Buchla Easel Command Module 208C

[Carmelo_P82]

At least the sound is - to me - fantastic

[Schranzformat]

Hi,
Just got the Easel Command, what an awesome machine ! That being said, I'm having a very wonky master volume know and looks like it's a normal thing with theses. Anyone else can confirm this ? Thank you and Merry Christmas !

Hi,

I was also worried about the topic with wobbly potentiometers and I found this thread.
Picked up my Buchla - Easel Command copy from the local dealer a week ago. Before picking it up, the seller told me that 8 copies arrived during delivery and one remained with them as a demonstration. The seller immediately told me to check everything on the spot and compare my copy with theirs (twist all the knobs, etc.). He immediately told me that he didn’t like the pots because they were wobbly and asked me to pay attention to them first and compare them with his specimen.
In general, I had the same thing. All the pots were wobbly to some degree, but the master was wobbly than everyone else. I can’t say exactly how much better I have, or the same as yours. But what I saw in the store was the same as on my copy - the master was more wobbly. I also noticed that the master's knob touches the head of the self-tapping screw under it - what I have, what is on the demo copy.
Even from your video, I saw that you, perhaps, the knob itself does not fit snugly to the body and because of this, the shakiness seems to be greater.
I recently had a story with Prophet 6, the same thing with a wobbly pot, but also the shaft itself inside tilted to the left when turning. But Sequential did not solve my problem in any way, they said that it was normal. Apologized and sent a package of knobs):

https://www.youtube.com/watch?v=yCUGA7bP6yc

https://youtu.be/vUV8DbQRzVs

Best regards

[Schranzformat]

I also forgot to add that the Easel does not sit flat on the walnut side trims - what is in the store and what is mine.

The same problem was on 0-Coast and recently on Waldorf-M - they also do not stand on four legs))

[Carmelo_P82]

I also forgot to add that the Easel does not sit flat on the walnut side trims - what is in the store and what is mine.

The same problem was on 0-Coast and recently on Waldorf-M - they also do not stand on four legs))

Also on mine. Looks like most of the unit have a wonky master volume.
My faceplate also arrived with few scratches here and there.

Anyway, if I keep it, I want at least a better unit than this one !

[Schranzformat]

In the evening I will shoot a video, as on my copy of Easel, the potentiometer Master Volume is wobbling.
Have Buchla sent an answer to this problem yet?

[Carmelo_P82]

Not yet but I've contacted them 4 days ago. With holidays I guess things can take more time to get sorted.

[ersatzplanet]

How much of a gap is there between the shaft and the hole, and how far is the pot body from the front panel? All the can add to the wobble. The best thing to do is the shoulder washer trick I mentioned above. Basically fill the gap between the shaft and the hole with something that will still be slippery enough to not hamper the shaft's rotation (nylon is great for this) but keep it from being able to be moved side to side. It will make the pot last longer. The larger knob on the master volume pot really helps to exaggerate this too.

Mouser has a few shoulder washers with internal dimensions of 1/4" that should fit over most pot shafts. They look like this:

Screen Shot 2021-12-29 at 4.12.53 PM.png (38.05 KiB) Viewed 1343 times

[Schranzformat]

Here's my video of my Buchla instance on the subject of wobbly pots:

How much of a gap is there between the shaft and the hole, and how far is the pot body from the front panel? All the can add to the wobble. The best thing to do is the shoulder washer trick I mentioned above. Basically fill the gap between the shaft and the hole with something that will still be slippery enough to not hamper the shaft's rotation (nylon is great for this) but keep it from being able to be moved side to side. It will make the pot last longer. The larger knob on the master volume pot really helps to exaggerate this too.

Mouser has a few shoulder washers with internal dimensions of 1/4" that should fit over most pot shafts. They look like this:

Screen Shot 2021-12-29 at 4.12.53 PM.png

After your message above, I looked at the options on Aliexpress and found many options, but you need to make a choice very carefully. Because there are many proposals with a fairly large thickness of nylon itself:

And I checked the thickness of the potentiometer bar in the housing bore by removing the knob itself. And I checked the thickness of the potentiometer bar in the housing bore by removing the knob itself. Approximately, not more than a millimeter (but this is without accurate measurements).

[Carmelo_P82]

Here's my video of my Buchla instance on the subject of wobbly pots:

How much of a gap is there between the shaft and the hole, and how far is the pot body from the front panel? All the can add to the wobble. The best thing to do is the shoulder washer trick I mentioned above. Basically fill the gap between the shaft and the hole with something that will still be slippery enough to not hamper the shaft's rotation (nylon is great for this) but keep it from being able to be moved side to side. It will make the pot last longer. The larger knob on the master volume pot really helps to exaggerate this too.

