Need battery/electronics help (Carvin S600B)

wood nacho · #1 08-19-2018, 11:50 AM

(Silly spelling mistake in the title :P)

I'm asking this to the wonderful people on this forum because I've discovered that Carvin no longer offers support for this P.A. :/

I have a Carvin S600B which gets almost daily use. It runs on a 12V 10Ah battery and I get somewhere between 2 1/2 to 4 hours out of it depending. The P.A. has a barrel-style female jack on the unit which accepts a 12vdc 2amps input if one wishes to use a powerpack or cigarette lighter out of a car to get some extra life out of the P.A. I'd like to use this feature when I'm playing an extended set and need some more juice.

One issue is that there is no indication of the polarity of this connector. Center positive? Center negative? It does not say in the manual or on the unit. Is there a way to test to see what the correct polarity is?

Also, this input is designed to be used with a powerpack/car jumper style box. Are these simply just a battery in a box? So, just a naked 12v DC SLA battery should work no? I would need a cable that takes the + and - terminals of the battery and connects them to a male barrel jack. I have an extra 12vdc 7ah SLA battery I would like to use and it would make life much simpler if i could just use this battery and a small cable to plug into the port on the amp to get some extra juice.

Thoughts? Any help would be greatly appreciated. Thank you!

jonfields45 · #2 08-19-2018, 01:51 PM

It is probably a 5.5mm/2.5mm positive tip barrel jack. That is the standard for most CCTV and computer networking products. There are plenty of these size male jacks already connected to wires on eBay (maybe too many). I also found them already attached to cigarette lighter male plugs too. Most of the stuff is very cheap and ships from China (about a month for delivery). If you buy from China, I've found it is useful to order a few spares as the quality might be low.

jonfields45 · #3 08-19-2018, 04:27 PM

Quote:

Originally Posted by wood nacho

Also, this input is designed to be used with a powerpack/car jumper style box. Are these simply just a battery in a box?

You've got it about right though they usually include some kind of battery charger too. And your extra 12v SLA could be attached to the S600B too.

MarkF_48 · #4 08-19-2018, 05:31 PM

I couldn't find a circuit diagram for the S600B, but did find one for the Carvin S400 SoundMate, which I suspect is similar. The tip/center on the barrel connector is (+). I would suggest if you make up a cable for a battery box type setup to include a fuse in the cable, perhaps an inline style fuse holder if that's convenient. Many of the cigarette lighter plugs will have a fuse internally in the plug (end cap unscrews). At a guess from looking at the circuit diagram I would suggest a fuse rated about 4 to 5 amps which would protect for a dead short at the end of the cable connector, as well as a fault within the amp. The S400 does have a charging circuit which besides charging the internal battery should do the external SLA also via the 12 volt connector.

BT55 · #5 08-19-2018, 06:40 PM

RadioShack sells the connectors you need. Same Chinese stuff shipped from the USA.

jonfields45 · #6 08-20-2018, 05:42 AM

Quote:

Originally Posted by BT55

RadioShack sells the connectors you need. Same Chinese stuff shipped from the USA.

Here in PA, Radioshack is long gone.

jonfields45 · #7 08-20-2018, 05:46 AM

If you've got a guitar stomp box 9v power supply handy, with everything turned off and unplugged from anything, see if the tip will go in the back of the Carvin. I am betting the outer diameter will look about right but it won't go in because the stop box standard is 5.5/2.1 mm OD/ID. This will confirm that 5.5/2.5 mm OD/ID is extremely likely to be correct.

wood nacho · #8 08-20-2018, 08:08 AM

Thanks for the replies everyone! Finding the right cable isn't a concern. I'm more worried about damaging the amp if I get the polarity wrong. I've heard this can be an issue with guitar pedals, so I'm concerned. Can anyone verify this?

jonfields45 · #9 08-20-2018, 10:47 AM

Quote:

Originally Posted by wood nacho

Thanks for the replies everyone! Finding the right cable isn't a concern. I'm more worried about damaging the amp if I get the polarity wrong. I've heard this can be an issue with guitar pedals, so I'm concerned. Can anyone verify this?

It is not possible to know if they put polarity protection into their design. Given the positive tip schematic for the S400 and that positive tip is standard everywhere except Ibanez Tube Screamer compatible stomp box supplies, I think the risk is very low as long as you wire it correctly (which is an easy mistake to make with clip leads on a loose battery).

Another approach that would eliminate any risk would be to run an inexpensive MSW power inverter off your battery and run the S600B on AC.

BT55 · #10 08-20-2018, 10:58 AM

Quote:

Originally Posted by jonfields45

Here in PA, Radioshack is long gone.

RadioShack.com

MarkF_48 · #11 08-20-2018, 11:38 AM

If Jon is correct on the size... https://www.amazon.com/Barrel-Connec...rel+connectors

might be able to find less of a quantity with a search, but this is cheap to have a few extra. Easy to wire up if you aren't up on soldering.

Or if you have a thrift store nearby look for old DC adapters you can salvage the barrel plug and cord from. A Salvation Army store near me usually have these for about $.99.