Demedash Effects - T120 Videotape Echo Pedal

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Demedash Effects - T120 Videotape Echo Pedal

Postby Seiche » 06 Apr 2019, 12:31

Saw this on Insta. Apparently it's the deluxe version with two switches that hasn't even come out yet.

Almost all the part values and connections are good to see, so one should be able to do pretty good trace of this.

The only tricky part is that there are smd parts on both sides of the pcb :blackeye

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Re: Demedash Effects - T120 Videotape Echo Pedal

Postby Seiche » 15 Apr 2019, 10:56

the most interesting part is probably the silent switching circuit without a microcontroller (using the cd4053 as a switch and the LM555 as a bistable flip flop to supply a control voltage to the cd4053 with a momentary spst)

http://www.geofex.com/article_folders/cd4053/cd4053.htm

https://todbot.com/blog/2010/01/02/mome ... using-555/

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Re: Demedash Effects - T120 Videotape Echo Pedal

Postby trampled_empire » 18 Apr 2019, 22:51

Hey, Steve from Demedash Effects here.
Let me know if you figure out how to overcome the issues inherent in the one design here. I ended up switching out a good chunk of it for something else.

Also, I tend to use different values than the silkscreen says lol so that might make it tricky.

Probably gonna just scrap this and start from scratch after finding this though.
I'm cool with sharing stuff in private and make a big effort to help anyone learn about this stuff... but I'm a single person operation running on a tight budget so this sort of thing isn't cool.

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Re: Demedash Effects - T120 Videotape Echo Pedal

Postby Seiche » 19 Apr 2019, 07:55

This is openly accessible on your instagram, why would you even post it?
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Re: Demedash Effects - T120 Videotape Echo Pedal

Postby PMowdes » 19 Apr 2019, 09:30

Seiche wrote:This is openly accessible on your instagram, why would you even post it?


Why shouldn't be post it?? It's not an open invitation for people to copy his stuff.

I now this is a DIY forum and tracing circuits is what it's all about but at least let the guy release the thing first and make a few bucks before you rob him blind.

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Re: Demedash Effects - T120 Videotape Echo Pedal

Postby Seiche » 19 Apr 2019, 10:34

PMowdes, are you yourself not selling clone pcbs of currently in production pedals on your website? Or is spaceman authorizing you to trace and clone their circuits commercially?

I reposted one picture that the builder himself posted on insta to this forum, that's all I did. Furthermore, it's mostly SMD on both sides of the board, good luck tracing that. If this is crossing the line, then this community can pack it up.

Nobody is even showing interest in tracing this so far. It looks like it's a PT2399 delay with modulation and some clever (active?) filtering to make it sound more or less lofi, together with some interesting soft switching and a momentary switch to toggle oscillation. Never seen that before (at least since 2014, maybe that's what makes it retro).

To be fair, the enclosure is awesome and hits all the right spots for nostalgia and the demos sound pretty good, so I wish nothing but the best to Steve, but talking about "robbing" anyone and "stealing" and the outrage is a bit much tbh. You know the main point of this forum is not to copy and make a quick buck and this has always been actively discouraged in the past. Hell, half the "pedal scandals" of well-known companies copying small builders were uncovered here (lovepedal amp11 for one).
Last edited by Seiche on 19 Apr 2019, 11:42, edited 3 times in total.

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Re: Demedash Effects - T120 Videotape Echo Pedal

Postby Seiche » 19 Apr 2019, 10:48

trampled_empire wrote:Let me know if you figure out how to overcome the issues inherent in the one design here. I ended up switching out a good chunk of it for something else.

I can only guess what you are referring to, but I assume it's about the lm/ne555. R.G. himself posted the following advice here, maybe it helps:
R.G. wrote:There is a useful rule in designing effects - don't use the NE555. The NE555 has huge current spikes in its power and ground supplies right at the places where its output switches. Instead, use the LMC555 or one of the other CMOS versions that do not have the big current spikes.
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Re: Demedash Effects - T120 Videotape Echo Pedal

Postby trampled_empire » 19 Apr 2019, 19:23

Seiche wrote:This is openly accessible on your instagram, why would you even post it?


I posted this photo. You commented "I'm gonna trace this".
I thought to myself, 'damn, I thought better of the people who follow me', and took it down. It is NOT up for anyone to see. Further, you did not get permission to repost PCB artwork.
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Re: Demedash Effects - T120 Videotape Echo Pedal

Postby trampled_empire » 19 Apr 2019, 19:47

Seiche wrote:I can only guess what you are referring to, but I assume it's about the lm/ne555. R.G. himself posted the following advice here, maybe it helps:
R.G. wrote:There is a useful rule in designing effects - don't use the NE555. The NE555 has huge current spikes in its power and ground supplies right at the places where its output switches. Instead, use the LMC555 or one of the other CMOS versions that do not have the big current spikes.

Nope. Again, just because the footprint just says 555, that doesn't mean that's the exact part I'm using. The CMOS thing is fairly well-known.
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Re: Demedash Effects - T120 Videotape Echo Pedal

Postby modman » Yesterday, 18:03

Hi Trampled Empire,

We have a thread devoted to these issues: viewtopic.php?f=6&t=11263
It is a thread in which we collected all similar objections (you are taking food out of my mouth). Your arguments make no sense whatsoever, it's just sales talk. From a technical perspective, the history of guitar pedals is one of constant cloning, copying, emulating and improving.

You claim to be the owner of the brand, still I cannot see any prove of that in your profile or registered email. However, you have been a silent member since 2017...

There was the JHS VCR (€219), and even a pedalpcb version using the FV-1 chip,
"The whole point of diy is diy. It's not dsoiyathodtr - do some of it yourself and then have others do the rest" (paulc)
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