Biyang Max Distortion DS10

[HarveyTBirdman]

Howdy, yall.

Just got back from the pawn shop and picked up this little baby boom distortion pedal. So far, it does what it's supposed to, sitting in the chain between my Joyo dyna compressor, and my EHX Lil Big Muff.

It seems to warm up my valveking nicely on lower gain settings, it gets a nice barking mid blues sound. I haven't had a chance to really push it yet, my amp rarely gets pushed past 2 or 3, so i'll wait for a gig before I really open it up and see if it sings. At higher gain even at low volumes it sustains for days, with lovely musical feedback anywhere on my fretboard.

For the $30 I paid, I couldn't be happier. I was looking at getting a TS9 clone (mad driver) and a RAT clone (tonefancier mouse), but then this popped up and I couldn't walk past it for the price.

My question is, does anyone recognise the circuit?

Sorry in advance for the tater quality pictures, I must invest in a camera and a pc.

http://imgur.com/obUn1c5,SJ2R3sT,8oBLGvy,KRWRrAQ,UkyYbaN,NuZFpMZ

There's an album of the guts. What I see is a LM308AN op amp, 5 electrolytics, 3 ceramic caps, 4 red film caps, 3 diodes, 3 leds (2 clipping, 1 indicator), 12 resistors, 3 pots, a jfet and then the switching board. The toggle switch traces to the diodes, gain and level are audio taper and the tone is log.

I was expecting to see SMT when I cracked it open, but lo and behold, it's all servicable.

I know it's hard to tell exactly what they've cloned from a vague description, i'm a guitarist, not an engineer. If somethings broke I'll fix it, but I can't match this unit to any of the rat schemes i've found on the net, call it lack of skill.

Has anyone else got one of these? Anyone know what it is? I'm leaning towards calling it a RAT copy, but there seems to be a few changes to the original goin on in here.

 

[Chiogtr4x]

I have the GFS Brownie Classic, which I think is the same pedal- it is a Rat copy (with the extra clipping modes which comfigure it as a Turbo Rat with LED diodes, and no clipping diode mode...) Biyang got one resistor value wrong (pointed out by TDPRI member 11 Gauge) and he corrected the value on mine as I know nothing about electronics- I just regurgitate!

see if thread below and pics look like your pedal:

http://www.tdpri.com/forum/stomp-bo...-users-important-rat-content.html#post3824426

 

[11 Gauge]

For the $30 I paid, I couldn't be happier. I was looking at getting a...tonefancier mouse...

The begging question that many Biyang users here have been asking is why don't they make a Baby Boom version of the Mouse, which is a Rat clone?

...What I see is a LM308AN op amp, 5 electrolytics, 3 ceramic caps, 4 red film caps, 3 diodes, 3 leds (2 clipping, 1 indicator), 12 resistors, 3 pots, a jfet and then the switching board. The toggle switch traces to the diodes, gain and level are audio taper and the tone is log...

The chip and the jFET are the "smoking gun" parts. It is a Rat clone, no doubt about it.

...I'm leaning towards calling it a RAT copy, but there seems to be a few changes to the original goin on in here...

Biyang is not in the business of coming up with their own designs, at least TTBOMK. My Mouse is a 1:1 Rat clone, my Compress X is a 1:1 Dyna Comp clone, and my Fuzz Star is a 1:1 Big Muff clone (better than the NYC RI by EHX, IMO!).

...The only "changes" in my Mouse are the inclusion of the two extra "modes" - one just lifts all the clipping diodes, and the other just sets it to Turbo Rat with the LED clippers.

Biyang did screw up with the Mouse in that most (but not all) of them have an error with one resistor - it's 56K and should only be 560 ohms! Hopefully, they didn't "clone their way off a cliff" and put that wrong part in the DS10.

Long story short - I'll be grabbing one of these, post haste. I love the small footprint of the Baby Booms, the quality is a little better than the Joyos, and the millenium bypass is excellent, IMO.

The Brownie under the GFS re-badging went under the radar a long time until someone discovered it was a Rat clone. This pedal has gone even longer!

What is funny is that these pedals have the "real LM308N," but most who try them just have a tepid response! It goes to show you that we hear with our eyes, IMO.

 

[MilwMark]

Has anyone used one of these?

What do the mode switches do? The descriptions on the web don't seem to match the names of the modes on the pedal! Can anyone confirm if the mode switches on Max have the same functions as on the Mouse (copping different Rat versions)?

