Another Completed Neovibe

[skaszyk]

Just finished a Neovibe build and thought I'd share some pix, sound samples, lessons learned and maybe get some advice on improving it.

I used a GGG board and the parts listed in the PDF there. The parts list, however, is not specific for some parts so I'll share links to the ones I used:

• Power jack - http://www.smallbearelec.com/Detail.bok?no=616 (would have preferred a round jack, this one is rectangular which made it more difficult to mount)
• Transformer - http://www.smallbearelec.com/Detail.bok?no=781 (24 Volt DC/100 ma)
• Lamp bulb - http://www.radioshack.com/product/index.jsp?productId=2102815 (removed long leads and wrapper from bottom to expose the short leads)
• DPDT switch - http://www.mouser.com/Search/ProductDetail.aspx?R=316-PPvirtualkey69100000virtualkey691-316-PP

For the transistors, I used all 2N5088s, except for Q13 (2N3904). I also did the volume drop mod mentioned in the PDF (R9=3.6k and R8=910).

I used an old Crybaby Wah shell for the enclosure, used a dremel to remove the original PCB mounts and to cut a hole for the power jack. I used a large piece of velcro to secure the Neovibe board inside (not optimal but forgot to order standoffs and didn't want to pay shipping for $1.20 in parts). Overall, this worked out well but led to some disappointment. Initially, I used this dual audio pot:

http://www.mouser.com/Search/ProductDetail.aspx?R=RV24BF-10-15R1-A100Kvirtualkey14860000virtualkey313-2420F-100K

but found that the speed control was crowded toward one end of the pot making the Wah kind of useless. Per the PDF, I switched this to a dual stereo pot:

http://www.radioshack.com/product/index.jsp?productId=2062359

However, this had the same exact issue and didn't sound as good. So, I replaced it with the first pot and did my best to tweak the mechanism that turns the pot so that I could get SOME speed control (although I still have very little - about a 1/3 of a turn at most). Any suggestions on increasing the sweep in a Wah setup would be greatly appreciated (seems like there may be some suggestions already on the forum, but I'm a newbie and don't understand a lot of it). While searching this forum for a solution I found that someone else came to the conclusion that using the wah to control the depth might make more sense. I may try this.

Another "issue" I had was in biasing the lamp. With the trim pot turned all the way down, the light was still on beyond an "orange glow". So, I basically had to keep it at its lowest setting to avoid getting any distortion. I was expecting the lamp to shut off at some point in the trim, but this wasn't the case. I would have liked to have had more control over this. Again, any suggestions?

I made the light shield from an Altoids canister and installed the LDRs not-quite-flush with the board (wasn't sure if I was going to come back and mess with them and didn't want to cut the leads too short-- so they're about an 1/8 inch off the board).

Overall, I'm happy with the end result. Once I've had a chance to enjoy it a bit, I'd like to go back and try understanding more about the mods mentioned on this forum to see if I can get more range out of each of the settings.

Thanks to R.G. and all those that posted Neovibe questions/answers. This is my third GGG build (loop switch and ITS8 were my first two) and was much more challenging but just as rewarding. Having your knowledge and experience to turn to helped me gain the courage to try this project in the first place. I would recommend anyone just starting this build thoroughly review the posts on this forum before even starting (especially before sourcing parts).

Here are a couple of sound clips (strat through Neovibe to computer)...

• Speed set as high as it goes (wah rocked to the heal): Neovibe_fast.mp3
• Speed set lower: Neovibe_slow.mp3

Here are some pictures...

(fyi, speed pot is wired incorrectly in this first one -- missed the left most bottom post -- the wiring diagram is unclear but the schematic shows it correctly)

[John Lyons]

Looks nice! Good job.

[tackleberry]

The part you linked to is for an audio pot which would jam everything up on 1 end same with the radio shack stereo vol control. The data sheet had a part # for a linear pot. Ive been meaning to make 1 of these as I have 3 empty dunlop housings under my bench. Its on my list but I have a rule I have to finish a project before I can start another 1. Other wise I end up with a confusing pile of parts scattered around and projects that never get done.

[trixdropd]

I'm digging the sound of that thing....How much did you invest to see it come to life?

[Eb7+9]

the cry-Vibe arrangement has one potential problem in that it needs stretching out of the std speed pot response ...
there's an optical solution to this that works well but it involves including a separate board and matching of two opto-couplers

the circuit snippet can be found at my Univibe Maximizer page

[skaszyk]

The part you linked to is for an audio pot which would jam everything up on 1 end same with the radio shack stereo vol control. The data sheet had a part # for a linear pot. Ive been meaning to make 1 of these as I have 3 empty dunlop housings under my bench. Its on my list but I have a rule I have to finish a project before I can start another 1. Other wise I end up with a confusing pile of parts scattered around and projects that never get done.

Thanks tackleberry, I'll try the linear pot and see what happens.

[skaszyk]

I'm digging the sound of that thing....How much did you invest to see it come to life?

I'm not sure. I'll pull the numbers together later and post it. Good question.

