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Alternatives for PT2399?

PostPosted: 08 Mar 2015, 16:05
by A1full
Hello there any other integrated as the PT2399 to make a delay? I have not found any, except the old giving a low repetitions.

Re: Alternatives for PT2399?

PostPosted: 12 Mar 2015, 23:58
by mictester
There are many echo / delay ICs available - both analogue (BBD) and digital. However, there's nothing wrong with the 2399 if you use it properly.

Re: Alternatives for PT2399?

PostPosted: 13 Mar 2015, 12:13
by Intripped
I'm interested in alternatives to the pt2399 as well

What I don't like of the pt2399 is the kind of white noise (shhhhh) that is audible with the repetitions, even at relatively short delay times. You can lower the intensity of this noise, but it's hard (or maybe impossible?) to get completely rid of it
I know there are some people who don't hear this noise, but I really do; probably is one of those things that once noted you cannot ignore anymore.

I know there is the FV1, but I've never experimented with this chip.
Does anyone here know how is the FV1 compared to the PT?

Re: Alternatives for PT2399?

PostPosted: 13 Mar 2015, 16:57
by ~arph
Well, I do not think there are ICs available that are comparable with the PT2399 in regards to ease of use for the average DIY'er

The strong point of the PT2399 is that it is a simple IC. With easy delay time adjustment and can be used in a full analog environment.
Using BBD's is trickier, requires biasing and an external clock (I do not know how they compare price wise)
Using digital ics like the FV-1 requires coding, flashing and sometimes even eternal memory ics to store your program and/or audio data.

The PT2399 is in a very good niche.

Re: Alternatives for PT2399?

PostPosted: 13 Mar 2015, 20:55
by Duckman
Just for pure curiosity: does anyone tried stacked 2399's? :scratch:

Re: Alternatives for PT2399?

PostPosted: 13 Mar 2015, 21:22
by mictester
Do you mean one on top of another, wired pin for pin? No. I haven't tried it, and it's unlikely to work. It also wouldn't reduce the noise....

I've found that if you give about 150µs pre-emphasis on the way in and the corresponding de-emphasis on the way out, you reduce the noise significantly while retaining a (more or less) flat frequency response. It's also essential to avoid clipping in the IC (there are several ways to prevent that). I also use a compander to compress on the way in and expand on the way out. I don't much like the sound of a single delay line, so I use three or four in parallel, each with different delays, and with convoluted feedback paths so that I get a whole mess of delayed signals at different repeat rates. If the straight to echoed signal ratio is set sensibly, I get a truly lovely "hall" echo effect at longer delay settings and smaller room sounds at shorter settings. I ended up using some preset resistors for the delay times, and selected them with 4066 ICs. One pedal that I make and I really like the sound of has short, medium and long preset delays, variable straight to echo ratio on a from panel pot and a "master feedback" pot to vary the overall amount of recirculated echoes. It uses both noise reduction tricks, four 2399s and has "tails". I've built a few of them now and their owners adore them! I'll put the basic circuit up on this site shortly.

Re: Alternatives for PT2399?

PostPosted: 13 Mar 2015, 23:52
by A1full
mictester wrote:Do you mean one on top of another, wired pin for pin? No. I haven't tried it, and it's unlikely to work. It also wouldn't reduce the noise....

I've found that if you give about 150µs pre-emphasis on the way in and the corresponding de-emphasis on the way out, you reduce the noise significantly while retaining a (more or less) flat frequency response. It's also essential to avoid clipping in the IC (there are several ways to prevent that). I also use a compander to compress on the way in and expand on the way out. I don't much like the sound of a single delay line, so I use three or four in parallel, each with different delays, and with convoluted feedback paths so that I get a whole mess of delayed signals at different repeat rates. If the straight to echoed signal ratio is set sensibly, I get a truly lovely "hall" echo effect at longer delay settings and smaller room sounds at shorter settings. I ended up using some preset resistors for the delay times, and selected them with 4066 ICs. One pedal that I make and I really like the sound of has short, medium and long preset delays, variable straight to echo ratio on a from panel pot and a "master feedback" pot to vary the overall amount of recirculated echoes. It uses both noise reduction tricks, four 2399s and has "tails". I've built a few of them now and their owners adore them! I'll put the basic circuit up on this site shortly.



Well you're an expert with the PT2399, in my opinion has a sound medium quality is far from quality digital delay as Tc electronics, t rex or Strymon. It would be good if you can show us how to better sound.
thanks for your answer

Re: Alternatives for PT2399?

PostPosted: 14 Mar 2015, 15:58
by karul
Deadastronaut jamming on his prototype with 4 PT2399 delay prototype on breadboard.

Link


Another example is madbeans Zero Point SDX Delay

Link


Another one: cpm's - delay over the top PT2399's
http://www.soundclick.com/bands/page_so ... ID=8355105
viewtopic.php?f=28&t=9648

Haven't you noticed that there are lot of commercial delay/reverb pedals using belton brick(s) wich are nothing more than 3 PT2399's

Re: Alternatives for PT2399?

PostPosted: 14 Mar 2015, 18:09
by karul
I've forgot to mention that some of the techniques and concepts Mictester have mentioned in his replay are used in examples above - so you can hear how good or bad PT2399 can be.

