Analog delay calibration

[leydenjar]

Is there a known link or thread concerning analog delay calibration?

I've worked on a couple of old Boss and Ibanez delays and I want to be able to calibrate these types of units if necessary.

DM-2 and AD9, that sort of pedal.

[doctor]

Is there a known link or thread concerning analog delay calibration?

I've worked on a couple of old Boss and Ibanez delays and I want to be able to calibrate these types of units if necessary.

DM-2 and AD9, that sort of pedal.

Here are adjustment procedures from manufacturers.

[doctor]

Here are adjustment procedures from manufacturers.

These adjustment procedures reuploaded once more.

[Audiotexan]

Hey Doc.. TY for reposting these!
Also, do you by chance have the entire service manual(s) for the AD-9? And if so, could you post it/them please?! As it would seem there may be some version variations worthy of note.

Also, apologies for the necro (you can blame/thank me for that, not Doc) but I'd asked for the repost since the previous attachment issues prevented...well, ya'll know the story/history with the forum glitches where attachments are concerned! lol

At any rate, I was wondering if I could ask the other techs for a bit of help here, as I've evidently got an oddball on the bench.

According to Dirk Henrik (a gentleman from the Netherlands) there are two versions of the AD-9. See: http://www.dirk-hendrik.com/ibanez.h...20Delay%20AD-9 I'm left wondering if there are also two versions of the AD-9 service manual (as I know Boss does version releases, as I have many in my file cabinet, but as I was never an Ibanez service facility, I'm not sure if they did as well).

He published schematics for the AD-9 that he professionally drew out, however, while he notes that the differing version values are listed in (), there seems to be an oddball that has decided to grace my workbench with it's presence. It's a very early serial number 164xxx (1982), and looks to be bone stock, other than the replaced compander (SA571 which I verified as a pin for pin replacement via datasheet.) The 1982 units I've worked on previously had upc1571c's (sn219xxx+), and 1983-84 units switched to NE570's (sn316xxx+) which were only S/N variations. So I don't expect any issue there.

However, during calibration, I noticed that the potentiometers were not laid out in the usual fashion. They appear to be stock, and the joints appear to be untouched. But it's at this point that I decided to revert them to the stock orientation, when I noticed that two of the values don't coincide with anything I've seen before in this pedal. But then again, I've not had one with a serial number this low on the bench either...Either way, I went full stop at this point. No point in trying to calibrate if they aren't the right pots, and no point using the above calibration procedures unless I know they're for this version/unit.

Delay time pot: 10kC (dirks matches, AD-80 shows: 500kA, CD-10 matches)
Repeat pot: 20kB (dirks: 100kB, AD-80 shows: 10kC, CD-10 shows: 100kB)
Delay Level pot: 10kB (dirks: 100kB, AD-80 shows: 50kB, CD-10 shows: 100kB)

Also, any insight from your experiences/recollections with any of these pedals (especially from the first year 1982) would be GREATLY appreciated!! This is the oldest unit I've seen, and the first/only with such an anomaly.

Again, these are without a doubt period correct and exact OEM factory style without a hint of having been changed (just reseated into the incorrect locations when the previous person (tech?) reassembled the unit).

Anyways, my gut tells me they should be 100k-B (linear) pots, but, this looks bone stock and that's what's throwing me. Unless they were replaced with exact old stock ibanez (maxon) parts, they've been in there since it left the factory.

Much appreciated,
Audiotexan

[doctor]

Hey Doc.. TY for reposting these!
Also, do you by chance have the entire service manual(s) for the AD-9? And if so, could you post it/them please?! As it would seem there may be some version variations worthy of note.

Also, apologies for the necro (you can blame/thank me for that, not Doc) but I'd asked for the repost since the previous attachment issues prevented...well, ya'll know the story/history with the forum glitches where attachments are concerned! lol

At any rate, I was wondering if I could ask the other techs for a bit of help here, as I've evidently got an oddball on the bench.

According to Dirk Henrik (a gentleman from the Netherlands) there are two versions of the AD-9. See: Dirk_Hendrik Guitar Effects stuff. Effects with a different View I'm left wondering if there are also two versions of the AD-9 service manual (as I know Boss does version releases, as I have many in my file cabinet, but as I was never an Ibanez service facility, I'm not sure if they did as well).

