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WIGGLING 'LITE' IN GUEST MODE

Is this Buchla 281 working properly???
MUFF WIGGLER Forum Index -> Buchla, EMS & Serge Goto page Previous  1, 2, 3, 4  Next [all]
Author Is this Buchla 281 working properly???
the bad producer
nanners
APETECHNOLOGY
WORKS!
great work cygmu
SlayerBadger!
going to try Dave brown style on my next one

EDIT...
if i set up the patch that Precarious originally posted about,
after 70% on the dial the pulse stops being generated on the second section.

hmmm.....
numan7
SlayerBadger! excellent!


cheers
batchas
the bad producer wrote:
nanners

+1
pickleinn
batchas wrote:
the bad producer wrote:
nanners

+1

+ applause
ym2612
Very cool! I'll try this out soon.
cygmu
APETECHNOLOGY wrote:

EDIT...
if i set up the patch that Precarious originally posted about,
after 70% on the dial the pulse stops being generated on the second section.

hmmm.....


It won't pulse if the envelope doesn't finish, so if you retrigger it before it ends every time then the second section will never pulse. At least, I think that is what happens. Does that explain what you're seeing?
thee ghost ov n_phay
Many thanks for taking the time to work this out!
taijmanman
Is also the Vintage Version the same?
cygmu
taijmanman wrote:
Is also the Vintage Version the same?


I don't know. Dave Brown told me that he thinks all the Roman versions have the same circuitry there, in which case the same would apply. But I have not seen anyone complaining that the sustain/transient modes do not work on other versions, which they definitely would not on an unmodified v3, so I am not sure.

If someone has a board to send me (UK) I'll gladly take a look smile
livefreela
EDIT: I spoke too soon - the mod as I've implemented it breaks the sustain mode on the vintage version... I'm looking into it...

I just installed this mod on the vintage version - it works great! Like the shameless hacker I am, I didn't pull out any components from the pcb, I just removed the wires to board pads and installed little shrink-tubed subassemblies of dave's circuit jumping the jack to the center lug of the switch.

I'm calling em "crack-trols'.

Cygmu, huge thanks for figuring this out - I owe you a beer! I already owe Dave many beers so I'll add it to the tab. Guinness ftw!

cygmu
livefreela wrote:
shrink-tubed subassemblies of dave's circuit jumping the jack to the center lug of the switch


It's funny: when we were discussing, Dave Brown suggested putting that bit of circuitry in place of the resistor, and I said I thought jumping it from jack to switch lug would be easier. In the end I put mine in place of the resistor and Dave's diagram is the jack to lug config. Ha.

Really great to know that it works on the vintage version PCBs, and even better to know I can collect on a beer one day!
taijmanman
Thank you cygmu,livefreela lol
cuttooth
I'm hopeless with DIY...now I'm sad about my vintage-version 281. sad banana

Who could I bribe to safely execute this mod? hihi
livefreela
EDIT: I spoke too soon - the mod as I've implemented it breaks the sustain mode on the vintage version... I'm looking into it...



Implementing this mod is really easy; Cygmu & Dave did the hard part in figuring it out! I performed it on mine in about 30 minutes. A half competent guitar tech should be able to pull it off. Using the discreet assemblies, it's also very easily reversible / further tweakable. I used 2.7n caps on mine (closest value axial I had on hand) and I'm thinking that constant may be a bit slow.

Next mouser order, I'll pick up some 1.8n and have a go with those. As it stands, the module’s a bit obstinate with the ranges where it will retriever those interesting polyrhythms - I recall my euro 281s being a bit more forgiving (built w. Toppobrillo boards), and I think I used 1.8n in those, I’ve not yet gotten around to compare the two side by side.. Still, I am able to recreate the patch from the 281h in the original post with my modded 281r 1.1 module…
cygmu
livefreela wrote:
EDIT: I spoke too soon - the mod as I've implemented it breaks the sustain mode on the vintage version... I'm looking into it...



Argh, that's a shame. If you want some help figuring it out don't be afraid to get in touch -- not that I am any kind of expert but I have enjoyed this.

I just double-checked the sustain mode on my v3 PCB and it works fine. Any input to the trigger jack of over about 2.8V brings the envelope up and holds it high until the input drops below the threshold.

What are your symptoms?
weedywhizz
Ok I removed the 4 parts in all 4 sections and installed the cap,resistor,diode combo.
Cathode of the diode to the bottom pad where the 100k resistor was located before / upper part of the cap/resistor combo to the upper hole where the 100k was located and....

nothing.

No cycling at all. Must have misunderstood something here. Any advice ?

Thanks
Steffen
cygmu
That's strange. I just opened mine up to make sure and yes, your mod looks the same as mine. The only difference is that I have not removed the other three parts (resistor, cap and diode) and there is a tiny chance that those parts somehow provide a little bias to the trigger circuit which is needed for triggers to get over the threshold. But I really doubt that, given some of the experiments I've done.

Do the sustain and transient modes still work if you send trigger / gate signals in?
cygmu
So... I just tried mine with the other three parts removed, and it did not cycle. Actually I didn't remove all the parts, I just disconnected the diode, but the impact should be the same.

This must be something like what I mentioned above about the trigger threshold level but it is a bit odd.

Anyway, if you reinstall the resistor, cap and diode that sit alongside your resistor/cap/diode assembly the thing should work. There must be another mod available so that you don't need to do that but I haven't figured it out yet. Please confirm whether this will work and accept my apologies for incorrect information above!

I will go back and edit my post above that describes the mod, if I am still allowed to do that.

[EDIT: in fact I believe that cycling is still possible with this mod but if you remove the original cap/resistor/diode then you need to send a trigger to get the cycling started. See post below
https://www.muffwiggler.com/forum/viewtopic.php?p=2829396#2829396 ]
weedywhizz
Thank you very much for testing.

Will but the parts back in tomorrow and report back.

Btw: When I put the 100k resistor back and apply the mod between the trigger jack and the mid-pin of the switch section B and D cycle - A & C don't.

Cheers
Steffen
cygmu
weedywhizz wrote:

Btw: When I put the 100k resistor back and apply the mod between the trigger jack and the mid-pin of the switch section B and D cycle - A & C don't.


WHAAATT??? Now I am never going to sleep again. Applying the mod from jack to switch is the same as putting it across those resistor pads, and I really don't understand why adding 100k in parallel would help get those sections cycling. Hmmm.

Anyway, I hope you succeed with the mod.
ghostcode
Thanks for sharing this. I applied this mod and it seems to work perfectly.
cuttooth
Was this mod ever confirmed as functional for the vintage PCB 281? I still need to get mine fixed somehow...by someone. waah Any input would be greatly appreciated.
ym2612
I applied this mod on my A and B channels, and their transient/sustain behavior is now correct, but they no longer automatically start cycling when switched to cycle mode. I have to kickstart them like on the Toppobrillo 281. I haven't looked into why this is.
pre55ure
cygmu wrote:
taijmanman wrote:
Is also the Vintage Version the same?


I don't know. Dave Brown told me that he thinks all the Roman versions have the same circuitry there, in which case the same would apply. But I have not seen anyone complaining that the sustain/transient modes do not work on other versions, which they definitely would not on an unmodified v3, so I am not sure.

If someone has a board to send me (UK) I'll gladly take a look smile


Yeah I have a V2 (blue pcb's) and it doesn't work either. It's something I had been meaning to take a look at before I saw this thread.
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