Joyo - JF-08 Digital Delay [gut shots]

All about modern commercial stompbox circuits from Electro Harmonix over MXR, Boss and Ibanez into the nineties.

Re: Joyo Digital Delay (pcb pic)

Postby Fender3D » 17 Sep 2014, 12:50

alexradium wrote:whatever you input,it always works on 5V.


This is not completely right...
78Lxx regulators can stand 0,7W without heatsink, then you should check the voltage drop would not exceed max power allowed.
ie with 12V it can feed 100mA, since you'll have 7V drop...
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Re: Joyo Digital Delay (pcb pic)

Postby zedsnotdead » 18 Sep 2014, 02:58

alexradium wrote:it is digital,because it utilizes a chip that converts analog signal to numbers,does its sampling work and then converts back from numbers to analog signal again.
So,in this case its a pure analog direct signal mixed with digital processed delay signal.
Pure analog delays are all those that use BBD chips such MN3007,SAD1024 etc.


Which chip is it?
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Re: Joyo Digital Delay (pcb pic)

Postby tabbycat » 18 Sep 2014, 03:15

zedsnotdead wrote:Which chip is it?

pcb details in the first posts in this thread, worth reading back...
viewtopic.php?f=1&t=15567#p174576

"Chips are PT2399, SA571N, RC4558P" to quote initial poster.
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"there is no excellent beauty that hath not some strangeness in the proportion" (francis bacon).
"ni dieu ni maître" (anarchist slogan).
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Re: Joyo Digital Delay (pcb pic)

Postby zedsnotdead » 18 Sep 2014, 03:22

So... SA571N? Is this the one that converts analog signal to binary?
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Re: Joyo Digital Delay (pcb pic)

Postby Dirk_Hendrik » 18 Sep 2014, 07:22

zedsnotdead wrote:So... SA571N? Is this the one that converts analog signal to binary?

I am aware forums are to ask questions. However there's also the concept of "how about figuring out yourself"? Since a 30 second search would have shown you the datasheets for the SA571 and the PT2399 chips. With those you could have answered the question yourself ;-)
Sorry. Plain out of planes.

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Re: Joyo Digital Delay (pcb pic)

Postby zedsnotdead » 18 Sep 2014, 13:38

Well... I took PT2399 out because it is one of the most used chips on the so called analog delays.

I thought that anything digital is something that has at least a DAC/ADC converter somewhere on the signal path, am I right?
So if it's not 2399 doing this, I thought it must be SA571, but I got confused because what i found is that this is a Compander chip, and according to datasheets it has nothing to do with binary code whatsoever.
http://www.onsemi.com/pub_link/Collateral/AND8159-D.PDF
http://en.wikipedia.org/wiki/Companding ("Companding is used in digital telephony systems, compressing before input to an analog-to-digital converter, and then expanding after a digital-to-analog converter.(...)")

So where is the ADC/DAC, if its not PT2399 or 571N chip?

There's something Im missing here.... a lot.
And to answer about the concept of "how about figuring out yourself", you can see im trying but I might be ignorant, but im not stupid...
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Re: Joyo Digital Delay (pcb pic)

Postby Fender3D » 18 Sep 2014, 13:57

Did you check PT's datasheet?
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Re: Joyo Digital Delay (pcb pic)

Postby zedsnotdead » 18 Sep 2014, 17:52

:slap: of course, you are right!
I took it out of the "equation" because it's been used for those so-called "analog" delays, or so i thought. But I was wrong, like deep blue delay it's digital/analog (and not analog only)...
Thank you all!
My bad sorry guys.
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Joyo Digital Delay Problems

Postby tuftywarden » 29 Mar 2017, 14:02

Hi!

I joined the forum as I have a faulty Joyo Digital Delay and very limited knowledge of electronics!

As far as I can tell the board looks to be in tact. I found another thread which recommended checking if the IC heated up during use. It doesn't.

There is power (the LED comes on. Guitar passes through when off, but not when on. If I turn up the Level pot it produces a horrible squeal.

If anyone has any clues on how to fix this, I'd really appreciate it!

Thanks

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