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Location: Fitzwilliam, New Hampshire | Sounds like the Reverb tank is missing. The circuit board is part of it but I don't recall Ovation using all electronic reverb. I don't think that was available then? There are a number of sites that have reverb tanks (E-Bay, etc) for not much in the $25 range? You could always borrow one from another amp if you have one just to try it. BTW, I had an Ovation K-6001 with a (4) 12" speaker cab with two horns. Getting a good distortion was tough but one trick I used was to jumper the two RCA's plugs together (bypassing the reverb tank) and it kicked it up the gain a notch. There use to be a Fender mod that had a little jumper module that did the same. Anyway, good luck. |
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Posts: 12759
Location: Boise, Idaho | I took the whole back off yesterday and discovered the reverb tank mounted to the top. Either the RCA plugs had fallen off or I pulled them off when I opened it up the first time. The wires were so short that they pulled out as soon as the back was opened a couple inches. I fixed the broken wire to the horn, took some pictures and closed it back up. The reverb tank has a female output jack on one side and an input jack on the other. I plugged the RCA plugs in, but the reverb didn't work. I couldn't tell which of the male plugs was the output and which was input, so I switched them and still nothing. The amp sounds pretty good, though. I'll try to post some pics this weekend.
Edited by Mark in Boise 2015-01-02 11:30 AM
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Location: Fitzwilliam, New Hampshire | Sounds like progress at least! My sounds good so far. Once I get a horn and wire the speakers to the power amp and close up the back I'll get a better idea how it all sounds! Did yours have insulation on the back panel? I know most closed back cabinets usually do. Mine had some stapled on but its not original for sure. The amp had been recovered, and a new grill cloth done at some point. I had a role of Fender black grille cloth kicking around to replace the torn cloth previously used. Once I get it all together I'll share some pics as well! |
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Location: Fitzwilliam, New Hampshire | BTW, my reverb tank was mounted using some rubber shock isolators on all four corners. In addition, there are two ground wires from the tank mounting bolt around the rubber isolator mount to chassis to maintain the ground. Make sure that is also intact since that would affect the operation too. I hope this makes sense. |
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Location: Boise, Idaho | I didn't check the grounding of the reverb tank. I did get some popping noise when I turned the reverb on after I hooked it up the first time. After I switched the RCA connectors I didn't get anything.
Yes, there was some dense foam, like carpet pad, about 2 inches think at the top of the back panel of the amp and some staples where it looked like similar foam had been attached to the bottom of the back panel. The foam that was left was falling apart, and was probably original, but I didn't have any suitable replacement. Another project.
I'm still not sure the horn is working correctly. The adjustment knob on the front doesn't seem to do anything, but the treble seems much stronger and the treble control makes a big difference. It didn't seem to do anything before I repaired a broken wire. The sound is far from crystal clear, but it's not bad and it sure is loud. The front cloth is in good shape and appears original. The side handles have been replaced with metal ones and the vinyl has some tears. It's been used so much that the labels for most of the inputs and outputs on the back are scratched off and the back has been removed so many times that most of the holes for the screws is stripped out. Somebody added a couple of new screws and moved the old ones just to hold the back panel on. I had a few screws missing by the time I turned 50, too. |
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Location: Boise, Idaho | I put some pictures of the amp innards in my album. I'll try to move some here when I get a chance. |
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Location: Fitzwilliam, New Hampshire | I found that my reverb actually works but there is a problem with Channel 1 which just hums as if a ground or open somewhere. When I cranked up the treble control on Ch1 and tapped the reverb tank I can hear it come thru. So some progress made. Ch2 (using the Ch2 isolated speaker output) works fine but the Reverb doesn't. So somehow it maybe tied to the Ch1 problem or someone rewired it and without a schematic it will take time to chase this down. Next step is to swap Ch1 and Ch2 preamp cards to see if the problem moves with the card. Had the chassis completely apart last night to investigate the reverb channel switch board since that is also where the speaker outputs connect to. The missing component on the reverb card is not the issue since the circuit etch goes to a terminal on the card socket that is not connected to anything! Interesting comment on the "popping" sound when using the switch for your reverb. I have the same issue but only on the "Fuzz" switch. |
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Location: Boise, Idaho | You are into it way deeper than I am. Fortunately, my amp is a bit simpler. If you can figure out which RCA connector goes to each end of the reverb tank, that would give me a start. 
