Almost finished Polyphase project, one snag. Help please.

[nelson]

Hi onlookers, Sages, newbies, tinkerers, breadboard boilers and jellyspoons.

I have almost finished the project documentation for the EH polyphase/deluxe phaser. I only have the Envelope fed LFO section to lay out. The schematic has a problem on it for which I need some help.







Circled in red is the confusing bit, it appears as if there is a 13K resistor intersecting ground. This can't be right, can someone explain/draw how it is supposed to be drawn?

There is also the little matter of the thermistor I have no idea what resistance it is supposed to be. I cant see why a thermistor needs to be used.


Any advise/help appreciated.

Thanks

[nelson]

Here is some circuit Porn.






The black outline is the size of a 1590BB

[hank reynolds 3rd]

Hi Nelson,
I'm not sure what this does, but is it something to do with the power rails (it looks like it's going to the 15v+ aswell)...
i think i've seen similar on other old eh schems....

Sam

[hank reynolds 3rd]

when do you find time for all this???
echoflanger,clone theory,now polyphase..damn!!

Gotta echoflanger to build when i get the spare funds, it's the lola ferrari of modulation, by the looks of things!!!

[nelson]

when do you find time for all this???
echoflanger,clone theory,now polyphase..damn!!

Gotta echoflanger to build when i get the spare funds, it's the lola ferrari of modulation, by the looks of things!!!

Dont forget the opamp muff 


I am a student, I have alot of holidays, I am still on holiday after the festive period right now. I should probably be studying, after the polyphase I am going to take a break and concentrate on uni work.

The echoflanger is an amazing pedal, it certainly gives you lots to play with. 
The echoflanger layout is the original layout only modified a little. Your simile doesnt stand.





I have wanted to clone these

[Dirk_Hendrik]

Regarding the PCB layout I wonder why you use so much "trace hugging" (as it's called). To me there doesn't seem to ba any need to have all traces following the same curves instrad of a direct connection. In some of the traces I don't see any logic.

Lemme maka an example. Give me a few minutes.

[hank reynolds 3rd]

hhmpphhh... i was thinking along  the lines of pedal porn and more knobs than most..... and it wouldn't stand anyways, as those huge breasts would have broke her back....

[nelson]

hhmpphhh... i was thinking along  the lines of pedal porn and more knobs than most..... and it wouldn't stand anyways, as those huge breasts would have broke her back....

[Dirk_Hendrik]

find the (quick MS paint made) differences:


When routing PCB layouts I always try to have connections as short as possible. Therefore I will never have  a trace following the curve of an adjacent trace if not required and definitely not add fully unnessecary curves. (for filling up board space?)

no flame intended

[nelson]

find the differences:


When rouring PCB layouts I always try to have connections as short as possible. Therefore I will never have  a trace following the curve of an adjacent trace if not required and definitely not add fully unnessecary curves. (for filling up board space?)

no flame intended

Then the trace would be running through where I plan to put the envelope follower section. Trace hugging is an easy way to conserve space and make the layout as tight as possible. If I was to have direct traces all the time the layout would not fit in a 1590BB box, which is my aim. As it is its still going to be very tight. I have to fit the schematic above in the little space that is left in the layout.

Trust me there is a logic to it, its not just to look nice. Although I think it does.

[Dirk_Hendrik]

I see,
Still, keep those traces on the right straight without loss of space. Don't get me wrong I'm not (as a matter of fact I am maybe) critisizing. At least not in a negative perspective. A few years ago I spent some 6 months in the PCB design department of a mixing console manufacturer. The first thing they had to get me rid of wat the "artistic" perspective.

[nelson]

I see,
Still, keep those traces on the right straight without loss of space. Don't get me wrong I'm not (as a matter of fact I am maybe) critisizing. At least not in a negative perspective. A few years ago I spent some 6 months in the PCB design department of a mixing console manufacturer. The first thing they had to get me rid of wat the "artistic" perspective.

I am not a professional, nor do I ever see myself doing it for a company.

Aslong as it doesnt cause noise, fits in my selected enclosure and maybe works, I am happy.

But thanks for your advise, I am just using a method that seems to work for me.

My boards look hand drawn, I mean I am cloning an effect from the 70's the original will have had curvy traces and probably involved a little trace hugging.

If I spent more time thinking about part placement and logically laying out the board autocad style, I might aswell use Eagle.
This sort of adhoc making sure there is maximum space available way I work suits me.

[nelson]

yeah, back to the topic.

I need some clarity on how the schematic is supposed to be.

Damn, its a voltage divider isnt it?

Edit: I cant believe I didnt see that.