#1

Hey guys, i was hoping you could make sense of the speaker outputs on my Ampeg vh140c head.

It reads, "70 watts RMS @ 8 ohms, 4 ohms total load impedance" Underneath this, there are four speaker outputs. The two on the left side are labeled "chorus", and the two on the right side are labelled "dry." I am pretty sure that this is because of the stereo chorus feature my amp has, but i don't know what type of cab to plug in to what input

Thanks in advance.

It reads, "70 watts RMS @ 8 ohms, 4 ohms total load impedance" Underneath this, there are four speaker outputs. The two on the left side are labeled "chorus", and the two on the right side are labelled "dry." I am pretty sure that this is because of the stereo chorus feature my amp has, but i don't know what type of cab to plug in to what input

Thanks in advance.

#2

hmmm, no one will stab this question?

www.ampeg.com/pdf/VH140C.pdf

you can plug 1 4 ohm speaker, 2 8 ohm speakers, or 4 16 ohm speakers in to those slots. the outs are run in parallel and the total load must be at least 4 ohms, so you can plug 2 16 ohm speakers up to it as well because 2 16 ohm speakers in parallel is 8 ohms and that is more than 4 ohms, etc.

on a side note this is a solid state amp, so the reason why you can run just about anything 4 ohms or over is because it uses impedance bridging rather than the impedance matching that tubes amps use.

www.ampeg.com/pdf/VH140C.pdf

you can plug 1 4 ohm speaker, 2 8 ohm speakers, or 4 16 ohm speakers in to those slots. the outs are run in parallel and the total load must be at least 4 ohms, so you can plug 2 16 ohm speakers up to it as well because 2 16 ohm speakers in parallel is 8 ohms and that is more than 4 ohms, etc.

on a side note this is a solid state amp, so the reason why you can run just about anything 4 ohms or over is because it uses impedance bridging rather than the impedance matching that tubes amps use.

#3

hmmm, no one will stab this question?

www.ampeg.com/pdf/VH140C.pdf

you can plug 1 4 ohm speaker, 2 8 ohm speakers, or 4 16 ohm speakers in to those slots. the outs are run in parallel and the total load must be at least 4 ohms, so you can plug 2 16 ohm speakers up to it as well because 2 16 ohm speakers in parallel is 8 ohms and that is more than 4 ohms, etc.

on a side note this is a solid state amp, so the reason why you can run just about anything 4 ohms or over is because it uses impedance bridging rather than the impedance matching that tubes amps use.

So are you saying that if i hooked up a 8 ohm 412 it would only use two of the speakers?

#4

Did you not read what he typed?

Plug your 4x12 into the amp in mono into the chorus side, or plug it in stereo mode with one input going into chorus and one into dry.

Or do whatever other combo you want.

Plug your 4x12 into the amp in mono into the chorus side, or plug it in stereo mode with one input going into chorus and one into dry.

Or do whatever other combo you want.

#5

Did you not read what he typed?

Plug your 4x12 into the amp in mono into the chorus side, or plug it in stereo mode with one input going into chorus and one into dry.

Or do whatever other combo you want.

would it be better for when it is in stereo mode to plug both of the imputs into chorus, or one into chorus and one into dry

#6

it would use the whole cabinet, just that the total amount of the circuit needs to be above 4 ohms. and an 8 ohm 4x12 fits the bill. if it's stereo 4x12 with L/R inputs at 16 ohms than we can play some tricks with it.

*Last edited by gumbilicious at Sep 18, 2009,*

#7

would it be better for when it is in stereo mode to plug both of the imputs into chorus, or one into chorus and one into dry

either will work, it is preference really and gets into stage tones. i personally like running 3 cabs for such things, 2 cabs for the effect on the outside and one cab for the dry in the middle, but in your case try them both and see what you like. 1 dry and 1 wet will make a signal that is not completely saturated with chorus, while 2 wet ones will be totally chorused up. your preference

#8

Depends on what you want. I'd go for using both in the chorus side and in the future if you get another cab use that for dry.

#9

Depends on what you want. I'd go for using both in the chorus side and in the future if you get another cab use that for dry.

+1

#10

Would i be able to then run an 8 ohm cab with l/r inputs in stereo, or would it have to be 16 ohms

#11

Would i be able to then run an 8 ohm cab with l/r inputs in stereo, or would it have to be 16 ohms

these things are hard to answer without knowledge of exactly what your working with.

http://en.wikipedia.org/wiki/Series_and_parallel_circuits

that teaches a man to fish so to speak. you see, if you are talking about an 8 ohm 4x12 run in mono, then that is different than a 4x12 run in stereo(L/R) because you have to wire the speakers together. if your cab is 8 ohms total mono, then the stereo ins are most likely 16 ohms, but it could be 4 ohms. we don't know because it's not our cab. but either way it is very unlikely the cabs mono inputs will be 8ohm and it's stereo inputs will also be 8 ohm. i wouldn't even know how they would do that. just to give you a better idea check this.

http://www.bcae1.com/spkrmlti.htm

so then it gets even more complicated because the amp is gonna take those loads and put them in a parallel circuit. so lets say your 8 ohm mono cab has 2x16 ohm stereo inputs, if you run 1 output on the amp to the mono input then the total load on the amp is 8 ohms; but if you run the amp output to a stereo input on the cab(usually when running 1 stereo input it is the 'right' one) then output the total load on the amp will be 16 ohms. but if you run 2 outputs on the amp to the 2 stereo inputs on the cab(L & R) then the total load will be the 2 resistances will be:

1/Rtotal = 1/R1 + 1/R2 = 1/16 + 1/16 = 2/16 = 1/8

1/Rtotal = 1/8 => Rtotal = 8 ohms

tada, 8 ohms is the total load on the amp. and the manual says you need at least a 4 ohm load(this changes from amp to amp btw, tube amps want an exact impedance while other SS amps may take any substantial impedance, ie >.001 ohms).

if you don't know what this all means, then you need to try and understand what those 2 links are trying to say.

*Last edited by gumbilicious at Sep 18, 2009,*

#12

thanks for all your help man i really appreciate it. The cab that i was looking at says 8 ohm mono and 8-12 ohm stereo so idk

#13

post the actual make and model of the cab, then i can look it up, tell you whats really going on.

#14

****, i haven't done this in ages, but i want to say that when we wired my cabs stereo they went to 8ohm from 16ohm mono... let me fact check that though before you take me at my word.

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