Jordan Electronics - Vico Vibe

Version_6 · Post by **Version_6** » 02 Jul 2012, 00:30

I swapped out diode for a 6v8 Zener and it's still doing the same thing on both boards. I think I may just have to move on to another project until my skill level and depth of knowledge are improved. It's a shame because it seemed like. Good circuit for my basic needs of fooling around on my little 5w combo and not having to remove my g-system from its rack.

LucifersTrip · Post by **LucifersTrip** » 02 Jul 2012, 02:28

I have a working one on the breadboard that I'm tweaking...these voltages may help.

e b c
Q1 - 0 , .1-.5* , .001
Q2 - 0, .55, 1
Diode cathode 6.43V**

*depending on 1M trim
**used 6.6V zener

LucifersTrip · Post by **LucifersTrip** » 02 Jul 2012, 04:36

After experimenting for a while, I have this thing almost exactly how I want it. It really is one of the cooler vintage sounding vibes for such a low parts count.

Firstly, the higher gain 5088's do make it a little brighter. I initially had ones with gains of ~400 in there and swapped em for ones with gains 600+. Though, I tried MPSA18's with gains of 700+ and it didn't sound any better, possibly worse.

Next I wanted it to go faster, so I removed the 3.3K cut off.

Lastly, for me, the trimmer actually had better/stronger effect than the actual depth pot. The trimmer can go from low depth to downright choppy where the depth pot had a much milder effect. Yes, there is a slow volume decrease as it gets choppier and about 50% turn of the trimmer, it's super choppy, then cuts off completely, so the last ~40-50% of the turn is wasted.

I was able to shift the entire sweep of the trimmer into something usable by adding a 1M resistor off the pot. Now I have a perfect sweep from low depth to total chop with no super low volume and no cut off.

The depth pot is no longer needed, so I set it at full.

Here's my final, so far...

LucifersTrip · Post by **LucifersTrip** » 02 Jul 2012, 21:25

Seiche, to comment on a couple things you tried & mentioned.

I tried the LED as you did earlier in the thread and it didn't work... It stayed on with no pulse and effect was lost.

...and I also initially thought that I could slow it down by increasing the 100K rate pot, but that didn't work, either.
As you increase the resistance, the depth just gets lowered until there's no effect...but it doesn't go any slower than what the 100K will do.

Seiche · Post by **Seiche** » 02 Jul 2012, 22:10

LucifersTrip wrote:Seiche, to comment on a couple things you tried & mentioned.
I tried the LED as you did earlier in the thread and it didn't work... It stayed on with no pulse and effect was lost.

Yeah I said that:

Seiche wrote:damn, I think the rate LED doesn't work that way. Somehow when I connected it that way, the LED turned on, but stayed on permanently and the tremolo didn't work anymore (didn't oscillate).

thanks for verifying I'm not stupid.

LucifersTrip wrote:...and I also initially thought that I could slow it down by increasing the 100K rate pot, but that didn't work, either.
As you increase the resistance, the depth just gets lowered until there's no effect...but it doesn't go any slower than what the 100K will do.

hmm, that's too bad. I didn't try that proposed mod, but I built the effect with two pots to switch speeds on the fly, I only had one 100k and a 50k. the 50k has the same fastest setting but the slowest setting is about half rotation on the 100k (which is much faster than the 100k slowest setting obviously). I assumed using a bigger pot value will continue this trend in the other direction but leave the fastest speed unaffected.

LucifersTrip · Post by **LucifersTrip** » 02 Jul 2012, 22:43

Seiche wrote:
LucifersTrip wrote:...and I also initially thought that I could slow it down by increasing the 100K rate pot, but that didn't work, either.
As you increase the resistance, the depth just gets lowered until there's no effect...but it doesn't go any slower than what the 100K will do.
hmm, that's too bad. I didn't try that proposed mod, but I built the effect with two pots to switch speeds on the fly, I only had one 100k and a 50k. the 50k has the same fastest setting but the slowest setting is about half rotation on the 100k (which is much faster than the 100k slowest setting obviously). I assumed using a bigger pot value will continue this trend in the other direction but leave the fastest speed unaffected.

that rate pot is just a variable resistor that goes from 0K (or 3.3K if you leave the cutoff in there) to whatever value pot you have. 0K (3K) is the fastest, so of course, that will stay the same no matter what size pot you use. And I didn't notice any slowdown after 100K, so using a larger pot than that is wasted. A 50K pot won't go as slow as a 100K, of course...

