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Carvin R600 Hi-Freq amp (amp 2) problem

Discussion in 'Amps and Cabs [BG]' started by cheeseman, Jan 5, 2003.


  1. cheeseman

    cheeseman

    Feb 3, 2002
    Austin, TX
    I posted this problem on the Carvin discussion board but thought TB'ers could help too. I have a Carvin series 2 R600. Last Monday it was doing as well as ever, and then I didn't use it until Thursday, when from the start it wasn't getting very loud and sounded distorted. I tried both active and passive basses, and different settings (preamp tube on/off, graphic eq on/off, boosts on/off, bridged/unbridged, full range/bi-amped).

    I've come to realize that it is not a preamp problem, but a dead amp 2 (hi-frequency) problem. I plugged a different preamp into the amp 1 (low freq) return and got a good clean sound. But when I plugged the preamp into the amp 2 (hi-freq) return I got no response whatsoever. I tried a few different settings but nothing changed.

    Is the power-amp 2 dead or is it something I could fix? I was already thinking about getting a new power amp (possibly a DCM1000), is this probably my best option?

    This problem started (or maybe just the first time I noticed it) after I hooked up a RL210T (in the hi-freq) and the 15" from the Cyclops (in the low freq). This is the first time I've ever hooked it up like this. I wasn't running bridged so I don't think the amp would have a problem with the impedence load.
     
  2. chucko58

    chucko58

    Jan 17, 2002
    Silicon Valley, CA, USA
    I paid for all my gear myself. Well, me and MasterCard.
    This is Chucko from the Carvin BBS. Did you give this amp the "deep tissue massage" treatment like I suggested? (Open it up, use good contact cleaner on every connector, disconnect and reconnect each connector several times to ensure good contact.)

    It only takes one bad line-level signal connection to make an amp fail. I bet that's what has happened to your amp. Carvin doesn't use the world's best connectors. That's part of how they keep the price down.
     
  3. cheeseman

    cheeseman

    Feb 3, 2002
    Austin, TX
    I'm planning on doing the cleaning tommorrow. Actually later today. Where can I get some contact cleaner? Everybody I ask tells me where to find contact lense cleaner.

    When you say connectors, do you mean the cables on the inside or the 1/4" jacks? I've never opened an amp except to change the tube.
     
  4. chucko58

    chucko58

    Jan 17, 2002
    Silicon Valley, CA, USA
    I paid for all my gear myself. Well, me and MasterCard.
    Any electronics store, including Radio Shack, Fry's Electronics in California, etc. Some Radio Shack stores even carry the Caig DeoxIT D5 that I prefer.

    I mean every connector! All the 1/4" jacks, flexible cables between circuit boards, tube socket, etc. Anything that can be disconnected should be disconnected, sprayed with contact cleaner, and reconnected. Run a 1/4" plug through each of the jacks, again after dousing the jack with contact cleaner.

    Pay special attention to the preamp/crossover out/power amp in jacks, because that is the most likely source of your problem. "Shorting" jacks (the technical term is "normally closed") like those have a nasty habit of getting dirty and failing to make contact.

    For example, I have a Carvin PB-15 preamp that had a bad shorting contact on the input jack. This caused it to hum when nothing was plugged in. I was able to fix it with some contact cleaner and judicious bending of the contacts. Now it's quiet as can be.

    I hope you find this helpful. I'm not trying to be a putz, just want to help you get your amp working again at minimal cost.
     
  5. Cheeseman. That is the exact set up I am using right now. The R210 cabinet is a full range cabinet and it will sound like total crap if you bi-amp it with the high's going to it. Push the full range button in and check amp 1 and amp 2. If you can control the volume with each amp you probably don't have a problem. Also try playing the 210 a little louder than the 15 in the Cyclops. You just might be surprised with the sound you get.
     
  6. cheeseman

    cheeseman

    Feb 3, 2002
    Austin, TX
    Actually, I run full range most of the time, I just tried bi-amping while I was trying to locate the problem.
     
  7. cheeseman

    cheeseman

    Feb 3, 2002
    Austin, TX
    OK, I did the "deep tissue massage" and when I put the amp back together and plugged in, he amp was working like before.

    Thanks guys. Here's some love: :D
     
  8. chucko58

    chucko58

    Jan 17, 2002
    Silicon Valley, CA, USA
    I paid for all my gear myself. Well, me and MasterCard.
    Good work, cheeseman! I'm glad I could help.
     
  9. You fixed your own rig!!!!!! :eek:

    So terribly cool!!! :D

    I'm telling you, electronics repair shops are expensive, my rig is in for repairs as we speak. I'll probably be into this repair (with shipping and insurance) for about $185.
    :(

    To those who helped cheeseman, good job!!!

    :cool:

    B
     
  10. Denimhorn

    Denimhorn

    Nov 25, 2002
    to anyone having this cut-out, distortion problem with their Carvin head - i have the same thing!!!

