Possible for my amp to be working for 4 ohms but not 8? Carvin ribbon cable issue?

Diesel Kilgore · #1 12-30-2012, 08:52 PM

Trying to troubleshoot my rig. Carvin R1000 and Peavey BX BW 115.

There doesnt appear to be anything wrong with the cab or speaker. Its clean and it does make sound.

Im beginning to think its gotta be the amp. If its been sitting for along time and then I power up. I will get a second of clean audio then silence.

However, this amp works with no problems, except some fuzzyness, on a friends Mesa 210 cab which I believe is 4 ohm. My Peavey is 8.

Is it a possibility my amp is having a problem with 8 ohms? I know Carvins are notorious for the dirty/loose ribbon cables. Could that be a cause of my woes as well?

Got2SadowskyNYC · #2 12-30-2012, 09:09 PM

If it's NOT under warranty open it up and check. Unplug each one, spray them with some Deoxit and reattach.

(Deoxit is a high quality contact cleaner. If you can't get it you can do the same thing with rubbing alcohol.)

If it's under warranty, call Carvin. Opening it will void it.

Diesel Kilgore · #3 12-30-2012, 09:13 PM

No its not under warranty. Im the 3rd owner. Its probably ten years old? Its a series 3. Im gonna open it up and check.

Diesel Kilgore · #4 12-30-2012, 09:50 PM

Okay I opened it up and found an issue by accident.

All of the inputs in the back have a plastic cover or box they are encased in individually. The main inputs little box is broken and pieces of it were laying loose in the head. It looks like there is a little collar of metal that once wrapped around the base of the input but it looks like its broken. Like it was sheared off somehow. The input also looks like it was once nice and silver but looks like brass now. Corrosion, water, crud build up?

Here is something I found on accident. I had it all plugged up and accidently touched the plug in the jack while resting my hand near the power module and got a good tingle. But as soon as I let go the cab poofed out with some audio! What does this mean? Just a faulty jack? Bad ground? How should I procede?

Got2SadowskyNYC · #5 12-30-2012, 09:59 PM

10 years, it's out of warranty.

Broken jack could cause bad ground. Replace the broken jacks. You don't have to use the same type just make sure you wire them properly, tip to tip etc.

BE CAREFUL what you touch, even when it's unplugged. There are parts that can hold voltage for several hours and it's enough to send you to the hospital. Or worse.

Diesel Kilgore · #6 12-30-2012, 10:24 PM

Im thinking of taking out one of the jacks already on the head that I wont use and switching it out for the bad input. Bad idea?

Got2SadowskyNYC · #7 12-30-2012, 10:28 PM

No. A 1/4 inch jack is a 1/4 jack. Just make sure you wire it properly.

Diesel Kilgore · #8 12-30-2012, 10:58 PM

They are soldered directly to the board at three points. It should be simple to pop one out and the other in.

T-Bird · #9 12-30-2012, 11:09 PM

Hi.

Quote:

Originally Posted by Diesel Kilgore

They are soldered directly to the board at three points. It should be simple to pop one out and the other in.

With a 3 leg jack there's probably not too many possibilities to get it wrong, but if there's switching contacts and only 3 legs are used, better to get one exactly the same.

I once spent 2 hours troubleshooting an amp that behaved very strangely, up until I finally discovered a non-standard jack in there.
It turned out that someone else had been there before me, and did a very clean job of replacing one of the jacks.
An incorrect one at that though it turned out to be

.

Regards
Sam

Diesel Kilgore · #10 12-30-2012, 11:42 PM

Ugh. Now that im getting in there it seems like its gonna be a pita.

Diesel Kilgore · #11 12-31-2012, 12:42 AM

Alright, soldered in the new jack. Clip and compression lights are blinking so it worked. But still no sound.

Back to the cab. Somethings gotta be up. Driver maybe? Bad voice coil? The amp worked on another cab but not mine. But I have gotten some blurps from the speaker. But not alot. Another project.

BassmanPaul · #12 12-31-2012, 09:04 AM

Do the battery test on the speaker cabinet to make sure it actually works. Try a different speaker cable.

Diesel Kilgore · #13 01-01-2013, 06:07 AM

Played the Carvin through my friends Mesa cab earlier tonight and it worked great. After replacing the broken jack the fuzz is gone from the amp that was there before.

Did the battery test on my Peaveys speaker and got nothing. So I am gonna do a basket replacement and hopefully all will be well.

With the money spent on this used rig + speaker replacement is an actual steal. I am very happy to be coming out with a great setup for so little money and a few sweat drops. Thanks for all your help guys.

Floyd Eye · #14 01-01-2013, 06:15 AM

Used an RL1000 for years. You ARE going to have issues with it. Luckily most of them are well known and easily remedied. That is up until it takes a dump on you, which it inevitably will.

If you bridge this amp it will run hot.
Your FX send/return jacks will get dirty so clean them regularly with deoxit.
Preamp has a pretty high failure rate, so it might be a good idea to get you a SansAmp to at least have on standby in case this happens on a gig. ( Personally I think the pre in this amp sucks anyway)

This is a powerful amp though. In my opinion, for best results get either 2 matching cabs or a single 810 and run the amp full range as opposed to using the bi-amp feature.

Diesel Kilgore · #15 01-01-2013, 06:42 AM

Thanks Floyd. There are alot features this Carvin has that I will never use.

Basically I am using the SPK 1 bi amp into the cab and thats it. The Carvin has the potential to do alot more if I need it to. But I really have no need for it, which hopefully keeps this thing servicable for quite some time. I only paid $50 for it anyways. So if I get a year out of it I am happy.

Floyd Eye · #16 01-01-2013, 06:50 AM

Quote:

Originally Posted by Diesel Kilgore

Thanks Floyd. There are alot features this Carvin has that I will never use.

Basically I am using the SPK 1 bi amp into the cab and thats it. The Carvin has the potential to do alot more if I need it to. But I really have no need for it, which hopefully keeps this thing servicable for quite some time. I only paid $50 for it anyways. So if I get a year out of it I am happy.

I got a great deal on mine too. It will serve you well as long as you understand it's limitations and operate within them. I still say the day will come when you want to add a cab. When you do, add a matching cab and run the amp full range.

BassmanPaul · #17 01-01-2013, 08:56 AM

Quote:

Originally Posted by Diesel Kilgore

Did the battery test on my Peaveys speaker and got nothing. So I am gonna do a basket replacement and hopefully all will be well.

Before you do this make sure that the cabinet's wiring is good. It could possibly just be a broken/disconnected wire.

Diesel Kilgore · #18 01-01-2013, 06:56 PM

Hey Paul. The wiring appears to be good. Its has 2 slip connectors on the ground and positive that hook to the jack. One thing I noticed however is the ground wire jack (plastic casing) on the speaker is coming apart.

Downunderwonder · #19 01-01-2013, 09:51 PM

Better replace that stuff that's coming apart then! You can solder direct to the contacts for a forever fix.

Diesel Kilgore · #20 01-01-2013, 10:32 PM

The jack on the speaker itself is coming apart. Which will get replaced soon. I may just solder up the slip connectors on the cab jack for safety.