A simple PT2399 diy flanger pedal?

Stompboxes circuits published in magazines, books or on DIY electronics websites.

Re: A simple PT2399 diy flanger pedal?

Postby ~arph » 16 Aug 2012, 14:08

Hides-His-Eyes wrote:you could try v_ref modulation like the little angel


I am trying this one of these days. I have some PT2396'es and yes, they are HUGE :shock: about twice the size of a pt2399.
In the quiet words of the virgin Mary: "Come again?"
User avatar
~arph
Cap Cooler
 
Posts: 601
Joined: 20 Sep 2007, 11:35
Has thanked: 62 times
Have thanks: 164 times

Re: A simple PT2399 diy flanger pedal?

Postby Dr Tony Balls » 16 Aug 2012, 19:21

the PT2396 may be huge, but its not exactly like there are a lot of small Flanger circuits around. Hardly a big deal, imo.
User avatar
Dr Tony Balls
Diode Debunker
 
Posts: 807
Joined: 07 May 2009, 15:29
Location: Brooklyn, NY
Has thanked: 2 times
Have thanks: 153 times

Re: A simple PT2399 diy flanger pedal?

Postby ppluis0 » 16 Aug 2012, 21:53

Hi there,

There is an "Echo processor IC" pin to pin compatible with the PT2399 that is named HT8970 and is manufactured by Holtek.

The datasheet of this chip are fond here: http://pdf1.alldatasheet.com/datasheet- ... T8970.html

The only difference with the PT2399 is that this IC has only 20 kilobits of storage memory and the minimun delay time attainable is of 30 milliseconds.

Is this time little enough to use as a flanger ??

As consecuence of search the web, I discover that there exist the HT8972 that looks to be identical and pin to pin compatible with the 2399...

Cheers,
Jose
User avatar
ppluis0
Cap Cooler
 
Posts: 493
Joined: 14 Jul 2010, 19:33
Location: Argentina
Has thanked: 33 times
Have thanks: 58 times

Dual PT2399 flanger

Postby merlinb » 17 Aug 2012, 09:36

A while ago I designed a PT2399 flanger using two devices, along the same lines mentioned earlier in this thread.
To avoid latency the dry signal was also mixed with the output, which also gave it a hint of reverb (interesting but unwanted). It does through zero and has a +/- phase switch. I got as far as designing the PCB, but in the end I decided I'd lost interest in it and would probably never use a flanger anyway, but I here is the unadulterated schem in case anyone else is interested.

http://dl.dropbox.com/u/57831278/flanger.pdf
merlinb
Solder Soldier
 
Posts: 175
Joined: 18 Nov 2010, 18:39
Has thanked: 0 time
Have thanks: 159 times

Re: A simple PT2399 diy flanger pedal?

Postby rocklander » 17 Aug 2012, 10:06

might have a crack at making a PCB for that.. thank you sir!
world's greatest tautologist ...in the world

Ronsonic wrote:...the lower the stakes the more vicious the combat.

User avatar
rocklander
Old Solderhand
 
Posts: 2887
Joined: 18 Apr 2008, 12:33
Location: Rotorua, New Zealand
Has thanked: 1555 times
Have thanks: 285 times

Re: Dual PT2399 flanger

Postby frequencycentral » 17 Aug 2012, 18:30

merlinb wrote:A while ago I designed a PT2399 flanger using two devices, along the same lines mentioned earlier in this thread.
To avoid latency the dry signal was also mixed with the output, which also gave it a hint of reverb (interesting but unwanted). It does through zero and has a +/- phase switch. I got as far as designing the PCB, but in the end I decided I'd lost interest in it and would probably never use a flanger anyway, but I here is the unadulterated schem in case anyone else is interested.

http://dl.dropbox.com/u/57831278/flanger.pdf


Wow! Holy grail Batman!
User avatar
frequencycentral
Diode Debunker
 
Posts: 704
Joined: 30 Mar 2009, 10:37
Location: United Kingdom
Has thanked: 30 times
Have thanks: 67 times

Re: A simple PT2399 diy flanger pedal?

Postby ~arph » 17 Aug 2012, 20:43

I want to hear it. 30ms still Seems too long
In the quiet words of the virgin Mary: "Come again?"
User avatar
~arph
Cap Cooler
 
Posts: 601
Joined: 20 Sep 2007, 11:35
Has thanked: 62 times
Have thanks: 164 times

Re: A simple PT2399 diy flanger pedal?

Postby ppluis0 » 17 Aug 2012, 23:45

~arph wrote:I want to hear it. 30ms still Seems too long


It's funny: the datasheet of the PT2399 indicates that have 44 kbit of ram, and a minimum delay time of 31.3 msec with the time potentiometer practically sort circuited.

