Does anyone have directions to true bypassing an AD9?

[liddokun]

I've got an AD9 that I bought from a fellow forum member. The only problem is, when he true bypassed it, he claims something went wrong with the bias pots
and now the pedal doesn't do single repeats. It jumps from no repeats to 3-4.

I tried rebiasing the pots, but no dice. I'm guessing it might be a wiring problem?

If anyone knows how to do this properly, I'd like to verify the wiring. Or, if anyone has a link to any resources that show me how to do this.
I'd love to be able to get the slap back delays again on this pedal.

[liddokun]

It's been a while, but I've finally started working on this pedal again. No one can point me in any directions?

[Thomeeque]

I've got an AD9 that I bought from a fellow forum member. The only problem is, when he true bypassed it, he claims something went wrong with the bias pots
and now the pedal doesn't do single repeats. It jumps from no repeats to 3-4.

I tried rebiasing the pots, but no dice. I'm guessing it might be a wiring problem?

If anyone knows how to do this properly, I'd like to verify the wiring. Or, if anyone has a link to any resources that show me how to do this.
I'd love to be able to get the slap back delays again on this pedal.

What exactly you do to make this "jump" from 0 to 3-4 repeats happen?

And maybe stupid question: do you get dry (non-delayed) signal at the output in effect mode?

T.

[liddokun]

Well, by turning the repeats pot. If I have the repeats pot all the way off (CCW), then I get no repeats, essentiall a dry signal (is that what you mean in your second question?).
Once I turn my repeats pot slightly to the right to get some repeats, I will automatically get minimum 3 repeats. So, it goes from 0 repeats, until the position on the pot where I actually get repeats, its 3-4.

[Thomeeque]

Btw. true bypassing an AD9 (how I would do it):

• remove C25*
• pull-out C31 (+) leg (C31+R42 junction) and connect it where C25 (-) leg was (U2.B pins 10+11)
• remove T8 and T12
• pull-out R44 leg from R44+R58+.. junction and connect it with U1.B pin 6
• pull-out C1 leg from C1+J4 (input jack) junction
• pull-out C43 leg and R66 leg (both from their junction with output jack J1), but leave them connected
• pull-out D7 anode out

Now is the circuit permanently on (and everything useless is removed from the audio path) and it is ready for standard true-bypass switching (loosen C1 leg makes circuit input, loosen C43+R66 junction makes circuit output, you have free holes on PCB to get to input and output jack tips, LED will shine if D7 anode grounded). It would be useful to put pull-down resistor (1M~2M2) between circuits input and ground.

T.

*I'm referring to Dirk Hendrik's Ibanez AD-9 schemo, which I'm not sure I'm allowed to link directly here so I won't, but it's googleable easily..

[Thomeeque]

Well, by turning the repeats pot. If I have the repeats pot all the way off (CCW), then I get no repeats, essentiall a dry signal (is that what you mean in your second question?).
Once I turn my repeats pot slightly to the right to get some repeats, I will automatically get minimum 3 repeats. So, it goes from 0 repeats, until the position on the pot where I actually get repeats, its 3-4.

OK, I've had some idea (that was the second question about), but it was probably wrong, let's forget about it..

IMO he did somehow messed wiring in the way, that delay signal is not picked from DELAY LEVEL pot anymore, but from REPEAT pot, that would explain this behaviour.. Has DELAY LEVEL pot any influence on effect now?

T.

[liddokun]

The delay level pot still does effect the effect. It basically dictates how much delayed signal is mixed in with dry signal. I think I get what yo uwere asking with that second question now.

The delay level pot blends delay signal with dry signal. AD9 is a stereo pedal, it has one output for the normal effect, and one dry signal output.

[Thomeeque]

The delay level pot still does effect the effect. It basically dictates how much delayed signal is mixed in with dry signal. I think I get what yo uwere asking with that second question now.

Well, whatever.. Being you, I would just printed-out the schemo, revised and/or reverted all changes done by your predecessor and basically started all over again..

The delay level pot blends delay signal with dry signal. AD9 is a stereo pedal, it has one output for the normal effect, and one dry signal output.

Yep, I've seen that on the schemo Plus there's a logic, which removes dry signal from effect's output if dry signal output is used (T8 and surroundings) - my "true bypassing an AD9" guide posted above would kill this logic btw. (I should have mention it over there - to not to kill it, T8 and R44 should remain untouched).

[liddokun]

Well, that's ok because I don' ever use that dry output anyways. So your guide has been most anyone has ever given me. I've posted this in other forums too, and have gotten no reply for about a year. Thanks a lot.

[Thomeeque]

Well, that's ok because I don' ever use that dry output anyways. So your guide has been most anyone has ever given me. I've posted this in other forums too, and have gotten no reply for about a year. Thanks a lot.

You're welcome! Just make sure, you understand what all those suggested steps of the guide are about before you start (feel free to ask if not sure of course ). Good luck! T.

[liddokun]

Well, I understand that the original circuit used electronic switching, correct me if I'm wrong, but some kind of flip flop circuit. The above steps are to remove the flip flop so circuit is always on.

While I'm at it, you wouldn't happen to know how to do the keeley mod where the old foot switch being pressed on will send the pedal into self oscilating mode, do you?

[liddokun]

Ok, I tried the steps you listed above, but it doesn't work. Maybe you can spot what I'm doing wrong...might be a common error.
When I engage the pedal, there is no difference in sound. The signal still flows through as if there's no pedal there.

