|
|
Joined:
September 2005
Posts: 29
Location: USA/Maryland | The electronics are not working on my 1975 - #1612 that I just got back after selling it a year ago. They didn’t work then either, but I never tried to diagnose the problem when I had it before.
Yesterday, while doing a string change I finally decided to check it out. I removed the preamp, battery, and jack from the body. I desoldered the pickup leads going into the preamp so I could better isolate the problem. I ran an audio source from my iPad into the preamp, and an out to an amp. I get sound thru the preamp, so I presume the pre is ok. I actually get sound regardless of whether a battery is in place or not. I assume this is because the iPad signal is already rather hot, (more than a pickup would provide). It IS a bit louder with the battery installed.
At this point I assume the pickup is the issue. While the strings were off, I pulled the saddle to check the pickup leads, I don’t ***see*** a problem, both still appear to be connected, (I did this also when I had it before, it was the obvious thing to check). I didn’t’ really want to be too aggressive and break a connection that wasn’t already bad.
So I guess my question is, what would cause the pickup to fail if the leads are still good? Is there another way to test the pickup?
I reinstalled the bridge, tied and supported the leads, and re-strung. The pre-amp is still out. What is my next step? I was really hoping this would be a preamp issue, as it would easier to repair the pre, than to find a replacement saddle/pickup.
Having the electronics not working is NOT a big deal on this O, but if it's a simple fix, why not.
Any ideas would be appreciated…. thanks, Jeff
Edited by JeffR 2015-08-03 9:15 AM
|
|
| |
|
Joined:
September 2005
Posts: 29
Location: USA/Maryland | Afternoon update... I jumpered directly from the pickup leads to a 1/4" cable going directly to my amp, LOUD AND CLEAR. The pickup seems fine.
However, no sound at all if I attempt to connect thru the preamp OR by bypassing the pre and connecting the pickup leads directly to the O's output jack, and then to my amp. The pickup passed my iPad's signal yesterday, odd.
BTW - circuit board on the O's pre is numbered 400010-B, just a single volume control. |
|
| |
|
Joined:
July 2015
Posts: 190
Location: SW Mintsoda | Is it just the output jack, possibly? |
|
| |
|
Joined:
September 2005
Posts: 29
Location: USA/Maryland | I've considered that, BUT..... it did pass my iPads signal yesterday.
Oops edit... my post above should read....
".....The ***PRE-AMP and jack*** passed my iPad's signal yesterday, odd."
Too late to edit other post.
Edited by JeffR 2015-08-03 4:29 PM
|
|
| |
|
Joined:
December 2004
Posts: 566
Location: Denmark | I dont think there should be signal passthrough without battery supply. Maybe the FET is dead? I think a 2N5457 will do.
Maybe you can find a schematic for the preamp here: http://ovationtribute.com/Schematics.html. If not I think the input stage is quite similar to the FET3 (which in addition has a 3-band eq.)
Edited by tpa 2015-08-03 4:52 PM
|
|
| |
|
Joined:
September 2005
Posts: 29
Location: USA/Maryland | OK thanks tpa. I didn't know that was there. The link doesn't seem to be visible on the main page.
DL'd the 'Volume Only Preamp' schematic. Thanks |
|
| |
|
Joined:
September 2005
Posts: 29
Location: USA/Maryland | Looks to be 2N5459 in there |
|
| |
|
Joined:
December 2006
Posts: 6994
Location: Jet City | I will double up on the jack suggestion.
My 1867 just died. I still had some signal coming through too, but changed the jack, all was back to norm. My tech also said the Ovation jack is different than most, sorta like a Rickenbaker, but I'm not an electronics repair sort, so I'll shut up now... after I say it one more time... check the jack first |
|
| |
|
Joined:
September 2005
Posts: 29
Location: USA/Maryland | Good to know, it does seem to be the common factor. It is a switching jack, ie plugging in the cable enables the battery. Thanks Damon |
|
| |
Electronics not working on my 1612, ideas?