yjm308 gating problems

[guitarmonky55]

i just finished perfin up a yjm308 per nabo's layout in the gallery, and after fighting with absolute silence for a while i managed to get full volume but a terrible gating and crackle...and ive got nothing.  any suggestions as to what can cause this and where i should look first?

[petemoore]

Your info is as good as the schematic, but not inclusive enough to go on...you will do well to follow through after reading 'what to do when it doesn't work'.
 Completely and we'll be able to do all we can to figure out ....
 Or even jsut battery and pin voltages would be likely to illicit an informed response.

[guitarmonky55]

i should have had patience and held out posting for 10 more mins..i found my problem to be a poorly soldered ground connection and then discovered my pot was acting funny on me.  got it fired up and its great!  2 things though:

1)this seems  alittle bassy, i prefer my stuff to be really crisp and sharp and trebly.  the only alternate part values i used were a 500k resistor where the 1M should be on pins 1&2 and a 22pF cap as opposed to 25 at the same place.  i was under the impression that a pedal toting yngwies name would be real bitey, so any suggestions on what to alter for a less boomy tone?

2)when i bypass the pedal, im getting a wierd high pitched squeel thats continous and changes in pitch as i rotate the gain pot...i have it wired up to a dpdt switch for true bypass so this makes no sense...could this be some wierd wires i have crossed too close or something?

[mrsage]

http://www.analogman.com/dodmod.htm

[NaBo]

hey, i think you're the very first person who's made reference to using one of my layouts!!!  did you listen to my sample of that circuit too???  thats the whole reason i recently put that strange (but free) counter on that page... to see if anyone even benefits from its existence

as for your latest queries:
1) boomy? yjm308?  same sentence???  SAME PARAGRAPH EVEN?  lol!  never heard it described like THAT before!  but i guess it can't make a humbucker into a single coil...  even still, the tiny input cap should filter out a bunch of the bass... i know if i use the bridge pickup on my sg deluxe (a somewhat shortlived 3-minibuckers version with a bigsby trem), it starts to fart out...  could that be what you're hearing maybe?

2) that oscillation problem is STRANGE.  it seems a few people are having it with Torchy's build too... So i think it's just the nature of the beast with some particular setups, maybe?  Try getting it in a box and see if that helps, if not, try using some shielded wire as kojjum suggests

Good luck!  Good to know someone has actually put one of my layouts to use!  :wink:  

[guitarmonky55]

hey, i think you're the very first person who's made reference to using one of my layouts!!!  did you listen to my sample of that circuit too???  thats the whole reason i recently put that strange (but free) counter on that page... to see if anyone even benefits from its existence

as for your latest queries:
1) boomy? yjm308?  same sentence???  SAME PARAGRAPH EVEN?  lol!  never heard it described like THAT before!  but i guess it can't make a humbucker into a single coil...  even still, the tiny input cap should filter out a bunch of the bass... i know if i use the bridge pickup on my sg deluxe (a somewhat shortlived 3-minibuckers version with a bigsby trem), it starts to fart out...  could that be what you're hearing maybe?

2) that oscillation problem is STRANGE.  it seems a few people are having it with Torchy's build too... So i think it's just the nature of the beast with some particular setups, maybe?  Try getting it in a box and see if that helps, if not, try using some shielded wire as kojjum suggests

Good luck!  Good to know someone has actually put one of my layouts to use!  :wink:  

yeah im more into perf than vero myself, as when i lay out circuits i find it hard to think in terms of how vero works so when i saw your perf layout i figured thats perfect.  easy to build, great job on it man.

anyway, i figured the oscillation out.  the 25pf(22 in my case as i didnt haeve and 25) cap across the pins of the opamp had a really poor solder job on one side and busted off when i was testing without me noticing.  i saw this and while it was bypassed i pushed it back into contact and the oscillation disappeared.  so at least for me that was the problem.

the boominess is bothering me.  i like sharp distortions, since i play alot of edgy sounding grit(think cowboys from hell).  for some reason it sounds like im running the signal through a huge capacitor at some point,  therefore doing exactly what i dont want the circuit to do.  i know its got to be a mistake, i listened to your sound sample and thats the sound im aiming for.  i guess ill do a runover of my part values and such.  

one thing i was thinking, for the 1M resistor, would using 500k instead(i dont have any 1M's) cause something of this nature?  i dont know much about how these actual circuits work at all, but i know that in a guitar control cavity lower value resistances in pots allow more treble to bleed off to ground, and was wondering if that could be my problem here.

[edit] i just realized i forgot to mention the other 2 part substitutions i deviated from.  i used a jrc4559 and red leds for the clipping diodes.  i dont have any other diodes handy so i threw those in(i build this thing almost entirely from salvaged parts from an old toy keyboard).

[guitarmonky55]

so you can get the idea of the sound issues im having, i recorded a sample here:
http://www.audiostreet.net/artist.aspx?artistid=11985

its the last one, the yjm od sample.

the first part is with the pedal engaged. i kick the pedal off after the pause.  im playing an ibanez s1620fb with a seymour duncan invader in the bridge, and im using the bridge position the whole time with the tone and volume controls on max.  the gain and volume on the yjm are maxed, and when i kick the pedal off im just using my amp.

when i play the yjm without distortion on my amp i get the same effect, just not so thick.//