Ludwig Phase II Clone Tech Notes

[Keppy]

Cool. I won't bother then. I don't have anything that low-gain.

I did think of another note for the build. I used a 48v DC .42A switching power supply from Mouser. I wired the power jack to one of the AC ins (pin 2 or 3, I forget which). No mods, just straight into one of the rectifier diodes. The regulator scheme on the board did fine with it, no whine from the power supply.

[digi2t]

Is there anyway to sub a resistor (a la fuzz face) to get some additional volume out of the fuzz circuit? Then maybe we can trim/balance the output volume between fuzz only and fuzz/formant combo to achieve unity between the two? Compared to my other fuzz pedals, the output is just plain weak.

[R.G.]

The fuzz circuit shows a relatively huge output in simulation - as in several volts of signal. I suspect the real problem is the amount of signal making it through the filters.

The output of the fuzz circuit is determined by the voltage on the base of Q21, which is modulated by the fuzz mix and modulation controls. Below about 1.8-1.9V it cuts off entirely. It may be that you have a bad part that is keeping it too low.

[pinkjimiphoton]

i'm tellin you guys, most of that gain is being swallowed up by the filters. when the ffm broke on mine, i had TONS  of fuzz, and tons of volume. as soon as i fixed it, the fuzz got weak again.

[R.G.]

@Keppy:

When you get the chance - like after the dust settles from moving  (*hate moving, hate moving*) - it would be useful to know the current drain on the clone board. I'm guessing it's well under 100ma, maybe well under 50ma.

[digi2t]

i'm tellin you guys, most of that gain is being swallowed up by the filters. when the ffm broke on mine, i had TONS  of fuzz, and tons of volume. as soon as i fixed it, the fuzz got weak again.

Then maybe we should find a place to cut into, and bypass the filters, when running straight fuzz. Maybe simulate the "problem" Jimi had, with DPDT switches? I WANT MORE, LOUDER, FUZZ!!!  The fuzz is really raunchy on this thing, and I'd like to use it on it's own sometimes, without the formants.

The output of the fuzz circuit is determined by the voltage on the base of Q21, which is modulated by the fuzz mix and modulation controls. Below about 1.8-1.9V it cuts off entirely. It may be that you have a bad part that is keeping it too low.

I'll have to test the voltage here then, but as soon as I hit any formant switch, it really boosts the volume. No formants, less volume. Maybe changing the value of R32 (470K) on the console board? What do you think R.G.? Also, it may explain why in Fuzz only mode, there is a sweet spot in the middle of the slider. Below it, you lose the fuzz, and above, it gets gated. I think Jimi reported that his unit has the same characteristic.

[R.G.]

i'm tellin you guys, most of that gain is being swallowed up by the filters. when the ffm broke on mine, i had TONS  of fuzz, and tons of volume. as soon as i fixed it, the fuzz got weak again.

Then maybe we should find a place to cut into, and bypass the filters, when running straight fuzz. Maybe simulate the "problem" Jimi had, with DPDT switches? I WANT MORE, LOUDER, FUZZ!!!  The fuzz is really raunchy on this thing, and I'd like to use it on it's own sometimes, without the formants.

It would be easy enough to pull the fuzz circuit out on its own as an effect. Then you could eat all you want.

I'll have to test the voltage here then, but as soon as I hit any formant switch, it really boosts the volume. No formants, less volume. Maybe changing the value of R32 (470K) on the console board? What do you think R.G.? Also, it may explain why in Fuzz only mode, there is a sweet spot in the middle of the slider. Below it, you lose the fuzz, and above, it gets gated. I think Jimi reported that his unit has the same characteristic.

I think Jimi's right - the filters really eat up the signal level. This probably happens two ways: one, they have to be kept to a low signal level so the filters don't distort, and two, bandpass filtering by its nature gives a lower output by removing most of the signal that doesn't happen to be in the pass band.

