Deluxe Memory Man questions

[Wazoo]

I just found a schematic for a DMM on the net and was thinking of trying to build a clone of it, but i have a few questions.

1. There is a symbol in the power supply section of the schematic that looks like a diode inside a square. I do not know what that symbol is for. There are connections to it marked 24V AC and 2.2watt, so I was thinking it was a symbol for a 24v power supply, but I'm not sure.

2. Since the power connections shown all require -15V, would it be easier to just buy a 15v wall wart to power it with?

3. There is a capacitor marked only as "?"  going from pin 9 of the NE570 chip to ground. Any idea what value this capacitor should be?

4. Finally, would it be fairly easy to add an effects loop to the feedback so that I can add other effects only to the delay repeats?

I'm just getting back into electronics after messing around with it as a youngster about a decade ago, so any help is appreciated. Thanks

[Andre]

1. There is a symbol in the power supply section of the schematic that looks like a diode inside a square. I do not know what that symbol is for. There are connections to it marked 24V AC and 2.2watt, so I was thinking it was a symbol for a 24v power supply, but I'm not sure.

It's a bridge rectifier. check this:http://en.wikipedia.org/wiki/Rectifier for more info.

2. Since the power connections shown all require -15V, would it be easier to just buy a 15v wall wart to power it with?

No problem I think, but make sure you use a regulated wall wart

3. There is a capacitor marked only as "?"  going from pin 9 of the NE570 chip to ground. Any idea what value this capacitor should be?

I found a value of 200pF for pins 8 and 9 in the datasheet.
In the PT-80 delay 100pF is used.

4. Finally, would it be fairly easy to add an effects loop to the feedback so that I can add other effects only to the delay repeats?

Should not be a problem, but I think you would need some input- and output buffering.

But....
Please keep in mind that this will not be an easy build.
Check the Rebote 2.5 at Tonepad or PT-80 at GeneralGuitarGadgets.
They are good quality delays and much easier to build.

André

[Wazoo]

After I posted this, it dawned on me that was a rectifier heh.

I thought about building rebote or pt-80, but I kinda had my mind set on an analog delay, and I've always liked DMMs.

I know it won't be an easy project to build, and I will definately breadboard it before I even think about building it or making a PCboard layout.

Thanks for the help.

[oldschoolanalog]

Check out the AD3208 at GGG. True analog sweetness. There is also a nice board available for it.
osa

[puretube]

Welcome to the Forum, Wazoo!

sorry for disappointing: that schemo with the questionmark at pin 9 got serious errors in it... 

(never trust a schemo on the web)

[Wazoo]

Oh? It was the only schematic I've found for it. I guess I'll try one of the other delay pedals mentioned here, probably the AD3208.

[oldschoolanalog]

(never trust a schemo on the web)

So true...

[Dimitree]

does anybody know what are these serious errors? thank you

[puretube]

around the compressor, and the pre-BBD filter (at least)...

[sfx1999]

If you think there is an error in the compander, try looking at the Boss DM-2, PT-80, Boss DC-2, AD-3208, etc. and compare.

[puretube]

OK, I tried:
searched for those schemos, compared (also with the DS & ANs),
and:
found another error, around the expander...


(we are talking about this schemo ?)

[Dimitree]

Puretube..please..could you underline all the errors on the schematic? I need to know exactly where the errors are.. Thank you very much..

[puretube]

http://www.diystompboxes.com/smfforum/index.php?topic=61535.0