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previous: bburns75 PCB layout for 808? -- 8/14/2000 2:40 PM

Re: PCB layout for 808? (warning: Long reply)

8/20/2000 2:19 AM
Charlie	Re: PCB layout for 808? (warning: Long reply) I etched and built up a TS using Willy's layout and R.G.'s "Anatomy of the Tube Screamer" for guidence and it worked out great on it's first "smoke test" Couple of notes on it. I used Radio Shack 1uF film caps in place of non-polorized electro's on the board and it was a bit of a tight fit but workable. The 1uF cap and the .22uF cap on the left side of the IC socket is up very close and tight so extra care needed when inserting what ever chip you use so the pins do not get bent, take your time here. Most of the resistors and the clipping diodes are soldered in place standing on end rather than laying flat on the board. A couple of the film caps near the forward end of the right side 1uF will also need to be tweaked in place to make the components fit. The circuit will fit into a Hammond 1590BB box with some careful measuring and using R.G.'s layout template for a guide (measure twice, drill once). I suggest using 16mm pots to get some adjusting room when placing the board in position. I did not have a 20k pot so I subbed a 50k for the tone control, seems to work fine. The input, output jacks are positoned equal to the stomp switch near the end of the box. The battery needed to be placed along side the circuit for a comfortable fit since the jacks and switch do not leave very much room where most layouts show battery placement. I used the standard bypass arrangement and left out the power jack for now and will add one later and replace the tone pot for proper value when I paint the box. I tested a few IC's in the circuit. A TL072, LM833 and a MC4558CN from Mouser. I havn't been able to to obtain a JRC4558 nor a "real" TS to A/B the pedal nor any audio testing equipment so using some sound clips from the net I gave each chip a go thru using a Strat, an Ibanez AC50 for guitars and a Fender BXR100 and a Crate VC30 for the amps. Each one did a very good job appoximating a TS sound compared to the sound clips IMHO and I settled on the MC4558, tho if I'm able to get hold of the JRC4558 it will have a home This circuit was a pleasure to build, experiment and play like all the rest of the circuits provided by some great people and I recommend it as well as using it for a 808 board, it lends itself very easy to mod. Execellent work on the circuit Willy Right up there with the rest. Thanks bro!

8/20/2000 2:19 AM

Charlie

Re: PCB layout for 808? (warning: Long reply)

I etched and built up a TS using Willy's layout and R.G.'s "Anatomy of the Tube Screamer" for guidence and it worked out great on it's first "smoke test" ;-)

Couple of notes on it. I used Radio Shack 1uF film caps in place of non-polorized electro's on the board and it was a bit of a tight fit but workable. The 1uF cap and the .22uF cap on the left side of the IC socket is up very close and tight so extra care needed when inserting what ever chip you use so the pins do not get bent, take your time here.

Most of the resistors and the clipping diodes are soldered in place standing on end rather than laying flat on the board. A couple of the film caps near the forward end of the right side 1uF will also need to be tweaked in place to make the components fit. The circuit will fit into a Hammond 1590BB box with some careful measuring and using R.G.'s layout template for a guide (measure twice, drill once).

I suggest using 16mm pots to get some adjusting room when placing the board in position. I did not have a 20k pot so I subbed a 50k for the tone control, seems to work fine. The input, output jacks are positoned equal to the stomp switch near the end of the box. The battery needed to be placed along side the circuit for a comfortable fit since the jacks and switch do not leave very much room where most layouts show battery placement.

I used the standard bypass arrangement and left out the power jack for now and will add one later and replace the tone pot for proper value when I paint the box.

I tested a few IC's in the circuit. A TL072, LM833 and a MC4558CN from Mouser. I havn't been able to to obtain a JRC4558 nor a "real" TS to A/B the pedal nor any audio testing equipment so using some sound clips from the net I gave each chip a go thru using a Strat, an Ibanez AC50 for guitars and a Fender BXR100 and a Crate VC30 for the amps. Each one did a very good job appoximating a TS sound compared to the sound clips IMHO and I settled on the MC4558, tho if I'm able to get hold of the JRC4558 it will have a home ;-)

This circuit was a pleasure to build, experiment and play like all the rest of the circuits provided by some great people ;-)

and I recommend it as well as using it for a 808 board, it lends itself very easy to mod.

Execellent work on the circuit Willy ;-)

Right up there with the rest. Thanks bro!

Replies:

Willy Thanks, Charlie. I'm happy it was u... -- 8/20/2000 7:11 PM