I believe that the terminal-strip amplifier was an attempt to patch the problem in the originals. Easy enough to do more of that today if needed.

Hey. Here's a question. Didn't you say your unit had a wire in place of the resistor at R22? Any chance of you opening that and measuring the current through it?
I'm off into power supply design. I think Digikey has an $11 wall wart that will do a nice job of powering this if the current's low enough. It's rated at 24Vac, but puts out 30Vac no load. So at low loads, you get peaks of about 45Vdc from it. This will only work if the current drain is well under 100ma, I think.

I'm in the middle of trying to decide how much of the clone boards ought to be pristinely original, and how much ought to be adapted to modern parts and techniques for ease of cloning. So the questions of whether to adapt it for voltage up-verting from 9V, a high voltage wall wart, or a switching wart, whether to put a post-filters amplifier in, and some others keep biting me. This is made somewhat worse by the current state of the PCB. It has the original circuit plus the terminal strip amplifier on it, and the console plus filter boards fit nicely into an economical form to get short batches made. And it's **full**.     Putting one more resistor into the filter board for the biasing of the terminal strip amplifier meant I moved about 1/4 of the components on the entire board to add in one resistor. The next addition will move a bigger proportion if the size is to remain the same and resistors aren't changed to Japanese-radio stand-up style. It's one of those little intellectual exercises.

[digi2t]

Hey. Here's a question. Didn't you say your unit had a wire in place of the resistor at R22? Any chance of you opening that and measuring the current through it?

Ouf!! Ummm, weeeelllllll, alright. Only for you guys. Bridge it with the DMM and measure the DC amps, right? Only for my homeys.

It would be easy enough to pull the fuzz circuit out on its own as an effect. Then you could eat all you want.

Yup, that would be cat's ass. When the formant switches are off, and the fuzz footswitch on, isolate the fuzz. I'd love to get that mega fuzz that Jimi was getting.

By the way, I measured the voltage on the base of Q21, in fuzz,and fuzz/voice modes, from minimum to maximum on the slider. In fuzz mode, it goes from 0.5 to almost 5 vdc. In fuzz/voice mode, it goes from 0.5 to 2 volts. 2 volts seems to be the magic number here insofar as the best fuzz sound is concerned. That's why it sounds great max'd in fuzz/voice, and about 1/3 of the way in fuzz. Anything higher, and it starts to gate.

Hmmm, I wonder what some BC109's would sound like here 

[pinkjimiphoton]

i'm getting pm's about building clones for some people guys. i don't really know how to respond at this point. i'm thinking maybe keppy, rg, dino and me should have a chat to figure out what to do...me and dino pretty firmly believe this needs to be unleashed for the diy community pretty much, i have no prob with trying to help people clone it, i don't even mind being a solder hand here and there...but should we maybe make this a partially commercial venture, and maybe sell a kit?
i was thinking it might be a nice way to pay for aaron's webhosting for the next couple decades or so.. just a thought.

[theehman]

i was thinking it might be a nice way to pay for aaron's webhosting for the next couple decades or so.. just a thought.

This is a most excellent idea.  I would gladly be a part of that.  I have a pile of 2N2646 to donate to the cause.  Not much, really, but hopefully it'll help.

[pinkjimiphoton]

hi ron.

that'd be hip, bro. let's see what the guys all say. maybe i can build you one for a REAL clone theory..lol.


heck, after this thing, i think i'll be able to build a space shuttle!

[theehman]

maybe i can build you one for a REAL clone theory..lol.

I may not have an EH collection anymore soon.

[pinkjimiphoton]

why bro? that would suck!

[Keppy]

R.G., I'll measure the current when I get a chance. One thing to keep in mind is the LEDs. I measured the current on those before I wired the board in, and the reading was 30+ mA. That's for 10 of them, in a mix of sizes & styles. If current is a factor, then builders might be limited on their lighting.

