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Guitar chord forum - chordie → Guitars and accessories → AMPLIFIER OHMS QUESTION
Hey everyone, got a question about my Crate GTD 65 amp. It has an extension speaker jack on the back but the owners manual doesn't tell what ohm rating size I can plug into it. It does show that the internal12" is wired in series to the jack at 8 ohms. I assume that I must plug in one that is also 8 ? I know little about series and parallel wiring. Thanks-Mike
Hi Pops ,
I'm not an amp head , but my little brother who is , has taught me some stuff ... This is something that you want to be very carefull about if you care anything about the equipment ... You'll want to find out ( on line or call crate ) , what the minimum ohm load is for this amp ... If the min. load is four ohms then you can plug in another eight ohm speaker if things are wired correctly ... But if the rated load is four ohms , you would not want to daisy chain two or more eight ohm cabs to this amp because then you are loading it to two ohms , which could cause catastrophic failure ... Hope I helped ......
Jerry
Hey Jerry, Thanks for the answer on this amp. Yea-I better be careful not to screw-up my new amp(new to me). Had too many the other night and plugged in my buds bass cab(4/10's@8ohms so he says) briefly and it sounded killer! Anyway thanks again,
Mike
Solid state amps are less sensitive to impedance than tube amps, because they generally do not pipe their output through a transformer.
So if the internal speaker is 8 ohms and the spare out is wired in series, and you add another 8 ohm speaker, the amp will see 16 ohms as a load.
If the amp makes, say 65 watts with an 8 ohm load, a parallel speaker would reduce the load (4 ohms) and ask the amp for more output (100+) while a series speaker would increase the impedance of the load (16) and cause the amp to make less output (~30 watts).
Though, a doubling of speaker surface area would increase the apparent loudness by about double, so you get almost the same volume (or just slightly more depending on the efficiency of the speakers) but you will get a much wider sound field and so, better coverage.
HTH
This link:
http://www.diyaudioandvideo.com/FAQ/Wiring/
does an excellent layman's job of explaining series v. parallel wiring, how to calculate R, how to wire, and what the implications are for screwing it up.
Hey thanks all, Got some studying to do now. Thanks for the link wonk, but now I'm confused as to why a manufacturer would wire this in series when the link suggests not to run speakers in series. Interesting tho. I found another bit of info in the manual which shows a "damping circuit" which runs from the ext. speaker to the power side?? Ok--neighbor and I are going to the Guitar Center wed. and I'll pick their brains and probably bring home a digitech 2 voice harmonizer and maybe an extra cab.
Thanks again all!! Mike
I just bought a small pignose amp. Does anyone have any input on this product. these are suppose to be a pretty good small amp. I am a hobby player. Just sold this big Delta blues amp from Peavy. it was a great amp, but just to big to haul around or store for me. Have not been happy with little fender amp it gets static easily.
I played through one once. It is a good little practice amp - distortion and all. Owners I've talked to have liked them.
I'd like to know more about this also. I have a 4ohm solid state acoustic amp that i'd like to connect with my 8ohm electric hybrid amp. The instruction manual says not to connect any cabinet or amp not of the same ohm rating or minimum watt handling because it could damage the amp and or speaker. I think there is still a way to do it safely but how? I'm not looking to get louder just a different sound and versatility.
From what the guys at GC told me ,you can run 8 ohm into a 16 ohm cab but not into a 4 ohm cab.luckily my Ibanez is 4/16-4/12 cab and my Blues Jr. is 8 ohm so I run throught the 16 ohm side,,WOW that 15 wat amp is LOUD!!!!!!.go from 1-12 to 4-12's and you best have your suspenders on as well as your belt . And I have a 100 wat.Marshall mg head that goes with the 4-12 cab,so I think I got enuff toys for now,,,,,,hummm phase ped,wah ped,mmmm 10 slide EQ,,, OK Dave stop it.
Guitar chord forum - chordie → Guitars and accessories → AMPLIFIER OHMS QUESTION