Also, any experience with how this pedal cleans up with pick attack/volume knob?

If it can do the Rat "OD - dist - fuzz" dance, while incorporating three versions in one tiny enclosure, what a value.

 

[11 Gauge]

What do the mode switches do?

One position uses the stock silicon 1N4148 clipping diode pair.

One position uses two red LED's as clipping diodes.

The center position uses no clipping diodes.

The LED clippers will cut less volume than the silicons will - that's how you can tell the difference - it's a really common setup, even with mod kits. You basically get 3 variations with just 4 diodes and a ON/OFF/ON switch.

 

[HarveyTBirdman]

So far, when I first got the pedal I was using it with level at midday, gain at 8 am and tone at 10am, and it was just a nice OD push, with the switch in the 'warm' position.

Volume at midday, gain between midday and 2pm, tone at midday, renders lovely, harmonic rich distortion. Diode clippers on.

Volume at midday to 2, gain on full and tone wherever seems to get close to lovely saturated fuzz, with the diode clippers on.

I am stoked, as I was planning to purchase a mouse but finding this locally and it having the exaxt circuit I wanted, it's just perfect.

It may even bump my EHX lil big muff to the bay if I can dial in all the tones I use from it. It seems versatile enough and it's tiny. I was also looking for a ts9 clone, but may not need that either with the way this sounds, now just to check the values of that known resistor problem..

 

[HarveyTBirdman]

Cheers 011.

That's the bits I needed to know. I'm halfway through pulling it and reading the values of the resistors to see if anything is abnormally high.

My guess with the way it sounds and that no one has looked to see if it can be improved is that no one has recognised what it's copying.

Anyway i'll post back here if i find anything out of the ordinary but I am very happy with this pedal so far so I'm not expecting to find much.

Edit:

So it's apart, and the resistor that feeds into c1, which looks like where the old mouse had the problem, is blue, and is coloured green, blue, black, brown, brown.

So this would most likely be the part of the circuit I am looking for as those colours read 560 x 10 1% tolerance. Equals 56000 ohms or 56k ohms. The multimeter confirms. ****, eh. Probably why I found it in a pawn shop.

I like the way it sounds wih my amp, since my amp is bright as **** running shuguang 12ax7's in the preamp, but i might need to go fixing it just to see what it is meant to sound like.

It's night here, and the component store is closed. I've found a large brown 560ohm in my harvest heap, and also a trimpot that's reading between 0 and 1500ohm, can dial it accurately to 560ohm.

I'm going to try the trimpot.

Long story short, same as the mouse with the same mismatch at resistor 8.

 

[poiureza]

One position uses the stock silicon 1N4148 clipping diode pair.

One position uses two red LED's as clipping diodes.

The center position uses no clipping diodes.

The LED clippers will cut less volume than the silicons will - that's how you can tell the difference - it's a really common setup, even with mod kits. You basically get 3 variations with just 4 diodes and a ON/OFF/ON switch.

Could that be similar to the Monte Allum mod I have in my YDR ?
Would make sense as the center position is loudest in mine (and best sounding to my ears btw)

 

[HarveyTBirdman]

Ok, so, the trimpots lugs were too fat for the pcb, so i've opted to use the 5% big ol' brown 560ohm resistor out of an amplifier section of an old 70's record player that I have in pieces for harvest..

What I immediately noticed is that the tone knob is now useful through the whole sweep. Before the sweet spots were between 10am and 11.30am, now the whole knob is a sweet spot.

It also loudened it up somewhat, and seems brighter overall.

It's too late at night to go cranking my 100w amp to give it a full test but if what everyone else sys about the mouse and brownie rings true for the max, then I should have a lotta fun with this pedal.

I've also drilled a couple of holes above the led clippers.

The LEDs are active with the switch in the 'normal' position.
From what 011 has said, i'd believe that the switch in the 'bright' setting bypasses all diodes, and that the 'warm' setting, which is noticeably quieter, would be the 4148 diode clipping setting.

I've found I like the normal or turbo rat setting, following that, the warm setting. I guess like the way diodes add dirt.

Even after just a little play, it's pretty safe to say I have a new favourite distortion pedal.

Cheers everyone for your input. Seems I got me an old RAT copy at a slice of the price.

 

[11 Gauge]

Could that be similar to the Monte Allum mod I have in my YDR ?
Would make sense as the center position is loudest in mine (and best sounding to my ears btw)

It's almost become a standard mod thing with a ON/OFF/ON toggle, not just with Allums. He's just following others IMO.

