Echo Base build complete, minor issues…

[TuffGnarl]

Still being made this fantastic circuit 

This one had a difficult start- bought a kit from musikding, built it, wet signal worked but the dry never did. As I debugged it the odd pad began to delaminate, I made jumper connections, then another one went, another jumper, then... well, you get the picture.

An error message that then popped up on my iron revealed the heating element was failing 

New iron, and given how good this sounded in samples, I decided to salvage what components I could from the board and re-build the thing on vero. Pleased I did because what I can hear sounds brilliant.


It's very nearly there and I'm wondering if anyone else has had this issue and might be able to help?

All controls work, in terms of adjusting sound parameters but I have constant bleed through of sound. Just fractionally louder when the effect (and LED) is on, but it carries on working as normal either way.

Also, endless (I think) feedback repeats that carry on when bypassed as normal and with the tails switch OFF still do carry on, though fade out over about 15 seconds. Interestingly, while these repeats are going on, flicking the modulation to on kills them in a second or so.

The feedback effect is very full on, about a quarter turn seems to max it, I'll try the 100k resistor swap shortly.

I mean, this pedal would be amazing for a noisy ambient end of a show, with repeats rattling on and folding in to themselves as the guitar in banged and moved... but I'd really like that bypass to kill things please 










Layout:



Voltage at power supply- 8.97V
Modulation off

IC1 072
Pin 1- 5v
Pin 2- 5v
Pin 3- 5v
Pin 4- 0.6v
Pin 5- 2.6v
Pin 6- 5v
Pin 7- 1.9v
Pin 8- 8.2v


IC2 072
Pin 1- 5v
Pin 2- 5v
Pin 3- 5v
Pin 4- 0v
Pin 5- 2.5v
Pin 6- 5
Pin 7- 5
Pin 8- 8.97

IC3 4066
Pin 1- 2.83
Pin 2- 2.83
Pin 3- 2.84
Pin 4- 2.84
Pin 5- 8.43
Pin 6- 0.65
Pin 7- 0
Pin 8- 2.47
Pin 9- 2.48
Pin 10- 0
Pin 11- 0
Pin 12- 0
Pin 13- 7.27
Pin 14- 8.97

IC4
Pin 1- 5
Pin 2- 2.5
Pin 3- 0
Pin 4- 0
Pin 5- 2.6
Pin 6- 2.5
Pin 7- 1.1
Pin 8- 1.3
Pin 9- 2.51
Pin 10- 2.51
Pin 11- 2.51
Pin 12- 2.51
Pin 13- 2.5
Pin 14- 2.51
Pin 15- 2.51
Pin 16- 2.5

Q1 78L05
1- 5
2– 0
3- 8.9

Q2 5089
1- 0
2– 0
3- 8.5

Q3 5088
1- 0
2– 0
3- 1

Any thoughts appreciated.

[antonis]

Hi & Welcome..

Could you plz post some pics of your build..??
(I suspect some shorts aw well as open circuits..)

A schematic to refer on:

[Mark Hammer]

The 4066 chip is critical to the working of the circuit.  It is also sensitive to static.  Not EASILY damaged, necessarily, but damageable.  If you have a spare, and the existing one is socketed, try a chip swap.

[TuffGnarl]

An FYI- yes, increasing resistance for that 20 helps with the feedback pot- added a 100k in series to get 120k and it's more like 3 o'clock now before the oscillations really build.

[TuffGnarl]

Hi & Welcome..

Could you plz post some pics of your build..??
(I suspect some shorts aw well as open circuits..)

A schematic to refer on:

Hi Antonis- there are pics here, but did you mean the underside, I'll need to dismantle everything, but will do if a chip swap doesn't work.
Did heavily score the gaps with a Stanley blade and clean everything with isopropyl so I'd hope there are no shorts there. As ever, possible though, entirely possible 😂

[TuffGnarl]

The 4066 chip is critical to the working of the circuit.  It is also sensitive to static.  Not EASILY damaged, necessarily, but damageable.  If you have a spare, and the existing one is socketed, try a chip swap.

Thank you- it is certainly possible it got damaged- struggling to find 4066's but have a couple of 4016's (same but draw a touch more power I believe) coming that I'll try imminently 👍

[duck_arse]

the 4016 was the earlier version, with higher ON resistance. the 4066 is the later version with improved, lower on resistance.

[TuffGnarl]

Tried two 4016's, and also several of the two NPN and PNP transistors. The "always on" issue is still there unfortunately
I could just wire it as true bypass I guess, but that wasn't the point of the circuit, and I'd lose the tails feature when switching it off.

Interestingly, the delayed/wet notes are a touch more feint when off and then louder when on. The dry volume remains the same.
Switching the dry signal off, via the switch results in jut the wet delay present when on and NEITHER the dry OR wet signal on when off. If the pedals off and I set that dry cut switch back on then both the wet and dry signals are back as before.

I can't make sense of this, bah.

[ElectricDruid]

Are the "A" and "B" signals switching like we expect?

Doesn't matter what the 4066/4016 is doing if it's not getting the right signals to switch it on or off...