Meaty Balls (My Meat Sack)

djmiyta

Active member
I’ve finally made progress on my Meat Sack. It now passes signal on and off by-pass all the LED’s are functioning as (I ) would expect fluctuating with the strength of my strum etc. so what’s the problem with mine fucktioning like it’s all good but not giving up the effect in other words all’s not right though it behaves like it should be all good . Here’s the board shots
 

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PJS

Active member
You have a damaged capacitor in the middle next to the TL074. From my experience that amount of melting of the case has almost certainly destroyed the capacitor. That may not be what is causing your problem, but I think you need to replace it.
 

PJS

Active member
Also, I think that if you are using an LED and LDR combo to make a vactrol you usually need to use tape or something similar to stop light getting in.
 

carlinb17

Well-known member
I’ve finally made progress on my Meat Sack. It now passes signal on and off by-pass all the LED’s are functioning as (I ) would expect fluctuating with the strength of my strum etc. so what’s the problem with mine fucktioning like it’s all good but not giving up the effect in other words all’s not right though it behaves like it should be all good . Here’s the board shots
I built one from Aion, I would imagine the principals are the same as your build although the build is different. I had two major issues, the first being I had some of my wiring for the expression pedal wired wrong. Secondly I went through about a dozen LM 1438 and LM358 IC's until I found one that trigged properly for me. A good idea and what helped me was I went through the schematics with an audio probe. Also of note some settings are better than others for testing (there are a lot of options for on this pedal. Kevin at Aion goes very in-depth and lost me several times in this document... but here it is maybe it can help shed some light on your problem.


He also goes into why he doesn't use the vactrol and uses the bare led/ldr which I would imagine is the same in your case. But follow it with a audio probe and see where you lose signal or where you don't get modulation that you should.
 

mdc

Well-known member
These builds are so prone to issues that I think there's a dedicated 50-page thread on DIYS about them. It's a fussy one for sure...
 

zgrav

Well-known member
Also, I think that if you are using an LED and LDR combo to make a vactrol you usually need to use tape or something similar to stop light getting in.
Oddly enough, the LED/LDR combos were not light-isolated in the Lovetone Meatball. And that lack of light-isoloation inside the case may have been a part of the Lovetone sound. See page 9 of the AionFX build document: https://aionfx.com/app/files/docs/spectron_documentation.pdf
 

zgrav

Well-known member
I would think that, inside the case, there would be no need for isolation. When the case is opened and the circuit run, however…
there are two of the LED/LDR pairs inside the case, with the option of setting them independently or out of phase with one another. there is a possibility for some "light pollution" coloring the sound. or "branding" the sound, perhaps.

you absolutely need to shield the LDRs from ambient light when testing the unit with the case opened.
 

djmiyta

Active member
I built one from Aion, I would imagine the principals are the same as your build although the build is different. I had two major issues, the first being I had some of my wiring for the expression pedal wired wrong. Secondly I went through about a dozen LM 1438 and LM358 IC's until I found one that trigged properly for me. A good idea and what helped me was I went through the schematics with an audio probe. Also of note some settings are better than others for testing (there are a lot of options for on this pedal. Kevin at Aion goes very in-depth and lost me several times in this document... but here it is maybe it can help shed some light on your problem.


He also goes into why he doesn't use the vactrol and uses the bare led/ldr which I would imagine is the same in your case. But follow it with a audio probe and see where you lose signal or where you don't get modulation that you should.

I also have the AION pcb's for the meatball and doppelganger waiting on the boxes and some jacks. I wanted to do a side by side comparison of the 4 pedals once finished. I've used my homemade vactrols in several other builds with no problems . This one is odd since EVERYTHING seems to be operating as should just no meatball effect when engaged although it was tested out of the box but in a semi dark room so hoping once boxed it will work as it should. Just hate taking it out of the box every time is another chance for me to mess something up.
The LM1458 and LM358 IC's you said you went through about a dozen. Did you have to try different combinations of the 2 just pulling one out and putting a differnt one in until you got effect?
Also 1 board uses a TL074 with a 1458 and the other one uses 2 TL072 and 1 LM358. any one know why ? just design choice or is one better than the other?
 
