Nautilus Problem

[twofootskunk]

I finished my Nautilus build last night and unfortunately I must have a problem with it.

Bypass sound works.
When the pedal is on I do get guitar sound to pass through but it is reduced/weak/thin. I can tell it has a small amount envelope effect.  I triple checked that all the resistor/cap values were in the right spot.
The electrolytic caps and diodes are in the right direction.  My IC's are in the same way as madbean's pic.
Offboard wiring looks correct.   

I didn't see any solder bridges.  My soldering isn't amazing and I mixed up two pots that I had to unsolder/resolder (which was a pain!)  I had the mini toggles which didn't fit but I got those soldered in and they test ok with continuity check.

I think the next step is just reflowing all the solder joints.  What do you think about cleaning the board with isopropyl alcohol after I reflow?

A couple questions...
The Range switch makes the LED get brighter/dimmer when toggled.  Is that LED supposed to be on all the time?  It does flicker when I play.

Also, for IC1 and 2 the BOM says TL074.  I just noticed that I have TL074CN.  Does that matter? 

I'll try to post some pictures tonight or tomorrow.

[madbean]

What type of vactrol or LED/LDR have you used?

The TL074 you used is fine.

[twofootskunk]

VTL5C3, I put the LED + lead into the square hole for alignment.  Was that correct?

[midwayfair]

When the pedal is on I do get guitar sound to pass through but it is reduced/weak/thin.

Is this true in all settings, and even with the gain cranked?

There are definitely a few settings that sound "broken" to me with the gain turned down and the sweep all the way up.

[madbean]

With the Gain fully down and the Sweep fully up you can expect this because there is minimal signal to drive the rectifier portion and the max resistance in line with the LED. Like I said in the build doc, the Sweep is for minute adjustments. One thing I did not mention is that these are most perceptible when the gain is at or near max. You could limit the dead areas more by putting a 5k1 resistor in parallel with the sweep pot to reduce it's value.

twofootskunk: can we get a couple clear pics of your build?

[twofootskunk]

Yes, but I'm at work and will have to do it this evening.

twofootskunk: can we get a couple clear pics of your build?

[twofootskunk]

Yes.  I tried twisting all the knobs/switches and got mostly the same results. Each control does have an effect on the sound. There's a point at the top of the sweep range that everything gets louder, but it still doesn't sound right.

How is the LED (the one from the pcb) supposed to react to input?  Does it stay lit and just flicker when you play?  Mine stays on even when the effect is in bypass (the bypass LED goes off though)
I guess in my mind I imagined it would light up and fade out with the "womp" of the effect when played.  But I don't really know.  Either way it's probably just a sympton of the real problem.

We'll see what happens after I reflow all the joints.  My first build (divided octave from BYOC) went so smooth I thought what could possibly go wrong! LOL  I guess troubleshooting is where I'll really start to learn more.  I'll definately post pics of both sides of the board, so you can take a look.

Is this true in all settings, and even with the gain cranked?

There are definitely a few settings that sound "broken" to me with the gain turned down and the sweep all the way up.

[twofootskunk]

Here's a link to some pics....

http://postimage.org/gallery/5yb8o4ag/

I reflowed a lot of the connections but still have the same results.  I guess I'll just reflow everything.
I suppose my hack job on the mini toggles could be an issue, but I did test continuity with my meter.  I also checked that the diodes weren't burned up. 

Let me know if you see anything that stands out.

[twofootskunk]

When I turn the gain up to max I get a stronger sound.  It's right at the end of the travel though.  Still doesn't sound quite right. 

[twofootskunk]

I took voltage readings from IC1 an IC2.  This was with the guitar/amp plugged in.  I wasn't strumming.  If someone could compare theirs to mine, hopefully that will give me some direction as what to look at.

IC1
1:   1.3mv
2:  -1.1mv
3   -1.6mv
4    8.8v
5    0
6  -1.6mv
7  -1.6mv
8    -0.8mv
9   1.3mv
10   0.1mv
11   -8.11v
12   0.1mv
13   -0.8mv
14    -3.7mv


IC2
1   0.6mv
2   0.6mv
3    0
4   8.8v
5   0.1mv
6   -0.2mv
7   -0.2mv
8  5.25v
9  3.514v
10   3.491v
11   -8.11v
12   0.1mv
13   2.9mv
14  2.125v

[madbean]

Voltages look basically correct. I think we need a little more info. When you say it doesn't sound right, can you be more specific? You mentioned that you get a stronger signal near max gain---but, are you getting the filter effect at all? Or is it just your regular guitar signal?

To answer a couple of your questions: the LED will be on or off depending on where you have the Range switch set. When the Range is high the LED will always be on (even in bypass), and as you play it will dim according to the output of the envelope. When the Range is low, it's the opposite: the LED will be off and then light up as you play.

