Amp head and cab question....

Posted: Sun Mar 17, 2013 5:44 am

How exactly do I hook a head to a cab? Im getting a Peavey XXL (tube heads are too spendy and too loud for what I need), but im getting an older Peavey 4X12 cab from a pawn shop. I dont know anything about the cab, other than that it has 4 Sheffield speakers.
Will the two work fine together? Or do I absolutley need the matching cab?

Joined: 27 Oct 2010 Posts: 721 Location: Greenwood, IN

As long as the impedance (ohms) of the cabinet are equal to or greater than the head you're good.

Posted: Sun Mar 17, 2013 1:02 pm

You link the two with a speaker cable: note, that's a speaker cable and not a guitar cable.

The two look very similar, but perform differently due to the fact that a guitar cable is shielded and a speaker cable isn't. If you use a speaker cable in place of a guitar cable to connect your guitar to your amp, you'll get all sorts of interference. Likewise, if you connect your amp head to a speaker cabinet with a guitar cable you run the risk of blowing up your amplifier.

You don't need the matching cab, per sé in that if you have for instance your Peavey, you don't need the specific Peavey cabinet to go with it. In fact, it doesn't matter what size your cab is, or how many speakers it has (although this will have an effect on your sound), but what does matter is impedance.

It's very important to match these correctly, because if you don't you'll end up with a blown up amp head. General rule of thumb is that your amp can push 'uphill', but not 'downhill'.

What that means is if your amp has an 8ohm output and your cabinet is 16ohms, you'll be fine linking those two. However, if your amp has an 8ohm output and the cabinet is 4ohms, you risk damaging your equipment. The ideal scenario is to match the ohms: 8ohm output - 8ohm speaker, 16ohm output to 16ohm speaker etc.

EDIT: Just noticed that you have a solid-state amplifier. Transistor amps are less at risk from the technical difficulties of tube amps, and you should be alright if you accidentally mismatch speaker load. That said, the thing about speaker cable still stands, and you should always match the ohm rating correctly anyways. Mr. Green

Posted: Sun Mar 17, 2013 1:53 pm

I was going to go tube, but I need a quieter amp. The XXL has a wattage selector to be quiet for bedroom use. Plus, ive read awesome reviews about it. Transtube goodness!!
Thanks for all of the help guys!

Joined: 04 Jun 2012 Posts: 345 Location: South-West Ohio

Teht ranstube is good, but there are like 1 and 5 wat tube heads if you wanted.

I second the above - you NEED to use a SPEAKER cable and NOT a guitar cable. I wouyld recomend that teh ohms out of teh heads matches the cab. its all relatively simple really.

Joined: 23 Nov 2009 Posts: 519

CongratZ been rockin the trandstube a while myself and have gotten compliments on tone.Peavey built like a tank.

Posted: Sun Mar 17, 2013 6:00 pm

tylerD wrote:

CongratZ been rockin the trandstube a while myself and have gotten compliments on tone.Peavey built like a tank.

I have a Bandit 112 currently. Youre right, built like a tank and doesnt sound half-bad. You got the XXL?

Joined: 28 Dec 2007 Posts: 1463

what-a-cool-username wrote:

EDIT: Just noticed that you have a solid-state amplifier. Transistor amps are less at risk from the technical difficulties of tube amps, and you should be alright if you accidentally mismatch speaker load. That said, the thing about speaker cable still stands, and you should always match the ohm rating correctly anyways. Mr. Green

Actually.................

Tube amps NEED to be impedance matched. You can get away with a mismatch, but it will stress your output tranny and tubes.

Solid State does not need to be matched UNLESS you are going BELOW the minimum impedance rating.

Going BELOW the min imp rating on a SS amp will kill the amp.

Going ABOVE min imp rating is PERFECTLY FINE, just results in less power output.

Posted: Sun Mar 17, 2013 6:17 pm

Robo Cop wrote:

what-a-cool-username wrote:

EDIT: Just noticed that you have a solid-state amplifier. Transistor amps are less at risk from the technical difficulties of tube amps, and you should be alright if you accidentally mismatch speaker load. That said, the thing about speaker cable still stands, and you should always match the ohm rating correctly anyways. Mr. Green

Actually.................

Tube amps NEED to be impedance matched. You can get away with a mismatch, but it will stress your output tranny and tubes.

Solid State does not need to be matched UNLESS you are going BELOW the minimum impedance rating.

Going BELOW the min imp rating on a SS amp will kill the amp.

Going ABOVE min imp rating is PERFECTLY FINE, just results in less power output.

Yeah, I get that. I thought I'd advise the OP to try and match the ohm rating wherever possible purely out of good practice.

Joined: 27 Feb 2006 Posts: 13396 Location: Earth

I dunno if I have ever seen an SS head that lets you match output. They usually have one or two outs with no selector for ohms. There is usually a disclaimer to not go below a certain level like 4Ω or 2Ω. There no matching that can be done otherwise. I have also never seen a mainstream company make a cab below 4Ω so just use a speaker cable and you'll be fine.

Posted: Sun Mar 17, 2013 7:57 pm

Don't mean to hijack the OPs thread, but want to know whether the necessity of matching impedance with tube amps is necessary when you're dealing with low, single-figure wattage?

I was looking at one of the 1-watt Blackstar heads the other day, but it only has an 8-ohm out. Wanted to use it with my Orange 1x12, which is a 16-ohm cab - asked the same question to the guy in the store a few times and he reassured me that the two would work together absolutely fine.

I didn't walk out of there with one because I thought it sounded pretty contrary to what people here have said. Is he right because of the such low wattage (~1 watt valve), or should I still try and match the output?

Just trying to save myself money from not getting another cab or the combo version, but if I'm going to damage my £170 amp I might as well fork out the extra £30-40 and get the combo.

Posted: Mon Mar 18, 2013 1:35 am

DrShredder97 wrote:

tylerD wrote:

CongratZ been rockin the trandstube a while myself and have gotten compliments on tone.Peavey built like a tank.

I have a Bandit 112 currently. Youre right, built like a tank and doesnt sound half-bad. You got the XXL?

I had an XXL years ago. Can't remember if I sold it to Northwinds or we traded or what. Use a speaker cable like everyone mentioned and don't go below the ohms like it says on the back and you will be fine. If you have the three channel switch for the head it's a plus for it too.
Use the channels on it. There are a bunch of dials on it so set it up to something that sounds good to you.