Neovibe Depth

[fpaul]

Finished my Neovibe last Sat. and it seems to be working okay.  I still need to make a box for it.

Much thanks to R.G. and others on the board.  I never would have thought about doing this without you guys.  ( on the other hand, addictions are BAD, right?)

I notice when I turn up the depth to max I get kind of an un-musical thumping noise, like I can hear the lamp turning on and off.  When I turn down the depth to about 2/3 open it goes away and sounds good, but looses some of the, well..., depth.

Is this normal?  If not how can I fix it?  I've looked at a lot of other posts; the only thing related seemed to be the 200ohm trimmer.  I don't want to take the shield off unless I have to though.

Other than that probably just needs a few tweaks.  I have used my Gibson L6-S (with humbuckers), but think this may be one of the few effects better for a Strat.  Unfortunately my Mex Squire Strat has a bad volume at the moment.  Probably fix next weekend.

Thanks again.

[Nitefly182]

Vibes are thumpy at max depth and they aren't like other phasers where max depth works well all the time. Its more of a width control anyway so settings between 10:00 and 3:00 seem to work best for me although my neovibe is unfinishedso it may be a few days before I can say for sure if that applies to the neo.                                 

[R.G.]

Make sure your power supply to the audio section is not being moved up and down by the current being fed to the lamp. More depth means the lamp pulls a lot more current on peaks. If that pulls down the power supply to your audio section, you'll hear a thump. That's one reason I put the 7815 regulator in there. But if your raw DC supply gets under 17Vdc when the lamp sucks current, you'll hear that as a modulation in the audio as the regulator runs out of headroom.

If this is what's happening, the fix is to get a burlier, higher current DC supply.

[SteveB]

If you are using a 4.7k for R49, try increasing the resistance value. As you increase this, the on/off ratio of the bulb will smooth out.

Are your photocells laying flat, facing the inside top of the light shield?

[fpaul]

Unfortunately my bulb blew after 4 days.  I had the whole wah, ff, neovibe, octavia thing going for about 5 minutes then nothing.  Funny thing is I'm getting over 20v across the bulb; looks like 20-28 mA also.  Not sure how with a 15v regulator?  I was using a 1.5v 25ma bulb from SB.

I have the cell face up with the copper/foil shield.  I think I cut the leads too short to do anything else now.  I was planning to try a 50K pot on R49 eventually; right now I'm heading to Radioshack and some troubleshooting.  My electronics knowledge is pretty basic but I can try and check the transistor voltages.

[fpaul]

ok, the regulator input branches off to the bulb, so the 20+ volt to the bulb should be expected I guess.  I'll put in a new bulb and check the rest of the voltages on the schematic.  So far they seem to be okay.  Regulator output is steady at 15.1v.  I am using an 18vdc 200ma wall wart.  Almost have a ggg 18v 4 output isolated ps almost ready to go so I can try that also, and/or a couple of batteries. 

[head_spaz]

I was using a 1.5v 25ma bulb from SB

IIRC ... Specs call for a 12 V to 14 V bulb @ ~25mA.

[andrew_k]

I was using a 1.5v 25ma bulb from SB

IIRC ... Specs call for a 12 V to 14 V bulb @ ~25mA.

ALthough I blew two while calibrating, I'm now using the 1.5v 25ma bulbs from smallbear without issue.

[head_spaz]

Oh yes... I totally understand. It's always best to ignore the specs and then post threads seeking help and asking why it doesn't work. Afterall, this is the very best way to discover that the designer is a goofbag, and that certain paint colors have a better mojo. I think I'm finally starting to understand the standard operating procedure.



All of you non-conformists are the same.

[Nitefly182]

Oh yes... I totally understand. It's always best to ignore the specs and then post threads seeking help and asking why it doesn't work. Afterall, this is the very best way to discover that the designer is a goofbag, and that certain paint colors have a better mojo. I think I'm finally starting to understand the standard operating procedure.



All of you non-conformists are the same.

Youre right. Thinking outside the box and asking questions never got anyone anywhere.

[andrew_k]

Oh yes... I totally understand. It's always best to ignore the specs and then post threads seeking help and asking why it doesn't work.

SmallBear sell the 1.5v 25mA bulbs specifically for neo/univibes and they work fine. A search will find posts by Steve stating such.

You're an ass. 

[head_spaz]

Androo_k:
I've posted here many times offering help to others, but you've all got your own little inside
clique going on. You're the one being rude. And you call me an ass? Take a mydol sissy britches.

And I stand by my original post.
1.) The SPEC indeed calls for 12V.
2.) SteveB didn't write the spec.
3.) I didn't quote SteveB's mod data.

Sarchasm: The gulf between the author of sarcastic wit and the person who doesn't get it.

[andrew_k]

Wow. You're probably having a bad day and need to vent via the internet. That's cool, we've all been there.
- You posted that his bulb was incorrect. You are correct.
- I posted that I'm using the same bulb without issue (as are many others); attempting to indicate that the bulb is not the source of the problem in this case.
- You seem to have taken that as a personal insult and posted your angry little attempt at sarcastic humor.
You're an angry man who appears to have an inadequacy complex (clique? I've never noticed one on this forum). I feel sorry for you and won't be replying to this thread again. I hope your anger subsides, it's not good for your health.

[fpaul]

Wow, didn't want to stir anybody up!  Anyway, I went to RS and looked the the 12v 25ma with the hair leads, then the 12v 50ma with the nice burly leads..., hum..., had to go with the 50ma.  Wasn't sure if it would work, but read R. G.'s Tech of Univibe and he said he used up to 80ma successfully. 

The bulb biased again, no problem.  It is a lot dimmer than the other bulb though.  The thumping at maximum depth has pretty much disappeared, maybe that's why.   I'm running it just under max depth. Effect on it's own is a little subtle.  It comes alive with a rangemaster clone in front for a good clean sound, and I like the bsiabII after for some dirt.  It seems like it plays with other effects much better with this bulb.  Would probably be better with maybe 30-40 ma but I can live with this.

The more I play this the more I like it.  There are many possibilities for tweaking to make it perfect, and trying with other effects(I'll definitely try the R49 thing).  But for now I'm calling this a successful build.  The bsiabII ended my distortion quest for awhile (not only sounds like a plexi, it actually FEELS like the 50w I used to play 20years ago), so it's great to build something besides a distortion/fuzz.  Now for some compressors...  Anyone have any ideas for a Binson diy substitute?

Thanks everyone for all the help.

Peace out.

[SteveB]

Androo_k:
I've posted here many times offering help to others, but you've all got your own little inside
clique going on. You're the one being rude. And you call me an ass? Take a mydol sissy britches.

And I stand by my original post.
1.) The SPEC indeed calls for 12V.
2.) SteveB didn't write the spec.
3.) I didn't quote SteveB's mod data.

Sarchasm: The gulf between the author of sarcastic wit and the person who doesn't get it.

He's talking about Steve @ Small Bear, not me. BTW, I use a 12V in mine.