Reliability: How much is enough? How do you get it?

[R.G.]

Reliability is an issue for everyone who's ever played in public. You can look downright silly and realize your worst stage frights when you pull off a Spinal Tap moment. So - how much reliability do we need?

I personally go for pro-quality stuff. You should be able to toss your pedals in the bag with the other junk at 3:00AM when the show's over and you have to get into the van to get to the next show and have some reasonable expectation that the pedal will work the next night.

Here are some critical reliability areas I've thought were important.
- Box Solidity: if you can't stand on the box on one foot and have the box not crush, it's too flimsy.
- Stomp switches: Should stand at least 1000 operations of a heavy foot.
- Connection wires: Should be stranded for flexibility, and mechanically captured a the board end by weaving through blank holes in the board before being inserted into the soldered pad.
- Boards should be mechanically fixed in place by screwed or clip retainers. Wrapping in foam is not something I trust for shorts or lead breakage.
- solder joints should be smooth, shiny and flowing, not cold or blobbed.
- All electronic parts except switches, battery clips, jacks and controls should have all leads soldered into the PCB.

There are probably others.

[GuitarLord5000]

I also like A.W. McKinley's Alpha Switch and Millenium Bypass PCB for mounting your switch and LED (I have my LED mounted on the board).  It seems very durable as I have mine screw mounted onto my box.

[Doug H]

- Connection wires: Should be stranded for flexibility, and mechanically captured a the board end by weaving through blank holes in the board before being inserted into the soldered pad.

I didn't think strain-relief was a big consideration for internal wiring except for battery clip wires. Good idea, though.

I agree with box solidity. I love my Arion chorus but mechanically it's a real piece of garbage. Every time I pull it out of my bag for a gig the battery door has fallen off. Now the knobs are starting to fall off. Plastic fantastic... I need to re-box that thing.

Doug

[Eric H]

Reverse-polarity protection. A diode across the power supply is mandatory (IMHO)
There's a better one here (scroll down):
http://www.blacet.com/tech.html
IIRC, Mr. Keen has a real fancy version using a mosfet --somewhere in the Stygian depths of GEOFEX


-Eric

[moosapotamus]

If you install an external power jack, how about including voltage regulation to safeguard against the use of whacked power supplies?
(beat you to it, Tom...   )

~ Charlie

[aron]

Here's a simple one.

Use Switchcraft jacks. Although not perfect, they are close as possible to it.
The worst moment is the cord not quite "fitting" to the cheap jack you used to save a few cents or that cheap plastic jack screwing up when you tighten them on the box.

Oh, and use good cords that work with your jacks. Some of the newer cords have a different taper on the plug I have noticed. This can cause problems with certain jacks.

[Peter Snowberg]

A thread after my own heart.

* Jacks, stompswitches, or any piece that is subject to mechanical "adjustment" via a foot should be anchored to the case and connected to the board with jumpers so that the solder joints don't break. That's the FAA approved method too.

* 25V should be the minimum voltage rating on electrolytics used in a 9V system with a DC adapter jack, or even better.... electrolytics should be eliminated in favor of tantalums for long life. Eric's addition of reverse polarity protection to the list should be 100% mandatory when tantalums are in the picture. OK, actually it should be mandatory regardless.

* Only quality jacks should be used. (Duh)

* Only quality 9V battery clips should be used. I've had too many problems with the soft plastic sealed types. The types with a hard plastic head have never given me a problem (yet).

* Any part with a decent amount of mass in relation to the lead size should be anchored by a blop of (clear) silicone rubber.

Charlie, I really like the idea of an LDO regulator on the DC input jack! The voltage drop is about the same as a Schottky diode and you get stable voltage to boot! That would mean the only part in possible jeopardy would be the input cap and that could be dealt with by using a reverse polarity Schottky & small resistor on the input. Very cool.

For super high reliability, I like the Frantone approach of using a relay to engage the effect so that it fails safe. Too bad the power requirements are so big when doing this.

Take care,
-Peter

[Doug H]

* Jacks, stompswitches, or any piece that is subject to mechanical "adjustment" via a foot should be anchored to the case and connected to the board with jumpers so that the solder joints don't break. That's the FAA approved method too.

Just to clarify, I would add- no pcb-mount tube sockets.

Doug

[WGTP]

I guess none of mine will be leaving the house

I'm happy just to get them working.  I don't worry much about keeping them working, that is too much to expect.   :oops:

[brett]

Hi.  This is a really excellent thread, especially as I've started to sell a few pedals (as a means of disposal more than a job - I just love building them and experimenting so much).

RE: I didn't think strain-relief was a big consideration for internal wiring except for battery clip wires. Good idea, though.

I agree that for light stuff like hookup wire, even when thrown to the floor, the forces will be very small.  When constructing, I use a light pull on wires to ensure they're secure.  That would be greater than any force applied from outside the box.

RE: Reverse-polarity protection. A diode across the power supply is mandatory (IMHO)

I agree.  Before I used polarity protection, a couple of my pedals got blown up with reverse polarity  (TL071s, I think).  I use an in-line diode.  With virtually no current flow, nothing can get damaged.  Although there's voltage loss, I haven't come across any pedals where it's an issue (though the BluesBreaker must come close).  

RE:Use Switchcraft jacks. Although not perfect, they are close as possible to it.

Yep.  Bad jacks are soooo annoying.

RE: Only quality 9V battery clips should be used.
I don't use batteries at all.  Just a 9V jack.  Batteries last for a long time, then go flat at the worst time.  They often sound dull as they go flat.  They're environmentally problematic.  I say ditch 'em.

RE: Any part with a decent amount of mass in relation to the lead size should be anchored by a blop of (clear) silicone rubber.

