things called D5 and D6 in the upper left corner of the PCB. I suggest taking them out and installing sockets in their place. The you can easily swap different diodes in and out and see what you like best.

It is hard to trace a schematic from photos of modern multi-layer PCBs (I assume this one is a two-layer) alone at the best of times. When there are pots in the way, It becomes much worse. So I would suggest you trace a portion of the PCB yourself. It will be much easier with the 3D real object in hand. And it is very good practice for learning to understand schematics and layouts. One section that should be fairly easy to trace and which is host to many popular and useful mods, is the tone section. A popular mod is to change the 100n cap C12 to something smaller like 22n or 47n for more mids. See here (end of the DS-1 section, just before SD-1):
https://reverb.com/news/simple-boss-pedal-mods-changing-from-stock-to-rock
The corresponding schematic in terms of parts numbering seems to be this one:
http://cdn.tonegeek.com/wp-content/uploads/Boss-DS-1-schematic.png
Your PCB seems to have a different numbering scheme and some different values. So you need to trace the tone section first to know what's what. Start at the three terminals of the 20k pot and work your way out. If you manage getting some useful photos from under the pot as well as from the backside of the PCB, we'll be glad to help.

Cheers,
Andy

[Rob Strand]

If this Rogue is indeed based on a DS-1, but the pcb layout differs drastically, it will be a challenge for me (noob) to identify which components line up with a real DS-1, making it difficult to know which parts to upgrade/mod.

The way to go about it is to find key features on the schematic then look for those key features on the pcb.

Schematic
https://0x4c.files.wordpress.com/2019/03/ds-1_schem.jpg?w=739

So for example
- On the schematic you can see the transistor Q2 which has a small capacitor C4 across its base and collector.
- On the pcb we see a transistor near a cap at Q2 and C7.  In that area of the schematic we can see 470k (R7) and 100k (R6) and then in the same area of the PCB we can see maybe 470k (R22) and 100k (R21).

The key idea here is to try to get a rough match then check the details between the schematic and the PCB.   There's no easier way than that when you don't have a schematic for your pedal.   With some perseverance you will get there.   The way to not stuff-up is to check stuff thoroughly and don't assume things are the same.

For few warnings:
- There are quite a number of versions of DS-1 builds and schematics.  I mean variations of the Boss originals.   So you might need to look at a few boss schematics to find the best match.    Mostly they are very close but (IIRC) there are two major variants.
- Sometimes you will find pots wired differently but they are functionally the same.   For the DS-1 circuit the risk of this type of thing is virtually zero because the way the pots are used very much dictate the exact wiring.
- Now an then people make little changes between the original and the copy.   If you find you are getting lost trying to match the schematic to the PCB, then you might need a different version of DS-1 schematic.  Or you might find the circuit just doesn't match any of them.

I'm really just warning you up front.   There's a good chance if you get a close schematic the rest will fall out without any problems.

[Psychophonic]

Thanks for the tips, guys. Very helpful. I am going to relocate the pots and jacks away from the pcb, and perhaps the switch as well. This will allow me to use a different housing, and also free up some space on the pcb for a better view. I will search for the various DS-1 schematics and begin comparing. I have Switchcraft mono and stereo jacks incoming. If I need new pots (I have a few), I will order those as well.

I have a few diodes of various numbers. Germanium 1N34A, 1N60, silicon 1N914, 1N4739A, 1N4742A.

How about that op amp chip?

[amz-fx]

Here is a DS-1 mod that a lot of players have tried and found useful:

http://www.muzique.com/news/fat-mod-for-the-boss-ds-1/

Best regards, Jack

[vigilante397]

My distortion tastes are simple, I've always beena  fan of 1N914 (1N4148) clipping.

How about that op amp chip?

There's nothing wrong with the LM358, but it has a standard dual op-amp pinout so if you wanted to try something new you could replace it with a socket and swap in some other choices like TL072, JRC4558, JRC4559, etc.

[amz-fx]

How about that op amp chip?

I stay away from the LM358 for audio use for a couple of reasons:

(1) It is noisy. For example, it has almost 6 times as much noise as the common RC4558. This can be important for circuits like distortions or compressors that have a lot of gain.
(2) The LM358 has a weak output stage and suffers from crossover distortion. There is even an appnote from TI that describes how to use an external resistor to try to minimize the effect (AN-116).



Th LM358 could be used in an LFO, or maybe a rectifier circuit, but it has limitations for audio use, IMO. However it is quite cheap, and manufacturers of inexpensive pedals will use them to cut a few pennies off the BOM cost.

Best regards, Jack

[willienillie]

I'm not a DS-1 fan myself, but Jack's 2-resistor mod above sounds like an improvement for sure.  I would recommend one more, since you are swapping pots anyway, make the volume pot an audio taper.

[Psychophonic]

As a noob, I am struggling to find the proper pcb single sockets for my diode locations. Perhaps I'm not searching the right words/phrase. Will these work well?

https://www.amazon.com/Single-Headers-Machine-Female-2-54mm/dp/B0187LHLDC/ref=mp_s_a_1_4?dchild=1&keywords=pcb+socket+female+gold&qid=1594824355&sr=8-4

[patrick398]

As a noob, I am struggling to find the proper pcb single sockets for my diode locations. Perhaps I'm not searching the right words/phrase. Will these work well?

https://www.amazon.com/Single-Headers-Machine-Female-2-54mm/dp/B0187LHLDC/ref=mp_s_a_1_4?dchild=1&keywords=pcb+socket+female+gold&qid=1594824355&sr=8-4

Yep they'll work. Useful to have these around as you can use them for socketing transistors or anything really, just snap off how many you need. Best way i've found is to liberally score at the point you want to snap then use pliers.

[Psychophonic]

As a noob, I am struggling to find the proper pcb single sockets for my diode locations. Perhaps I'm not searching the right words/phrase. Will these work well?

https://www.amazon.com/Single-Headers-Machine-Female-2-54mm/dp/B0187LHLDC/ref=mp_s_a_1_4?dchild=1&keywords=pcb+socket+female+gold&qid=1594824355&sr=8-4

Yep they'll work. Useful to have these around as you can use them for socketing transistors or anything really, just snap off how many you need. Best way i've found is to liberally score at the point you want to snap then use pliers.

Great, thanks. I ordered them. I have a few op amp sockets already, I can use one of those in order to try a RC4558.

Just looked, I only have JRC4580D, JRC2114D, and LM358N on hand. Are any of these worth a try in this particular design/pedal?

[Ripthorn]

As long as they have the usual dual opamp pinout, there's nothing wrong with experimenting. According to EE's, most of what we do for guitar pedals is considered "abuse", so there isn't really anything wrong or right, just what sounds good to you.

[patrick398]

I like 4580ds, they're used in a certain brands desktop 4 Chanel mixer which sounds brilliant when you slam everything. I keep meaning to design a pedal based on it but never get round to it. As noted, any pin compatible dual op amp is fair game, just comes down to personal preference in the context of the circuit

[Psychophonic]

Watching and hearing this op amp comparison video, I'm hearing very little, if any, difference between the 4580 and 4558. I realize it's a YouTube video and I'm listening on my phone, so should I be hearing more of a difference?

https://youtu.be/PH2uj9bWfM4

4580 1:30
4558 3:30

[anotherjim]

I think the original MIJ DS-1 opamp was also a single supply type that became obsolete -  so the 358 might be a good substitute. The original also had a crossover distortion reducing resistor which was kept even after Boss changed the opamp. In a distortion effect, I wouldn't dismiss any opamp if you like the sound of it.