Building the Meat Sphere

[bloke_zero]

I didn't think home rolled vactrols would make that much difference, but diffused green and 2m really made it feel good, better range and smoother response. And super easy to make with heat shrink. Tempted to try 1m to tame the peaks.

[vigilante397]

Every time this thread pops up in my list I'm reminded of my half-populated board sitting in my now overflowing "not built yet" box of PCBs I even snagged one of the pre-drilled slanted enclosures, that is also just sitting in my garage gathering dust. One of these days for sure....

[BetterOffShred]

I got diffused green and 1M in mine and I love it.  Also used NE5532 for the opamps, not sure if you saw that recommendation a ways back.  Definitely try it before you complete the boxing.   

Every time this thread pops up in my list I'm reminded of my half-populated board sitting in my now overflowing "not built yet" box of PCBs I even snagged one of the pre-drilled slanted enclosures, that is also just sitting in my garage gathering dust. One of these days for sure....

Yeah I had to drill out the rotary holes a little bigger, it was not wide enough

Turned out ok.

[bloke_zero]

I bought the kit from musikding and the vactrols that came with it didn't work at all. I'll try  1m tonight.

I'm thinking the moog mod is probably essential as there are huge spikes as the envelope closes. Overall though I like the sound better than the mutron 3 clone I built, feels like the filter is less nasal and the expressive possibilities are greater (on the bass).

[Govmnt_Lacky]

Just for clarity...

Original Meatballs used an LM1458 for the dual op amp and used diffused Green LEDs and 2M Dark LDRs

[bloke_zero]

Thanks Govmnt_Lacky - I'll try that - so far I'm really liking the diffused Green LEDs and 2M Dark LDRs, and swapping out the opamp seems fun.

I just did the 'moog mod' which I like a lot (no more massive hump at the bottom end as the envelop sweeps down) but I'm getting a weird glitch.  When I switch the switch I get a sound like flicking a glass with your finger and some times the audio doesn't reach the output but flipping the switch a couple of times or plugging and unplugging the cord from my bass brings it back - the soldering on the switch looks ok - I was worried I'd lifted the pad when I unsoldered the 10k resistor but it seems to work ok  -any ideas?

[vigilante397]

Well, two years or so after buying the PCB I finally got around to finishing the stuffing and am moving to the debugging bit.

When I first stuffed it I didn't have matching vactrols, so I just grabbed whatever I had in the bins, which was one XVIVE something or other and one Macron VTL5C* workalike (don't remember what model), both from Smallbear I think. It sounded okay-ish. Swapped the op-amp to an LM1458, sounded pretty good. Found a pair of Macron VTL5C3's on the bench so I swapped them in tonight, and the filter is dead. There's one position (LP filter I think?) that gets clean signal through, but I have tried every setting and most give no sound, the others give clean sound with no filter.

Should I just roll my own vactrols? I don't keep LDRs on hand because I've always been terrified of rolling my own, but it sounds like the way to go on this build. Has anyone else tried it with Macron VTL5C3 workalikes from smallbear?

[Kevin Mitchell]

I've tried NOS VTLs for this circuit on breadboard.

The biggest issue I've had with it (on a couple of builds) was lack of response with the opamp in the envelope section. I'm not sure why but I've had to try a half dozen different ones before it sounded right to me.

Totally roll your vactrols. I've done that with two builds and it sounded just as well as any other demos I've heard (green diffused LED)

[Alex.H]

I just ordered the kit from musikding but sadly they had no fitting knobs in their shop. I wanted some knob as close to the original as possible, so I searched a lot of shops (musikding, reichelt, conrad, mouser, mammothelectronics, smallbear, amazon usw.) but found only at the mouser store a fitting knob. Called PKAP70B1/4 from TE Connectivity (Alcoswitch). But that thing costs 7,16 EUR. A piece! And you need six!

