uJOVE, micro version of JUVE multimode filter

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neonmercury1
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Post by neonmercury1 » Fri Sep 13, 2019 4:25 am

HI so i finished my build a little while ago and i have been trying to troubleshoot whats happening to no avail. everything seems to be working properly except the filter circuit. so i can hear audible changes to the input with manipulation of resonance or the other controls but the cutoff freq does nothing. i have reflowed all of the chips and i was wondering about test points to that i can check to see if a chip has been zapped. can anyone recommend where to start?Image

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synthetek
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Post by synthetek » Fri Sep 13, 2019 4:53 am

Have you tried to adjust the trimmers on the bottom?

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neonmercury1
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Post by neonmercury1 » Fri Sep 13, 2019 6:08 pm

synthetek wrote:Have you tried to adjust the trimmers on the bottom?
yes i have and the freq trimmer has no effect. the res trimmer adjusts the res just fine

TL072
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re: level

Post by TL072 » Sat Nov 30, 2019 8:37 am

Before, I get neck deep in trying to troubleshoot a non-existent problem, can anyone else confirm for me whether uJove is a more quiet filter? I did some some troubleshooting, the module seems more be more or less working yet I realised that the output volume is considerably less than my other filter which is Ripples.

Looking at the schematic, I have a feeling that if there is an issue it will be in respect to either the output amplification or the input amplification.

Many thanks for any suggestions!

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Re:

Post by yusufkeys » Fri Feb 21, 2020 3:07 pm

neonmercury1 wrote:
Thu Apr 11, 2019 2:17 pm
Silver wrote:Anyone have a mouser cart set up for this? Thanks
i just placed a mouser order and im pretty sure its all correct and there but of course it would be best to check and make sure. but here is the mouser project.

https://www.mouser.com/ProjectManager/P ... 71683d176d
Just a heads up this order is missing the TL072s...

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hndmrsh
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Re: Re:

Post by hndmrsh » Fri Feb 28, 2020 3:51 am

yusufkeys wrote:
Fri Feb 21, 2020 3:07 pm
neonmercury1 wrote:
Thu Apr 11, 2019 2:17 pm
Silver wrote:Anyone have a mouser cart set up for this? Thanks
i just placed a mouser order and im pretty sure its all correct and there but of course it would be best to check and make sure. but here is the mouser project.

https://www.mouser.com/ProjectManager/P ... 71683d176d
Just a heads up this order is missing the TL072s...
Yep, the linked Mouser cart is for v1.0/v1.1 boards - it's missing the two TL072s, has an extra TL074 that's no longer needed, and is missing two 100nF caps.

I've updated the project here: https://www.mouser.com/ProjectManager/P ... 3dcbb65686. Note that I haven't updated the customer codes, so they won't match the board correctly - use the interactive BOM instead!

skautkurt
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Re: uJOVE, micro version of JUVE multimode filter

Post by skautkurt » Sun Mar 08, 2020 10:47 am

Hi,
I just finished building a uJove v1.0 with the fix, but I have a slight problem understanding the calibration process, this part in particular:
The resonance trimmer is used to ensure that there is minimum resonance when the resonance knob is fully CCW. Set the frequency knob at about 12 o’clock and look for a resonance peak on the square wave in 12 dB mode using an oscilloscope. Adjust the input gain so that the output square wave is 10 Vpp. Then use VR7 to to trim away the resonance peak so that the square wave is flat.
Does is mean I should have an amplifier before the input of the uJove so I can amplify the squarewave? Or how do I adjust the input Gain? My oscilloscope only shows a P2P of ca. 3v at the mentioned settings.

But nontheless a quite fun build, and from what I heard from my uncalibrated module a fantastic sounding filter.

cheers

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miqraw
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Re: uJOVE, micro version of JUVE multimode filter

Post by miqraw » Mon Mar 09, 2020 5:04 am

My uJOVE is very quiet at input and loud(and noisy) at the output. Which resistor to replace to increase the input sensitivity?

skautkurt
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Re: uJOVE, micro version of JUVE multimode filter

Post by skautkurt » Mon Mar 09, 2020 10:49 am

skautkurt wrote:
Sun Mar 08, 2020 10:47 am
Hi,
I just finished building a uJove v1.0 with the fix, but I have a slight problem understanding the calibration process, this part in particular:
The resonance trimmer is used to ensure that there is minimum resonance when the resonance knob is fully CCW. Set the frequency knob at about 12 o’clock and look for a resonance peak on the square wave in 12 dB mode using an oscilloscope. Adjust the input gain so that the output square wave is 10 Vpp. Then use VR7 to to trim away the resonance peak so that the square wave is flat.
Does is mean I should have an amplifier before the input of the uJove so I can amplify the squarewave? Or how do I adjust the input Gain? My oscilloscope only shows a P2P of ca. 3v at the mentioned settings.

