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DIY Stompboxes => Building your own stompbox => Topic started by: differo on October 26, 2009, 06:43:29 AM

Title: Ts-808 problem need help
Post by: differo on October 26, 2009, 06:43:29 AM
Hi everyone,
I just built my first diy pedal (layout & schematics from tonepad.com awesome site!!) and it works (etched my board..). But!
the sound is not good at all - it sounds like the battery is drained (its not..) if you know what i mean - like some germanium fuzzes,
all the components are stock, all the pots are doing what they should and when i lower the drive it cleans out the signal nicely
but again, when the drive is up it distorts the signal indeed but its kinda cranky, like its disappearing for a (very) short while.
hard to explain but I was hoping that someone might encounter this problem sometimes and might recognize it.
Thanks for any ideas where to search for a problem.
Title: Re: Ts-808 problem need help
Post by: yyz_2112 on October 26, 2009, 11:44:29 AM
I have the same problem with my build, also from the tonepad layout. Not my 1st build by far, but the issue is the clipping is very farty and buzzy anywhere past 1/3 of the gain level.
Title: Re: Ts-808 problem need help
Post by: dougman0988 on October 26, 2009, 11:59:19 AM
I noticed in the build that there is no bypass capacitor from 9v to ground.  I'm assuming other people have built this pedal and got it to work fine, but it might be worth trying.  Put a small (maybe 100-200pF) across 9v and ground.  It should help keep the circuit stable when at high gain, which is when the problem occurs.  Another thing to check might be the ground connection.  How is the grounding done for this build?  Make sure its a good connection.
Title: Re: Ts-808 problem need help
Post by: bipedal on October 26, 2009, 12:08:46 PM
I've had good success using Tonepad's TS808 layout, no changes needed.

Try the usual troubleshooting steps, check for reversed transistors, missed traces and solder bridges.

Can you post a pic of your build?
Title: Re: Ts-808 problem need help
Post by: differo on October 27, 2009, 05:52:29 AM
I fixed it. Now, the problem is, which i really hate, is that when i fix something and i do not know how i did it. :) the reason for this is that i did some debugging and changed stuff sometimes without checking: checked all solder joints (re-solder) and not testing the circuit after EVERY small fix. I think thou that the electrolyte cap. in the input stage did the magic, i changed it to another one (same capacity but different brand) and the gain pot seemed to have bad solder joint. Now it works like it worked from the beginning. I'm gonna try to  add a small cap between the 9v and the ground.
Now another question about overdrive-type of effect in general: how do you proceed with the shielding the signal from/to jacks/switch/PCB? this is kinda a foggy area - I always shield it from the guitar side, but maybe it is sufficient with the plain wire on the output side?? It's hard to measure the noise introduced if a cable is not shielded on the output side. It just doesn't seem to have any effect but then again..
What are your experiences/practice?
Title: Re: Ts-808 problem need help
Post by: anchovie on October 27, 2009, 06:44:22 AM
I've never used shielded cable in a TS or any overdrive of similar gain, just a metal enclosure. I've only needed it for high-gain circuits like the Dr Boogey that risk oscillation when the input and output are connected close together on the footswitch.
Title: Re: Ts-808 problem need help
Post by: differo on October 27, 2009, 11:44:10 AM
thank for that, I'll try to see if there is a difference in wiring with standard wire only. it's kinda messy with shielded cables they just take too much space! :)
Title: Re: Ts-808 problem need help
Post by: petemoore on October 27, 2009, 12:58:36 PM
  If it's workin' I wouldn't change it until I 'had' to.
  Shielded wiring won't hurt, but for the troubles/benefits it's not worth messing with.