[tackleberry]

Theres a good write up on the univibe on geofex. It says for a panel mount pot you want to use a reverse log taper dual pot, not sure how easy 1 would be to find. And I read on another write up somewhere that there is an issue w getting enough range using a crybaby as there isnt enough travel on the pedal for full pot rotation. The geofex article also tells how important it is to match your jfets for the LDRs. And this site, http://www.lynx.bc.ca/~jc/pedals.html, has some good info on improving the design.

[skaszyk]

the cry-Vibe arrangement has one potential problem in that it needs stretching out of the std speed pot response ...
there's an optical solution to this that works well but it involves including a separate board and matching of two opto-couplers

the circuit snippet can be found at my Univibe Maximizer page

Thanks Eb7+9. I had checked out your page previously but hadn't read as much as I should have (too busy admiring the pictures/sound clips).

Univibe Speed Controller Mods
For some time now I've been messin' with a simple single-pot opto control circuit that replaces the dual pot and matches well with the limited (2/3 rotation) pot travel in a cry-baby against the speed range of the Univibe oscillator ... it uses a standard 100k wah pot for control - I will be drawing this up shortly ...

I didn't see the drawing on your site. Where does the "opto" part come in? Do you know if there's room for this second board in the crybaby?

[skaszyk]

Here are the costs (not including the basic tools, etc. you'll need anyway):



 
 
 
 
 
 
 
 


 

Store	Items	Cost
Lowes	drill bit, velcro	$7.11
Radio Shack in store	pot	$3.74
Small Bear	power supply, ldrs, jacks	$38.80
Radio Shack in store	lamp	$1.60
Radio Shack Express	pot, spst	$6.40
Mouser	caps, res, toggles, etc.	$53.33
General Guitar Gadgets	PCB	$22.50
	Total:	$133.48

[R.G.]

Some notes on the Neovibe.

I seem to remember that the rack and pinion in a stock wah pedal rotates the pot reverse to normal, so that a 100K dual audio taper is running fastest at toe down. Check that before you jump in. Small Bear has dual reverse log 100Ks in stock if my memory is faulty.

Geo has a trick for using a single pot for speed control of the Neo and other phase shift LFOs - seehttp://geofex.com/circuits/ldrlfo.htm. It's flexible enough to use only a section of the stock wah pot with a little judicious application of current limiting resistors.

Here are the costs (not including the basic tools, etc. you'll need anyway):
Total: $133.48

It's funny how things stay the same. Here's a quote from the first Guitar Effects FAQ, from before there was a world wide web internet:

Effects Economics 101
... Notice that the electronics that do the work are only 1/3 to 1/10 of the cost of the finished article.

The stuff other than the effects electronics are almost always the biggest hunk of the cost.

Something I've been messing with is a Neovibe PCB specifically set up to mount on the mounting bosses of the Crybaby rocker. It bolts to the existing holes and integrates essentially all the 'vibe tricks I've come up with over the years; the forumvibe has caught up with most of them, but I think the packaging is still a little unique. Unfortunately, getting all that in the space of a crybaby mount requires standing resistors on end, but that's easy with a PCB.

[trixdropd]

Here are the costs (not including the basic tools, etc. you'll need anyway):



 
 
 
 
 
 
 
 


 

Store	Items	Cost
Lowes	drill bit, velcro	$7.11
Radio Shack in store	pot	$3.74
Small Bear	power supply, ldrs, jacks	$38.80
Radio Shack in store	lamp	$1.60
Radio Shack Express	pot, spst	$6.40
Mouser	caps, res, toggles, etc.	$53.33
General Guitar Gadgets	PCB	$22.50
	Total:	$133.48

Thanks... That give's me a good round number to think of when considering this. It sounds great though, so I'm gassing...

[Jaicen_solo]

Something I've been messing with is a Neovibe PCB specifically set up to mount on the mounting bosses of the Crybaby rocker. It bolts to the existing holes and integrates essentially all the 'vibe tricks I've come up with over the years; the forumvibe has caught up with most of them, but I think the packaging is still a little unique. Unfortunately, getting all that in the space of a crybaby mount requires standing resistors on end, but that's easy with a PCB.

Don't suppose you're planning on releasing that are you? How about selling me a  PCB

[zeeman]

• Speed set lower: Neovibe_slow.mp3

Well, I'm standing here... 

zeeman

[R.G.]

Something I've been messing with is a Neovibe PCB specifically set up to mount on the mounting bosses of the Crybaby rocker. It bolts to the existing holes and integrates essentially all the 'vibe tricks I've come up with over the years; the forumvibe has caught up with most of them, but I think the packaging is still a little unique. Unfortunately, getting all that in the space of a crybaby mount requires standing resistors on end, but that's easy with a PCB.

Don't suppose you're planning on releasing that are you? How about selling me a  PCB

I don't have time or inclination to make PCBs to sell any more. However, J.D. Sleep at General Guitar Gadgets has licensed my PCB layouts for a few years now. You might want to email J.D. and see if he wants to do an experimental run.

I also did a PCB for an 8 stage Univibe.

[Jaicen_solo]

I also did a PCB for an 8 stage Univibe.

drool........