Building the Meat Sphere

[Taylor]

hi, i have a question about the vactrols:

i notice on the schmatic the two vactrols are mark 120k and 220k

Actually, no, the LDRs each have another resistor in parallel with them, of the values 220k and 120k. Because of that, the values of the LDRs themselves aren't too important but you can be safe choosing something with similar light/dark values and speed as the optocouplers listed in the bill of materials.

[nocentelli]

one more thing, does anyone know a good and cheap place to buy stomp switches in the uk? or a toggle equivalent? i tend to use my effects on table tops and not the floor...

Bitsbox has a cheapish range of toggles and flat £1.50 shipping, drtweek has reasonably priced 3PDT stomps and reasonable shipping.

[LaceSensor]

rapid do Alpha DPDT stomps for £1.65

[samE]

hi,  regarding the Vactrols would this one be fine to use:
HCPL-817 Optocoupler

all so, could i use 3PDT On-On 2-position 3-pole toggle.
inplace of the stomp switch and still have a true bypass?

sorry if im a bit Noobish, just want to get it right....

thanks.

[Vince_b]

I don't know for the vactrols but the switch will be fine. The only difference is that you will have to use your fingers instead of your foot to switch it on.

[thedefog]

Populated the board tonight... But cracked 3 of the pots in the process of getting it to fit in the case. Definitely a good idea to mount them in the case PRIOR to putting the board in. Luckily I have the pots, only without the legs so I'm going to have to wired them now...

[Vince_b]

I'm sorry to hear that, but you should have remember what I said when I posted the drilling template:

It's easier to mount the switches and pots on the enclosure before soldering them to the pcb. If you try to solder everything on the pcb before mounting them on the enclosure it might be harder to make each components fit in their holes.

At least you didn't damage the pcb.

I have completed mine yesterday, I will post some pictures when I will have the time today.

[Vince_b]

Here are the pictures:






Thanks to Taylor for this pcb. I wanted to build one for a while but I didn't really wanted to do all the offboard wiring for the switches and pots.
This is not a plug and play effect but if you take the time to understand how each of the controls interact with each others, you can achieve some really cool sounds.

[Taylor]

Great guts Vince!

[thedefog]

I replaced the busted pots with new ones. I originally had mounted them all in the pedal as suggested, but they didn't reach the solder pads. I thought I'd be able to bend them gently and get them to reach, and they did, but when I tightened them down with the nuts they snapped.

So now I have everything wired up, but it doesn't seem to be working in filter up mode. The envelope just doesn't trigger and the low and bandpass modes turn off the output. Works fine in Down mode though. Maybe I have a bad switch. Either way I'm going to have to spend some time debugging now...

EDIT: Is this just my build and I did something wrong, or does the intensity get reversed when it goes between up/down mode? My build seems to be working right, just wasn't expecting that odd behavior from it. Also, the blend seems somewhat useless on mine, as far left is the clean signal, moving towards middle ramps clean volume to nothing (no output), then past that to the far right is the effected output.

[Vince_b]

The blend is obviously not right on your build, you should still have output when the knob is in the middle position.
I don't think that the intensity is supposed to get "reversed" when you change from up/down but on some settings backing off the intensity knob a bit can make the effect sound more intense.
I can't really help you more as I don't know what can be the cause of your problems.
I'm sorry to hear that you had so much trouble with the pots. It really suprises me that they snapped like this.

[soggybag]

What's so special about the LM1458? 1458 type op-amps are pretty bog standard. Can you use any variety of 1458? or is there special about the LM1458?

Second question, I notice in your image the status LED is soldered to the board. But, the wiring diagram shows these pads wired through the stompswitch? From the scheme it looks like this LED monitors the envelope. I'm guessing your need to wire this through the switch to turn it off when the effect bypassed?

[Barcode80]

What's so special about the LM1458? 1458 type op-amps are pretty bog standard. Can you use any variety of 1458? or is there special about the LM1458?