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Location: Fitzwilliam, New Hampshire | Ok, my reverb tank is actually stamped "input" on the right as I'm looking at yours above, and "output" on the left. I didn't notice at first since the stamping was a little hard to see with the oxidation of the housing. Mine looks identical to yours and is horizontally mounted. Not sure who the manufacturer is since there are no distinguishing model numbers etc on it! But it looks like a common Accutronics from that era. I also noticed that one of the RCA cables has a shield but is NOT connected. Since the outer ring on both input and output jacks are riveted direct to the housing(no insulator), they are essentially grounded so only one cable shields needs to be tied to ground. I thought it was a mistake at first but I found some good documentation on reverb tanks that says certain models do this! |
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Location: Boise, Idaho | I could see the stamping on mine, too, but couldn't figure out which of the RCA plugs was for the input and which was for the output. I put all the screws back in the back panel. The foam is falling apart and makes a big mess, so I may wait to get some replacement foam before I take it apart again. |
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Posts: 137
Location: Fitzwilliam, New Hampshire | Ok another angle. The "output" RCA cable on mine does NOT have the shield landed on the connector for the reverb circuit card. Only the input cable had the shield landed. So that may be an easy way to distinguish which one is which. If all Ovation amps used the same reverb tank then hopefully the same grounding scheme as I mentioned earlier. |
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Location: Boise, Idaho | I assume my reverb had some issues before I bought it, because one of the RCA plugs was heavily wrapped in electrical tape. I might not be getting a decent connection to the reverb tank no matter which way I plug in the connectors. |
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Location: Boise, Idaho | There's a "Little Dude" listed as an Ovation K6323 on ebay right now, supposedly working well with bidding under $12 and no reserve. The horn has been replaced, though. If Miles has an original horn, that might be nice for one of us Ovation Collector's. It's the same amp that I have, but I mine has both original speakers. |
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Location: Fitzwilliam, New Hampshire | interesting for sure Mark. I've been scanning E-Bay, Craigslist etc for anything on these old amps but not too many pop up. I wonder how many they made in the short time they existed?? |
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Location: Boise, Idaho | The shipping to my house was only $45! I think that estimate may be low for that beast. You'd probably pay 10 times the cost of the amp to ship it to Massachusetts. |
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Location: Fitzwilliam, New Hampshire | Yes from California to Mass would be crazy. Nice little unit though and all working!!!
Anyone remember the Ovation TUB speaker they came out with in the late 60's? I was working at a music store at the time after school and the owner came back from the NAMM show with a show special he bought. It looked like a big wash tub mounted on a pivot bracket to a large base that housed the power amp. I don't know how many were actually made but I've never seen one since!!! |
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Location: Boise, Idaho | I don't remember that tub speaker, but that was a couple years before I got into Ovations. The 6323 is up to $26! |
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Location: Boise, Idaho | I just remembered to check ebay and the Little Dude amp went for $150. Not bad for either side. |
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Posts: 137
Location: Fitzwilliam, New Hampshire | Maybe a few more will pop up and I can find some parts for mine! |
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Location: Fitzwilliam, New Hampshire | Hey Mark,
Just bought a real nice 9702 speaker on E-Bay for my restoration. Still need one more, but one step at a time. I'll post a picture next.
Gary |
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Location: Boise, Idaho | Great! I need some motivation to fix up my amp. |
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Posts: 243
Location: Pewaukee, WI | It looks like there is one of these speakers at Dave's Guitars in LaCrosse WI. a 9722. Taking the bell cover off, it has a stamp of being manufactured by Eminence.
http://davesguitar.com/products/eminence/12-alnico-speaker/
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Posts: 137
Location: Fitzwilliam, New Hampshire | Yes it looks like some of the speakers I've seen on E-Bay and the one in Mark From Boise's amp. Its different than my 9702 that I posted pictures in a different thread. That's good info however for most of the Ovation Audient speakers I've seen!! A little piece of info here helps to narrow down the missing info on these speaker variations! Thanks! |
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Ovation Speakers
