Carvin bass

[owendavis]

I need some advise, I just got this [Invalid or Expired Link Removed],

As is I'm in at $400.

It came across the country to D.C., the neck is bowed back and the active electronics don't work. The seller claimed it played and sounded great, but, the neck is bowed back and the active electronics don't work. So, the seller has agreed to take it back and refund my money, if I pay to ship it back, about $35 or I can buy new electronics from Carvin for $100 and try to fix the neck or pay someone to fix it.

So, I can send it back for a loss of 35 or try to fix the neck my self and replace the electronics and be in the bass @ $500.

Any suggestions?

 

[Dr. Eagle]

is the truss rod in good shape? when you say the electronics don't work, just mean no sound? Did you try it in passive mode?

 

[TimboZ]

What electronics are in it. A common problem with some of the carvins electronics is if you put the battery in wrong it will blow the op-amp. I replaced the op-amps in mine (less than a dollar) and also installed a diode so it would not happen again.

 

[pica]

If you like it enough to keep it and get it fixed that's what you should do. A new Carvin would cost at least three times that much so you still come out ahead. Just my opinion.

 

[TimboZ]

That looks like it has the 9V 501B Active/Passive electronics.

If your electronics work when in passive mode (pulling out on the volume pot) then there is a very good chance it it the OP-amp as stated in last post.

The op-amp part number is MC33078N (an 8 pin IC) looks like this

Also get a diode 1N4001 ant put in-line with the battery (on the red wire and grey ring of diode to pc board)) so it will not pass voltage to the IC if installed backwards.

Also another smart thing to do is install a socket to put the IC in so if it blows again you can remove it without a soldering iron.

 

[owendavis]

The pickups do work in passive mode, in active I get no sound at all, it has the 501B, that was standard from 95-07 according to the website.

 

[TimboZ]

I hate the battery box that carvin uses. It is too easy to put the battery in backwards and fry the electronics.

 

[Roy Vogt]

If the neck is back-bowed and the truss rod is OK, a good repairman can fix that easily. I'd also check the battery clip. I've had to replace battery clips before and it's solved "dead electronics" issues.

 

[owendavis]

I just managed to adjust the truss rod, I found a socket to fit and turned the socket with a screwdriver, and the neck is about perfect now. Hopefully it will not change overnight, but at least now I know the truss rod is working.
So now I just have to find the op-amp.

I am definitely keeping the bass now, it plays and sounds great, at least in passive mode for now.

 

[Dr. Eagle]

Worse comes to worse you could spend the money and get a new electronic kit, Carvin still sells them. I have one of these in my desk here for my fretless that I haven't gotten around to replacing.

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The one thing about Carvin basses is that the necks definitely notice the change in humidity. Here in Northern California that means that I will have to adjust the neck in Spring and Fall. You may find it a bit more finnicky in DC... I don't care, I have the most amazingly low action on my Carvins and they sound absolutely awesome.

 

[SJan3]

Worse comes to worse you could spend the money and get a new electronic kit, Carvin still sells them. I have one of these in my desk here for my fretless that I haven't gotten around to replacing.

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The one thing about Carvin basses is that the necks definitely notice the change in humidity. Here in Northern California that means that I will have to adjust the neck in Spring and Fall. You may find it a bit more finnicky in DC... I don't care, I have the most amazingly low action on my Carvins and they sound absolutely awesome.

I think most necks, if they're wood, notice a change in humidity. I would consider an adjustment 2x a year NORMAL.

 

[James Judson]

I think you found a good deal, even with repairs if neccessary. My Carvin LB70 has some awesome tone and the neck is rock solid. I sometimes store this bass for up to a year at a time (I have others that I play that are just as awesome) and when I do pull it out??? Guess what, you can tune a tuner with it. Oregon has it climate changes but it must be the right kind cuz this Carvin is rock solid.

 

[Dr. Eagle]

I think most necks, if they're wood, notice a change in humidity. I would consider an adjustment 2x a year NORMAL.

I agree, I wasn't complaining. Although I have never adjusted my P bass and I think I have adjusted my Tbird once. But its is normal, the reason I mentioned it is because people often complain that the necks on Carvin's are "unstable" to quote and I totally disagree with that having owned more than 5 of them in my life.

 

[barebones]

Good that you got the neck dialed in. I didn't see anything mentioning if you actually checked the battery itself in the bass. Probably pretty obvious, but sometimes we forget to troubleshoot the basics first.

 

[Roy Vogt]

I just managed to adjust the truss rod, I found a socket to fit and turned the socket with a screwdriver, and the neck is about perfect now. Hopefully it will not change overnight, but at least now I know the truss rod is working.
So now I just have to find the op-amp.

I am definitely keeping the bass now, it plays and sounds great, at least in passive mode for now.

FWIW Carvin sells their proprietary truss rod wrench in their catalog for $2.99. I'd get a couple:
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[SanDiegoHarry]

If the bass plays good, then that's 99.99% of the fight; You got a good enough deal that you can always just replace the electronics altogether if you like and STILL have a nice bass that was cheap!

 

[Roy Vogt]

FYI, the "old style" battery clip on your bass totally failed on two of mine. I ended up soldering a conventional battery clip to the circuitry and putting it in the body cavity and totally not using the battery clip on mine.
If you don't want to do that,carefully remove the clip from it's holder and try bending the prongs forward a bit. That may totally solve your problem. It's worth a try, anyway.

 

[SJan3]

I agree, I wasn't complaining. Although I have never adjusted my P bass and I think I have adjusted my Tbird once. But its is normal, the reason I mentioned it is because people often complain that the necks on Carvin's are "unstable" to quote and I totally disagree with that having owned more than 5 of them in my life.

I had a CARVIN B4 and it was a great bass with an excellent neck. Sorry I didn't keep it. I think people tend to jump on the "me too" bandwagon about things like this. I mean really, do we think CARVIN uses an inferior type of wood on their necks? I think not and I'd go as far as to say that it's probably much better than your "average" instrument. More than likely neck mass and climate, as you implied, are the major factors.

 

[Handyman]

What electronics are in it. A common problem with some of the carvins electronics is if you put the battery in wrong it will blow the op-amp. I replaced the op-amps in mine (less than a dollar) and also installed a diode so it would not happen again.

Yes, the brilliant designer at Carvin failed to put in any sort of polarity protection into those old preamps. And as been said, the battery trays from that era like to get bent contacts.

Does it work when you pull up the master volume pot and put it into passive mode? If that works, diagnosing your problem should be a lot easier.

 

[SanDiegoHarry]

Carvin *is* a funny company, isn't it? They do some things *so well*... and other things...