Could it be I got my inputs and outputs wrong on the pedal? Also, for the LED, I didn't disconnect the anode. I just used the 3rd set of poles on the switch, when pedal engaged, led is connected to ground. When not engaged, its ungrounded, turning led off.

What do you think I made a mistake doing?

[george]

Well, that's ok because I don' ever use that dry output anyways. So your guide has been most anyone has ever given me. I've posted this in other forums too, and have gotten no reply for about a year. Thanks a lot.

Sorry to butt in here but it seems you're going to a lot of hassle for very little return ...

I notice that the gurus on this forum have long given up trying to talk people out of true bypassing pedals that don't need TB... that probably explains why it's taken a while to get the information you have so far.   And the lack of response on other forums.   It may well not be worth doing especially to a (vintage?) Ibanez 9-series pedal, because a) it doesn't buy you much and b) you are affecting it's resale value and c) it's distracting you from making music

Correct me if I'm wrong ...

[Thomeeque]

Ok, I tried the steps you listed above, but it doesn't work...

Wow, that was quick! Did you first try to revide and/or revert changes done by previous owner? You have to do that first before trying to follow my guide - it will work only if the rest of circuit works.

What do you think I made a mistake doing?

It's really hard to say from so little info available - can you create few hi-res pictures of actual guts? More angles, both sides, take care to make all offboard wiring visible.. This could help a lot.

Sorry to butt in here but it seems you're going to a lot of hassle for very little return ...

...

Correct me if I'm wrong ...

You are missing the fundamental fact, that he tries to recover already true-bypassed pedal by previous owner..

T.

[liddokun]

George, I actually wouldn't waste my time true bypassing this if I had gotten it stock. Only problem is, I bought it used, and the original owner had attempted to true bypass it, only he make a small mistake which causes the problem outlined in my first post (no single repeats). Otherwise, I'm generally a lazy guy and wouldn't wanna fix something unless its actually broken.  I don't think I'll plan on selling the pedal, I'd trade it at most, and if so, I'd like to trade at least a working pedal.

T: I've gotten it to work. I figured out the problem almost immediately after posting that it didn't work (silly me). Your guide states to remove one end of R44 and attach it to UB1 pin 6 (jrc 4558).  Dirk's schematic has R44 labelled as 47K, but on my pcb I found a 10k resistor in the R44 position. I ended up changing it to 47K, thinking I should follow the schematic. I was wrong, and that was my problem. The schematic has a bunch of different values compared to mine...perhaps vintage vs. reissue? At any rate, I changed the 47K back to a 10k and that fixed the problem.  The original owner didn't seem to do much to this circuit...I noticed one diode removed, and T7 was removed, which I replaced (same transistor as T12, which was removed).

I also figured the oscillation mod, just run two wires from each pole of the momentary switch to lug 1 and 2 of the repeats pot. stepping on the momentary just simulates maxing out the repeats pot.

Now, time to figure out the proper bias. 

[george]

Sorry to butt in here but it seems you're going to a lot of hassle for very little return ...

...

Correct me if I'm wrong ...

You are missing the fundamental fact, that he tries to recover already true-bypassed pedal by previous owner..

T.

I stand corrected!   liddokun, glad you got it to work.  I'll remember you if I'm ever trying to fix someone else's dodgy work ...

[anchovie]

This schematic covers the component values for both versions: http://www.dirk-hendrik.com/Ibanez_ad9_analog_delay.pdf

I don't think your repeats problem is anything to do with bias - yes there is a trimpot involved but bias is not what it is setting. R43 is adjusted to fine-tune the level of the signal coming off the repeats pot - set the main pot to your 3-4 repeats level and adjust the trim to try and get to just 1 echo. If the number of repeats does not change, it may be that the trimpot is damaged.

[Thomeeque]

I don't think your repeats problem is anything to do with bias - yes there is a trimpot involved but bias is not what it is setting. R43 is adjusted to fine-tune the level of the signal coming off the repeats pot - set the main pot to your 3-4 repeats level and adjust the trim to try and get to just 1 echo. If the number of repeats does not change, it may be that the trimpot is damaged.

1 echo = no feedback (and REPEAT pot controls amount of feedback), think about it..

[liddokun]

Well, I kind of figured the repeats problem had nothing to do with bias a long time ago. The person I bought this from suspected it was a bias problem, but I suspected it was a wiring problem with the true bypass job that was the problem. Which is why I posted this topic, to try and redo the true bypass job. I've figured out what all those trimpots do though. 

[Thomeeque]

T: I've gotten it to work. I figured out the problem almost immediately after posting that it didn't work (silly me). Your guide states to remove one end of R44 and attach it to UB1 pin 6 (jrc 4558).  Dirk's schematic has R44 labelled as 47K, but on my pcb I found a 10k resistor in the R44 position. I ended up changing it to 47K, thinking I should follow the schematic. I was wrong, and that was my problem. The schematic has a bunch of different values compared to mine...perhaps vintage vs. reissue? At any rate, I changed the 47K back to a 10k and that fixed the problem.  The original owner didn't seem to do much to this circuit...I noticed one diode removed, and T7 was removed, which I replaced (same transistor as T12, which was removed).

Congrats!

T7 should be bypassed now (if you have followed all my steps), so you did not have to put it there, but should not make any harm either

I also figured the oscillation mod, just run two wires from each pole of the momentary switch to lug 1 and 2 of the repeats pot. stepping on the momentary just simulates maxing out the repeats pot.

There would be other ways (this one won't work well if the REPEAT pot will be at minimum, because signal will get grounded), but not as simple..

T.