If you want to change the LED so it is always off when the effect is bypassed you can remove R20 from the PCB, wire from the neg side of the LED to R20, and the other end of R20 goes to the same lug you use on your 3PDT for your indicator LED.

The filter effect itself is very sensitive to where the Gain pot is set. You get the most effect when it is near max, so do not be surprised if much of the travel of the Gain pot doesn't do a lot. This also depends on what type of gear you are using....you can expect it to behave a little differently with humbuckers or bass or bass with active pickups.

But, if you are getting no swept filter at any setting, then something definitely is amiss. I'm just not sure if that's the case here or not.

[twofootskunk]

Voltages look basically correct. I think we need a little more info. When you say it doesn't sound right, can you be more specific? You mentioned that you get a stronger signal near max gain---but, are you getting the filter effect at all? Or is it just your regular guitar signal?

With the gain set to anything below max the volume coming out of the amp is about half and the sound is very thin/trebly.  When I turn it up to max there's a definite point (probably at 99% clockwise) where the sound jumps up in volume to where it's the same as the bypassed.   I am getting the filter effect, it's very weak until the same point the volume jumps then it sounds pretty full.

To answer a couple of your questions: the LED will be on or off depending on where you have the Range switch set. When the Range is high the LED will always be on (even in bypass), and as you play it will dim according to the output of the envelope. When the Range is low, it's the opposite: the LED will be off and then light up as you play.

Ok when my range is set to high the LED is on all the time and does dim with the envelope effect (but only when the gain is set to max).

When my range is set low, the led does not turn off.  It does get fairly dim, but not off.   It gets brighter with the effect.  Also when set to low, even with the gain up full, the sound is about half as loud as bypass and very thin/trebly.  I do hear the effect a little.  It sounds the same as when the gain is down.

If you want to change the LED so it is always off when the effect is bypassed you can remove R20 from the PCB, wire from the neg side of the LED to R20, and the other end of R20 goes to the same lug you use on your 3PDT for your indicator LED.

Thanks, that sound like a great mod once I work out the bugs.

The filter effect itself is very sensitive to where the Gain pot is set. You get the most effect when it is near max, so do not be surprised if much of the travel of the Gain pot doesn't do a lot. This also depends on what type of gear you are using....you can expect it to behave a little differently with humbuckers or bass or bass with active pickups.  

But, if you are getting no swept filter at any setting, then something definitely is amiss. I'm just not sure if that's the case here or not.

Additional info:
I'm using a strat with Lace sensors.
Testing with the gain pot at max I'm pretty confident that the peak, sweep and 3 position rotary switch are working.

Given that the LED is not off when the Range is set to low and I used the mini toggles that didn't fit in the PCB, I think I'm leaning towards it being a switch issue or possibly a short/solder bridge somewhere.  I've looked over the pcb about a million times for solder bridges, so maybe just swapping out the switch will help.  

[twofootskunk]

I just went to radio shack (ugh..) to grab a couple dpdt toggles.  But before I set down to unsolder/resolder the new ones in, I used a toothpick to scrape away some left over rosin/flux (whatever that crap is) around that area.   Is that stuff conductive?

With the gain at max I'm getting both the high and low setting on the range to give me an envelope effect.  Actually sounds pretty good.

So that leaves me with a couple more questions.

If the envelope effect and volume is working at max.  What should I expect to hear as the gain pot is decreased?  Currently mine is acting essentially as volume knob for the whole signal with the envelope strength decreasing as well.

When range is set to low should I expect the LED to completely out when not playing?  Even with the input unplugged the LED is lit, but dim.

[madbean]

You only need to look as far as the schematic to understand what the gain pot does. It's a series resistor at the effect input. So, when it's fully counter-clockwise you have a 1M resistor in series with input (plus R1), hence less signal. When it's at max, the only resistance at the input is R1, which is 3k3.

From the build doc: You will likely find the Gain control quite sensitive in the last quarter of its range for some settings on the Nautilus.

If you want to change the behavior a bit, it's easy. Just use a lower value pot for the Gain control. 250k is probably a good choice. 100k is likely to be too small.

For the LED: don't worry if it is a little dim rather than fully off. That just means there is enough voltage there to light it up a bit when you are not playing. If you wire it to the 3PDT like I mentioned earlier then it will go fully off.

[marauder]

Juansolo's build he put together today has a very similar issue, no output, but the LED is showing the envelope happening.

I've audio probed each opamp, and it does sound very funky until the final one, no signal at all.  I checked on the switch side of the 220nf cap, and its there, but after nothing.  I'm getting continuity between the bottom 220nf cap pad and ground.  Something is amiss in this area, but won't get a chance for a thorough debug until Wednesday.

I can tell this is a great sounding effect already, just need to get the funk out of it!