For PCB version PVPA20’1 : invert polarity of C8 (4µ7) for best results.
The display has a tendency to behave strangely, dots apearing where they shouldn’t and so forth. Stabilising the PIC circuit with a 100 nF condenser between GND and VCC solves the problem.
Best Regards
Jakob Caspersen
hello,
i have a question:is there a standard ‘‘tone’’ u use to check performence?
for example: a sinus-tone , 1.000 Hertz, at 0 dB.
thank u.
dennis buijs.
If you have a generator, you can test your unit in this way.
hi,
I got and solderet a K8098 too.
Now I got one Erratum and one problem.
The Erratum is that the wiring of sk1 doesn’t fit the manual shipped wih it. On the bord it reads 1 - gnd 2 + 12V 3 gnd 4 SIG.
If you use the plug for sk1 shipped with the kit that results in 3 (gnd) = red 4 (SIG) = brown 1 (GND) = yellow 2 (+12V) = orange. The manual however reads that red is +12V and brown is -12V/GND and the other two is SIG and GND.
So if I connect it as i reads on the board (i.e. pin 1 (yellow) to -12V and pin 2 (orange) to +12V my K8098 starts. I can switch the modes and settings all correctly. It displays any of them correct.
My next step was t o connect an audio signal to pin 3 and 4. So I connected an output of my cd player to these. SIGnal to pin 4 and the GND to pin 3 as written on the board.
However…nothin is displayed all I get is empty scales for each mode but nothing is in there as if the K8098 doesn’t get the input at all. Now my question is what can be the reason for this? I mean the K8098 has only a few parts and its allmost impossible to solder them wrong (resistors and cermaic condensors don’t care about polarity) and for the electrolytic condensors the board shows correct polarity (double checked before soldering them). ICs are in the right way (wouldn’t do anything if the pic were mounted vice versa I guess). C12/C13 and X1 are not used according to manual (no parts shipped for those anyways).
What I didn’t do is soldering C8 in reverse as said above. Could that be the problem?
Do you have any suggestions?
greets
Sebastian
I am at a loss to why connecting c8 backwards would make this work better? if it a question on a negative going signal with respect to ground, would not a non polarized capacitor work better or am i missing something? I just built my kit it seems a year after this post and there was an error that was possibly corrected ?
Please read carefully: this errata is for PCB version PVPA20’1 only.
Most likely, you have PVPA20’2. Check your PCB version #
In this version, the polarity of the cap. has been inverted on the PCB, so no need to mount the cap. inverted.
Today i’m gonna start building this kit. I’m a little bit disapointed that there is a little scratch on the upper side of the lcd. Althoug Velleman clearly secured the lcd. So You can’t help this.
Argh maybe I just forget about the scratch. Our local dealer had just one in stock and otherwise I have to wait longer.
I bought it in Hasselt.
Looking forward to make a nice project with it…just like the pre amplifier.
I share projects and things on CIRCUITSONLINE. username Offie.
A firm out of the USA sended me 2 cases…i’m gonna take a look what is possible.
update. Still doing the soldering…beautifull parts. Very perfect fit and a nice PCB!!! Keep up doing the great work Velleman.
Sorry for the scratch.
If you return the item, we are willing to exchange it.
no worries…things can happen. Overall who don’t knows it will not see it. But thank you very much for this nice proposal!
Ps.: the kit works like a charm. Now I’m looking for building it inot something nice for giving it an extra good finish.
A beautifull kit!