Second question, I notice in your image the status LED is soldered to the board. But, the wiring diagram shows these pads wired through the stompswitch? From the scheme it looks like this LED monitors the envelope. I'm guessing your need to wire this through the switch to turn it off when the effect bypassed?

I don't know anything about any kind of rule regarding special opamps or anything. I used tl072 and 4558 in my pisotones build and it worked great. You should be able to use any dual opamp at all.

[Taylor]

What's so special about the LM1458? 1458 type op-amps are pretty bog standard. Can you use any variety of 1458? or is there special about the LM1458?

Second question, I notice in your image the status LED is soldered to the board. But, the wiring diagram shows these pads wired through the stompswitch? From the scheme it looks like this LED monitors the envelope. I'm guessing your need to wire this through the switch to turn it off when the effect bypassed?

I don't know anything about any kind of rule regarding special opamps or anything. I used tl072 and 4558 in my pisotones build and it worked great. You should be able to use any dual opamp at all.

No, you can't use just any old opamp and expect it to always work. Basically, as I understand it this type of envelope follower relies on how linearly the opamps operate towards the power supply rails. There is a lot of info on this site regarding this with nurse quacky/docotr Q, Q-tron, etc. type circuits.

Now, Barcode, you may have gotten lucky and had TL072s work somehow. In my experiments I could never get this circuit to work with any of these jelly bean type opamps. There was absolutely no envelope. Even though it worked for you, it isn't going to work for everybody, and since the 1458 type opamps are easily available and cheap, I see no reason to gamble or sit there and try 20 opamps.

Also, and this explains why I have LM1458 in the build document: I have to write these directions so they can be understood and followed by people of varying experience/knowledge levels. If I leave something open-ended or if I give instructions that might, maybe, kind of work, it will confound noobs and I have to answer literally hundreds of emails about a single thing like opamps.  That's also why it says to use film caps, etc. - I don't care about cap dielectrics, but for people who have no idea about buying parts, this seems like an important question, and if I specify something like that in the doc you can assume I have previously received a few hundred emails about it! 

So, other brands of 1458 should work just fine. If you feel like experimenting, other opamp types may also work. But, I can guarantee that LM1458 works, for those without the knowledge or time to try to find something else based on the important parameters.

[Vince_b]

Second question, I notice in your image the status LED is soldered to the board. But, the wiring diagram shows these pads wired through the stompswitch? From the scheme it looks like this LED monitors the envelope. I'm guessing your need to wire this through the switch to turn it off when the effect bypassed?

You have to solder (or wire) one leg of the led directly to the board and the other leg has to go to the 3pdt (as you can see in the build document). Otherwise the led will stay lit even when the effect is bypassed.

[soggybag]

Thanks, that's what it looked like, but I thought I would confirm.

[LaceSensor]

Hoping to get this one finished this week. Here is my work in progress!

[thedefog]

The blend is obviously not right on your build, you should still have output when the knob is in the middle position.
I don't think that the intensity is supposed to get "reversed" when you change from up/down but on some settings backing off the intensity knob a bit can make the effect sound more intense.
I can't really help you more as I don't know what can be the cause of your problems.
I'm sorry to hear that you had so much trouble with the pots. It really suprises me that they snapped like this.

Maybe I damaged the blend pot as well in the process somehow. I'm also surprised, I didn't apply a whole lot of force while tightening the nuts (finger tightened). I think something just shifted and they all kinda snapped from the excessive force on them. No biggie though, as it is working now. Just have to play around with the resistor value for my bright green LED and i'm done!

[LaceSensor]

Finished mine.
Some setting give wierd results that dont sound "right" but ive found a good place to put the colour intens and blend that produce nice sounds with all other switch settings.
Something wierd goes on in the down setting, if you max the colour intensity and blend the signal all gets cut.
Im not sure if its just the idiosynscrasies of the device, but the standard lovetone "pure meatball" setting is unacheivable due to this oddness.

Anyway, heres the guts.

[lwatford]

proably a dumb question, but how do you set the switches for the correct number of positions and throws?