Connecting combo to speaker

randerson

So I decided to see what my Yerasov combo would sound like through my AC30 speaker cabinet. I have had the AC30 modded so that I can unplug the speaker cable from a jack input on the underside of the amp. The Yerasov has the same arrangement stock.

So I simply connected the cable from the AC30 using a female / female adapter to a speaker cable into the Yerasov amp. Both are at 8ohm I think*. But no sound at all. I the tried the reverse - Ac30 amp in to Yerasov 1x12 no sound either. What am I doing wrong please?

*If they weren't and the AC30 was 16ohm I would have damaged the amp(?) and that hasn't happened so..

ecc83

The difference, 8-16/16-8 is not a problem but you could damage the amplifier if you have left it without a load i.e. the cable arrangement is open circuit (if you had a short it would still not work but little chance of damage*)

HAS to be said, the only female line jack connector worth a ***t is the locking Neutrik jobby.  I did a lot of ad hoc speaker/amp swapping and just soldered 2-3-4 or more  chassis mount jacks (the side contact plastic jobs) pin to pin, did not even bother to insulate them but YOU should!

I doubt you have a meter? No, so plug up the speakers and then BEFORE inserting into an amp "plop" the plug across a PP3, an old, knackered one will do.  No ploppy, NO connecty!

*Had it been a solid state amp and if it is a short, likely bye bye amp.

Dave.

randerson

Thanks Dave. Bit lost here though - 

No, so plug up the speakers and then BEFORE inserting into an amp "plop" the plug across a PP3, an old, knackered one will do.  No ploppy, NO connecty!

A PP3 battery? And what exactly do you mean by 'ploppy'? 

ICBM

Sounds like either the cable or the female-female connector is faulty.

As Dave said, don’t use a standard female-female connector for speakers, they aren’t reliable enough and could leave the amp with no load. Only the Neutrik one is any good.

If both amps still work OK with their own speakers then no harm has been done. It’s very unlikely unless the amp was really cranked up anyway.

ecc83

"A PP3 battery? And what exactly do you mean by 'ploppy'?  " The thing you put in a pedal! The tip and sleeve of the jack will make contact and the DC will cause a loud PLOP! That indicates that you have a correct connection and can plug safely into an amp. No plop means you either have an open or a short that needs investigating.

Dave.

randerson

Awesome thanks again guys

ecc83

randerson said:

Awesome thanks again guys

Welcome. N.B. you can also use the battery to test for correct phase in a multi-speaker setup.  +ve on the jack tip should cause the cones to move OUT of the cabinnet but I understand some brands do the opposite?

Dave.

ICBM

ecc83 said:

N.B. you can also use the battery to test for correct phase in a multi-speaker setup.  +ve on the jack tip should cause the cones to move OUT of the cabinnet but I understand some brands do the opposite?

Yes, JBLs and I think some old Jensens, maybe more. That’s why you need to check, particularly when mixing speaker types.

Just remember not to keep the battery connected to the speaker for any longer than to hear the pop or see the cone move - it’s not good for either of them if you keep the current going for long.

ecc83

Yes IC, just a blip! There is ONE possible no-no. Rechargeable batteries, the sealed Lead acids especially can put out prodigious currents and so a 9V SLA into a 4 Ohm speaker is 20 watts! Bog S alkalines will however collapse at a few 100mA.

I used to keep a couple of knackered ones about for such purposes. Down to 6-7V they are also handy for testing LEDS (bloody eyes can't see the flat!) But! non-tech peeps DON'T  test LEDS on a good battery! Will pop and possibly burn main widdling finger.

Dave.