[Build Thread] Jasper, an EDP Wasp Clone

[Very Little Fun]

And even if you have never even seen a soldering iron before, it's always always better to diy than even consider getting all stinky with Behringer shit

TRUTH!

[thejo]

Hello

I've just finished building the Jasper. It's all working beautifully. What a rave monster. So much fun. Anyway my question is I've got some hum going on. It's definitely not coming from the oscillators or any modulation source. Mainly 100hz fairly low level. -60. Photo of spectrum attached. Is this integral to the circuit or can it be fixed?

I appreciate any help.
Regards
Jo

[Attis]

Hello!
I have soldered everything and got 5v on IC sockets first but the LED lamp did not light up. I put the ICs in to test but nothing. I still had to remove the LED and resolder a new one because I put it flat on the circuit board instead of the height of the panel. I removed ICs again.

I had some trouble removing the LED and one of the little metal ring on the circuit board on the underside came loose. I soldered a new LED and connected to power but suddenly got 8v+ on IC sockets. As if the Voltage regulator (IC13) no longer did it´s job.

At the moment I get power on the LED poles but still no light and all IC sockets show too high volts (8+).

I am a complete beginner in troubleshooting but I replaced the voltage controller (IC13) with no effect.
What can be the fault and how should I measure to find it? Please explain as if I were 7 years old

Thanks

[cnicht]

Hello

I've just finished building the Jasper. It's all working beautifully. What a rave monster. So much fun. Anyway my question is I've got some hum going on. It's definitely not coming from the oscillators or any modulation source. Mainly 100hz fairly low level. -60. Photo of spectrum attached. Is this integral to the circuit or can it be fixed?

I appreciate any help.
Regards
Jo

It seems related to the power supply your using as it's twice mains frequency (assuming it's 50Hz)

Try a different/better power supply.

[Attis]

It seems related to the power supply your using as it's twice mains frequency (assuming it's 50Hz)

Try a different/better power supply.

Power supply is 9V DC 1300 mA - 50 ~ 60 Hz.

I did a test with 12v batteries also... Higher volt readings (see image), no voltage regulation (same error).

Could this small metal ring that came loose on one of the LED poles mess things up? Or will it just result in the LED not working as it should?

Regards

[cnicht]

The voltage regulator or associated components seem to be faulty to give that voltage.

[Attis]

The voltage regulator or associated components seem to be faulty to give that voltage.

But I have already replaced the voltage regulator an I still get the same result. Same goes for the diode (D8 I think). I checked all components related to the power. Capacitors have correct value and orientation. I've measuered them and they seem to be ok. No short circuits.

[cnicht]

Make sure all the ground connections are continuous

[thejo]

Hello

I've just finished building the Jasper. It's all working beautifully. What a rave monster. So much fun. Anyway my question is I've got some hum going on. It's definitely not coming from the oscillators or any modulation source. Mainly 100hz fairly low level. -60. Photo of spectrum attached. Is this integral to the circuit or can it be fixed?

I appreciate any help.
Regards
Jo

It seems related to the power supply your using as it's twice mains frequency (assuming it's 50Hz)

Try a different/better power supply.

I've tried a few different power supplies. No change.

[cnicht]

It may be an artefact of the voltage regulator.

[thejo]

It may be an artefact of the voltage regulator.

Ok cool, if I replaced the voltage regulator might that fix it? If so would I use the same value or different value regulator?

Thanks for the help!

[cnicht]

Replacing the regulator, unless it’s damaged, may not help.

Check the components around it.

[elmo2k]

Hey folks,
i finished my first JasperSynth and it was an very awesome experience.
Definitely not my last DIY SYNTH and maybe not my last JasperSynth.

But i have a huge problem with the keyboard sensitivity.
If i plug the power supply (12V / 1500mA) in a single socket without any other device, everythings works fine, super nice sound and normal accuracy from the keyboard.
But if i plug the power supply in a power strip with other devices (notebook charger etc.) the Keyboard randomly triggers different notes when i press the C0 and C0# keys. If i touch a GND spot, everything is instantly fine.

I used the thread search and found several posts about exactly the same problem, but i cant find a solution that works for me.
The IC´s have 5,01v and working GND. I resoldered all Sockets but the problem still there.

Also i tryed different power supply 12V/1500 mA, 9V/900mA but the probem is the same.

Does anyone know what i can do?


Thx
Matt

[Altitude909]

So im back to build another jasper. That new case was too hard pass up, so #2.

Has anyone tried using 3080s for the filter? I'm thinking about just making an adapter to use those instead of the 13700, it looks like it should be a simple drop in deal

[spacekid71]

I have built my Jasper 2016 and it is making sound but the attack and decay dont seem to work. It is just droning continuously.

Any idea what I might be missing?

[Techman]

I have built my Jasper 2016 and it is making sound but the attack and decay dont seem to work. It is just droning continuously.

Any idea what I might be missing?