It's the same thing with the "hi cut mod" for the Boss DD-_ pedals:

- toggle up is a certain amount of cut

- middle is no cut

- down is a different amount of cut than the first

The toggles are crude (IMO), but popular nonetheless.

IMO, it makes much more sense to actually target very specific forward voltages with combinations of different diodes. You may also want to take the asymmetric route, and "just a pair of this and a pair of that" will seldom give you asymmetric clipping, because you are at the mercy of something other than the diodes to get it.

...In the case of the Rat, the LM308N has such an abysmal slew rate that it's clipping w/o the diodes, especially as hard as it's driven.

Also in the case of the Rat IMO - it is a rare instance of a drive box design where the "overly standard" application of a pair of 1N4148 silicon diode clippers sounds really REALLY good.

...I have personally come to the conclusion that the forward voltage of the 1N4148 is "all wrong" for getting the best clipping from drive boxes. And IMO, something like 2X red LED's is actually not much better. Evidence of the most "progress" can be found with the diodes in the Zendrive or the V1 Marshall Bluesbreaker. And yes - it applies to either soft or hard clipping.

It is interesting to note that "the best sounding DS-1's" had different clipping diodes with a higher forward voltage - close to 1000mV vs. 1N4148's ~650mV. Same thing with the old 808's - the "magic blue stripe" diodes had a Vf of ~950mV or so.

...And yet we keep going round and round with a toggle that IMO tends to give clipping thresholds or "proximity to clip" that tends to be too low or too high.

Or better yet - the 1N4148's get subbed out for epoxy rectifier diodes like the 1N4001 (the number at the end, from 1 to 7, is irrelevant - all have the same forward voltage). All that the epoxy recto does is give a slightly lower forward voltage - IMO not enough for anything audible unless you are combining it with other different diode types.

Getting back to the Zendrive's clippers - Hermida did a lot of "legwork" on that one. Pedal tweakers would be wise to take note of the specific "cumulative" forward voltages (there's two - it's asymmetrical clipping), as well as the "ratio" of asymmetry. It's not a "cookbook standard" thing, but it really does give insight on how to intelligently approach the diode clipping issue.

Getting back to the Rat - much of this diode stuff goes right out the window because of the circuit and the chip (even if it isn't the 308). You obviously get the obligatory volume boost when going to LED's and then no clippers at all, but that's a standard thing. Like I said, it's a rare instance of just a pair of 1N4148-types sounding REALLY good.

IMO.

 

[waparker4]

It is interesting to note that "the best sounding DS-1's" had different clipping diodes with a higher forward voltage - close to 1000mV vs. 1N4148's ~650mV. Same thing with the old 808's - the "magic blue stripe" diodes had a Vf of ~950mV or so.

Sorry to go off-topic but I am really interested and confused here.

1.) The TS808 -- what were these magical diodes? And what combination of common diodes that I can pick up at RadioShack will give that same threshold? Is it adding a 1N34a to the 1N4148 going to get me there?

side-bar, I find it interesting that the geofex article I have read so many times over makes no mention of a difference in diodes/forward voltage between the TS808 and the 9, 5, 10, 7 ...

2.) Reading a diode spec sheet.
e.g. http://www.vishay.com/docs/81857/1n4148.pdf

Says the diode has a forward voltage of 1 Volt. Everybody quotes it at 650 mV. There is a Temperature/current/voltage graph on that sheet. Obviously we are not using the 10 mA curve that the "1 Volt" spec is based on. So what temperature and current are we talking about when we talk about forward voltage in distortion pedal applications?

 

[StormJH1]

Great stuff, 011! I had heard him say that Biyang were slightly better quality than Joyo (which are also pretty good), but I didn't own one until I got my Tri-Reverb. Everything about that pedal feels like 150 bucks, and it's almost as small as a BOSS!

I think I'll end up with both the Fuzz Star and Max Distortion down the road. I'll probably weed a few more out to get there, so I don't become a blatant hoarder. The Fuzz Star videos sound awesome, and the Max Distortion seems quite good, too.

 

[StormJH1]

It may even bump my EHX lil big muff to the bay if I can dial in all the tones I use from it. It seems versatile enough and it's tiny. I was also looking for a ts9 clone, but may not need that either with the way this sounds, now just to check the values of that known resistor problem.