Mouser has a few shoulder washers with internal dimensions of 1/4" that should fit over most pot shafts. They look like this:

Screen Shot 2021-12-29 at 4.12.53 PM.png

After your message above, I looked at the options on Aliexpress and found many options, but you need to make a choice very carefully. Because there are many proposals with a fairly large thickness of nylon itself:

30-M3-M5.jpg

And I checked the thickness of the potentiometer bar in the housing bore by removing the knob itself. And I checked the thickness of the potentiometer bar in the housing bore by removing the knob itself. Approximately, not more than a millimeter (but this is without accurate measurements).

To be honest yours is fine to me. Mine really acts like a joystick ..

[kwaidan]

I got one last week, and it has a couple of loose knobs. The reverb knob has a slight wobble to it, and the monitor level knob wobbles quite a bit. The other knobs, including master level, seem to be tightly mounted. The monitor level knob is pretty bad.

[Carmelo_P82]

I got one last week, and it has a couple of loose knobs. The reverb knob has a slight wobble to it, and the monitor level knob wobbles quite a bit. The other knobs, including master level, seem to be tightly mounted. The monitor level knob is pretty bad.

Looks like a common thing with this system. If I get another one with less wonky knob and no scratches on the faceplate, I'll be happy !

[Carmelo_P82]

Ok .. Looks like I'm having another trouble (or again, perhaps I'm missing something which I doubt in this case).
Without any patch, the modulation oscillator of my EC got his pitch very high when the frequency slider is at min and even when set to low (should act as a LFO). When I increase the frequency slider, the pitch started to be lower.
I've disconnected the midi cable but nothing changed and I had to do a reset (off / on) as you can see on the video to make it work properly again. Midi coming from the Octatrack was only used to send the Pulse to the Pulser.

[antonriehl]

Without any patch, the modulation oscillator of my EC got his pitch very high when the frequency slider is at min and even when set to low (should act as a LFO).
<snip>
I had to do a reset (off / on)

It sounds at some point you sent it a high midi note, and then never sent it a new note. On the 208C all incoming pitch controls are summed together before offsetting the oscillator pitch, so it is definitely possible to get extremely high frequencies. And since the oscillator is analog, you can easily add enough offset to go into very high frequencies, even in the low mode.
The fact that resetting the unit returned the oscillator to the expected range definitely indicates there was some message sent to get the pitch that high.
Here is how the signal flow is summed: https://buchla.com/guides/208C_frequenc ... v2-sum.pdf

Turning off keyboard tracking instead of the Low/High switch would be a better test to see if the issue is with the oscillator or the pitch offset.

I've disconnected the midi cable but nothing changed

MIDI is not a constant voltage, but instead a message to set a voltage. Once a high MIDI note message is received, that note is the expected note to be held until a new MIDI note message is sent, regardless of the cable status.

When I increase the frequency slider, the pitch started to be lower.

This sounded more like sidebands on your speakers than pitch from the oscillator.

[Carmelo_P82]

Without any patch, the modulation oscillator of my EC got his pitch very high when the frequency slider is at min and even when set to low (should act as a LFO).
<snip>
I had to do a reset (off / on)

It sounds at some point you sent it a high midi note, and then never sent it a new note. On the 208C all incoming pitch controls are summed together before offsetting the oscillator pitch, so it is definitely possible to get extremely high frequencies. And since the oscillator is analog, you can easily add enough offset to go into very high frequencies, even in the low mode.
The fact that resetting the unit returned the oscillator to the expected range definitely indicates there was some message sent to get the pitch that high.
Here is how the signal flow is summed: https://buchla.com/guides/208C_frequenc ... v2-sum.pdf

Turning off keyboard tracking instead of the Low/High switch would be a better test to see if the issue is with the oscillator or the pitch offset.

I've disconnected the midi cable but nothing changed

MIDI is not a constant voltage, but instead a message to set a voltage. Once a high MIDI note message is received, that note is the expected note to be held until a new MIDI note message is sent, regardless of the cable status.

When I increase the frequency slider, the pitch started to be lower.

This sounded more like sidebands on your speakers than pitch from the oscillator.

Hi mate, thank you so much for the input.
As you can see on the video, both "keyboard" of the MO & CO were off and I only use Midi to send the pulse to the pulser.
I don't understand how a data can be sent causing a high note as shown

[antonriehl]

Hi mate, thank you so much for the input.
As you can see on the video, both "keyboard" of the MO & CO were off and I only use Midi to send the pulse to the pulser.
I don't understand how a data can be sent causing a high note as shown

What MIDI are you using to drive the pulser? It should be "Note On # 9-11 (A-B)" (pretty low notes) if that's the only thing you want to drive. Are there any other MIDI devices on the system? I have had a mixer send out constant high notes as part of it's clock, and had to filter that out in my DAW (until I got rid of that mixer...)

[SonicAdventurer]

I've made the experience -- without deeper research for the reasons -- that it is better to start the Easel Command without MIDI/USB MIDI connected and to connect MIDI/USB MIDI afterwards, when the Easel Command is running. Otherwise mostly the frequencies behaved weird.

