Cusack - Tap-A-Phase [gutshots]

culturejam · Post by **culturejam** » 22 May 2010, 04:37

The layout and look of it on the inside reminds me a lot of the Malekko Ekko 616.

Jack Deville · Post by **Jack Deville** » 22 May 2010, 05:26

I dunno.
Different component selection, power/signal tracking follows a different scheme, ground plane on one side instead of both, 3PDT switch employed instead of relay/controller scheme, even the silkscreen looks different. There's a few other big differences I can spot.
Maybe though...who knows.

Nice design and execution.

culturejam · Post by **culturejam** » 22 May 2010, 19:31

Jack Deville wrote:I dunno.
Different component selection, power/signal tracking follows a different scheme, ground plane on one side instead of both, 3PDT switch employed instead of relay/controller scheme, even the silkscreen looks different. There's a few other big differences I can spot.
Maybe though...who knows.

Hey, I've been totally wrong on a number of other occasions, so I don't see why this would be an exception.

Dirk_Hendrik · Post by **Dirk_Hendrik** » 22 May 2010, 20:55

Jack Deville wrote: Nice design and execution.

I second that.

(even while being in the Atmel and not Microchip PIC camp)

quaternotetriplet · Post by **quaternotetriplet** » 23 May 2010, 12:19

any one traced the relay switch that cusack uses?

marshmellow · Post by **marshmellow** » 23 May 2010, 13:37

There ain't much to trace. The microcontroller is waiting all day long of his boring life until the guitar player stomps on the switch and then toggles the output that is connected to the relay. Probably via an additional switching transistor due to the current demand of the relay.

quaternotetriplet · Post by **quaternotetriplet** » 23 May 2010, 13:53

marshmellow wrote:There ain't much to trace. The microcontroller is waiting all day long of his boring life until the guitar player stomps on the switch and then toggles the output that is connected to the relay. Probably via an additional switching transistor due to the current demand of the relay.

his claim it last longer than our good old friend 3pdt.. is that true?

Jack Deville · Post by **Jack Deville** » 23 May 2010, 15:40

marshmellow wrote:There ain't much to trace. The microcontroller is waiting all day long of his boring life until the guitar player stomps on the switch and then toggles the output that is connected to the relay. Probably via an additional switching transistor due to the current demand of the relay.

I wouldn't dismiss the system so quickly. There is a bit more to this design than you will observe with the first glance.
I think the controller is doing a little more than relay management in this one too.

quaternotetriplet wrote:his claim it last longer than our good old friend 3pdt.. is that true?

Certainly is. IIRC that relay is rated at 10^8 cycles, compare w/ the 3PDT switch which is rated at 2*10^4.
I've personally observed over 400,000 cycles of my relay system without fault/failure/performance loss. Can't say I've seen a 3PDT switch pull that kind of duty.

marshmellow · Post by **marshmellow** » 23 May 2010, 17:04

Jack Deville wrote:I wouldn't dismiss the system so quickly. There is a bit more to this design than you will observe with the first glance.
I think the controller is doing a little more than relay management in this one too.

Sure, it also serves the tap tempo/LFO duties. And I didn't mean to dismiss anything at all. As I already mentioned in the other recent Cusack thread, I really like his approach for the bypass, because I do it just the same way. The only thing I would have added, since already using the µC for the LFO, would be an envelope control mode.

But still, I'm with Mr. Hendrik on the Atmels.

Jack Deville · Post by **Jack Deville** » 23 May 2010, 17:08

marshmellow wrote: But still, I'm with Mr. Hendrik on the Atmels.

Dirk_Hendrik · Post by **Dirk_Hendrik** » 23 May 2010, 17:16

marshmellow wrote: since already using the µC for the LFO, would be an envelope control mode.

Which is an entirely different task compared to a simple timer for the taptempo, bypass control or waveform generation (which are just way simpler and less complex when being done in software).
To do envelope control one requires AD conversion. That's fairly easy for an average PIC or AVR but one can wonder if the usual 8-bitters in these controllers are fast enough to follow the signals envelope and convert that information to the control output (assumed PWM) accordingly.

muki · Post by **muki** » 07 Jun 2010, 17:48

Dirk_Hendrik wrote:one can wonder if the usual 8-bitters in these controllers are fast enough to follow the signals envelope and convert that information to the control output (assumed PWM) accordingly.

yes they can. I've done it.

jimbob_400 · Post by **jimbob_400** » 09 Jun 2010, 22:20

There more to the switching system.

If you hold down the switch you can turn the bypass LED on or off, at least on my screamer fuzz you can.

Also when the battery is going low the LED will start to flash and then after a while when you plug it in the LED will flash and the pedal will refuse to turn on until the battery is replaced. I think if you press the switch with a low battery the LED flashes and the pedal stays in bypass.

Jack Deville · Post by **Jack Deville** » 10 Jun 2010, 00:22

So it begins...

There's more too.