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Speaker Cable Connection - CLASS 2 Wire Only????
by jmccosar on 2012-07-01 21:10:41

The back of my HD100 MK II (under the Speaker Output Section) reads "Use Class 2 Wire only".

Why?  Does this affect the sound?  Does it protect the Speakers/cab?  If someone answers it doesn't affect your tone, cab or serve any other purpose.....why would Line6 put that in plain print on the cab?  How can you tell a Class 2 from a Class 3 cable if its not printed on the cable itself?

Any feedback out there?

Re: Speaker Cable Connection - CLASS 2 Wire Only????
by Crusty_Old_Rocker on 2012-07-02 04:26:56

I t's about not using instrument cables like a guitar cable as speaker cable.  That would be very bad for your amp as it will mess with the output resistance.  Never use a guitar cable as a speaker cable.



Re: Speaker Cable Connection - CLASS 2 Wire Only????
by Crusty_Old_Rocker on 2012-07-02 04:29:32

When buying a cable from a music store you will see that they are labelled as speaker cables.



Re: Speaker Cable Connection - CLASS 2 Wire Only????
by jmccosar on 2012-07-02 07:18:28

Thanks Crusty,

In doing some research, I see that there is Class 2 and Class 3 Speaker cables as well.  So, is there really a difference between a Class 2 and Class 3 Speaker cable?  From what I am reading, sounds like somethig that has to do with a max/min voltage.  Im assumeing that since Line 6 says Class 2 only, there must be some kind of voltage that is a must through the class 2 cable.....Thoughts anyone???

Re: Speaker Cable Connection - CLASS 2 Wire Only????
by mtnman82 on 2012-07-02 18:31:15

A little Googling: The only difference between class 2 and class 3 is that Class 3 rated wiring is rated for a maximum of 300 volts and Class 2 has no such voltage rating. Is this important? For an example, an audio amplifier driving a pair of 8-ohm speakers, and delivering 300 volts peak-to-peak will provide an incredible 26 amperes (I=E/R) of current for a total RMS power delivery of something like 5600 watts (P=I2R).  With this in mind, even at peak levels, I doubt we see anywhere close to 300 volts p-p, so I would say the class 3 wire is overkill.

Re: Speaker Cable Connection - CLASS 2 Wire Only????
by jmccosar on 2012-07-02 18:41:32

Ok, so get ready for this, Class 2 type cable MAKES A HUGE DIFFERENCE in the signal/sound.

Why, I dont know, but the cab is more Crisp, responsive and "pumps" now.  With the Monster cable that i was using previously (labeled CL3 for Class 3)  the  HD100 mkII head sounded dull, it had bad tubes or something.  I went to the local Sam Ash and picked up a Class 2 type of cable ( which most of the people in Sam Ash had no clue the difference either and didnt know where to find a Class 2)  after about 20 mins one veteran worker went and picked one up in the back for me and I purchased it.

Re: Speaker Cable Connection - CLASS 2 Wire Only????
by spaceatl on 2012-07-02 18:48:05

Actually, if memory serves this specification has to do with the class 2 wiring inside the amplifier...It's a 400 volt amplifier internally. I think that means once you are class 2 in the circuit, you must remain that way to termination (speakers)...I think this has more to do with a safe design in terms of the power tubes shorting closed and 400 volts going through the output transformer...I think it's more of a safety thing with an inefficient high power device like a tube power amp....

Anyway, I use quad class 2 11 AWG. wire to run a 212 off my SV112...basically each speaker is a homerun and I will never have to worry about it...for the rest of my life...long live the garden hose!

Re: Speaker Cable Connection - CLASS 2 Wire Only????
by mtnman82 on 2012-07-02 20:13:20

I'd be willing to bet you just got a bad cable.  I've never had good luck with the Monster Cables and have A/B's them with relatively inexpensive cables (but not cheapies) and they suck IMHO.  Next time you're playing with a Monster Cable try slapping the cable against the floor (not carpeted) - you'll be surprised what you hear!  Rapco/Horizon are the only cables I use now - several different levels of quality and you can't beat the quality for the price.

I think the main point to the note on the amp, as mentioned earlier, is to used speaker wire (i.e. balanced wire) and not the shielded cords (i.e. instrument/patch cords).

Re: Speaker Cable Connection - CLASS 2 Wire Only????
by jmccosar on 2012-07-02 20:37:10

No doubt about the potential bad cable.  Im sure that could have had something to do with it.

But, not too sure why the back of the SPV MKII would have printed below the speaker outputs "USE CLASS 2 WIRE ONLY" if it was for internal/inside the amp, you'd think they'd have that printed on the inside for the tech's or something.  Regardless, the amp sounds great again.  Got me a 12 AWG speaker're right its like a stinking garden hose!   Peace my brotha!!!

Re: Speaker Cable Connection - CLASS 2 Wire Only????
by tcunningham4 on 2013-03-12 14:02:28

I know this is a somewhat old post -- but I thought I'd clear it up.

Class 2 wiring refers to the National Electircal Code class for wiring, which indicates to the installer what type of wiring practice is needed, and to the inspector as an indicator of the specifications of the equipment without having to contact the manufacturer for every single item.

This is aguideline for safety from shock and fire protection. For home use, it is really meaningless, unless you are installing the wire from room to room, or within the walls, on a high-power system or for

General guidelines for class 2 are that the voltage be under 30v and the total power under 100VA, For a speaker wire to an 8 ohm system, the voltage at 100W would be about 30V. Anything over 100W should trechniically be class 3, but for runs within a room, class 2 is fine.

More important to me that class are practical considerations, such as:

1. Don't use shielded cable (a guitar cord or phono cable) for more than 20 watts per channel and then only temporarily. As noted already, it can cause heating problems, and the capacitance can afect frequency response. It has other, less audible effects, but my 50+ ears can't tell.

2. Don't run wires acoss the floor, especialy under rugs. It is asking for damage, and shorting a speakler wire can be an expensive trip to the amplifier repair shop.

3. Instead of remote speakers from a central amp, think about powered speakers in a remote location -- more felxibility.

4. Buy bulk wire and make your own cables instead of name brands -- they use the same materials anyway. I challenge anyone to be able to spot the sound of different wires, unless the wire is defective, or something way out of bounds -- like using telephone wires for speakers.

5. Wires within walls should have a protective jacket ove the individual insulated wires, just in case something else is pulled through the same wall. It helps prevent costly damage later.

6.You don't have to have a professionsal installer for long runs or hidden wiring, but it can avoid simple mistakes. If you want to do it yourself, do some research. Not just online, go the library and get a book. Even old books on wiring for sound can prevent headaches. It might even make for a wise consumer if you hire an 'expert'.

The information above may not be current, and you should direct questions to the current forum or review the manual.