Seiche · Post by **Seiche** » 02 Jul 2012, 22:58

thanks for testing this. I understand the 0k part, don't really know why the 100k won't work. too bad it won't go slower. I simply assumed (like Mark with the LED) that, from my experience with the 50k, upping that pot would make it go slower.

maybe there is an alternative solution?

LucifersTrip · Post by **LucifersTrip** » 03 Jul 2012, 00:35

I was surprised, too, but I'm not a technical guy. I'm sure you can slow it down by altering other part(s) of the circuit...but unless you know what you're doing, you may wind up changing the character.

...I just disconnected the alligators from the breadboard & was ready to solder...maybe I should've experimented longer

mr. microphone · Post by **mr. microphone** » 25 Sep 2012, 16:52

LucifersTrip wrote: Lastly, for me, the trimmer actually had better/stronger effect than the actual depth pot. The trimmer can go from low depth to downright choppy where the depth pot had a much milder effect. Yes, there is a slow volume decrease as it gets choppier and about 50% turn of the trimmer, it's super choppy, then cuts off completely, so the last ~40-50% of the turn is wasted.

I was able to shift the entire sweep of the trimmer into something usable by adding a 1M resistor off the pot. Now I have a perfect sweep from low depth to total chop with no super low volume and no cut off.

The depth pot is no longer needed, so I set it at full.

Hi, I'm new to this stuff (and new to the forum), and I'm wondering if you could lend some insight.

I tried your modification, except instead of turning up the 100K depth pot and using the 1M trimmer to adjust depth, I replaced the 1M trimmer with a 1M linear pot and replaced the 100K pot with a 100K resistor.

When the 1M-l "depth pot" is turned all the way up I experience the "slow volume decrease" problem you mentioned, but I'm not sure why. Would this be a result of using a pot in place of a trimmer? Aren't they basically the same thing?

The volume slowly rolls off to nothing and returns when I switch the circuit off and back on.

Also, I'm using a 100K resistor in place of the 220K resistor that connects to the base of Q1 (didn't have any 220Ks on hand).

Sorry if these seem like dumb questions. I'm still trying to "get my head around" the theory. Many thanks!

LucifersTrip · Post by **LucifersTrip** » 26 Sep 2012, 08:20

mr. microphone wrote:
Hi, I'm new to this stuff (and new to the forum), and I'm wondering if you could lend some insight.

I tried your modification, except instead of turning up the 100K depth pot and using the 1M trimmer to adjust depth, I replaced the 1M trimmer with a 1M linear pot and replaced the 100K pot with a 100K resistor.

When the 1M-l "depth pot" is turned all the way up I experience the "slow volume decrease" problem you mentioned, but I'm not sure why. Would this be a result of using a pot in place of a trimmer? Aren't they basically the same thing?

they are the same thing...only difference is that the trim is usually internal and is small and cheap and solders to the board

did you add the extra 1M resistor on the left side of the pot in my mod?

either way, you will probably get some volume loss as you increase the depth. As the depth increases, you hear the actual guitar less and less...and at full depth you are basically just hearing the effect....so, it makes sense.

Also, I'm using a 100K resistor in place of the 220K resistor that connects to the base of Q1 (didn't have any 220Ks on hand).

that will have some change...maybe overall volume or distortion. just use two 100K's in series for 200K

mr. microphone · Post by **mr. microphone** » 28 Sep 2012, 01:14

did you add the extra 1M resistor on the left side of the pot in my mod?

either way, you will probably get some volume loss as you increase the depth. As the depth increases, you hear the actual guitar less and less...and at full depth you are basically just hearing the effect....so, it makes sense.