    Trust me im on my way to Radio Shack right now to get some cleaner. Just wondering if anyone else was having the problem on and off....like at higher volumes (maybe sound vibrations cause it to go in and out??) i noticed that mine will temporarily (like 1 min) fix itself if i give the head a little tap.

    I sooooooooo hope this fixes my problem.
     
  11. Denimhorn

    Denimhorn

    Nov 25, 2002
    well i cleaned everything out last night....seems ok for now....real test will be on sat. when we have practice and i crank it up.

    If this fixes it....its new Ricky basses for everyone. My treat. This forum rocks. Thanks for the help.
     
  12. Captain Awesome

    Captain Awesome

    Apr 2, 2001
    PDX
    I have an occasional cutting-out problem with my Carvin R600 (doesn't quite cut out but gets very weak and distorted sometimes) and I have isolated it to the preamp (I never have any problems if I run my bass into the power amp jack.)

    There are ribbon connectors connecting the preamp to the power amp and the routing jacks in the back. It looks like they're sealed to the circuit board, but I know nothing about electronics. (Are they sealed?)

    I'm gonna guess it has something to do with the headphone jack or the routing jacks shorting out so I'll just clean those this time. Do I just spray the stuff directly into the jack or do I need to take everything apart and spray the contacts from inside?

    BTW, I'm using Radio Shack "Precision Electronics Cleaner." I hope that's the right thing to use.
     
  13. cheeseman

    cheeseman

    Feb 3, 2002
    Austin, TX
    The ribbon connectors are not sealed, you can pull them off. I sprayed directly into the jacks and around them also. I took the board completely out of the amp when I did this. But I suppose you could just spray it into the jacks if you wanted to.

    Also, I don't think you are supposed to let the cleaner touch your skin, so wear some latex gloves if you can.
     
  14. Denimhorn

    Denimhorn

    Nov 25, 2002
    bad news everyone....i tried the head out again this weekend - Hi Frequency - Full Amp (not bi-amp) and i still have the same problem - the distortion and the power cut out. Majorly disappointed. Any ideas on what to try? I cleaned all the connectors (didnt remove the board from the casing) and i still get the same problem.

    SWR here I come!!
     
  15. Captain Awesome

    Captain Awesome

    Apr 2, 2001
    PDX
    Denimhorn -- I had the occasional distortion/cutting out problem with the preamp on my series II R600. (the power amp is fine in my case.) 2 days ago I sprayed some Radio Shack electronics cleaner into the return jacks (the only ones that would cut the sound if they shorted) and moved a 1/4" plug in + out of each of them a few times after spraying in the cleaner. So far I haven't had any problems. Then again I've only played through it for about 3 hrs. since I "fixed" it.
     
  16. Captain Awesome

    Captain Awesome

    Apr 2, 2001
    PDX
    Well I guess that didn't fix it, I got the preamp problem (distortion, low output) to happen again today for a couple minutes.

    Here's what I know:
    -The problem definitely occurs before the signal reaches the power amp. It has nothing to do with the power amp.
    -I have cleaned the return jacks and cleaned the tube prongs(?), apparently both did nothing.

    Next time the problem happens I'll mess around with the preamp controls and observe the noise gate, compressor, and clip lights so I can have a better idea of just where the problem is.
     
  17. Denimhorn

    Denimhorn

    Nov 25, 2002
    Primussdude....isnt this fun!! Looks like we should consider buying new amps huh? It drives me crazy thinking about this. You would think someone from Carvin would read these boards and jump in with some advice....maybe we should post to their forum?
     
  18. Captain Awesome

    Captain Awesome

    Apr 2, 2001
    PDX
  19. Denimhorn

    Denimhorn

    Nov 25, 2002
    yeah i saw that posting over there as well....any luck on your end primusdude?

    Im almost at the point of trying to take it back to Carvin...i live here in San Diego. Maybe i can get them to take a look. I tried once before and of course i couldnt duplicate the problem and they found nothing.

    Maybe i will take it apart again to see if there is something else. So far i used the cleaner on all the ribben connectors and also the clamp connectors whic attach to the board. What else should I try? How can i isolate where the problem is? You mentioned you know its the preamp. How did you determine this?
     
  20. Captain Awesome

    Captain Awesome

    Apr 2, 2001
    PDX
    I know that whenever my sound starts dropping out, I can plug my bass into the return jack (power amp in, bypassing the preamp) and not have any problems. That's how I determined it's somewhere in the signal chain before the power amp. If it's the same problem as the guy on the Carvin board, it's something in the rear routing jacks circuit board shorting out. Tomorrow I plan to start working on it.

    One way you can isolate where the problem is to some extent is when your amp starts acting up again, see if you can get the clip light and the compressor light to go on, if they behave as they would to a full signal then the problem occurs after that part of the circuit.