ADA Depot - A Forum To Support Users of ADA Amplification Gear

Let's Get Technical => Schematics & Modifications (mods) => Topic started by: kfowler8 on September 04, 2014, 07:22:36 PM

Title: MP-1: Is this a mod
Post by: kfowler8 on September 04, 2014, 07:22:36 PM
I took off my covers tonight to change out the battery and start prepping for the rear jack mod. I noticed this black jumper wire that looked out of place. Is this some kind of mod? If so, what? The only mods I know that have been done on this unit is the battery mod and the update to version 2.

Thanks,

(https://nvm0yq.bn1302.livefilestore.com/y2pmy4myTyTT9Xph0SZbNubbqOmV4mKPamPHN_2Q40w1AOTjK6lDRxeVIt1AHsBW585_M3lLHal6OzT0zpNBV2W3Rtxpo-KGhCrQrs6iOvJqf4/WP_002101.jpg?psid=1)
Title: Re: MP-1: Is this a mod
Post by: MarshallJMP on September 05, 2014, 03:24:50 AM
This is normal,no mod.
Title: Re: MP-1: Is this a mod
Post by: kfowler8 on September 05, 2014, 05:24:25 AM
Thanks!!!!!!
Title: Re: MP-1: Is this a mod
Post by: El Chiguete on September 05, 2014, 06:18:06 AM
I guess someone notice they forgot to do that in the board design and had to do that to ALL of them latter! jejeje.
Title: Re: MP-1: Is this a mod
Post by: MarshallJMP on September 05, 2014, 01:09:08 PM
This was fixed in the V2 mp-1's.This is a sort of factory mod to fix some ground problems.
Title: Re: MP-1: Is this a mod
Post by: kfowler8 on September 08, 2014, 08:06:03 PM
Got it all working now. Took longer to de-solder everything than it did to run the new lines. Works great.
Title: Re: MP-1: Is this a mod
Post by: rnolan on September 08, 2014, 11:48:00 PM
Good to hear  :thumb-up: :whoohoo!:
Title: Re: MP-1: Is this a mod
Post by: WickedBlade on September 09, 2014, 12:10:18 AM
Hey guys,

I just noticed that I don't have that wire on my v1 MP-1.
MJMP, would you advise to do this little wiring? I don't think I have ground issues, so maybe "if it ain't broke, don't fix it" should apply?
BTW my board is 423 rev E, whereas kfowler8's is ref F so maybe the issue was introduced with rev F...
Title: Re: MP-1: Is this a mod
Post by: MarshallJMP on September 09, 2014, 01:39:49 PM
Like i said not all mp-1's have this,can you take a pic of the board so i can check?
Title: Re: MP-1: Is this a mod
Post by: WickedBlade on September 10, 2014, 02:03:17 PM
Here's a picture of my actual board.

I should mention that it was taken years ago, before I applied any mod, but I don't think that affected the board (I applied the noise mod, MDRT, new filter caps).
I may have applied some fixes from the april 1992 'troubleshooting' mail too, but not the MIDI board Ke/Kd wire thing (that I remember of, anyway). I suspect that is the subject at heart, here...
Title: Re: MP-1: Is this a mod
Post by: MarshallJMP on September 10, 2014, 02:07:48 PM
That's an old board,what is the REV letter of the mainboard.Can you also take a pic of the mainboard?
Title: Re: MP-1: Is this a mod
Post by: WickedBlade on September 10, 2014, 02:13:01 PM
Wow, you're fast! BTW I just edited my message above.

Mmmm the main board is a Rev B (B is handwritten). See the attached picture. As before, this was taken before any mod was done (so you can see the original tranny which I changed from the MDRT).
Title: Re: MP-1: Is this a mod
Post by: RobbHell on September 10, 2014, 03:54:33 PM
Not that its a must be the red wire on the  (KB connector)  was clipped. I noticed your T2 trimpot was set rather low. Are you a little gain user?
Title: Re: MP-1: Is this a mod
Post by: MarshallJMP on September 11, 2014, 02:50:39 AM
Well this is an old board and it will work without the wire like it is.You can do the update but only if you have ground problem,else i would leave it like it is.

I attached the PDF update file,the update is #8 and #9.

Do you still have the ZETA chips in there?If so i would replace these with the VACTEC's see #6
Title: Re: MP-1: Is this a mod
Post by: WickedBlade on September 15, 2014, 01:00:15 PM
Sorry guys, I was away for a few days.

Quote from: RobbHell on September 10, 2014, 03:54:33 PM
Not that its a must be the red wire on the  (KB connector)  was clipped. I noticed your T2 trimpot was set rather low. Are you a little gain user?
As I said, the pictures were taken years ago, as I was unpacking my latest acquisition. I have no clue how my T2 trimpot is set today, but I am entirely satisfied with my gain. I'm using a Pornograffitti-style tone, so there's enough gain for me, and plenty more on tap.

Quote from: MarshallJMP on September 11, 2014, 02:50:39 AM
Well this is an old board and it will work without the wire like it is.You can do the update but only if you have ground problem,else i would leave it like it is.

I attached the PDF update file,the update is #8 and #9.

Do you still have the ZETA chips in there?If so i would replace these with the VACTEC's see #6
Thank you for the advice, I'll leave the unit as it is now, since I have no ground issue.
I had done the mods described on your paper already (while I was doing the noise-mod) and I do have Vactrols in place now. That picture is seriously out-of-date :)

Thanks again.
Title: Re: MP-1: Is this a mod
Post by: MarshallJMP on September 16, 2014, 01:35:39 PM
Ok!