Hi all, I finally got my Nautilus allwired up but it's not working right. I first had the footswitch done wrong but I figured it out. Now everything seems to except for one thing: the "wah" doesn't really trigger and the overall volume is way too high. I can hear the filters and all 3 switches are working but I only get the "w" sound, not "waaww" if you know what I'm saying. Any idea what should do?
Thanks!
Put the sweep at minimum and try both range settings. Any better?
Make sure R14 is 330R, not 330K. This would make the attack so long it wouldn't really do anything.
Thanks Jon, but it's a no go. R14 is right on spec. The filter is really not "opening and closing" as it should. My buddy built one at the same time as me and I know how it should sound.
Could my Vactrols be bad? I might have burned some component with too much heat?
Quote from: Natman on April 22, 2014, 01:10:16 PM
Thanks Jon, but it's a no go. R14 is right on spec. The filter is really not "opening and closing" as it should. My buddy built one at the same time as me and I know how it should sound.
Could my Vactrols be bad? I might have burned some component with too much heat?
Doubtful. They're as robust as a resistor and an LED, which is what they are.
Does your filter indicator LED light up when you play?
Yes it does!
Have you tried swapping in new IC's? I built mine and it worked great, started doing some mods, then one day it didn't work so well. It turned out that one of the TL074's had gone bad. It still had volume but the filter didn't work.
My Nautilus had issues until I removed the vactrols and put new ones in. I couldn't get a good filter sound on the "sweep up" section
As silly as it may sound, I socketed the vactrols the second time around and after the change, it worked perfect.
Quote from: chordball on April 23, 2014, 02:29:56 PM
Have you tried swapping in new IC's? I built mine and it worked great, started doing some mods, then one day it didn't work so well. It turned out that one of the TL074's had gone bad. It still had volume but the filter didn't work.
Dag, I sure hope not -they're not socketed and I don't have spares! Is there enough data out there that would allow my multimeter to locate the problem or is that wishful thinking?
I'd give you my voltage readings but my Nautilus is still not built (and I've had the board for at least a year). Hopefully you'll fix yours way before I actually build mine. ;)
Quote from: Natman on April 22, 2014, 08:34:19 PM
Yes it does!
Measure across the vactrols' LDR sides. Does their resistance change when you play?
I'll check. in the meantime, here's a gut shot. I can't find anything wrong and my solder joints look clean.
(http://i301.photobucket.com/albums/nn73/Nathan_C/Nautilusgutshot_zps057f58a0.jpg) (http://s301.photobucket.com/user/Nathan_C/media/Nautilusgutshot_zps057f58a0.jpg.html)
Quote from: midwayfair on April 24, 2014, 03:57:28 AM
Quote from: Natman on April 22, 2014, 08:34:19 PM
Yes it does!
Hey Jon yes they do. I notice I have to hit the strings very hard to get a change however. Still is not making the open & closed sound you expect!
Measure across the vactrols' LDR sides. Does their resistance change when you play?
Audio probe pins 14 and 8 of IC2.
You're losing signal somewhere in the envelope section.
Also, you're not doing yourself any favors trying to troubleshoot this when it's boxed up.
I finally got around to checking all of my resistances and it turns out the 5k Sweep pot is bad, reading over 12 Megs. I think this might be the problem ;)
My R5 is also off, reading 124k instead of 390k. So I'll replace these parts and see what happens.
Quote from: Natman on May 14, 2014, 03:36:31 PM
I finally got around to checking all of my resistances and it turns out the 5k Sweep pot is bad, reading over 12 Megs. I think this might be the problem ;)
My R5 is also off, reading 124k instead of 390k. So I'll replace these parts and see what happens.
If you're measuring in-circuit, the 390K may very well read significantly lower.
The sweep pot sounds like it's not connected, or perhaps the pot itself is broken. I'm pretty sure there aren't 12M pots in your parts bin that you could grab by accident!
Alright, I replaced the sweep pot and she almost works properly now. Now I need to figure out the insane output!
The volume trimmer is all the way down but I need to turn my amp volume way down to make this usable. Could I just swap the trimmer for a different value?
I wish I had it external on its own external pot because it's way above unity gain.
Thanks again for your help!
I am sure Jon can help you out with that
Glad to see you got it working!
The volume trim is a gain trimpot.
This effect is almost always above unity when the gain control is up. You can simply add a volume control to the output. The current output wire to lug 3 of a pot, lug 2 to the output, lug 1 to ground. You can use basically any value you like, 10K, 100K, etc.
Of note, there's no output pulldown resistor in this effect, so this could be beneficial in more ways than one.