But nontheless a quite fun build, and from what I heard from my uncalibrated module a fantastic sounding filter.

cheers
Just some fault on my board, one leg of U2 wasn't connected correctly. Reflowed it, now everything works :)

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Re: uJOVE, micro version of JUVE multimode filter

Post by mrerdat » Wed May 20, 2020 4:36 pm

Finally had the time to install the fix boards in my pair of 1.0 uJoves. This is an absolutely essential fix imo. Its noise floor is dead quiet compared to before making it so much more fun to use without the bleed now, not to mention I can finally hear clean sub bass. Just had the realization of how much that bleed steered me into using cleaner filters that would close all the way for a lot of situations, but I don't have to worry about that anymore.

The improvement in sound quality is actually better than I expected!

TL072
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Re: uJOVE, micro version of JUVE multimode filter

Post by TL072 » Sat Jun 06, 2020 2:40 pm

mrerdat wrote:
Wed May 20, 2020 4:36 pm
Finally had the time to install the fix boards in my pair of 1.0 uJoves. This is an absolutely essential fix imo. Its noise floor is dead quiet compared to before making it so much more fun to use without the bleed now, not to mention I can finally hear clean sub bass. Just had the realization of how much that bleed steered me into using cleaner filters that would close all the way for a lot of situations, but I don't have to worry about that anymore.

The improvement in sound quality is actually better than I expected!
Can you describe what the problem sounds like? I ordered the fix pcb along with some other things recently because I suspect it is an issue on my board (pcb board v1) but I was having more serious problems with the build which I think I have mostly fixed, however I am not sure if the remaining problems relate to "the bleed problem" or something else I need to fix.

I basically have some high frequency noise if I open the low-pass filters up fully and/or it is there on the high-pass filters. I was also getting a low level hum before I played with the filter trimmer. Does that sound like the same issue?
Last edited by TL072 on Sat Jun 06, 2020 4:05 pm, edited 2 times in total.

mrerdat
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Re: uJOVE, micro version of JUVE multimode filter

Post by mrerdat » Sat Jun 06, 2020 3:01 pm

TL072 wrote:
Sat Jun 06, 2020 2:40 pm
Can you describe what the problem sounds like?
The bleed problem is basically if you try to close the filter all the way (any mode), you'll still hear a quiet "copy" of the unfiltered signal underneath.

It's not a hum, but maybe what you're hearing as noise could possibly be the unfiltered bleed layered on top of the filtered audio.

TL072
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Re: uJOVE, micro version of JUVE multimode filter

Post by TL072 » Sat Jun 06, 2020 4:07 pm

Going through the calibration process seems to I think to have fixed the high pitch noise but many thanks for explaining. Will keep an ear out. Sometimes in the excitement of fixing something, I have found my brain edits out problems with a module which I later hear!

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Re: uJOVE, micro version of JUVE multimode filter

Post by shiddyunzo » Thu Jun 25, 2020 12:55 pm

i got mine from a builder in germany (i am based in berlin)

i have quite strong noise problems with it (strong hum, large noisefloor). two examples (direct input into my soundcard - unity gain)

1. fully open lowpass
2. fully closed lowpass

its the uJove v1.0

I dont know if this is the same behaviour which can be fixed with the extra pcb ...
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TL072
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Re: uJOVE, micro version of JUVE multimode filter

Post by TL072 » Tue Jun 30, 2020 4:43 pm

shiddyunzo wrote:
Thu Jun 25, 2020 12:55 pm
i got mine from a builder in germany (i am based in berlin)

i have quite strong noise problems with it (strong hum, large noisefloor). two examples (direct input into my soundcard - unity gain)

1. fully open lowpass
2. fully closed lowpass

its the uJove v1.0

I dont know if this is the same behaviour which can be fixed with the extra pcb ...
I also have a lot of noise but I think it is on the input itself because when I close the low pass filter, I hear it filtering it down. I was able fix another noise problem on a module testing it on a small linear power supply. I am using a switching one. If it fixes things I will mention it here.

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