Buchla 200X serie 208X build thread

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boops
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Re: Buchla 200X serie 208X build thread

Post by boops » Thu May 06, 2021 3:16 am

It’s true,ive made the pic before ive changed it .The Fm modulation didn’t work with this diode backward.
00A90A14-F3F0-4A92-815E-DF1DEAA57355.png
208X 200X modules serie ,Buchla 200 upgraded viewtopic.php?f=17&t=243688&p=3444875#p3444875
FS :custom buchla 203 style càbinet ,skiff new design,boat ,hardware for diy cabinet ,easel case ,new 1u to 10u to 56u and more. / New 208 buchla card 12 price down atm/
HQ small case buchla psu PCB
viewtopic.php?p=3118393#3118393
viewtopic.php?t=211862&highlight=

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Re: Buchla 200X serie 208X build thread

Post by Radiance2021 » Thu May 06, 2021 1:03 pm

boops wrote:
Thu May 06, 2021 3:16 am
It’s true,ive made the pic before ive changed it .The Fm modulation didn’t work with this diode backward.
00A90A14-F3F0-4A92-815E-DF1DEAA57355.png
So, what are you suggesting here? Should we follow the silk screen or the picture?

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Re: Buchla 200X serie 208X build thread

Post by boops » Thu May 06, 2021 3:04 pm

Radiance2021 wrote:
Thu May 06, 2021 1:03 pm
boops wrote:
Thu May 06, 2021 3:16 am
It’s true,ive made the pic before ive changed it .The Fm modulation didn’t work with this diode backward.
00A90A14-F3F0-4A92-815E-DF1DEAA57355.png
So, what are you suggesting here? Should we follow the silk screen or the picture?
The silkscreen of the pcb ,of course.
208X 200X modules serie ,Buchla 200 upgraded viewtopic.php?f=17&t=243688&p=3444875#p3444875
FS :custom buchla 203 style càbinet ,skiff new design,boat ,hardware for diy cabinet ,easel case ,new 1u to 10u to 56u and more. / New 208 buchla card 12 price down atm/
HQ small case buchla psu PCB
viewtopic.php?p=3118393#3118393
viewtopic.php?t=211862&highlight=

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Re: Buchla 200X serie 208X build thread

Post by Radiance2021 » Fri May 07, 2021 9:47 am

Hey Boops, thanks for your answer.
I just inspected my kit and it seems I'm missing 1 ua 726. The plastic holder is there but it's empty, see picture attached.
I'm sorry I did not check this earlier but I've been suffering from covid and did not have time nor energy to tackle this project...
IMG_0077.JPG

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Re: Buchla 200X serie 208X build thread

Post by steviet » Fri May 07, 2021 2:16 pm

Hope you feel better soon @Radiance2021!
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Re: Buchla 200X serie 208X build thread

Post by Radiance2021 » Sun May 09, 2021 5:27 am

Thanks @Steviet! ...long covid is a bitch :-(

Boops, I'm going to leave this issue unresolved cause I just don't have the energy for it.

However, I do need another ua 726 to finish this project. Is anyone here selling these? Or should I go with the replacement option?
Maybe I should sell my remaining ua726 to fund the replacement...what might be a good price?.. and are people actually buying these since the replacement is so much cheaper ?

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Re: Buchla 200X serie 208X build thread

Post by boops » Sun May 09, 2021 7:45 am

Radiance2021 wrote:
Sun May 09, 2021 5:27 am
Thanks @Steviet! ...long covid is a bitch :-(

Boops, I'm going to leave this issue unresolved cause I just don't have the energy for it.

However, I do need another ua 726 to finish this project. Is anyone here selling these? Or should I go with the replacement option?
Maybe I should sell my remaining ua726 to fund the replacement...what might be a good price?.. and are people actually buying these since the replacement is so much cheaper ?
I was really ill,too the last 2 days.
Pm you,for a free another one,sorry,they were so much parts to manage .
Hope we will feel better,soon
208X 200X modules serie ,Buchla 200 upgraded viewtopic.php?f=17&t=243688&p=3444875#p3444875
FS :custom buchla 203 style càbinet ,skiff new design,boat ,hardware for diy cabinet ,easel case ,new 1u to 10u to 56u and more. / New 208 buchla card 12 price down atm/
HQ small case buchla psu PCB
viewtopic.php?p=3118393#3118393
viewtopic.php?t=211862&highlight=

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Re: Buchla 200X serie 208X build thread

Post by Radiance2021 » Sun May 09, 2021 11:38 am

That's very kind Boops! & sorry to hear from your illness.

