Building the Meat Sphere

[lvckv]

Yep, I'm counting the pins right. 1 is upper left when turned around.

The side of the 1.8m resistor closest to the TL074 gives the same reading as pin 12 – 1.58.
The other side of the resistor gives a reading of 4.42.

Checked the MC1458 again and pin 4 gives 8.94, pin 8 gives 0.00.

The soldering isn't like professional level but it's all in condition where you'd expect things to be working. No solder bridges or anything like that.

I don't understand your "settings". Not clear which switches you are referring to.

Just basically turn the switches to these and this is the sound that comes out. Switches from left to right as you look at pedal.

Bandwidth switch in any position - UP - filter range is LO, 1 or 2 - any pass = filter with a quiet high pitched buzz
Bandwidth switch in any position - DOWN - filter range is LO, 1 or 2 - any pass = regular guitar tone
Bandwidth switch in any position - DOWN - filter range is HI - any pass = white noise
Bandwidth switch in any position - UP - filter range is HI - any pass = jangly regular guitar tone that sounds like a bridge pickup

[idy]

OK, so you are getting proper power to both ICs. Better.
There is still the mystery of pin 12. I would remove that IC (you did socket them?) and then with power on, recheck that voltage. Until there is around 4.5 (meter could load it a bit below that, maybe 4.2ish) you will not have a chance.

And now that the power is reaching the 1458, what are the other pins? try with the up/down switch in both positions. Does the visual LED go on and off when you do this?



If people keep mentioning solder joints it is because even joints that look perfect under a magnifying glass can be loose inside, "cold solder joints." I can't tell you how many times I have been just where you are, with a mis-biased opamp, rechecking everything and scratching my head, until I discovered that one resistor that looked *perfect* would move ever so slightly when touched!

Remember: a vintage Meat Ball would cost an arm and a leg. This one may only cost you a few grey hairs.

[bluebunny]

I would say that power *isn't* getting to the 1458 - at least, not the right way round.  If you've really got the power backwards, it's likely zorched.  And you then need to work out why it's backwards: socket wrong way round, or bad layout?

[Govmnt_Lacky]

Checked the MC1458 again and pin 4 gives 8.94, pin 8 gives 0.00.

This is backwards. You should have 0V at Pin 4 and ~9V at Pin 8.

[lvckv]

I resoldered the 1M8 next to the TL074 and it still gets the same readings. Just removed the MC1458. Think I'm done. Don't have the tech ability to test and fix whatever is wrong here. Thanks for trying to help.

[Govmnt_Lacky]

I resoldered the 1M8 next to the TL074 and it still gets the same readings. Just removed the MC1458. Think I'm done. Don't have the tech ability to test and fix whatever is wrong here. Thanks for trying to help.

Couple of questions before you throw in the towel:

1) Could the low voltage on Pin 12 of the TL074 be due to the impedance of the multimeter?
2) Are you positive that the diodes (D1 & D2?) are BOTH installed in the correct orientation?
3) Are you positive that the MC1458 is installed with the proper orientation? (Pin 1 of both ICs should be facing the pots at the top of the PCB)
4) With the MC1458 removed, do you get a direct short between Pin 8 and Ground?

I think your problem is going to be obvious and easy once you find it. Don't give up just yet 

[idy]

Well, OK, we all put a few in the fail pail. But next time you order try an LM358, and maybe a LM1458(not MC). But especially the 358. I have had these not fire up, meaning trigger, with the 1458, and then work with 358. I know the original used 1458, but its not an engineer's first choice. They had a batch that happened to work. They are not all equal. It could be that simple.

The PCB is super clear and it is unlikely that you have actually reversed the power, more likely we are just not communicating clearly.

And the VTL opto couplers, although specified, have given poor results for many, so we do as love tone did, green diffused LEDs and LDRs with dark resistance over 1m. Cheap solution and you can see the LEDs light up if you want, be sure that part is working.

[lvckv]

Can get some LM358 and LM1458 to try if that'll do anything. There seems to be so much wrong with it though – would changing that really fix most of the pots and switches not doing anything?

The VTLs both give 0.00 readings at the top and 4.6~ on the bottom if that's worth anything. The LED+LDR thing is something I'd need a whole tutorial for tbh.

I resoldered the 1M8 next to the TL074 and it still gets the same readings. Just removed the MC1458. Think I'm done. Don't have the tech ability to test and fix whatever is wrong here. Thanks for trying to help.

Couple of questions before you throw in the towel:

1) Could the low voltage on Pin 12 of the TL074 be due to the impedance of the multimeter?
2) Are you positive that the diodes (D1 & D2?) are BOTH installed in the correct orientation?
3) Are you positive that the MC1458 is installed with the proper orientation? (Pin 1 of both ICs should be facing the pots at the top of the PCB)
4) With the MC1458 removed, do you get a direct short between Pin 8 and Ground?