The HT8970, having 20 kbit of ram, has a minimum delay of 29.78 msec... :scratch:

I assume that the amount of storage ram is directly correlated to min and max delay times... or not ?
User avatar
ppluis0
Cap Cooler
 
Posts: 493
Joined: 14 Jul 2010, 19:33
Location: Argentina
Has thanked: 33 times
Have thanks: 58 times

Re: A simple PT2399 diy flanger pedal?

Postby merlinb » 18 Aug 2012, 15:52

~arph wrote: 30ms still Seems too long

It is. That's why you have to use two of them...
merlinb
Solder Soldier
 
Posts: 175
Joined: 18 Nov 2010, 18:39
Has thanked: 0 time
Have thanks: 159 times

Re: Dual PT2399 flanger

Postby hbo » 27 Sep 2012, 22:59

merlinb wrote:A while ago I designed a PT2399 flanger using two devices, along the same lines mentioned earlier in this thread.
To avoid latency the dry signal was also mixed with the output, which also gave it a hint of reverb (interesting but unwanted). It does through zero and has a +/- phase switch. I got as far as designing the PCB, but in the end I decided I'd lost interest in it and would probably never use a flanger anyway, but I here is the unadulterated schem in case anyone else is interested.

http://dl.dropbox.com/u/57831278/flanger.pdf


I was curious to know what this circuit would sound like so I built one on vero.

Image

I initially had problems with the LFO not working properly, but eventually found out that it wasn't getting enough voltage with the series 1N4001 on the power rail. Having sorted this it worked almost flawlessly, but I found there's a sort of vibrato pitch wobble thing happening towards one end of the sweep. This may of course be due to a mistake on my part, but I don't know enough theory to even know where to begin fixing this.

Anyway, thought I'd share my findings.

For this message the author hbo has received thanks:
aishabag23 (14 Oct 2016, 06:03)
hbo
Breadboard Brother
 
Posts: 101
Joined: 10 Apr 2009, 17:46
Location: Oslo, Norway
Has thanked: 31 times
Have thanks: 204 times

Re: A simple PT2399 diy flanger pedal?

Postby drbob1 » 11 Oct 2012, 16:02

Hides-His-Eyes wrote:I'd love to see an eagle library for one of those!

I wonder if you could make a flanger by modulating the length of a spring. :idea: :scratch:


You know, if you're going full mechanical, why not a pair of small tape recorders (say Goodwill dual cassette decks) and have an LFO vary the tape speed in an alternating manner? If you change the rate of both decks alternating you'll have true TZF. YOu just have to work out the ability to record/read simultaneously on a 2 head deck...
drbob1
Cap Cooler
 
Posts: 458
Joined: 21 Dec 2010, 21:30
Has thanked: 8 times
Have thanks: 38 times

Re: A simple PT2399 diy flanger pedal?

Postby Dr Tony Balls » 09 Oct 2013, 16:28

Anyone other than Harald try this? Im curious about it.
User avatar
Dr Tony Balls
Diode Debunker
 
Posts: 807
Joined: 07 May 2009, 15:29
Location: Brooklyn, NY
Has thanked: 2 times
Have thanks: 153 times

Re: A simple PT2399 diy flanger pedal?

Postby wasweissich » 07 Nov 2014, 11:57

I tried it some time ago, and it worked.
I think i´ll try it once again.
wasweissich
 
Posts: 1
Joined: 04 Jan 2014, 18:46
Has thanked: 0 time
Have thanks: 0 time

Re: Dual PT2399 flanger

Postby OnTheTundra » 01 Dec 2016, 22:22

hbo wrote:
merlinb wrote:A while ago I designed a PT2399 flanger using two devices, along the same lines mentioned earlier in this thread.
To avoid latency the dry signal was also mixed with the output, which also gave it a hint of reverb (interesting but unwanted). It does through zero and has a +/- phase switch. I got as far as designing the PCB, but in the end I decided I'd lost interest in it and would probably never use a flanger anyway, but I here is the unadulterated schem in case anyone else is interested.

http://dl.dropbox.com/u/57831278/flanger.pdf


I was curious to know what this circuit would sound like so I built one on vero.

[ Image ]

I initially had problems with the LFO not working properly, but eventually found out that it wasn't getting enough voltage with the series 1N4001 on the power rail. Having sorted this it worked almost flawlessly, but I found there's a sort of vibrato pitch wobble thing happening towards one end of the sweep. This may of course be due to a mistake on my part, but I don't know enough theory to even know where to begin fixing this.

Anyway, thought I'd share my findings.


I built this and the sweep goes from non existent to very slow. What steps should I take to increase the speed of the lfo?
OnTheTundra
 
Posts: 39
Joined: 19 Sep 2010, 16:47
Has thanked: 1 time
Have thanks: 9 times

Previous

Return to DIY Stompbox designs

Who is online

Users browsing this forum: No registered users and 2 guests