PDA

View Full Version : '67 Ampeg Reverberocket II gutshots


Tres Mellow
02-08-2010, 10:55 PM
So I need to replace the caps in the trem circuit and I have leaky cap in the reverb circuit (I get bursts of staticy signal through the reverb), so I thought I would post a link to the "before" pics here.
This is a 1967 black tolex model, and it seems they were starting to integrate some pcb in with the turret board. This is the first time I've had the chassis out since I got this a few weeks ago. Right away I notice that, despite the 3-prong cord, the "death cap" (Black Cat) is still installed and it looks like the neutral and hot AC are reversed from how they should be hooked up. The hot (black) should be running to the fuse, no? Do I then just remove the death cap once I've fixed the AC power wiring?
The amp is pretty quiet, except for the reverb static bursts, so I'm planning on leaving the cap can and big 40MF electrolytic cap alone. I'll test all the small electros and tubular caps and replace them as necessary.
One resistor has obviously been replaced, judging by the burn marks left behind, but otherwise, the components seem pretty original. The trem module is mini and mounted on a small pcb, so I hope I don't have to replace that anytime soon.
Thanks for any input.:aok
Here's the link:
http://ovationfanclub.ning.com/photo/albums/ampeg-reverberocket-ii

BigPapiFan
02-09-2010, 09:29 AM
Here is my '66 Blue-checkered Reverberocket II after a more complete cap job, three prong cord added, and death cap removed.:

http://i15.photobucket.com/albums/a398/23miles/Reverberocket2.jpg

Tres Mellow
02-09-2010, 09:59 AM
very nice...are you using the cap can at all now?

BigPapiFan
02-09-2010, 10:12 PM
very nice...are you using the cap can at all now?


No. It is there just for looks, and so there isn't an empty hole in the chassis.

Tres Mellow
02-09-2010, 10:57 PM
I just re-capped mine tonight except for the big electrolytics. I think I'll do those like yours instead of redoing the cap can.
I've added the "after" pics to the album:
http://ovationfanclub.ning.com/photo/albums/ampeg-reverberocket-ii
I rewired the hot and neutral AC legs and removed the death cap, too. The tremolo is now much deeper and more lush than I thought it would be, and the reverb is clean and clear of staticy bursts. The tonal range seems better, too, so I think it was due. I have a low to moderate hum that sounds like the filter caps are not pulling their weight, but it's not bad at all. I do get a "pop" when I power off now. I'm not sure what that's from, but I'll tackle that later.

Tres Mellow
02-10-2010, 08:04 AM
Here's a question...my schematic calls for a 70/40/40 cap can and then there's the 40 MF on the eyelet board. I've seen recap kits from Fliptops with a 22MF on the board instead. Is that an improvement? BigPapi, I see you went with the 40MF. I assume you must have a 70MF hiding under the other two 40MF caps in your photo.
Thanks!

mark norwine
02-10-2010, 08:39 AM
1.) do it right...use a new can. CE makes an 80-40-30-20 that will work great.

1a.) Replace the wafer while you're in there....

2.) by the time you get to the last stage of the rail, the ripple is pretty much gone and your current requirements are very low. 20uF is plenty. The can I suggested is a 4-section can.....you won't need anything on the board.

BigPapiFan
02-10-2010, 08:45 AM
Here's a question...my schematic calls for a 70/40/40 cap can and then there's the 40 MF on the eyelet board. I've seen recap kits from Fliptops with a 22MF on the board instead. Is that an improvement? BigPapi, I see you went with the 40MF. I assume you must have a 70MF hiding under the other two 40MF caps in your photo.
Thanks!


Oh-oh. I am afraid I may have mislead you. I didn't mean to pose as an electronic mastermind. I was fortunate to find an excellent tech - he did the work. He has a degree in electrical engineering, decades of experience in the guitar and amp business, and is a gigging musician. I had a lot of trouble finding the schematics on the web and the one in the cabinet was a bit flaky (literally!). My tech said he had his own set, so I let him do whatever he thought he needed to do.
All I can tell you is that the capacitor that he put in did not hurt the amp. This baby sounds great and better now than before he worked on it. I have a '66 Gemini II that he subsequently recapped and I always thought the Gemini was one of the best amps I ever heard - but this one beats it. This Reverberocket II has terrific definition, touch sensitivity and great high end sparkle, and is dead silent at idle.

Tres Mellow
02-10-2010, 11:08 AM
1.) do it right...use a new can. CE makes an 80-40-30-20 that will work great.

Voice of Reason...again.

Thanks, Mark. Great solution to get that big cap off the board, too.

BigPapiFan, I have a Gemini I which I love for the pure "oomph" of it. The RRII was fantastic before the recapping, and phenomenal after. Once I get rid of the low level hum with a new cap can, It will be perfect.

AL30
02-10-2010, 12:15 PM
Here is my '66 Blue-checkered Reverberocket II after a more complete cap job, three prong cord added, and death cap removed.:



:huh Well, someone's gotta ask... Why replace ALL the caps in the amp? It seems unlikely they were all bad. A cap job generally means just the electrolytics although coupling caps do go from time to time. I'm not knocking on you - it's your amp. Just curious as to the reasoning.

AL

BigPapiFan
02-10-2010, 03:01 PM
:huh Well, someone's gotta ask... Why replace ALL the caps in the amp? It seems unlikely they were all bad. A cap job generally means just the electrolytics although coupling caps do go from time to time. I'm not knocking on you - it's your amp. Just curious as to the reasoning.

AL


Ignorance may have played more of a role than pure reasoning. Going into the checkup I figured that the electrolytics would need to be replaced, and my tech offered / suggested just that. I figured as long as he had it (he is a couple hours away) just have him do them all with good quality components and that will be that. Why not, they had lasted 40+ years. If I can get another 40+, I'll have been dead for 10 - 20 years and I wouldn't have had to fuss with it again in my remaining "golden years."
I didn't care about the cap can issue, which I consider mostly cosmetic. My first concern was that the amp function safely (i.e. three prong cord and death cap removed) and as designed. Replace caps, new cord, remove death cap, small repair to the original CTS speaker, refasten loose tolex, shine the face plate - under $200 - seemed like a reasonably good investment.

Tres Mellow
02-10-2010, 03:12 PM
I can't speak for Big Papi Fan, but I had four failing caps in the tremolo circuit (3 for the speed and one for the intensity) and an obviously leaky cap in the reverb circuit giving me spurts of static in the reverb. I went ahead and tested the remaining 8 caps and 5 showed intermittent leaky voltage even though I wasn't hearing any scratchiness yet. I decided to change the remaining three because there were only three remaining. Afterwards, the amp sounds much better and all of the controls have a more balanced, useable range. It's also much quieter.
As I understand it, Ampegs are notorious for leaky caps, so I wasn't surprised.