Sabrotone Pareidolia Help

[squirrels]

Hey everyone, I just gave building the Catalinbread Pareidolia a shot using the layout on Sabrotone. I get the modulated signal, the pots work and the lights pulse but it seems that I have no bass frequencies coming through and low output. Any idea what could be causing this?

http://www.sabrotone.com/?p=2528

[induction]

Have you tried replacing C10 with 250p (layout calls for 5n)? Some people report that it makes all the difference, and that 5n may have been a tracing error or something. Read this.

[squirrels]

Thanks for the help, much appreciated.

Just swapped C10 and got no change. I noticed that I had R9 connected to the gate and source of Q4 instead of gate and drain. Fixed it. Not a fan actually. Very harsh sounding in front of the amp and all I get is wet signal in the loop, doesn't sound good with either cap.  Very disappointing.

[squirrels]

I checked my voltages and the IC's are roughly the same, as the ones that were posted with the layout, a little higher since my power supply is giving me 9.15v. My transistors are off though.

Q1:
9.14
8.12
3.04

Q2:
8.12
3.36
0

Q3
1.19
1.19
0

Q4
9.14
8.33
3.06

Q5
8.33
4.32
0

Q6
1.19
1.19
0

Any and all help would be much appreciated. Could that misplaced resistor done some damage?

[rocket88]

hmmm. did you check the stupid stuff yet? like solder bridges, grounding, etc.? also, can you take pics of the board top and bottom, as well as everything all wired? it would help tremendously, especially if there's a part misplaced and whatnot.

[squirrels]

Thanks for the reply. Since I tried laying my resistors as flat as possible, it's tough to see the board connections. I'm pretty sure I have everything right this time. I wonder if I fried something when I had the resistor hooked up wrong earlier. I think all my gaps are clear. I also connected volume 3 to the board and 2 to output as suggested in the comments.

http://i275.photobucket.com/albums/jj316/elessar820/image.jpg1_zpsbxjeihlm.jpg

http://i275.photobucket.com/albums/jj316/elessar820/0af1280e-2b7c-4d29-8b1d-e5abe670571f_zpsuwrrylvl.jpg

Ever give the Quantum Mystic a shot? I saw the Ross/Bax layout in contributions.

[rocket88]

I haven't had much time to build, maybe this weekend or next week I'll give it a crack. Figured someone should haut double check the layout to see if it looks good before the first build. I'll go back over it though and see. Should be good.

[Beaker]

I think I see you problem - look at the electro cap (C17, 1uF  on column 8 on the layout). You have one leg (+ leg) through the bottom hole of the board, into the cut, and therefore not connected to anything. You need to move that loose leg up one row, then solder it in place.

Also check R12 (below Q5) as it looks like it might be shorting out on the link wire next to it.

[Beaker]

Squirrels, I hope you don't mind if I offer you a little constructive criticism.

First of all, your soldering is really excellent - neat and shiny!

Sabrotone layout have many standing resistors/diodes (only spanning one or two rows). I would strongly suggest that in future you place these components in a standing position, as it will cut down on the risk of shorting out on adjacent components.
 
It's worth mentioning that on the layouts on this site, the use of standing components is only used in exceptional circumstances!

Try to find a way to ensure your link wires and resistors stay flat when soldering - do just a few at a time, and maybe use masking tape to hold them to the board when you flip it over for soldering.

Also, I suggest that when you have a component in place, use a pair of needle nosed pliers or tweezers to straighten each component out, as neatly and evenly spaced as possible. Try to get caps standing nice and vertical too.

Doing this makes your boards look neater, avoids shorts, and makes de-bugging a hell of a lot easier. Spending extra time here pays off in the long run.

Don't worry about it though - my boards looked well rough when I started. You will get neater the more you build. I tended to rush everything to start with, then payed for it later!

Keep up the good work though mate, you are doing fine!

[squirrels]

Beaker, I'll have to check out C17 when
I get home, it may just be a piece of something that got stuck on my board, hopefully not then I hope to be good to go with this one.

Usually they are much neater but I decided that I was going to lay everything as flat as possible, next layout with standing parts remain standing. I do use 1590a's a bit. I lay down my electros for those.

Thanks for the advice. I appreciate it

[squirrels]

Rocket, hopefully it'll work. I'm really liking the Quantum Mystic. It squeals when nothing plugged into the input but it's a beast of a pedal. I had to wait for new ICs to come in before I was able to really use it, my old ones were fried. But what a pedal it is. It's pretty much doom in a box, doesn't seem suited for much else actually.

[squirrels]

I still haven't looked at the board but when I zoom in at the component side C17 looks connected to the right hole.

[Beaker]

Ok, looking again, I think you have a scrap of wire or debris stuck in the cut hole, and what I thought was the + leg on cap 17, is probably the link wire.

Sorry!

EDIT: actually I think you may have another short between R21 and the link wire just to it's left.

[motterpaul]

I think I see some solder that is bridging an adjacent copper row, 6 spaces in from the right and 12 rows from the top (on the solder side).

Do you have a continuity tester on your Multimeter? I would check all your rows and make sure you don't have any unwanted connections.

Also, there is a resistor (R12?) on top that is leaning pretty hard on a link. (above the greenie, below the tantalum) - a few things like that are enough to make it not work.

[squirrels]

It may check continuity, I'll have to look... and learn how to. None of the components are actually touching and all placement is OK. I didn't mess with it today, I needed a break. I'll check for that bridge in the morning but I'm fairly confident I cut anything that may have been there.

Tremolo circuits have not been kind to me. I've tried maybe six or seven different ones with only one being successful.

[Beaker]

If all else fails, rebuild from scratch. I know it's a pain in the arse to have to junk a circuit, but sometimes it's the only way.

I've built several layouts before now which have not worked, and I've ended up spending a ridiculous number of hours trying to de-bug them, before admitting that they were DOA, and could not be revived.

Every one has worked first time, and with no issues when rebuilt.

If you want a good tremolo pedal though, I highly recomend  the Schaller Trem on the main site - it's my favourite trem by far, and I'm a tremolo junkie. Easy, low parts, and it sounds great. (The very similar Hearthrob is a modded Schaller, but to my ears, does not sound as nice). It nails that hot, hard, pulsing 50's amp tremolo sound.

[squirrels]

Yeah, I'm no stranger to that one. I think I'm going to just scrap this one. I have parts coming in for a Crimson Drive and Ghost Echo. I'm using the Sabrotone layout for that one so I'll definitely be standing my resistors up when needed, save myself the headaches. After I'm done with those, I'll figure out what's next, I'll definitely look into the Schaller.

Thanks again guys, I appreciate the help.

[squirrels]

I guess I could try swapping the transistors out as a last ditch effort. I'll socket them this time (lesson learned). I don't have any more 2N5484's right now so I'll have to try it out with some MPF102's.

[squirrels]

Tried swapping the 2N5484s to the MPF102s I have on hand and it's good to go. My voltages are a bit higher than the ones posted since my supply is a little more that 9v but close. Thanks for the help. Very nice effect.