Re: Alternatives for PT2399?

PostPosted: 15 Mar 2015, 04:53
by A1full
karul wrote:Deadastronaut jamming on his prototype with 4 PT2399 delay prototype on breadboard.

Link


Another example is madbeans Zero Point SDX Delay

Link


Another one: cpm's - delay over the top PT2399's
http://www.soundclick.com/bands/page_so ... ID=8355105
viewtopic.php?f=28&t=9648

Haven't you noticed that there are lot of commercial delay/reverb pedals using belton brick(s) wich are nothing more than 3 PT2399's


The sound quality is not the best, of course is not a dsp, but wondered why some intermediate alternative, other than the PT2399 or switch to a dsp for something better, in the middle there is nothing?

Re: Alternatives for PT2399?

PostPosted: 15 Mar 2015, 15:40
by karul
A1full wrote:but wondered why some intermediate alternative, other than the PT2399 or switch to a dsp for something better, in the middle there is nothing?


Answer was already given.
mictester wrote:There are many echo / delay ICs available - both analogue (BBD) and digital. However, there's nothing wrong with the 2399 if you use it properly.


Search for BBD IC's.

For example, most common BBD chips come from Panasonic/Matsushita MN3xxx series:
http://www.electrosmash.com/mn3007-buck ... de-devices

MN3005 - Ibanez AD-80, BOSS DM-2, Electro Harmonix Memory Man, etc

-----------------------------------------

You may not like those pedals either.

Re: Alternatives for PT2399?

PostPosted: 15 Mar 2015, 23:38
by Duckman
Some very interesting considerations about 2399's here:

http://sound.westhost.com/project26a.htm

Re: Alternatives for PT2399?

PostPosted: 15 Mar 2015, 23:47
by Mbas974
I think PT is still the best DIY solution fo a good delay.

..what I do not understand is the delay for work stacked PT;
I have on breadborad this http://postimg.org/image/zdho7og5z/
and I supposed to get min delay of 250ms (2x 125ms as per 6K8+1K resistence..) well the min delay is clearly under 100ns...

I'd like someone could explain how this "current mirror" circuit as well..THANKS

Re: Alternatives for PT2399?

PostPosted: 16 Mar 2015, 16:02
by Dirk_Hendrik
Perhaps cascade the delaylines instead of physically placing em in parallel?
After that, that's not a current mirror. That's 2 transistors which sink current to ground. Because they happen to be connected to a similar source in the PT chip and are controled by the same pot they will sink similar currents.... but not as a mirrror.



(And can those who keep op soldering IC's in parallell please stop?)

Re: Alternatives for PT2399?

PostPosted: 14 May 2015, 09:05
by tabbycat
you could maybe do something building on the belton brick and pt2399 idea. maybe take the schematic of the brick and twist it around a bit as a discrete unit rather than the stock brick. add another pt2399, put layers of dirt between them, or modulate one one way and the next another way to make a mutant brick. kind of as mictester was sugesting but take the standard brick schematic as your start point template and tweak it beyond recognition.

karul listed a couple of brick pedals above, another is the eqd ghost echo of which i'm a big fan. a massive space on tap.

Re: Alternatives for PT2399?

PostPosted: 17 Sep 2015, 08:39
by matt239
mictester wrote:I've found that if you give about 150µs pre-emphasis on the way in and the corresponding de-emphasis on the way out, you reduce the noise significantly while retaining a (more or less) flat frequency response. It's also essential to avoid clipping in the IC (there are several ways to prevent that). I also use a compander to compress on the way in and expand on the way out.


"150µs pre-emphasis?" What are you saying there?

Care to share some of your other tricks for getting this chip to work well?
Thanks. :)

Re: Alternatives for PT2399?

PostPosted: 17 Sep 2015, 09:28
by Dirk_Hendrik
he's saying 150µs pre-emphasis.

1) find out what pre-and deemphasis is. Hint: every Boss and Ibanez analog delay show examples
2) find out why filters can be determined as having a delay time (hint: An allpass filter is delay-only)

Re: Alternatives for PT2399?

PostPosted: 18 Sep 2015, 22:27
by matt239
I get the basic concept of pre & de-emphasis. I just didn't know why he was describing it in micro-seconds, and was hoping he would expand on that.

I was dimly aware that filters cause delay..
Alas, my filter kung fu is not strong..

I wasn't saying he was saying it wrong, just that I was not understanding.

Re: Alternatives for PT2399?

PostPosted: 22 Sep 2015, 23:55
by Darth Florist
If you still want to stick with Bucket Brigade Devices, someone is STILL manufacturing Panasonic MN3102 and MN3207 chips. Try your luck at...

support@truetone.com

Re: Alternatives for PT2399?

PostPosted: 24 Sep 2015, 04:14
by matt239
... filters have delay...
and that filters only filter because of time constants,
and that frequency = period, so it's a time thing.

It's just not the shorthand we normally use around here to describe simple stompboxes.
Why not just say it's 1kHz?

P.S.: it's (about) 1kHz.

- I'm only a simple un-frozen-caveman guitar player..