Here's the supply I used: 48v DC, 420 mA, about $17.50 once you get the plug for your home country's electrical system. Works great.
http://www.mouser.com/ProductDetail/Phihong/PSAA20R-480-R/?qs=tRFR47brQK8R9AbFIo4HGw%3d%3d

[R.G.]

Ouf!! Ummm, weeeelllllll, alright. Only for you guys. Bridge it with the DMM and measure the DC amps, right? Only for my homeys.

You're too kind!

Yup, that would be cat's ass. When the formant switches are off, and the fuzz footswitch on, isolate the fuzz. I'd love to get that mega fuzz that Jimi was getting.

By the way, I measured the voltage on the base of Q21, in fuzz,and fuzz/voice modes, from minimum to maximum on the slider. In fuzz mode, it goes from 0.5 to almost 5 vdc. In fuzz/voice mode, it goes from 0.5 to 2 volts. 2 volts seems to be the magic number here insofar as the best fuzz sound is concerned. That's why it sounds great max'd in fuzz/voice, and about 1/3 of the way in fuzz. Anything higher, and it starts to gate.

Hmmm, I wonder what some BC109's would sound like here 

Good info. I am doing all the figuring on how it works from simulation and mental imagery. There is nothing like actually listening to it.

Oh, and BC109s sound like turnips with a touch of sage and honey... 

i'm getting pm's about building clones for some people guys. i don't really know how to respond at this point. i'm thinking maybe keppy, rg, dino and me should have a chat to figure out what to do...me and dino pretty firmly believe this needs to be unleashed for the diy community pretty much, i have no prob with trying to help people clone it, i don't even mind being a solder hand here and there...but should we maybe make this a partially commercial venture, and maybe sell a kit?
i was thinking it might be a nice way to pay for aaron's webhosting for the next couple decades or so.. just a thought.

I don't want to be part of any commercial venture. That doesn't limit you three, of course.

Do your homework well before you get a little bit pregnant, though.

[pinkjimiphoton]

i don't wanna do it commercially...just thought it may be a good way to pay back aaron for this forum's expense.

i just wanna build 4 of them, so i can have quadrophonic phase II's.

i'm going to thailand for stem cell therapy, my extra pair of legs should be ready by the time i get there.

[digi2t]

I don't want to be part of any commercial venture. That doesn't limit you three, of course.

Do your homework well before you get a little bit pregnant, though.

I'm with R.G. on that. No such thing as "a little bit pregnant". Personally, I would hate to f**k with karma, especially since there have been a lot of people here that have helped me with my diy adventures. I truely feel blessed in that respect. The only thing I can recommend is if Aron would like to sell a batch of boards, we can give him the layout, parts list, etc., and let him have at it. If that would help cover his expenses for the forum, so be it.

I don't have the time, resources, capital, or kohonas, to invest in such a dicey venture. Besides, I don't consider myself anything special, just a piece of the puzzle where this adventure is concerned. Someone would have pieced this together sooner or later. But, I must admit mihos, I'm damn proud that it was us. Got to work with 3 amazing individuals to boot. Bonus upon bonus.

And THAT, is good enough for me  .

[pinkjimiphoton]

works for me. i just hate some nefarious bass turd taking the work we've done and making it commercial. i WOULD like to see aaron come out ahead, as i believe if not for him this never would have been done...

but i agree, let's keep the karma clean. i have no prob helping peeps out, that was the whole reason i had envisioned this project in the first place.

is it ethical to sell a few clones? i don't see a problem with it. build one for yourself, maybe a couple friends, help others out if they get stuck..but we need to keep it open for the diy community. like dino said, yah, we could clone 'em...but they still will never be worth what the originals are.

so...let's move along, brothers. nothing to see here!

[theehman]

bass turd

I beg your problem?  Some bias against us bassists?

[pinkjimiphoton]

i am a bassist, dude....fretless, 5 string and upright. 

i mean like as in a fish poo sniffer.