[aquifer]

The MO receives MIDI notes on channel 3 separate from the Keyboard MIDI pitch. The Pulser will receive notes on Channels 1 to 5 - (these should be 1/8 notes or 1/16 notes of course, not 24 ppqn pulses or other sync standards). Maybe the OT is sending out on Channel 3? Also, make sure that there's no MIDI clock being sent either (just in case that's messing things up). I'd also go with SonicAdventurer's advice and connect MIDI after powering up.

[Carmelo_P82]

Hi mate, thank you so much for the input.
As you can see on the video, both "keyboard" of the MO & CO were off and I only use Midi to send the pulse to the pulser.
I don't understand how a data can be sent causing a high note as shown

What MIDI are you using to drive the pulser? It should be "Note On # 9-11 (A-B)" (pretty low notes) if that's the only thing you want to drive. Are there any other MIDI devices on the system? I have had a mixer send out constant high notes as part of it's clock, and had to filter that out in my DAW (until I got rid of that mixer...)

The Octatrack. Because the fact his lowest note is C-1, I'm using CH5 / note A-1 to drive the Pulser which can't send a high pitch note this is why I'm surprised / concerned. That being said, the Midi OUT of the Octatrack goes to a Midi Thru Box (Midi Solutions) which has 4 outputs. All the other Midi tracks used for my other gears were muted so I don't think there was another data that was sent to the EC.

[Carmelo_P82]

I've made the experience -- without deeper research for the reasons -- that it is better to start the Easel Command without MIDI/USB MIDI connected and to connect MIDI/USB MIDI afterwards, when the Easel Command is running. Otherwise mostly the frequencies behaved weird.

Well, I'll try that too. But I've asked for a replacement. Too much issue for one unit, especially for that price...

[Carmelo_P82]

The MO receives MIDI notes on channel 3 separate from the Keyboard MIDI pitch. The Pulser will receive notes on Channels 1 to 5 - (these should be 1/8 notes or 1/16 notes of course, not 24 ppqn pulses or other sync standards). Maybe the OT is sending out on Channel 3? Also, make sure that there's no MIDI clock being sent either (just in case that's messing things up). I'd also go with SonicAdventurer's advice and connect MIDI after powering up.

Mmh. Good call.
The Octatrack is sending his clock and midi notes thru his Midi Out I'm using.
I'll keep looking for that even I've asked for a replacement because of other issues such as super wonky knobs and scratches on the faceplate
That being said, I love the sound and the philosophy of patching even I do already have a Verbos system

[antonriehl]

One other thing I just noticed is that MIDI channel 1 happens before the Keyboard on/off switch, but MIDI channel 3 happens after (meaning the switch does not affect whether it follows MIDI channel 3), and channel 1 and 3 will sum together, so you could use channel 1 for a sequence, and channel 3 to transpose that, etc.. This could be part of the issue you were having.

[Carmelo_P82]

One other thing I just noticed is that MIDI channel 1 happens before the Keyboard on/off switch, but MIDI channel 3 happens after (meaning the switch does not affect whether it follows MIDI channel 3), and channel 1 and 3 will sum together, so you could use channel 1 for a sequence, and channel 3 to transpose that, etc.. This could be part of the issue you were having.

Will check this during the weekend. Thanks !
Beside that, I'm having a lot of fun with the Midi possibilities with the Octatrack and CC !

[Carmelo_P82]

Hi while I was trying my new EC (no more wonky knobs or scratches really happy), the pitch of the Modulation Oscillator went really high even it was set to " low / LFO " without any patching or incoming Midi Data. I tried to reproduce it and here is a case when it happens. It looks like this is something related with the Cross Modulation between the Complex and Modulation Oscillators when both range are at max.

Here is the videos :



What do you guys think ? I'm not a mad scientist but is it possible that the waveform gets stucked when cross modulated like that ?

Happy week-end !

[01235813]

Hi while I was trying my new EC (no more wonky knobs or scratches really happy), the pitch of the Modulation Oscillator went really high even it was set to " low / LFO " without any patching or incoming Midi Data. I tried to reproduce it and here is a case when it happens. It looks like this is something related with the Cross Modulation between the Complex and Modulation Oscillators when both range are at max.

Here is the videos :



What do you guys think ? I'm not a mad scientist but is it possible that the waveform gets stucked when cross modulated like that ?

Happy week-end !

I have seen this behavior on a few rare occasions, only when using a USG to cross modulate. After turning the easel off and on it went away.

This never happened when using the CO to modulate to MO. Does this behavior consistently take place?

[Carmelo_P82]

I have to units at home and both acts like that.
To try it, put the Mod Osc switch to low, connect the c.osc audio out to the f.m. in of the Modulation Oscillator. Then put the waveshape of the Complex Oscillator to spike and turn the waveshape fully right. Incrise the f.m in amount to max and play with the frequency of the Modulation Oscillator, at some point, even it is set to low, the high pitch will appear.

I can reverse the situation by changing the waveshape of the CO as you can see on the video.

Looks like part of the design to me