#9

To be perfectly frank, I’m not quite sure. I’m going to have to look at it a bit more. LED’s are lighting up on both channels, responding perfectly. Audio stopped working on both channels, and it’s very quiet. I got it to work on both of them briefly.

#10

Maybe worth noting that I sometimes have trouble with the CV in of the DLPG. Some of the Math outputs don’t work for example.

This was very validating! For future searchonauts, my newly made DPLPG is happy with all sorts of CV in, but not the Maths unity outputs (it actually somehow pushes the maths output continually high? I guess there’s some kind of loop being made?). Take the same envelope from the attenuverted channels and you’re fine, but if you’re, say, cycling a Maths channel, you’ll get one pass through the unity out and then it will stick high. Electricity!

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#11

Interesting I have a similar problem with my Rampage. If I use either A or B out it goes high then gets stuck, but if I use Max or Min, it works properly.

#12

I had the same issue with Rampage and DPLPG. A passive attenuator or buffered mult fixes it.

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#13

reviving this ancient thread to see if anyone might be able to help me troubleshoot my DPLPG.

i’ve had mine for a couple years and never had any problems with it until recently when i discovered that the bottom channel wasn’t passing any audio through! the LED lights up when i send an ansible trigger in, but no audio… top channel works perfectly though. I resoldered all the through-hole parts that I could reach but was still unsuccessful. any thoughts?

IMG_6514
IMG_65143024×4032 1.89 MB

IMG_6515
IMG_65153024×4032 1.6 MB

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#14

This has also happened with one of my DPLPGs! I’ve been mystified.

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#15

This started happening to mine last night as well. Big bummer.

#16

Here I was thinking I was going crazy. I didn’t even think That a possibility might not be user error.

#17

There isn’t a lot of parts on these little dudes. It be nice to learn a fix.

#18

honestly it’s probably a dead vactrol -
I based my 2xVLPG (KOSMO Format) on Meng Qi’s and they work great.
Have you tried a different vactrol?

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#19

Here’s a schem for it

dual lpg
dual lpg848×750 76.3 KB

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#20

I replaced a dead vactrol on one of mine a couple years ago, it’s a fairly quick swap if you can get your hands on the part. Believe I grabbed mine through thonk. Just keep track of what leg goes where/where pin one is.

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#21

Thanks. I’ll be on the look out for a replacement vactrol!

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#22

I found some replacement vactrols on eBay for very a reasonable price. Thanks for the schematic. Having the part number made it easy.

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#23

I got myself a DPLPG yesterday and sadly I had to start searching web knowledge on why Maths unity outs did not work. Ended up here and want to ask if someone can explain why this is happening and if there’s something to ‘fix’ it without workarounds, buffered mults, attenuated outputs on Maths etc.

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#24

It’s a known issue with the maths circuit (and the classic function generator circuit it is based on) when used with a passive lpg. I don’t understand it fully but I believe it has something to do with impedance?

The direct outs of channels 1 and 4 if maths are unbuffered while the scaled/combined outputs are.

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#25

With Rampage I found that even a passive attenuator would fix the problem.

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#27

Yes, I’m having the same problem. A byproduct of it not drawing power? Any workarounds?

#28

I have the same question

#29

My solution was to patch from the attenuated outputs of Maths. That solved it. From what I understand this is something that happens to all DPLG / Maths. Not faults in ours. It’s got to do with how electronic circuits work, that’s where I left the issue.

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