I think your problem is going to be obvious and easy once you find it. Don't give up just yet 

1. Don't think so having read up on it.

2. All diodes are facing cathode left which is what the board indicates.

3. MC1458 was in the right orientation. Removed now so can't do anything with that unless I get a new LM1458.

4. When I test where the MC1458 used to be I get 9.25 on 8 and 0.00 on 1-7.

[Zoot]

It has been answered in this thread, and you are right. I doesn't make any difference.

[Jbakelaar]

I have two questions that are intrelated:
I had purchased 1/4 Monocraft #11 switches for all 4 required audio switches
http://smallbear-electronics.mybigcommerce.com/1-4-in-mono-switchcraft-11/


1) I want to add the expression pedal to the Intensity control...

On page 20
Adding the Intensity expression jack is worth doing -- it should be possible on the Meatsphere by running wires from pins 1 and 3 of the Intensity pot (wire it to the board as normal) to an insulated jack, with one on the sleeve, the other on the tip. Use a high impedance expression pedal.

Nice wah-ish effect.


I know it must be a TRS type of 1/4 audio input.
What audio jack do I need? 

2)On page 27

The return jack needs to be a switching type, like this one:

http://smallbear-electronics.mybigcommerce.com/1-4-in-mono-nys2152/

It can be mono or stereo, doesn't matter. You'll be connecting the Send jack to the tip-switch of the jack (in the jack above, that's the terminal on the left of the image, which is connected to the tip terminal when no plug is inserted into the jack). It sounds like you may have used a non-switched stereo jack and wired that to the ring terminal instead. So if you have a switched jack, you may just need to swap that wire over. If that doesn't fix it, once you can upload a photo of your build we might be able to spot what's up.


What do the other 3 audio jacks should I be using?


I don't want to use the uninsulated jacks that I currently have, as most builds seem to be using plastic sleeved or insulated unless someone can verify that what I have will work flawlessly.
No point in ruining my build over $15-20 of the correct jack.


Since it has been made clear which jack to use for return, please advise which jacks are best for In, Out, Send and for an Expression pedal.


Thank you Taylor for making this possible on so many levels and providing guidance - & to everyone else who provides knowledge!

[idy]

In, out, send, return do not need to be insulated, only the expression pedal. The four audio jacks are using a common ground; the expression is putting a pedal in parallel with the intensity pot, which does not go to ground. Any mono or stereo, insulated jack will work.

None of the jacks need to be TRS. They are all tip and sleeve, or "mono." I have used switchcraft or these, which are TRS and switched, I just don't use the Ring or the switching except on the return.

https://www.taydaelectronics.com/hardware/6-35mm-1-4-plugs-jacks/6-35mm-1-4-stereo-phone-jack.html

the data sheet has a tiny schematic that shows this model, the PJ-629HAN has tip and ring N.C. switch terminals. Cheap, versatile.


The return needs to be switched, i.e. normally closed. When nothing is plugged in, the signal goes from send to return. When something is plugged in, this connection is broken and the send/return is an effects loop. This also allows one signal (input) to trigger the filter (perhaps a drum?) while something else is fed into the return to be processed. Any switched N.C. jack will work.

[Jbakelaar]

Anyone have a printable graphic they would be willing to share?
I tried making my own and am frustrated getting spacing and sizing correct, and dealing with the printer 

My enclosure was drilled using this template:
https://drive.google.com/file/d/10MXV805zvi-eQg-G3M1ztVRzw934D-bD/view?usp=sharing

[idy]

Yes the switches can be rotated to three different but equal positions.
This question has been answered lots of times on this thread. It would save time to at least skim the thread before you get too far along...Partake of the collected wisdom and avoid our mistakes! 

There are quite a few places you can get caught. My unsolved frustration is still dealing with the different height of the rotary switches and pots... I end up bending the legs of the pots to straighten them... I think I have tried putting them so the ends of there legs just barely go through the PCB... I don't buy from a place that has the "long pin" pots in all values and don't know if they will work. I think the original Meat Ball enclosure was "stepped," the part with the pots was lower than the part with the switches.

[idy]

Meatspherers: What say you about long pin pots for this? I am using conventional flat enclosures and have been bending the pot lugs straight... Or using solid core wire and solder terminal pots... Are the long pin pots the right length to even up with the rotary switches? Other good options?

[Govmnt_Lacky]

Meatspherers: What say you about long pin pots for this? I am using conventional flat enclosures and have been bending the pot lugs straight... Or using solid core wire and solder terminal pots... Are the long pin pots the right length to even up with the rotary switches? Other good options?

I have found that when using the typical Alpha rotary switches that the right angle pots seem to just barely be long enough to solder when placed into the holes. I often just solder resistor bits on to solder lug pots and work from there.

[Jbakelaar]

My build(s) are going great!  I have a longer post coming with some things I learned that may be helpful especially for other newbie DIYers.

Has anyone built an effects loop bypass?
Yarg started the discussion over 6 years ago (p. 22) and Granny Gremlin posted a circuit design on p.26.