Thanks for getting back to me. Indeed, it does make sense after thinking about it.

Yes, the 1M is there. After further investigation it turns out the rate control is the issue. The depth control can go all the way up or down with no problem, but when the rate is set all the way down to slowest oscillation the signal fades out to silence after about 10 or 15 seconds.

Until I can come up with a solution, I may just have to remember not to turn the rate all the way down but that kind of feels like putting tape over the "check engine" light.

There are two more differences that I left out, but I'm not sure if they factor in. One is that I couldn't find a 39K resistor so I'm using a 33K. The other is that I put the 3.3K cut off resistor back in.

Also, thanks for the tip regarding placing two resistors in series. I ended up acquiring some 220K resistors, but that'll come in hand I'm sure.

LucifersTrip · Post by **LucifersTrip** » 28 Sep 2012, 02:39

mr. microphone wrote: Yes, the 1M is there. After further investigation it turns out the rate control is the issue. The depth control can go all the way up or down with no problem, but when the rate is set all the way down to slowest oscillation the signal fades out to silence after about 10 or 15 seconds. Until I can come up with a solution, I may just have to remember not to turn the rate all the way down but that kind of feels like putting tape over the "check engine" light.

that is exactly the problem I had when I tried to slow it down even more with > 100K. remember, the 100K rate is just a variable resistor, so you just have to lower it. measure the pot at the point right before silence, then use this calculator to figure out what resistor to put across lugs 1 & 3 of the 100K pot:
http://diyaudioprojects.com/Technical/E ... ulator.htm

for ex, let's say it goes silent at 80K, then you'd put a 470K across the pot to bring it to 82K

There are two more differences that I left out, but I'm not sure if they factor in. One is that I couldn't find a 39K resistor so I'm using a 33K. The other is that I put the 3.3K cut off resistor back in.

33K should not be a big prob, but I try to get a little closer. removing 3.3K let's you go faster

mr. microphone · Post by **mr. microphone** » 01 Oct 2012, 05:15

that is exactly the problem I had when I tried to slow it down even more with > 100K. remember, the 100K rate is just a variable resistor, so you just have to lower it. measure the pot at the point right before silence, then use this calculator to figure out what resistor to put across lugs 1 & 3 of the 100K pot:
http://diyaudioprojects.com/Technical/E ... ulator.htm

for ex, let's say it goes silent at 80K, then you'd put a 470K across the pot to bring it to 82K

This worked! It was only fading out after 99% or so of the turn, so a 3.3M resistor jumping terminals 1 and 3 of the rate pot fixed it.

Everything seems to be working correctly and I was able to put it together without the 1M trimmer.

This is a great effect and a great mod. Thanks again for your help.

LucifersTrip · Post by **LucifersTrip** » 02 Oct 2012, 04:49

sounds cool...now try it after a thin, buzzy fuzz!

andregarcia57 · Post by **andregarcia57** » 27 Oct 2012, 01:58

Somehow how light LED with effect?

andregarcia57 · Post by **andregarcia57** » 27 Oct 2012, 18:14

Led on Vico Vibe!

thanks GrAmorin
http://www.handmades.com.br

elrengofa · Post by **elrengofa** » 17 Nov 2012, 00:22

if i use 2n3904 instead of the 2n5088 i'll have a volume drop, isnt?
in that case, could i use a booster to up the volume?

elrengofa · Post by **elrengofa** » 17 Nov 2012, 01:00

wich is the function of the dpdt switch in this circuit?

Seiche · Post by **Seiche** » 17 Nov 2012, 15:09

elrengofa wrote:wich is the function of the dpdt switch in this circuit?

to turn the effect on/off. the actual circuit doesn't have true bypass you only use the switch to turn the tremolo effect on or off. A single switch would suffice, but a dpdt can be used if you want an LED indicator.

elrengofa · Post by **elrengofa** » 18 Nov 2012, 15:30

excelent. Here is my version of this circuit, without the spst , made with Eagle, in the rar you have pdf schematic, pdf layout and pdf pcb ready to print.

Jordan Electronics - Vico Vibe [schematic]