He published schematics for the AD-9 that he professionally drew out, however, while he notes that the differing version values are listed in (), there seems to be an oddball that has decided to grace my workbench with it's presence. It's a very early serial number 164xxx (1982), and looks to be bone stock, other than the replaced compander (SA571 which I verified as a pin for pin replacement via datasheet.) The 1982 units I've worked on previously had upc1571c's (sn219xxx+), and 1983-84 units switched to NE570's (sn316xxx+) which were only S/N variations. So I don't expect any issue there.

However, during calibration, I noticed that the potentiometers were not laid out in the usual fashion. They appear to be stock, and the joints appear to be untouched. But it's at this point that I decided to revert them to the stock orientation, when I noticed that two of the values don't coincide with anything I've seen before in this pedal. But then again, I've not had one with a serial number this low on the bench either...Either way, I went full stop at this point. No point in trying to calibrate if they aren't the right pots, and no point using the above calibration procedures unless I know they're for this version/unit.

Delay time pot: 10kC (dirks matches, AD-80 shows: 500kA, CD-10 matches)
Repeat pot: 20kB (dirks: 100kB, AD-80 shows: 10kC, CD-10 shows: 100kB)
Delay Level pot: 10kB (dirks: 100kB, AD-80 shows: 50kB, CD-10 shows: 100kB)

Also, any insight from your experiences/recollections with any of these pedals (especially from the first year 1982) would be GREATLY appreciated!! This is the oldest unit I've seen, and the first/only with such an anomaly.

Again, these are without a doubt period correct and exact OEM factory style without a hint of having been changed (just reseated into the incorrect locations when the previous person (tech?) reassembled the unit).

Anyways, my gut tells me they should be 100k-B (linear) pots, but, this looks bone stock and that's what's throwing me. Unless they were replaced with exact old stock ibanez (maxon) parts, they've been in there since it left the factory.

Much appreciated,
Audiotexan

So, if you really need the AD9 service manual...

[doctor]

So, if you really need the AD9 service manual...

Strange, but it did not work.
I will try once more as a zip.file.
Now it is okay.

[Audiotexan]

Doc, you're a saint!

I can't say thank you enough. This also confirms that my gut would have been wrong! They ARE in fact the original pots (and also confirmed whoever put this back together last was lazy, and didn't take the time to note which pot went where!)

Glad I not only waited for confirmation, but got the proper version of the schems for this pedal! Again, thank you so very much Doctor!

I'll try to make sure and update everyone once I find the problem!
Best regards,
Audiotexan =)

[Audiotexan]

Talk about a nightmare. >.<

Unit was basically DOA (no audio in bypass, or active mode), with only the little red light taunting me when switched on. So at least I knew the switching section worked. PSU voltages were also good, so another step in the right direction.

Anyways, the 4558 was toasted. Along with C102, and C139 both exhibiting signs of leakage.

Once I got the 'basic audio' back up and going, I find that half my wave form is 'missing' (only have the positive sine).

So I go hunting, expecting to find another bad cap somewhere shorting the negative half of the signal. After removing cap after cap after....and even start leaving them completely out of the circuit to see if it's being injected via feedback loop, and completely remove the new 4558, I still had only a half sine at CP3 (c103).

After a couple hours of this nonsense, I take a break and come back to basics.
If the moron that put this back together can't even put things in the right locations, then God only knows what else they did. So I start checking the wiring again.

Enter the grey wire. The one that SHOULD be going to the tip on the 'dry out' jack is tied to the sleeve on the *input* jack. >.< Blue was also on the wrong pin of the 'dry out' jack. As was ground. Once I get these all properly resituated, hello full sine wave! XD

From there out, it was an easy alignment. Looking back now, with as much stupidity that this poor pedal's experienced/endured, I'm amazed that the 3205 wasn't cooked/shorted.

I know we ALL hate cleaning up after someone else, and obviously I was overdue in this dept...as it's been a good long time since I've had to deal with a case this bad. But this one "like to drove me nuts!" as my grandfather used to say. lol

Thanks again for making it possible Doc! Without the complete manual, there's no way in hell I would have been able to find everything that the last 'tech' did.

Best regards,
Audiotexan

[Jazz P Bass]

Glad you persevered.

Quotes I liked:

After removing cap after cap after....

After a couple hours of this nonsense, I take a break and come back to basics.

Enter the grey wire.