jc 120 reverb repair

finboy · Post by **finboy** » Mon Aug 11, 2008 12:12 pm

so i found a jc120 that has been converted to a head, but the reverb isn't working, anyone know if it is easy to fix or not?

Post by **Doog** » Mon Aug 11, 2008 12:17 pm

Could be as simple as an unplugged or faulty cable to the tank, or the tank itself could be borked. Try and have a lookie inside.

finboy · Post by **finboy** » Mon Aug 11, 2008 12:18 pm

schematics in this link...
http://music-electronics-forum.com/show ... php?t=4505

amp on ebay...
http://cgi.ebay.com/Roland-JC120-head-c ... dZViewItem

Post by **Doog** » Mon Aug 11, 2008 12:22 pm

I'd imagine if the guy had rehoused it, he would have noticed if the phono plugs to the tank were loose, so it may not be an easy-as-pie fix.

I'd grab it and investigate, unless the 'verb makes all the difference. I'm sure it'd be fairly straightforward and quick for a tech to sort out.

Justin J · Post by **Justin J** » Mon Aug 11, 2008 2:54 pm

does it even have a reverb tank?

Post by **Doog** » Mon Aug 11, 2008 11:52 pm

I was thinking, maybe the tank was somewhere else in the combo, and he's just ripped it out... buuut, the few pics I found of the back inside of a JC120, there didn't seem to be a tank lurking. Guess it could be in the main chassis?

jeff · Post by **jeff** » Tue Aug 12, 2008 12:08 am

I have a JC-120, and it's a spring reverb, so it does have a tank. I believe that it hangs down under the amp's guts, rather than resting on the floor like a Fender. Unfortunately, it's at my practice space so I can't pull it out and check.

But, from that picture, it looks to me like they pulled out the reverb tank when they converted it into a head. There's not a lot of room in there to hide a reverb tank.

Also, keep in mind that the best thing about the JC-120 is that it's a true stereo chorus, so unless they have it wired up to feed a stereo cab or two matching cabs, you're not going to be getting the best feature of the amp.

finboy · Post by **finboy** » Tue Aug 12, 2008 3:14 am

"Stereo 1/4â€� output plugs installed for use in stereo cabinet to enable stereo chorus effect"

i have a reverberator, kaoss pad, and am looking at a quadraverb, i'm thinking a lack of reverb might not so bad

jeff · Post by **jeff** » Tue Aug 12, 2008 4:12 am

Whoops. Didn't read words... distracted by pictures. The JC-120 reverb is just okay anyway. If you can grab it cheap, go for it!

jeff · Post by **jeff** » Thu Aug 14, 2008 4:13 am

Checked my amp tonight. The reverb tank hangs down underneath the amplifier above the left speaker (left when looking at the amp from the front). It's not very big, not quite half the width of the cabinet. But it's definitely not present in that head.

NickS · Post by **NickS** » Thu Aug 14, 2008 8:04 am

Is it possible the tank is hidden inside the metalwork now? In answer to questions the guy said it's there.