Five weeks ago I caught Covid for the second time. I was not very ill like the first time (feb 2020) but somehow I never completely recovered.
Very tired since, not able to do much work. Having a hard time reading schematics and parts lists...no focus.
Hope I'll get my Vaccine soon cause it seems it will cure the so called "Long Covid" symptoms...

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Re: Buchla 200X serie 208X build thread

Post by ikkini » Tue May 11, 2021 12:47 pm

I've found the issue with my sequencer !

I didn't notice this sentence :
'208X card1 only X parts with 2N3904/2N3906 transistors turn them at 180 degrees on the pcb card1 V4'

I reversed the transistors and now the sequencer works perfectly ! :)

Cards 1, 2, 3 and 4 = OK !

Now it's time for cards 5 and 6....

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Re: Buchla 200X serie 208X build thread

Post by ikkini » Tue May 11, 2021 2:56 pm

Ok, new cards, new issue !

I tried the MO to modulate another module, and it works very slooooooooowly. The three different waveforms seem to work.

BUT it doesn't receive frequency input, from the slider or from CV or from the switch from hi to low. It always stays at a very low frequency.

I remember I had to desolder and resolder the Ua726, could it be at the origin of this issue if this component has been damaged during the process ?

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Re: Buchla 200X serie 208X build thread

Post by boops » Tue May 11, 2021 5:43 pm

ikkini wrote:
Tue May 11, 2021 2:56 pm
Ok, new cards, new issue !

I tried the MO to modulate another module, and it works very slooooooooowly. The three different waveforms seem to work.

BUT it doesn't receive frequency input, from the slider or from CV or from the switch from hi to low. It always stays at a very low frequency.

I remember I had to desolder and resolder the Ua726, could it be at the origin of this issue if this component has been damaged during the process ?
You can control the ua726,it’s a matched 2 npn transistors in pin 9/10/1 and 2/3/4+Internal temperature compensation .You can use any npn transistor x2 to test,but check the pinout before.

Try to change the lm301 ,too.
B4FFC20C-68B7-4F1F-8220-BCF153E390FF.png
208X 200X modules serie ,Buchla 200 upgraded viewtopic.php?f=17&t=243688&p=3444875#p3444875
FS :custom buchla 203 style càbinet ,skiff new design,boat ,hardware for diy cabinet ,easel case ,new 1u to 10u to 56u and more. / New 208 buchla card 12 price down atm/
HQ small case buchla psu PCB
viewtopic.php?p=3118393#3118393
viewtopic.php?t=211862&highlight=

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Re: Buchla 200X serie 208X build thread

Post by boops » Wed May 12, 2021 2:30 am

Don’t use the card 5

Use a scope to probe pin 4 ,the MO audio signal .

The ua 726 is used ,indeed in the frequency (pitch )circuit.

I use to install the lpg card 11
And card 12 with only U2 the quad op amp to listen the audio.


Psu/4UX boat mouser basket updated,in the first post ,new external brick available.
208X 200X modules serie ,Buchla 200 upgraded viewtopic.php?f=17&t=243688&p=3444875#p3444875
FS :custom buchla 203 style càbinet ,skiff new design,boat ,hardware for diy cabinet ,easel case ,new 1u to 10u to 56u and more. / New 208 buchla card 12 price down atm/
HQ small case buchla psu PCB
viewtopic.php?p=3118393#3118393
viewtopic.php?t=211862&highlight=

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Re: Buchla 200X serie 208X build thread

Post by Radiance2021 » Sat May 15, 2021 7:26 am

Just received my missing Ua726. Mercie bien Boops!

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Re: Buchla 200X serie 208X build thread

Post by boops » Sun May 16, 2021 4:17 pm

Radiance2021 wrote:
Sat May 15, 2021 7:26 am
Just received my missing Ua726. Mercie bien Boops!
Yes...;) ive received my first vaccine.
208X 200X modules serie ,Buchla 200 upgraded viewtopic.php?f=17&t=243688&p=3444875#p3444875
FS :custom buchla 203 style càbinet ,skiff new design,boat ,hardware for diy cabinet ,easel case ,new 1u to 10u to 56u and more. / New 208 buchla card 12 price down atm/
HQ small case buchla psu PCB
viewtopic.php?p=3118393#3118393
viewtopic.php?t=211862&highlight=

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Re: Buchla 200X serie 208X build thread

Post by Radiance2021 » Mon May 17, 2021 3:17 am

boops wrote:
Sun May 16, 2021 4:17 pm


Yes...;) ive received my first vaccine.
That's great! I just received my invitation. We must be old LOL...