So I looked further and found a perfect knob on ebay: https://www.ebay.de/itm/Potiknopf-Kunststoff-Bakelit-17-20mm-fur-6mm-Achse-Drehknopf-Reglerknopf-4-Stuck/302214564047?hash=item465d6448cf

I'm not affilitated with that shop by any means, but it took me ages to find those knobs and maybe some of you can profit by my find.

[duck_arse]

we have had very similar and popular knobs here for many a time - this inst 2.85 puny AU$ each:

https://www.jaycar.com.au/20mm-knob-black-plastic-aluminium-insert/p/HK7786

[Alex.H]

we have had very similar and popular knobs here for many a time - this inst 2.85 puny AU$ each:

https://www.jaycar.com.au/20mm-knob-black-plastic-aluminium-insert/p/HK7786

That is real great for all australian folks.

I posted my find in the musikding forum and the admin told me, they already have such a knob in the shop. I just overlooked it.  Stupid me! It took ages to find the replacement on ebay.

For all folks in europe I have here two more sources of that knob:
https://www.musikding.de/Doppelnasenknopf-18mm
https://www.uk-electronic.de/onlineshop/product_info.php?products_id=3301

[Govmnt_Lacky]

Does anyone have a good drill template for this build in a 1590XX/1790NS?

[Govmnt_Lacky]

I guess no one has a drill template... 

Another question:

Looking at the Meatsphere pcb and comparing to the original, it looks like the LED attached to the on/off stomp is designed to operate in conjunction with the vactrol LEDs. This is the same as the original pedals however, I do not see a stand-alone on/off LED that is connected to the 9V input and provided the GND via the stomp like the original. Originals have an external Green LED attached to the vactrol circuit to show the envelope and also a Red LED to indicate the pedal is on or off.

In other words, the Meatsphere LED connected to the stomp will only light up when the envelope is actuated. So, you will only see it light up when you play. Otherwise, it will be off all the time. Where is the connection for the Red LED?

Finally, why connect the LED to the stomp at all? If you solder it onto the pcb where it says, the LED should light up with the envelope and go off when it is not actuated (like the original units)

Is this correct?

[Taylor]

If you want to have two LEDs, one showing the envelope and one showing bypass status, I would solder your envelope LED straight to the board, and wire up your status LED in the normal true bypass way with its own resistor.

[mikeford]

Diffused LEDs and Tayda LDRs are good. Make sure the LDRs can get to 2M dark.

Make sure your 1458 IC is known good. Don't use Tayda or eBay clones. Go with a reputable seller for these. Bad or out-of-spec 1458s will cause the pedal to not function properly.

Would that be the  small bear sku#8104?    27 - 60K is the  min to max Light resistance and it states that     2 Meg MINIMUM dark resistance. THANKS

[Taylor]

For those who have been asking, the Meat Sphere board is back in stock.

[mikeford]

For those who have been asking, the Meat Sphere board is back in stock.
[/quote]

it's sounding pretty killer!

just got mine going. Had to roll my own vactrols with the diffused green leds.

[idy]

I notice wires coming off all the pots. Are you intending on experimenting with expression pedals or something? I haven't but think about it. Would like to be able to use it like a wah. Maybe detector off, direction down, and a pedal in series with the intensity...

[mikeford]

I notice wires coming off all the pots. Are you intending on experimenting with expression pedals or something? I haven't but think about it. Would like to be able to use it like a wah. Maybe detector off, direction down, and a pedal in series with the intensity...

No , I just stuck this one up for the Hades of it,so to speak. You could mod this for an expression/wah setup. The original Lovetones had all sortsa killer inputs/outputs/loops. I wouldn't be the one to atte,pt it on this board,as I am pushing my luck. I would check out the Meaty Balls pcb/build by DeadEnd Fx. https://www.deadendfx.com/product/meaty-ball Deano has all the bells n whistles on his version. (might take a stab at that version a bit later,tho.) Best of luck.

[ficelles]

Here is my Meatsphere build, showing both my original horrible wiring and my just-completed rewire. I had a Lovetone Meatball a few years back and this is easily as good, glad I dived in and built it