poindexter is very quiet

[Dangerhawk]

Hello!

I recently ordered a few boards and the first build was a poindexter.  everything is all wired up correctly, I get bypass and the LED lights up when engaged (though, for a water clear high bright, it isn't very bright).  When the circuit is engaged, the volume drops to almost nothing, if I crank the amp volume way up, I can hear that the effect IS working,  all the pots do as intended, I can even hear the radio signal being picked up.  it's just SOOO quiet.

I've double checked my caps, diodes, resistors, and trannys. they're all in the proper orientation (Ok, C1 and C6 were backwards, but not anymore) and they're all the correct value, with the exception of Q5. I had to sub a 2n5854.

I'm all out of troubleshooting ideas. everything seems optimal, but I've got a really quiet effect. help! 

[madbean]

In this case, I think an audio probe would be the best course of action for a debug. You want to check near the collector pins of each transistor to see where the volume loss occurs. Pay particular attention to just before and after Q5. Also, try checking both sides of C11. It sounds like a lot, but it should actually only take about 5 minutes, and it may save you some frustration.

Keep us posted.

[Dangerhawk]

okeedoke, finally ran to radio shack for some alligator clips and built that audio probe. totally sweet tool to have. sure enough the substitute for Q5 was killing it.  bought a 2n3904 at radio shack (holy shit, the shack actually had the part I needed!) that solves my volume issue. summbitch is loud as hell now. 

but now I have a new problem. i'm getting gnarly fuzztones, but I'm not hearing any octave up.  What can I do?

also thanks a bunch for the help and suggestions. you're the man. 

[madbean]

The octave will be most noticeable when you play around the twelfth fret. Try your neck pickup with the tone knob rolled down. Any better?

[Dangerhawk]

yes it is definitely more noticeable when I do that. but shouldn't there be a ring mod quality when playing lower notes? and sweet double stop dive bombs?  maybe it's more subtle than I expected?

[madbean]

In my experience, it's not all that subtle. The ring mod quality should definitely be there, esp. when you play the notes lightly. And the dive bomb, too, when you play double stops in the upper register.

Any chance you could record a small sound sample?

[Dangerhawk]

http://soundclick.com/share?songid=9246062

kinda loud sound sample. the knobs in the pic are what they were set at for the recording. sounds pretty rad through the half stack, but not quite right.  I admit my girlfriends paint job is far superior to my wiring job, and I'm planning to redo the wiring so the PCB sits trace down.  I accidently bought axial caps so some leads are in danger of rubbing up against things and shorting out.  sometimes I'm a moron.  Anyway! any thoughts on how I can get more octave out of this thing?

[madbean]

I forgot to ask: what types of germanium diodes did you use? 1n270 or 1n34a?

You could try swapping out those. Also, altering R13 from 2k2 might help, as well. I can't offer a precise value, but you could socket and try a few values above and below.

[Dangerhawk]

1n270's for both. tell me these aren't like transistors and there is a possibility of getting a shitty pairing or something like that.

R13 is on Q3 emitter to ground, right?

my assumption is if I lower R13, that gain stage will get boosted. maybe???

[madbean]

1n270's have a slightly higher Vf, IIRC. Changing them to 1n34a's might help pronounce the octave a little more. In my build, I used 1n34a's. Mine sounded pretty spot-on to the demo video on the zVex site.

Yes, lowering the value will increase the overall gain at that stage. So, lowering it to 1k5 or even lower might be the way to go.

[Dangerhawk]

right on. I'll put in an order for them diodes post haste. 

so then, effects that have an on/off switch for the octave up are just swapping diodes? 

[madbean]

There are different ways to generate octave effects, for instance using a small transformer like the Tyco Brahe. I'm by no means well versed in Octavias...admittedly my knowledge is pretty shallow. But, from experience I can offer up the advice regarding the types of germaniums making a difference. For instance, if you put two sets of those in a Big Muff in place of the regular silicon diodes, you get a very sweet slight octave with just a bit of note bloom in the decay.