DIY Through Hole Jupiter 8 CLone


Wuuuooo. Darf man vorsichtig fragen was an Zeit und Invest ca. geplant ist?

100% Clone oder ein paar kleine Updates hier und dort?
Hallo Jan_B
keine 100% Kopie.
Es gibt ein paar kleine Updates hier und dort.
Die ADSRs werden durch einen Prozessor und einen 14-Bit-DAC ersetzt. Abgesehen davon ähnelt das Voice Board dem Original sowie der Struktur des Blockdiagramms.
Heute habe ich noch keine klare Vorstellung von den Gesamtkosten. Aber ich werde Sie auf dem Weg des Fortschritts informieren.
Es tut mir leid, wenn die deutsche Sprache nicht so richtig ist. Ich verwende Google Translate.
As I am continuously designing in SMD, I've started the voice board in SMD.
But, no worries, a Through hole voice board will come.
Currently the voice board holds 351 components (one will need 8 )
To controll 4 voice boards (4 for upper and 4 for lower) one processor is used.
So we will have 8 voice boards (or two big boards with 4 voices), one processor board with two processors.
All envelope generators for the 8 VCF's and 8 VCO's and 8 ADSR's are real time calculated.
Here's an extention from the original. Calculating the envelope allows for additional shapes (3 additional in this case)
Then we have the User Interface board.
As this already contains many Through Hole rotary and slide potentiometers,
I'm designing this board Through Hole as from start.
Unfortunately, there will be an SMD processor on this PCB as well.

So, for overall complexity, this should not be a first project.
One has to be pretty swift with a soldering iron to make this to a success.

Estimated total of components for now is around 3150.

Before starting this project, I first tried to get the filter built without the original IR3109.
Here's a sound file comparing the bread board filter with the original IR3109 filter.

The next sound file is a comparisson of the original's saw sound and the SMD clone's voice board

The below screen dumps show a comparisson of the original's saw wave and the clone's saw wave for C1 and C4

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Wow... einfach WOW....
Ich habe zwar ein Original, aber so ein gut klingender Clone ist nicht zu verachten.
Roland selbst bringt das ja nicht auf die Reihe....


Leben am Limit
Hi, @Analog Enthousiast.
Thanks alot for your detailed answer.
Over 3.000!
Sounds like a real winter project. :agent:

Due to the fact that SMD soldering isn't easy for some DIYers (also me ;-)): Might it be possible to order the SMD boards pre-soldered? Could you imagine to offer this service?
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Hello all,
here are the answers to your questions.

Hey, does this mean you are creating the VCOs / VCFs digitally?
Or did I misunderstand that sentence.
No, fortunately it doesn't.
VCO's are almost 100 % original jupiter 8, for the VCF I reconstructed the IR3109 with analog parts.
The sound comparisson is in this 'Filter_Compare_6' sound file above.
It's all analog, the only thing digital is the creation of the control voltages for the filters.
The complete audio generation, filter and VCA path is all analog.

I suppose it is OK to post the corresponding Muffwiggler link here, right? :D
Yes, thanks !

Wow... einfach WOW....
Danke !

Due to the fact that SMD soldering isn't easy for some DIYers (also me ;-)): Might it be possible to order the SMD boards pre-soldered? Could you imagine to offer this service?
For DIY I'm planning to foresee both TH and (un)populated SMD PCBs. I will build populated SMD PCBs anyhow for selling the complete assembled product.
Time will tell wich way is the best one to go. But Through Hole will ceretainly be there for the User Control Board and the voice board. The processor board will be SMD by definition.

I'd wish for one of the updates to be velocity...
sssssst, ..... don't tell to anyone, just between us :lol:,
it's already implemented in the VCA controll,
still have to add it to VCF controll.
Hello all,

just to keep you a bit updated about the progress.
The JPTR-8 will provide a stereo audio image with 2 differential XLR Pro-audio outputs build around the THAT 1646 differential drivers and 3 Jack outputs for Left, Right and Mono.
An additional Pro-audio Headset output is also foreseen.
All Jack outputs are independent buffered.
The board contains power supply filtering and has separated analog GND and Chasis GND.
EMC filtering is foreseen on all outputs except the Headset output.
Overvoltage protection on the differential outputs has also been foreseen to protect the drivers agains faulty connection to a mic. input with fantom supply switched on.

Below some renders of the Audio IF board and the MIDI IF board.

Hallo Leute,

hier gibt es wieder eine update, aber im English....

A preliminary picture of the prototype voice boards on the debug board below,
and two sound files using the two Voice Boards.

The second one is a sound scape containing some artifacts and noise in part two,
but pls listen to the sounds and try to avoid listening to the artifacts.

The first file contains some sounds like mentioned in the timestamps I've added.
Enjoy !

Dual notes a quint apart, thus two oscillators per note, and further UNISON, thus four oscillators per note, tuned and slightly detuned.
00.00 dual tones (Quints)
00.34 VCLPF cuttoff variation
00.41 pizicato like attack
01.28 bending VCO (I'm an amateur ;-))
01.58 4 oscillators gently fading to detune
02.10 some nice basses
02.24 LPF attack delay, some string sounds
02.47 some basses
03.06 LPF attack and cutoff modifs
04.02 some more bass
04.28 Pad like bass
04.37 Cello like
Pls let me know what you think.

I'll post a better picture over the next days.