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zgrav

Well-known member
you can lay a cloth on top of the opened box to block out the indirect light to see if it is working. take a look at the manual for the meatball to read about the settings, since the attack and release knobs need to be set in ranges that do not stop the controls from working.
 

djmiyta

Active member
Thanks for the info everyone! I had read that audio probing this pedal is difficult due to the vactrols not being isolated and ambient light and all.
so should I probe as I would any other pedal?
 

carlinb17

Well-known member
Thanks for the info everyone! I had read that audio probing this pedal is difficult due to the vactrols not being isolated and ambient light and all.
so should I probe as I would any other pedal?
you can throw something small over them even a folded piece index card will work
 

carlinb17

Well-known member
I also have the AION pcb's for the meatball and doppelganger waiting on the boxes and some jacks. I wanted to do a side by side comparison of the 4 pedals once finished. I've used my homemade vactrols in several other builds with no problems . This one is odd since EVERYTHING seems to be operating as should just no meatball effect when engaged although it was tested out of the box but in a semi dark room so hoping once boxed it will work as it should. Just hate taking it out of the box every time is another chance for me to mess something up.
The LM1458 and LM358 IC's you said you went through about a dozen. Did you have to try different combinations of the 2 just pulling one out and putting a differnt one in until you got effect?
Also 1 board uses a TL074 with a 1458 and the other one uses 2 TL072 and 1 LM358. any one know why ? just design choice or is one better than the other?
I"m not sure why either use the components that they do, it might be an accessibility factor. for the IC's I just pulled and tried, and pulled and tried. Like @mdc said its prone to issues... But setting it in a. "standard" mode while trouble shooting will definitely help.

On another note with your doppelgänger are you using B1K or B2K for the span pots? Originally they came out and said B2K for the span pots and had a section noting that this was for more range but said you may have issues with the LED's for rate. I noticed that they took the B2K's off the parts list recently and only have B1K's...
 

djmiyta

Active member
I"m not sure why either use the components that they do, it might be an accessibility factor. for the IC's I just pulled and tried, and pulled and tried. Like @mdc said its prone to issues... But setting it in a. "standard" mode while trouble shooting will definitely help.

On another note with your doppelgänger are you using B1K or B2K for the span pots? Originally they came out and said B2K for the span pots and had a section noting that this was for more range but said you may have issues with the LED's for rate. I noticed that they took the B2K's off the parts list recently and only have B1K's...
yeah I read a thread Lace Sensor wrote (might even have been between someone fron AION and Lace Sensor not sure ) about the LED's locking up and that 2K is a mod and only a suggestion which yeah the more range sounds good so I went with the 2K on the DEFX board will go with 1k on the AION board they should be here Saturday with my boxes . I haven't started the Aion meatball board yet . So I have the 2 DEFX builds and neither have I gotten to work properly both pass signal but I think I'm alot closer to getting the meatball right since I can visually see the pots and guitar effecting the LED's I just cant hear any effect like Ive heard on youtube. Not even close just clean sounds with extremely subtle changes in volume as I rotate knobs and switches
 

djmiyta

Active member
so testing my Meat Sak again(I just like saying) I now do get very subtle effect this is without swapping out any IC's so can I assume by swapping out ICs until I get an effect that sounds good to my ear? Does swapping IC's change the intensity of the entire effect or is once you can hear the effect that its up to you to find something now that you like. in other words now that I can hear the effect its still in no way as extreme an effect as I've heard on youtube keep experimenting with swapping chips? or any other suggestions?
 

carlinb17

Well-known member
The changing of the chip for me allowed the envelope to trigger. Part of my problem at the time was my effect signal was cut off at the expression pedal input because I wired it wrong. So using an audio probe helped because while I still had sound when it was engaged it was dry sound with no wet. I would definitely start following the audio path through with a probe. I jumped all my loop and expression pads initially to sort it out. Kevin at Aion in his build doc talks about how even he had issues with triggering and changed around ics.
 
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