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Re: Buchla 200X serie 208X build thread

Post by boops » Thu Jun 03, 2021 6:26 am

A first version of a 208X build guide ,available in the post 1,a HD file one soon .

https://www.modwiggler.com/forum/viewto ... 7&t=243936
208X 200X modules serie ,Buchla 200 upgraded viewtopic.php?f=17&t=243688&p=3444875#p3444875
FS :custom buchla 203 style càbinet ,skiff new design,boat ,hardware for diy cabinet ,easel case ,new 1u to 10u to 56u and more. / New 208 buchla card 12 price down atm/
HQ small case buchla psu PCB
viewtopic.php?p=3118393#3118393
viewtopic.php?t=211862&highlight=

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Re: Buchla 200X serie 208X build thread

Post by Radiance2021 » Thu Jun 03, 2021 1:36 pm

Thanks Boops, it's a complete project now!

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Re: Buchla 200X serie 208X build thread

Post by Radiance2021 » Thu Jun 03, 2021 1:49 pm

A quick question regarding connecting pin 15 & 16 on card 12.
Why is this necessary? As I understand it, these two grounds (0V and noise Ground as you call these) are connected on the PSU card right?
To also connect them on card 12 kinda defeats the purpose of having two grounds no?

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Re: Buchla 200X serie 208X build thread

Post by boops » Thu Jun 03, 2021 2:57 pm

Radiance2021 wrote:
Thu Jun 03, 2021 1:49 pm
A quick question regarding connecting pin 15 & 16 on card 12.
Why is this necessary? As I understand it, these two grounds (0V and noise Ground as you call these) are connected on the PSU card right?
To also connect them on card 12 kinda defeats the purpose of having two grounds no?
The two grounds have to be shorted,some psus grounds have not them shorted,on the card 12 ,it a good (best)place to do this.
Sometime a cap is added ,too,look the original schematic.
208X 200X modules serie ,Buchla 200 upgraded viewtopic.php?f=17&t=243688&p=3444875#p3444875
FS :custom buchla 203 style càbinet ,skiff new design,boat ,hardware for diy cabinet ,easel case ,new 1u to 10u to 56u and more. / New 208 buchla card 12 price down atm/
HQ small case buchla psu PCB
viewtopic.php?p=3118393#3118393
viewtopic.php?t=211862&highlight=

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Re: Buchla 200X serie 208X build thread

Post by Radiance2021 » Fri Jun 04, 2021 3:07 am

boops wrote:
Thu Jun 03, 2021 2:57 pm


The two grounds have to be shorted,some psus grounds have not them shorted,on the card 12 ,it a good (best)place to do this.
Sometime a cap is added ,too,look the original schematic.
Ah, I see....
Is there a schematic available from the original PSU?

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Re: Buchla 200X serie 208X build thread

Post by boops » Fri Jun 04, 2021 3:08 am

Look at the original card 12 schematic.
208X 200X modules serie ,Buchla 200 upgraded viewtopic.php?f=17&t=243688&p=3444875#p3444875
FS :custom buchla 203 style càbinet ,skiff new design,boat ,hardware for diy cabinet ,easel case ,new 1u to 10u to 56u and more. / New 208 buchla card 12 price down atm/
HQ small case buchla psu PCB
viewtopic.php?p=3118393#3118393
viewtopic.php?t=211862&highlight=

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Re: Buchla 200X serie 208X build thread

Post by Radiance2021 » Fri Jun 04, 2021 4:10 am

boops wrote:
Fri Jun 04, 2021 3:08 am
Look at the original card 12 schematic.
Yes, I've seen the card 12 schematic.
Just wondering if there's a original PSU schematic as well...

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Re: Buchla 200X serie 208X build thread

Post by ikkini » Fri Jun 04, 2021 8:39 am

Hi,

The build guide is almost complete. I did it after the building of the 208X so I couldn't check everything. Moreover, as I'm French, there may be some mistakes.
Don't hesitate to give feedbacks if you use it to improve it.

I will upload an HD version as soon as it is finished (next week I think).

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Re: Buchla 200X serie 208X build thread

Post by Radiance2021 » Fri Jun 04, 2021 2:37 pm

Thanks ikkini!

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Re: Buchla 200X serie 208X build thread

Post by steviet » Fri Jun 04, 2021 3:22 pm

Sounds great ikkini! I will reference it during my build and provide any feedback I can, thanks for doing that.
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