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Projects => Tech Help - Projects Page => Topic started by: pk1802 on May 11, 2013, 03:14:07 AM

Title: Current Lover - Noise
Post by: pk1802 on May 11, 2013, 03:14:07 AM
Hello gentlemen,

I've built myself up a Current Lover with a MN3007 running at 15v with a tl1054 roadrage(pulled pin 1). I've used both a switching supply(like the godlyke powerall) and a transformer based supply.

I am getting a lot of lfo noise. I am getting modulation, so that is nice, but the noise makes it unusable. MN3007 is good, I tested it in my Collosalus. I've adjusted the trimmers multiple times, no help. Is there a quick fix like on the Collosalus where I can just swap out some diodes and be done with it? or do I need to do more hunting? I can post IC voltages if need be.

Thanks
Title: Re: Current Lover - Noise
Post by: marauder on May 11, 2013, 06:30:03 PM
Are you running it out of an enclosure?

Its very noisy out of the box, and ths results in it being hard to set the trimmers.

Title: Re: Current Lover - Noise
Post by: pk1802 on May 11, 2013, 11:31:08 PM
Quote from: marauder on May 11, 2013, 06:30:03 PM
Are you running it out of an enclosure?

Its very noisy out of the box, and ths results in it being hard to set the trimmers.


Thanks for the help - I rocked it before I boxed it, I figured the noise was from it not being in an enclosure, so into a box it went. It's inside an enclosure now, jacks are grounded to the enclosure. I've tried lid on, and lid off, no good either way.

I'm going to post my IC voltages here: My multimeter is trash, some readings jump around, others stay steady. I can re-read if something looks fishy.

Input voltage: Steady 9.4v

LT1054:
3.58
6.17
0
-2.9
-3
2.37
.68
9.4

L7815CV:
17.2
0
14.9

IC1:
7.48
7.48
3.75
0
6.79
7.47
7.45
14.85

IC2 MN3007:
14.85
Varies 6.6-7.3
4.9
0
0
6.9-7.3
3.6-3.9
3.7-3.8

IC3:
14.6-14.8
6.8-7.2
6.4-7.3
6.2-7.2
7.0-7.3
6.9-7.3
6.9-7.3
0
6.3-7.2
6.4-7.3
6.5-7.3
6.9-7.2
0
6.5-7.3
6.3-7.2
0

IC4:
6.3-7.2
7.0-7.3
9.9-13.1
0
7.1-7.3
0
0
0
0
0
0
0
14.8
14.8

IC5:
7.46
7.46
6.7
14.8
1.6-2.9
1.6-3
1.6-6.5
.6-13.5
6.5-6.8
4.0-9.2
0
6.7
6.7
4.7-6.8

IC6
0
1.66-5
1.8-4.2
0
14.84
14.84
10-13.7
14.7-14.84

Again, you are all awesome.
Title: Re: Re: Current Lover - Noise
Post by: jimilee on May 12, 2013, 01:47:31 AM
Some readings are suppose to just one around, I believe that's the lfo working. I have nothing else to offer as far as a solution goes though, sorry.
Title: Re: Re: Current Lover - Noise
Post by: pk1802 on May 12, 2013, 05:32:30 AM
Quote from: jimilee on May 12, 2013, 01:47:31 AM
Some readings are suppose to just one around, I believe that's the lfo working. I have nothing else to offer as far as a solution goes though, sorry.

Haha, I made the educated guess that the jumping numbers were the lfo running, but that doesn't change the fact that my meter is trash. :) It was $3 at harbor freight - you get what you pay for...

Anyone have any word on whether a diode and cap swap like on the Collosalus will solve this problem?
Title: Re: Current Lover - Noise
Post by: pk1802 on May 12, 2013, 08:13:21 AM
Well gents,

Going from the fix for the Collosalus, I swapped C6 on the Road Rage out from 10uf to 100uf. It fixed the noise at "sleeping family" volume, so I will see what happens tomorrow morning when I kick up the volume.
Title: Re: Current Lover - Noise
Post by: pk1802 on May 13, 2013, 11:58:52 PM
Well, the cap swap made it better, but it's still not usable at gigging levels. Any other ideas?
Title: Re: Current Lover - Noise
Post by: pk1802 on May 16, 2013, 04:50:52 PM
I switched out the charge pump from the LT1054 to a 7660(connected pin 1&8).
(Is the current draw of the Current lover too much for the 7660?)
Now, I have no more sweep noise, but now I have another problem.

I'm getting a repeating pop that keeps in time with the rate knob. If I increase the rate, the popping gets faster, and if I decrease it, the popping gets slower.

I'm going to switch C6 on the road rage back to 10uf to see if that helps.

Any other ideas?