Ibanez - AD-80 Analog Delay [schematic]

[analogguru]

Here they are:

Ibanez AD-80 guts

enjoy,
analogguru

[markm]

Very cool pics here AG!

[bajaman]

A nice sounding bbd delay, similar to the Boss DM2, from the same era.
For a more realistic "tape echo" delay sound, try reducing the coupling capacitor from the wiper of the repeat potentiometer - you will have to make it a lot smaller in value - experiment and tune by ear. What you are looking for is a gradual reduction of low frequencies with each suceeding repeat ( 4 repeats ), so the echo gets progressively thinner in sound.
Another cool mod is to lower the value of the resistor in series after this capacitor ( you could replace with a preset or external control ) to get the endles repeat thing happening
Have fun
Cheers
Steve

[bajaman]

And now for something completely different....

I built a BOSS DM2 clone for a friend (he has one, and challenged me to build a clone).
As you know the BBD chips MN3005 are like rocking horse shit to find these days - yes i know the MN3205 and clones are available but they don't sound as good - I won't go into depth here why - my friend has two DM2 pedals one with each chip in, and we can both here the difference in sound quality.
Anyway....
I chose to use the Princeton Technologies PT2399 digital chip (heresy I know for analog freaks )
By careful analysis with osciloscope, oscilator and my ears I was able to come very close to the same sound as his MN3005 model.
I will post the schematic one day soon for the group, but not at the moment, it is well past my bed time - (yawning) and I have to get up early and do my tax accounts tomorrow morning.
Still, it has been a fun night, hope my contributions have been constructive
Bye Bye for now
Steve

[Mr. SD-1]

I'd like to mod my AD-80 to have true bypass switching. Removal of the momentary switch and installation of the 3pdt switch should be pretty easy. Rewiring the LED circuit should be pretty straightforward as well. Most importantly, I have to remove Q104 and replace Q105 with a jumper. Are there any other components that I should remove or replace to properly disable the flip-flop JFET circuit?

Anyone know the proper AD-80 trimpot calibration procedure?

[soulsonic]

You could likely fit a very small DPDT in the place where the momentary switch is now. Small Bear sells one for their "Bypass on Board" concept. You could wire this like the usual DPDT thing and rig up RG Keen's Millenium Bypass thing to switch the LED.
OR (especially if you run this on a wall wart, cuz it'll probably eat batteries...)
You could keep the original flip-flop in place and use it to actuate a relay for true bypass.

Either of these options would preserve the original appearance of the unit and not look chopped up. It would be slick.

[Mr. SD-1]

If I recall correctly, the 3pdt can be cleanly mounted to the stock enclosure with no permanent modification - just like keeley does the TS808 reissue TB mod if you're familiar with that. I'll be using a power supply, so there'll be plenty of room for the switch wiring in the battery compartment. I'm mainly looking for some insight concerning the JFET flip-flop circuit work. Is it necessary/beneficial/problematic for me to remove any components like R139, R136, D102, D103, C128, C130, R135, etc?

[soulsonic]

Yeah, I was looking at some pics and now I see what you mean about the footswitch.

If it were me, and I didn't care about the collectible value, I would do the following:
Remove...
Q107
Q106
Q108
Q104
Q105
R151
R152
R153
R149
R150
R147
R148
R146
R145
R135
R136
R137
R138
C130
C131
C132
C136
C137
C138
D102
D103
D104
CR1
CR2
Then...
Jumper between where the D&S pins of Q105 were.
Connect wire to pad where Q108's Collector was to go to the footswitch for LED on/off.

OR

The "Bare Bones" way that would make it easy to return it to stock would be this:
Remove:
Q104
Q105
Q108
Jumper where Q105 was, as described above
Take wire from where Q108 was, as described above.

That should do it.

[Mr. SD-1]

Thanks! Are there any significant tone/function/reliability advantages to removing all of those components? If not, I'll stick with the "Bare Bones" approach.

[The Rotagilla]

As you know the BBD chips MN3005 are like rocking horse shit to find these days.

Never heard that one before. Soda almost came out my nose.

[Dirk_Hendrik]

Do yourself a favour and leave it as it is. The gain of making the thing TB is far less than any TGP-er or famous pedal modder will tell you. Or sell the thing for good bucks and get yourself another delay that's TB already.

Basically,
Too many great pedals were already destroyed by the ill-argumented wish if TB-ing it. TB-ing doesn't make it "far better". TB-ing is a disease of the last 10 (??) years. Prior to that people just had and played pedals, without having problems.

Please!!!!

[soulsonic]

Thanks! Are there any significant tone/function/reliability advantages to removing all of those components? If not, I'll stick with the "Bare Bones" approach.

I say Bare Bones is probably the best way to go... at least if you want to keep Dirk's health in consideration.

The long list is just all the parts that are part of the original FET switching. If you're not using it any more, it would be fine to remove all of it. I've seen pics of some of the newer Maxon pedals like TS9 or whatever that they did as true bypass and you can see more than half the board is "missing" parts.
I don't think there's any real advantage to it, other than, just removing stuff that isn't needed.

But, bare bones is the best choice, and be sure to save the old parts so it can be put back to its original state.

[Igloo]

Well,
Why not build yourself a simple single loop box. 1 3dpt, one enclosure, problem over. Leave it on in your rig and switch as you please.
Really it's my final conclusion with these things. I have an old Boss Fl-1 which I cherish but it's horrible bypassed. Simple + good and you have changed nothing of the original.

[Dirk_Hendrik]

and be sure to save the old parts so it can be put back to its original state.

How many pedals have you had on your bench where the owner was sure he kept those parts... somewhere...but where!???

[Greg]

I just scored an old Ibanez AD-80 Delay.. this is the original model with the square switch and 18 volts.. considered by many to be the 'creme de la creme' of Analog Delays.

Surprisingly I've had it for 3 days and haven't pulled the back of yet.. but if anyone wants gutshots or other info, please just ask and I'll get it done.

It's a beautiful delay.. very airy.. spacey sounding and quite clear for an analog... slightly less warm, but noticeably less muddy compared to others I've tried (quite a few), probably due to the higher voltage I'm guessing.

[KindaFuzzy]

Gutshots of course, I've got another mn3005 waiting for something like this.

[Greg]

Gutshots of course, I've got another mn3005 waiting for something like this.

no problem.. I'll try to get them up later today Aussie time..

[Greg]

Here you go... MN3005 is smooth and shiny like the old 4558s.
Let me know if you need better pics or any details.

[Greg]

A bonus.. Maxon re-issue AD-80 w/ MN3205.. this guy is smoother and warmer, repeats are more blurred..lacks the air of the original... still a very nice Delay.

[Greg]

BTW - you might notice the layout of the re-issue is a little similar to a pic posted of an AD-9 (also built by Maxon) here:-

http://www.freestompboxes.org/viewtopic.php?f=1&t=523

The AD-9 board is marked AD-140.

The only AD-9 I ever tried was a Keeley modded one and sounded quite sterile to me.. may have been the Keeley mods though... from my experience he overdoes the "hi-fi" thing.
I like the AD-80s a lot more than the Keeley AD-9.