Have you got the VCA Env. hold switch on?

[carynrich]

a few things came up with my build that might be causing some issues. just some thoughts.

1. I was also getting a hum, and found out that there was a splatter of solder that was connecting the circuit to ground. that's never happened to me before, but I guess I was being careless. it may be as simple as inspecting the board carefully to locate the source of the ground.

2. if the touch keyboard is bent or warped in any way, the envelopes don't trigger correctly. this would happen every time I screwed the PCB onto the case. a solution was to put a thin plastic washer below the right side of the keyboard and it seemed to relieve the tension/warping of the PCB. the envelopes worked fine after that.

[Donpepperoni]

I'm having a few issues with my Jasper and I hope someone here can help me get to the bottom of it? I've read the 33 pages of this thread but the ideas I had from posts of other people's issues didn't seem to help unfortunately.

Immediately after building, the Jasper was working great but when I put the front panel on I started having an issue with the keyboard, it plays the same octave twice from C sharp to C sharp. The bottom C plays something very erratic and low in pitch.

I tried a few things like swapping some of the IC chips that are duplicates, inspecting all solder joints which seem good. I checked there were no shorts on the ribbon cable and inspected the cables for punctures from sharp solder points. I put some electrical tape under just to make sure. I checked the voltage of my 12V wall wart supply and it was a bit out, 14.1V. I swapped it for another 12V which read 13.4V. Then I tried a 5V supply and although the synth worked the keyboard sensitivity was way out but crucially, still the same thing on the scaling.

One thing I noticed is that there is continuity between -V and G on the pcb, does that suggest a short somewhere?

I'm kind of reaching the limit of my skills but I wondered if someone who knows a bit more would be willing to explain a bit how the circuit works from keyboard touchpad to the pitch cv to the VCO? Hopefully that would help me to try a bit of troubleshooting in that area? I look at the schematics and understand the component symbols and understand very vaguely but think I need a bit of help... How does the keyboard work, is it some kind of octave divider? What section of the schematics should I be looking at?

I appreciate anyone who has a little time to answer, all the best folks!

[Donpepperoni]

Just to expand a bit on my last post about the keyboard playing the same octave twice, I've just booted up the Jasper midi card and I'm having the same issue over midi. :(

I read a bit more about the functionality of the original wasp and it says the following on the attached screenshot:

Screen Shot 2020-03-16 at 00.10.43.png

I don't fully grasp the concept but would I be correct to assume IC30 could be the culprit?

I'm finding it a bit tricky to compare the two schematics but can I ask if IC30 on the old wasp schematics is the same equivalent as on the Jasper IC30? (CD40174)
Unfortunately I don't have a second one to try so it'd be good to know I'm barking up the right tree?

Thanks again!

[Donpepperoni]

IC30 was the culprit, I got everything working by changing it. I suspect I might have shorted it with something metal on my workspace while testing with the back off the synth....

[makhho]

So im back to build another jasper. That new case was too hard pass up, so #2.

Has anyone tried using 3080s for the filter? I'm thinking about just making an adapter to use those instead of the 13700, it looks like it should be a simple drop in deal

Which new case did you acquire?

[Altitude909]

the newer clockout. I do have the adapters ready and it looks like there will be all sorts of time coming up

[makhho]

the newer clockout. I do have the adapters ready and it looks like there will be all sorts of time coming up

I initially 3D printed parts for my jasper case and the Jasper worked flawlessly up until I tried to swap into a clockout case.
My jasper started shorting out, and I tried using electrical tape on the powder coated surface to try and isolate the contact issue region, but I've had no luck trying to figure out what is causing the shorting.

Let me know if your jasper functions properly after enclosing it in the clockout case.

I haven't seen anyone post about their assembled jasper in a clockout case yet, so hopefully yours is functioning?

[mangros]

Mine is from the last batch of cases - working well.

90673089_214965749743432_7121917527963659408_n.jpg

The only issue I have with the case is that the keyboard edge screws seem slightly narrower than the Jasper board so if I tighten them there is a slight bow upwards. Might enlarge the holes on the PCB at some point.

[grizzle]

I have the same issues. The VCA and envelop don't trigger correctly and the keyboard sensitivity goes bonkers when it is in the case. My Jasper worked flawlessly until I put it in the case. I tried messaging the makers of the case on the platforms I ordered through and they just stopped responding unfortunately. I was confused regarding exact case, sorry. I have a psycho case.

the newer clockout. I do have the adapters ready and it looks like there will be all sorts of time coming up

I initially 3D printed parts for my jasper case and the Jasper worked flawlessly up until I tried to swap into a clockout case.
My jasper started shorting out, and I tried using electrical tape on the powder coated surface to try and isolate the contact issue region, but I've had no luck trying to figure out what is causing the shorting.

Let me know if your jasper functions properly after enclosing it in the clockout case.

I haven't seen anyone post about their assembled jasper in a clockout case yet, so hopefully yours is functioning?