Building the Echo Base PCB

[telebiker]

A quick question, does anyone remember which position of the waveshape pot corresponds the square / triangle setting? For example, do I remember correctly that CCW for waveshape is a triangle?

Thanks.

[spilla]

I've just finished up the Echo Base pcb. All seems to be working except the depth knob is changing the pitch of the repeats when the LFO SW pads are connected.

Does the depth knob behave that way normally?

I have the LFO wave shape mod also installed (it works when the LFO SW  pads are disconnected)

[telebiker]

I have the LFO wave shape mod also installed (it works when the LFO SW  pads are disconnected)

Do you have the triangle wave on the CCW (top left) position of the pot?

[garcho]

The depth knob is supposed to do just that. It changes the delay time at the rate of the LFO. Changing delay time changes pitch, slow down = pitch down, and vice versa. It comes from wanting to emulate the old tape machine delays. It can also make a great “laser” synth sound when the rate and depth is up and the shape is square.

[garcho]

Telebiker, are you asking because you want to design the graphics for a build but haven’t built it yet? I think the triangle will be CW, it’s tapped off of U1A. Are you using the musicpcb schematic/build doc?

[spilla]

The depth knob is supposed to do just that. It changes the delay time at the rate of the LFO. Changing delay time changes pitch, slow down = pitch down, and vice versa. It comes from wanting to emulate the old tape machine delays. It can also make a great “laser” synth sound when the rate and depth is up and the shape is square.

Great, thanks!

and just to clarify the lfo depth pot changes the pitch of the delay even when the modulation is turned off?

[telebiker]

Telebiker, are you asking because you want to design the graphics for a build but haven’t built it yet?

No.

Are you using the musicpcb schematic/build doc?

Yes.

Already figured it out. While testing the PCB forgot to note which side of the waveshape pot is triangle. I have it on a CW side.

[spilla]

Sorry to bump the thread again

But could someone confirm/deny if the "lfo depth" pot is meant to change the pitch of the repeats when the modulation is turned off (LFO SW pads disconnected)?

Thanks!

[telebiker]

I hope that I will be able to check this next week.

[eh là bas ma]

Sorry to bump the thread again

But could someone confirm/deny if the "lfo depth" pot is meant to change the pitch of the repeats when the modulation is turned off (LFO SW pads disconnected)?

Thanks!

On my unit, with LFO switched off, if the Waveform's pot is set on triangle or square, or something (I don't really know for sure what is what), Depth will change the sound of the delay's repetitions  in various ways.
 If Waveforms is on sinusoidal (clearest and most transparent setting, I think), Depth will be audible when I turn the pot (alarm siren kind of sound), and it seems to add some depth to the delayed signal. In any case, Depth is alive and interacting particularly with Waveforms. It is welcome, in my opinion.

[spilla]

I contacted musicpcb and they confirm that the depth pot does change pitch of the delay when mod is off.

It is welcome, in my opinion.

Yeah im really happy with how it sounds now, glad thats how its intended. I was considering leaving it this way had i found out i messed something up!

[eh là bas ma]

Yes, assuming your capacitors are rated for more than that,  it's safe to use a regulated 12 volt supply. You can use any voltage between 9 and 15 volts, over 15 volts and you will damage the CD4066.

This answer is 9 years old now.
Can someone confirm that Echo Base from 2019 or 2020 still can be safely powered with 12v, please ? It will be very useful to know.

[garcho]

Echo Base from 2019 or 2020

what does that mean? is there a new one? these types of threads get longer than they are useful over the years.

safely powered with 12v

Most op amps can take 12V but make sure you check the datasheet for the op amps that you're actually using in the build. A TL072 can take 36V. The `4066 can most likely take 12V, but again read up on the datasheet for the model you'll actually put in the build. These are old ICs, from the higher voltage and bipolar supply days, but more and more, they and their contemporary versions are being made for today's low power electronics.
It would destroy the PT2399 but it's getting regulated voltage off the 7805, so no worry.
Linear voltage regulators like the 7805 will be fine but the more voltage across it, the more heat to be dissipated. In this case, probably not a problem.
Don't sweat the other stuff for voltages like 9 and 12.