Geofex parametric EQ PCB and layout

[Morocotopo]

Hi, someone asked me for my layout for the parametric EQ at Geofex, so here it is:

[Aharon]

Thanks  for posting it.
Aharon

[QSQCaito]

Muchisimas gracias morocotopo, era yo el que te lo habia pedido..
Un par de preguntas.. los pots son todos lineales no??
Y el capacitor 7, vos lo usaste electrolitico no??
El diodo y el cap A y B los agregaste vos no?? para filtrar un poco? y el diodo para q?

Muchas Gracias che.. ya toy por hacerlo..

Okok, in english

Thanks a lot morocotopo, it was me who asked for the layout.

Couple of questions, are all the pots linear(b)??
Cap 7, you used it electrolitic right??
And..  the diode and capacitor A & B, where added by you right? to filter, and the diode, what for??

Thank you a lot, im about to do it..

Muchas Gracias, Thank you a lot

Chau, Bye bye

Diego Andrés Cao

PS Como suena?? How does it sound?

[Morocotopo]

Comments:
I built it with the parts values specified in the article, works OK, the freq range is a bit limited, i think it´s best for shaping electric guitar thru electric amp sounds. Good when shaping distorted sounds (after a OD/dist), there it shines for fine tuning the tonal response of said FX. Some settings sound as a fixed wah wah (always nice!). I never experimented with changing the freq of each filter, might be worthwhile.
I replaced some components values, can´t remember wich ones, I think 51K R, not available here. Op amps: TL072. Components
A and B are for reverse voltage protection and power filtering, optional. The article doesn´t mention how much dB it cuts/boosts. R.G.? the empty holes in the PCB are for getting 9V, gnd and 1/2V to another circuit, I added a shaka boost at the output, to be able to vary level, but in retrospect it wasn´t really neccesary. Lotsa pots and knobs! Some resistors don´t lay flat in the board, they fit semi-standing (like this / ). The pot lugs might be identified wrong, if the knobs work the wrong (opposite) way, swap point 1 for point 3 in all pots. I replaced R2 for 1Meg, as suggested by ¿Bioroids? I believe the PCB is ready to print at the right size, but check before printing to PnP, i´m not that expert at manipulating graphics images  .

Geofex= goldmine!

Hope it helps someone, Thanks to all that helped me in this forum! Questions welcome.

Morocotopo

[Morocotopo]

Oh, don´t type so fast guys!!!   

QSQ: yes, the pots are linear. The cap 7 I - think - I used electrolitic, it´s already boxed... I believe, from what i saw in other circuits, and by the value (47uF), that it should be electrolitic. This cap and the diode I added, answer above.
Escribo en ingles para que todos puedan leer, esta bien? De paso, practicamos ingles...

morocotopo

[QSQCaito]

Gracias morocotopo. Por la resistencia de 51k, voy a hacer alguna combinacion R2 va a ser 1meg.. Y respecto al rango, estuve buscando en internet, y EN TEORIA cubre el rango de una guitarra electrica 40-2000Hz.. Asi que apenas llegue a Bs As lo empiezo a hacer..

por lo que veo, el shaka boost que garegaste, no lo agregaste en el pcb no?? Igual con toda la cadena de efectos q voy a tenerm no creo q sea necesario.. el capacitor A voy a ver si le pomngo de mayor valor porq voy a usar un transformador, pero igual va a estar filtrado..(geo's spyder).. Los circuitos integrados voy a usar tl072 tmb..
Si dps te acordas si cambiaste de valor algun otra cosa y dio resultado positivo aivsame chau gracias..
Muchas gracias

In english? Thanks morocotopo, for the 51kR, i will made some combiantion, to reach that 51k asked , R2=1M, And regarding the Fq range, i was searching on the net and IN THEORY it covers all the range of a guitar 40-2k HZ.. As soon as i arrive to Buenos Aires(capital of Argentina) I'll start building it
I see the shaka boost is not added on the layout, hopefully it won't be necessary. Capacitor A ill try to give a bigger value, because i'll use no battery.. i'll use the Geo's Spyder.. which is already filtrated anyway.. ill use tl072 too.
If you remember which other value you changed, which made it sound better, please let me know.

Thank you alot

Gracias, Thanks
Chau, Bye
Diego Andrés Cao

PS Excuse my english

[Morocotopo]

Los parlantes de electrica reproducen hasta 5K en general, este EQ no llega hasta las frecuencias mas altas de la electrica, en los graves mi EQ no llega hasta el mi de la 6ta al aire, mas bien hasta el la de la 5ta,  creo que llega + o - hasta 100Hz, creo que el mi esta cerca de 70 Hz... siempre hablando de la frecuencia centro de los filtros. Yo quiero un EQ que me sirva tambien para acustica ( que abarque todo el espectro de frecuencias audibles), estoy investigando otros circuitos.. Igual es un circuito piola para hacer y tener.

[QSQCaito]

= no te olvides que por cada tl072 que agregas, agregas tambien dos estapas mas.. con tres controles cada una.. y el rango de frecuancias lo podrias elegir.. en mi opinion personal, yo lo haria de 3 etapas, porq 12 potenciometros ya es mucho.. con 3 etapas podrias cubrir bien todo el espectro de una electrica

[BDuguay]

Sorry for the interuption but, Hey Aharon! Check your P.M. you silly boy!
Brian