That has been a frequent strategy of mine. The Chinese imports have little or no resale value, but eBay will still pay decent money for a TS9, Catalinbread, etc. If I end up with a Joyo/Biyang that basically duplicates the tonal range of a better known pedal I own, I'll sell that for value and keep the import. I've held on to some of them that I like (Fulltone OCD, etc.), but at the end of the day, if it's a choice between me owning something out of pure prestige vs. clearing up money to buy something else, I'm going with the latter.

I don't have ANY fuzz pedals at the moment, however, so that Fuzz Star is at the top of the list.

 

[Chiogtr4x]

FWIW I have 3 Biyangs that are absolutely kick-butt values- each one was $50:

The fullsize GFS Brownie Rat variant, with these great clipping modes- it's really a 'dirt factory'!

The Baby Boom Series Mad Driver- TS clone (JRC4558 chip) also with clipping opitions (I use the mode that relaxes the mids just a bit and leaves a bit of a fuzzy trail on the OD sound)

The Baby Boom Compress-X- a Dynacomp clone that honestly, works fine- I just don't think I'm a comp man- just find I don't need it, and I like a bare-bones pedalboard!

 

[HarveyTBirdman]

22

 

[HarveyTBirdman]

It's almost become a standard mod thing with a ON/OFF/ON toggle, not just with Allums. He's just following others IMO.

It's the same thing with the "hi cut mod" for the Boss DD-_ pedals:

- toggle up is a certain amount of cut

- middle is no cut

- down is a different amount of cut than the first

The toggles are crude (IMO), but popular nonetheless.

IMO, it makes much more sense to actually target very specific forward voltages with combinations of different diodes. You may also want to take the asymmetric route, and "just a pair of this and a pair of that" will seldom give you asymmetric clipping, because you are at the mercy of something other than the diodes to get it.

...In the case of the Rat, the LM308N has such an abysmal slew rate that it's clipping w/o the diodes, especially as hard as it's driven.

Also in the case of the Rat IMO - it is a rare instance of a drive box design where the "overly standard" application of a pair of 1N4148 silicon diode clippers sounds really REALLY good.

...I have personally come to the conclusion that the forward voltage of the 1N4148 is "all wrong" for getting the best clipping from drive boxes. And IMO, something like 2X red LED's is actually not much better. Evidence of the most "progress" can be found with the diodes in the Zendrive or the V1 Marshall Bluesbreaker. And yes - it applies to either soft or hard clipping.

It is interesting to note that "the best sounding DS-1's" had different clipping diodes with a higher forward voltage - close to 1000mV vs. 1N4148's ~650mV. Same thing with the old 808's - the "magic blue stripe" diodes had a Vf of ~950mV or so.

...And yet we keep going round and round with a toggle that IMO tends to give clipping thresholds or "proximity to clip" that tends to be too low or too high.

Or better yet - the 1N4148's get subbed out for epoxy rectifier diodes like the 1N4001 (the number at the end, from 1 to 7, is irrelevant - all have the same forward voltage). All that the epoxy recto does is give a slightly lower forward voltage - IMO not enough for anything audible unless you are combining it with other different diode types.

Getting back to the Zendrive's clippers - Hermida did a lot of "legwork" on that one. Pedal tweakers would be wise to take note of the specific "cumulative" forward voltages (there's two - it's asymmetrical clipping), as well as the "ratio" of asymmetry. It's not a "cookbook standard" thing, but it really does give insight on how to intelligently approach the diode clipping issue.

Getting back to the Rat - much of this diode stuff goes right out the window because of the circuit and the chip (even if it isn't the 308). You obviously get the obligatory volume boost when going to LED's and then no clippers at all, but that's a standard thing. Like I said, it's a rare instance of just a pair of 1N4148-types sounding REALLY good.

IMO.

Interesting food for thought, about halfway through the read I really wanted to start experimenting with diodes with a higher forward voltage, but by the end I'm not so sure it's worth the bother..

Maybe i'll lift all 4 diodes and add them to a breadboard, alongside another set, one pair with 950mv and one pair with 1150mv forward voltage, and a second toggle.

This biyang could quickly turn into Ratzilla if I get carried away with this.

 

[11 Gauge]

Sorry to go off-topic but I am really interested and confused here.

Sorry for that!

1.) The TS808 -- what were these magical diodes?

All of my data indicates that it was a MA150 made by Panasonic. I've included a little snippet of the data sheet at the bottom. There are Vf's for min/typical/max, and typical is .95 volts (the table headings got cut off), which equals 950mV.

