Help needed: Calling all jupiter 4 owners

the19thbear · Joined: Apr 19, 2007 Posts: 103 Location: denmark

Here goes:
If i turn the LFO RATE pot up and down i get no change in LFO speed. If i turn the LFO BEND up and down (the one located left to the LFO rate pot) i get a change in lfo rate, but i have to have the "normal/wide" switch set to "normal" to be able to change the LFO rate.

It seems the LFO RATE is broken somehow, and before i try to fix it, i want to know how this synth is supposed to work.
Is it normal that you can change the LFO rate with the LFO BEND pot?

UPDATE:

Ok. Fixed it. A bad opamp.
And apperently the LFO bend IS in fact for controlling the LFO speed. Have a look at the jupiter 4 demo video from retro sounds on youtube. My J4 behaves the exact same way now.
What about the LFO in general. If i set the LFO to square wave, MEDIUM SPEED, and set the VCO OSC. waveform to OFF, (sub osc OFF too) and th VCF LFO MOD to MAX. do you get clicking from the LFO?
On some synths this is normal, on others it might indicate old caps..

Thanks alot!

the19thbear · Joined: Apr 19, 2007 Posts: 103 Location: denmark

radek tymecki · Joined: Mar 22, 2009 Posts: 70 Location: PL

no it should change amount of modulation

the19thbear · Joined: Apr 19, 2007 Posts: 103 Location: denmark

Thats what i thought.
Thanks a lot!

the19thbear · Joined: Apr 19, 2007 Posts: 103 Location: denmark

Ok. Fixed it. A bad opamp.
And apperently the LFO bend IS in fact for controlling the LFO speed. Have a look at the jupiter 4 demo video from retro sounds on youtube. My J4 behaves the exact same way now.
What about the LFO in general. If i set the LFO to square wave, MEDIUM SPEED, and set the VCO OSC. waveform to OFF, (sub osc OFF too) and th VCF LFO MOD to MAX. do you get clicking from the LFO?
On some synths this is normal, on others it might indicate old caps..

Thanks alot!