This seems a good idea, but I've wondered about that acetic acid (vinegar) smell that silicone gives off as it cures.  Acetic acid is a conductor, which worries me about using silicone.  Is it ok?  Anybody tested its resistance?

Again, great thread
cheers

[Joe Davisson]

Avoid roadie-wrapping your cords! Saves time with the real long cords but those are the most expensive ones...

-Joe

[will]

Hi Brett,

RE: Any part with a decent amount of mass in relation to the lead size should be anchored by a blop of (clear) silicone rubber.

This seems a good idea, but I've wondered about that acetic acid (vinegar) smell that silicone gives off as it cures.  Acetic acid is a conductor, which worries me about using silicone.  Is it ok?  Anybody tested its resistance?

It seems to be ok once cured. I destroyed a power transformer putting a whole bunch of silicone inside. I was trying to reduce the mechanical hum. Problem is it takes forever to cure when applied thick and silicone is very conductive until it’s cured. Opps

Regards,
Will

[Dai H.]

A thread after my own heart.

* Only quality 9V battery clips should be used. I've had too many problems with the soft plastic sealed types. The types with a hard plastic head have never given me a problem (yet).

-Peter

I kind of agree with you on those cheap nylon jobs, but it is easy to re-tighten the contacts easily w/pliers on those, but I wonder if you can do it w/the (hexagonal?) contact + plastic ones (or is the contact more permanent on those--i.e. won't loosen?).

if you gig, then have lots of spares, gtr. strap, strings, toobs, cables, etc., Deoxit for oxidized connections, fuses, etc.

oh yeah, keep the knobs away from where they could be damaged by feet

make sure the battery can't flop around like in wahs--could lead to batt. wire severing

might be good to build in such a way so that non-enclosed pots are enclosed by the housing so less exposed to the environment--might lead to scratchiness?

[Chico]

This is a small consideration, but in many high volume commercial pedals I have used, e.g., Boss, DOD, etc., the design of the enclosure allows for a "battery compartment" that separates the battery from the remainder of the circuit.  

With most of us, either custom building al. boxes or using Hammond 1590b and bb style boxes, removing the bottom lid exposes the electronics and all.  Does anyone use a cover or any device to compartmentalize the box?

Also, I know the topic was mentioned above concerning wrapping the pcb in foam vs using standoffs.  I prefer standoffs, but this raises several new questions.  In my early projects, I epoxied a couple nuts to the box, then used screws and plastic sleeves to make standoffs.  A very elementary DIY approach, I know.  In subsequent builds, I modified this technique so that my pcb would sit down over my mounted pots.  The idea there being that I could spread out my pots in more aesthetic patterns and still not worry about pcb placement.   I have also tried the adhesive backed nylon standoffs from Small Bear.  Those work well, but do not give enough height to mount the pcb over the pots.

So, the question is, do mount the pcb next to the pots or over them.

Do you use adhesive standoffs (anyone have the adhesive break loose?  Epoxied standoffs?  Or do you drill holes through the face of the box and bolt the pcb through the box?

[Kleber AG]

 Take care on what can get into the insides of the potentiometers, like when you're soldering, using solder fluid, or cuting conponent legs etc, etc, etc...

Take care with excess tighten of mechanical parts as jacks, pots, switches, they can go bad...

Kleber AG

[Scott Swartz]

I like eyelets for mechanical stability for wires leaving the PCB - no worry about the solder pad lifting.

[RDV]

Duct tape & Bailing wire, wherever possible!....oh yeah, & super glue!!

RDV

[Nasse]

Duct tape & Bailing wire, wherever possible!....oh yeah, & super glue!! / RDV

:oops: That´s what I have used... :oops:  And even cheaper tape, fixed my Tube Sound Fuzz with tape and a piece of cardboard... just some extra insulation here and there because stuffed it in too small box made of thin aluminium, input jack touched the box when plugged in. My friend tested it and reported it sounds *very* good. Indeed he might have been so happy with it he tested it for few weeks... But he returned it to me and was not talking very much then, just said "it does not work anymore". I opened it and noticed the pcb touched the enclosure, a little piece of tape and cardboard and it was rocking again...

Maybe it is 85% of perspiration and 15% inspiration, but that inspiration part is very important...

Good 3D thinking and pre-planning helps. And imagine you are an old gipsy woman who can see what can happen to your pedal in the future...

I remeber when one of my commercial fuzzwahs was new. The bassplayers friend had nice shoes, thick soles made of wood, you know like they use in Netherlands. Those shoes were too much for a stompswitch, it cracked in two pieces. Later I read a review of Pete Cornish. He said he used round rings made of plywood around the switches, so they are not so high and can take more abuse... Replaced it with similar looking switch, which was not good for low power use, you know...[/code]

[petemoore]

My standoffs screw heads are visible on the outside of the box.
 I've been using a simple screw either tapped into the perf, which IMO works jez Fine...quite sturdy actually, if you used a self threading screw and don't push hard toward while drilling the phelonic board. I just use a rubber something [foot] betweent the case and the Circuit board...I wouldn't be able to recommend this like 'regular' standoffs, but they certainly work great for me, very easy to install also...
 One of my main shortcuts that ended up being the long way around is RS switches...if using junk like this, leave enough room so When [not if] they fail, a decent Stompswitch can be fitted as more permanent replacement...The blue ones Aron sells are very nice IMO...

[Jered]

Stay far away from the mini alpha dpdt switches. I've seen 6 broken in the last month, more than I've wrecked in my whole life of other types. They simply breakin in half, the metal housing separates from the plastic.  Seems MXR is trying to save a buck, bad move in my opinion.
 Jered