I think Maxon has even "gotten it right" with the semi-recent OD808, and it comes with the MA150's. Go here and click the info tab:

http://www.proaudiostar.com/maxon-od808.html#info

...The MA150 is clearly referenced in the verbiage, even if there is nothing really definitive about what makes that diode different from the 1N4148.

There is a Temperature/current/voltage graph on that sheet. Obviously we are not using the 10 mA curve that the "1 Volt" spec is based on. So what temperature and current are we talking about when we talk about forward voltage in distortion pedal applications?

Don't concern yourself with most of those metrics like the temperature.

If using a data sheet, you'll typically want to look for an If of 100mA, and you (IMO) can disregard most other numbers.

But I would submit that "being chained to" a single diode or simply going by data sheets alone is not going to get you far, if you intend to experiment.

So that data sheet is just a starting point - you need a meter that tests diodes to go the rest of the way down the rabbit hole. Again, you want to chain combos in series to get different Vf's.

IMO, every 50mV "increment" or so is important, unless you are up in the range of LED's. Once you get to Vf's of 1700mV vs. 1900mV (they are different depending on the color), there just isn't that much clamping left - that's another important facet with "diode bound" circuits.

Suffice it to say that IMO, for the vast amount of drive boxes, a Vf of less than ~800mV will usually be a little less than optimal. And ~1400mV is kind of a good target upper end. But NONE of this is cookbook/slam dunk stuff - the clipping thresholds/proximity to clip must be determined WRT all other circuit facets - some need more, some need less. Some might benefit from asymmetrical, others really don't need it, IMO.

Along with germanium 1N34A, 1N270, etc., you can get the smaller Vf's from Schottky barrier diodes like that BAT41 and BAT42. A 1N4001 combo'ed with a 1N4148 will put you a little over 1000mV. And actually, two 1N4148's in series yield ~1200mV, which is usable for some stuff.

Actually, there are some situations where IMO a LED with a Vf of around 1600mV works well, but not with another LED - the "other diodes" in parallel need to have a lower cumulative Vf.

I personally do not like "big asymmetrical spreads," or ratios. In the case of the SD-1, it's 2:1 obviously.

Oh yeah - you can use transistors as diodes, or something like the popular 2N7000 is really just exploited for its "body diode." But just a regular bipolar transistor will typically give you ~750mV or so.

I do want to reiterate - I don't think the Rat is a good candidate for playing around with different diodes. It really is a rare exception IMO. You want something where the op amp plays a smaller role - it will have a slew rate as high as the 4558 or maybe even a little higher. Even the LM741 has a MUCH higher slew rate than the LM380N.

There are literally thousands of diodes to choose from. Somehow, the majority of drive box design kind of got stuck with just using the 1N4148. I really think that it's not even a decent "median choice" if using only a pair of them.

Keep in mind that tastes really enter the picture here, and different clipping thresholds will work better depending on how much overdrive/clipping/distortion you prefer.

 

[HarveyTBirdman]

Thanks again 011 for an absolute trove of information, without many of your posts people like myself wouldn't know where to begin mucking around with these circuits.

With what you've provided I think I might find a od10 and start playing with diode values just to see and hear how they affect the overall tone. No better way to learn than diving in head first.

 

[waparker4]

Thanks 11g very informative as usual!

 

[11 Gauge]

Thanks again 011 for an absolute trove of information, without many of your posts people like myself wouldn't know where to begin mucking around with these circuits.

With what you've provided I think I might find a od10 and start playing with diode values just to see and hear how they affect the overall tone. No better way to learn than diving in head first.

Yeah, this requires experimentation, for certain. It's amazing the small number of companies or builders who've really dug in on this one, IMO.

And I love passing on info/ideas/musings, as long as it isn't verbose and therefore meaningless stuff. It's a hard thing for me to do, and I often wonder if I'm really helping with my choices of words or phrases.

It's a big fear of mine to get techy and have it be unuseful, even unuseful by just the casual reader. I'm also sticking my neck out since companies and vendors would typically prefer that I don't share much of this stuff - they'd rather that no one understand it, for (IMO) reasons both benign and malign. Communicating simply for the passion of something and with no ulterior motive almost always can eventually have consequences. Remember - those "mode" toggles are VERY popular! They aren't just found in thirty dollar mod kits or on mass produced pedals from Biyang or Joyo. The very fact that they are called "modes" says something in itself, IMO. Why not "diodes 1/diodes 2/etc."? It becomes quickly and clearly obvious.