I have a 4 position stomp switch but I'm having a hard time figuring out how to wire it up to keep the effects pedals live when the meatball is off.



I added some terminal numbers to Granny Gremlin's diagram.

Can anyone say if this idea works?

I just can't make sense of where positions 3, 6, and 9 are meant to be integrated into the circuit.

Can anyone shed some light?

[telebiker]

Meatspherers: What say you about long pin pots for this? I am using conventional flat enclosures and have been bending the pot lugs straight... Or using solid core wire and solder terminal pots... Are the long pin pots the right length to even up with the rotary switches? Other good options?

I was using solder lugs pots.

I just opened one of mine and tried different values for the caps selected by the "range" switch. I have labeled one on mine "low, high, higher highest" because to me the second lowest already sounds like an angry mosquito and the other two settings maybe are to drive cats crazy.. or maybe bats.

The circuit adds three values to one tiny cap in parallel. (There are two poles doing this to two sets so that two stages of the SVF get equal caps.)
Stock values
2.2n
3.3n (=5.5)
6.8n (=9)
15n (=17.2)
My new ones
3.9n
4.7n (=8.6)
15n (=18.9)
33n (=36.9)

I think I have moved the range down an octave. I was kind of worried about what might happen with bass... there are warnings about not starting earthquakes with the original. With the guitar the new values sound very normal. I want to try some even larger values. I still feel the lowest is a midrange filter.

I guess the point is those values were maybe not handed down from Mt Sinai or conjured up by a real EE. Does anyone ever use the highest settings on the stock pedal?

Very nice and interesting idea! Wanna try.

[telebiker]

Anyone have a printable graphic they would be willing to share?
I tried making my own and am frustrated getting spacing and sizing correct, and dealing with the printer 

My enclosure was drilled using this template:
https://drive.google.com/file/d/10MXV805zvi-eQg-G3M1ztVRzw934D-bD/view?usp=sharing

The following pic was shared by @skarkowtsky a little bit earlier:

[telebiker]

Anyone have a printable graphic they would be willing to share?
I tried making my own and am frustrated getting spacing and sizing correct, and dealing with the printer 

My enclosure was drilled using this template:
https://drive.google.com/file/d/10MXV805zvi-eQg-G3M1ztVRzw934D-bD/view?usp=sharing

The following pic was shared by @skarkowtsky a little bit earlier:

http://i104.photobucket.com/albums/m168/jl122/meatball_zps7qgt2myf.png

[idy]

A recent thread brought up new Meatball clone, Aion's Spectron. The build doc has many interesting observations, which I thought I'd present here as of interest to all Meatball fans.

The original does not use light shields (like heat shrink) over the LDR/LED combos. Aion thinks the lack of shield may actually affect the sound. Interaction?

Aion finds no available Vactrol with the same specs as the original LDR/LED combo. Some may work, but the effect becomes a different animal.  The GL5537-1 is recommended as spot on for original function and sound. VTL5C3 may work, but Aion advises lowering the resistors around the LEDs to 100ohm. I can confirm that VTL5C3 don't really work without tinkering. I just ordered some GL5537-1s.

The original trigger chip had the label sanded off, so the specification of LM1458 is based on early researchers trying one and finding it "worked." Aion found (and I confirm) that 1458s "sometimes" work "sort of," but replacing this chip with an LM358 "always" works and works like the original.

The Spectron includes both the original expression jacks and a separate trigger jack...the original allowed an external trigger bu plugging it onto the return without using the send, but forced you to set the "blend" to 100% to avoid bleeding the trigger into your audio path...This is an improvement.

Spectrum changes two of the rotary switches to toggles. Definitely something to think about. The "mode" and "range" require the respectively 3 poles and 4 positions, so they stay, but the others are kind of unnecessary.

Aion adds the "Moog mod". I have begun hardwiring the Moog mod always on, because it seems like bass players need it, and guitarists can't tell its on, and this thing already has a lot of switches....

Aion puts the two rotary switches on daughter boards to fix the height difference with the pots. More wiring, but solves an issue.

I'm still loving my Meatspheres with a switch to select the clean side of blend between send and return (buffered). I have also tried adding a switchable phase inverting buffer here. You can definitely hear the difference, can't say the out-of-phase settings (original has HP and LP out-of-phase) sound bad or weak, but in-phase sounds richer. Its a little awkward to "explain" to a user that the switch has BP in-phase and HP and LP out in one position, and vice versa in the other... In a perfect version I would add a fixed inverter stage to the BP and "normalize" the action of the switch.

Another observation: I recently couldn't find in my drawers any LDRs with a high on resistance (above 1-2k) so I used what I had and added series resistors and was happy. I am having trouble with the data sheet... maybe GL5537-1 has a 20-30k light resistance? Seems high...https://www.kth.se/social/files/54ef17dbf27654753f437c56/GL5537.pdf

Science marches on. Keep it Meaty people!