MXR Digital Delay

[rasco22862]

Hi, im trying to get gilmour tone. Now i should build a delay.Is there any layout for this project? Or another project that can replaced him

Thanks

[Mark Hammer]

DO NOT, under any circumstances, try to build the MXR digital delay.  For what it would cost you in time and parts, you could easily purchase a wide variety of top-notch digital delay units that easily surpass the MXR in quality and features.  The MXR has some nice quirks (I own one), but nothing so compelling that it would justify that level of self-torture.  You would be much smarter to try Scott Swartz' AD-3208 or PT-80 projects, over at www.generalguitargadgets.com .

[msurdin]

Which out of those 2 delays from GGG has longer delay.

Thanks

[Seljer]

the PT80 uses the PT2399 chip, with the longest delays being somewhere around 650ms, with it loosing fidelity from about 300ms and up unless you lower the pre and post delay cutoff frequencies

the AD3208 is an analog delay using BBD chips, depending on which you use you can get somewhere around 400ms


the PT80 will work fine for what you're going for

[msurdin]

I mess around in the 300 to 500 area. I want something really warm. I play alot of floyd. This will do it?

[mudmen]

Hi, im trying to get gilmour tone. Now i should build a delay.Is there any layout for this project? Or another project that can replaced him

Gilmour used two models of MXR delays. Both were rack units. The frist one was used from '77 to around '84 and it was MXR Digital Delay. The other one appeared in 1984 and is used up to now - it's the MXR Delay System II. I think that those units are different from the stompbox - MXR Analog Delay (the green one) which schematic is avaliable online...

For Echorec-like delay I think that projects like PT-80 from GGG with some mods (like tape saturation sim) will do the job. For modern sounds there's always Boss with DD series

[bent]

i build the SHEcho    http://www.generalguitargadgets.com/index.php?option=content&task=view&id=219&Itemid=244

it can go around 800ms (i read that somewhere in the forum, but personally never test it) ,

i build one for my friend that play a lot of Pink Floyd and he really like it ....

bent

[msurdin]

What are all the mods I could do to the pt-80. I love that echorec sound.

[mudmen]

Here's one that came to my mind first. For other mods - use search as there're tons of them here...

http://home3.netcarrier.com/~lxh2/tapesat.html

http://www.diystompboxes.com/smfforum/index.php?topic=46035.0
http://www.diystompboxes.com/smfforum/index.php?topic=25096.0
http://www.diystompboxes.com/smfforum/index.php?topic=30045.0

[msurdin]

Would the pt-80 be decent without mods for that gilmour delay?

[calculating_infinity]

Nice links mudmen, I hope to build a pt80/rebote someday soon!  Thanks.

[Mark Hammer]

The PT-80, in tandem with the expertise around here, can be modded to sound like a lot of things.  The secret to "warm" delays is often the tweaking of the lowpass filtering after the delay chip.  A more muted delay signal often helps to place it perceptually in the background, such that the player can wail away, despite long delay time and lots of repeats, without creating "audio clutter".  Personally, I find a bit of additional lowpass filtering in the feedback loop to progressively remove a little more treble from each repeat a real winner.  But that's me, and not necessarily David Gilmour.

[sovtek50]

My DIY Echo favorite is a modded Danelectro Fab Echo. I'm actually building my 3rd one at the moment, because the other two I had to sell to friends of mine. I think the How to is somewhere in the Lounge. You'll have to replace an SMD resistor with a pot, in order to have a delay control. Apart from that, I rehouse them in a Hammond C enclosure.
It's a very warm, analog-sounding echo, with a psychedelic vibe to it, and looong delay.

[Stompin Tom]

The Dano is based on the same pt chip as in the pt80, I believe? So you're kind of talking about the same thing...

[Mark Hammer]

Correct.  For that money, and with the delightful illustrated how-to (see thread below), I don't know why you'd want to start anywhere else unless you had to.

Note that the "mod" simply replaces a fixed resistor value with a variable one.  If a person wasn't that fussy, however, it would be entirely reasonable to stick a 3-position toggle in that empty 3rd hole, and use the toggle to select one of three resistance values and corresponding delay times: short, medium, long.  That would avoid the problem of trying to install a pot.  Sometimes 3 choices is all you really need.  Hell, for $15, buy two and mod one of them for 3 kinds of short delay and the other for 3 kinds of long. Stick the short-delay one ahead of the long delay and you got yourself one helluva combo.

[Stompin Tom]

I like the way you think, Mark. It seems totally worth it to me to put two of those in a bypass loop together... one short, one long. Why have one delay time when you can have two for $30?! Throw a flanger/chorus/phaser in the loop for a little extra fun... Oh, but I don't need yet another delay pedal...

[rasco22862]

what about the Rebote 2.5 from tonepad.com¡???

[rasco22862]

any difference?

[Stompin Tom]

If you look at the schemo, it also uses the same chip...

[Skreddy]

what about the Rebote 2.5 from tonepad.com¡???

The Rebote 2.5 uses, IMO, a very excessive amount of low-pass filtering, resulting in a dark delay tone.   You can ditch basically all of the low-pass filters on the input side (other than a cap between pins 15 and 16) and maybe use a couple of low pass filters just on the output side to get rid of any hiss or distortion that chip makes at higher delay settings.