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cboshdave

8 ohm Output jacks on Spider IV 150

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So, I am guitar player -- not a sound/jack/cable guy (yet).  I just picked up a Spider IV 150.   Love the amp!  I am now learning about monitor speakers.  Amazing how the first time I gigged, I could not hear myself and was pretty lost.  I hope you all remember those days and can help me out. :-)  Great hobby!  Lots to learn!

 

Couple dumb questions...

1.  Can I attach monitors to a Spider IV 150?

2.  What specs am I looking for in a monitor?  What wattage? I know ohms are a measure of resistance, but I don't really know what that means in speaker terms. 

 

1 possibly really dumb question (forgive me).  I also have a Line 6 4x12 150 watt half cab.  Can I use my Spider IV 150 amp to be a "head" for my cabinet until i get a head for it?  

 

Thanks,

Dave

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If you plug a cable into the rear speaker jack(s) on the amp, it will cut out the speaker(s).   So you cannot plug some type of monitor into the amp.

If you use your 4x12 cabinet, you will want to make sure you use 2 cables, left and right amp jacks to left and right inputs on the cabinet.

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Use "speaker cables" not guitar cables. <snip per post below>. Consult your owner's manual - Spider heads IIRC need to run in stereo 2 x 8 ohm loads not one (which would be 4 ohms and could damage the amp). There is a Spider I, II, III, IV FAQ so look that up prior to experimenting. :)

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Do not use a combo chassis as a head. The boards are programmed for the specific amps.

The 150 combo is not programmed to act like a 150 head.

 

That sort of thing would explain some of the Spider IV's that come across my bench,...

dead program boards and blown amp chips. That explains a lot.

 

 

Do not do that.

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Thanks.  Given all the suggestions of what I should not do, what is the purpose of the 8 ohm jacks on the back of the amp then?  When would I ever use them?  Use my amp to create the tones and send the signal to a mixing board?  If I cannot monitor (with monitor speakers) I don't know what else i would do with jacks.

 

I assume it would be the same with a Spider Head unit?  No monitors can be run on that either?

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Well I am not going to dispute "The Man" ^

 

FWIW I picked up a "chopped" SV MKI 2x12 which had no cab attached anymore and use its aux outputs to power external cabs. I had no choice you do.

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I guess with an SV 212, there's a bit more lee-way on that. Those boards come in two varieties,

combo and head. Just one thing, use the specified 5881WXT power tubes,... have to be matched pairs.

And of course, use the correct bias voltage, should be in the Knowledge Base.

 

Even with the power off and main unplugged, you can still get a couple hundred Volt zap from a capacitor

discharge, if you touch the wrong thing. Hurts like hell, so be careful, got accustom to having you here on

the Forum. Wouldn't want you shocked by a tube amp, so stay safe.

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I can understand why psark would tell people NOT to use external speaker cabinets - because some people would use incorrect loads (other than 8 ohms) or would only plug into one side of the amp, setting up a biasing which could blow components.  But it is perfectly acceptable to plug an 8 ohm speaker cabinet/load into each side of the speaker output jacks - with speaker cables obviously.  If it wasn't, then the combo amp would not have those jacks. 

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Correct.

Good idea for them to check with the user manual first

before haphazardly plugging things in.

 

No biasing needed for the Spider IV 150, just the Spider Valve series (being tubes and all).

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