Making an Auxiliary Amp

RayRay

Hey guys

I have recently received two 20 Watt loudspeakers and plan on making an auxiliary amp for my Blackheart Little Giant Tube Amp (BH112)(http://www.blackhearteng.com/bh112.html).

I so far have mounted both and have connected them. It works if I plug it into my stereo, but I don't have it quite right when connecting it to my BH112.

The auxiliary does not have its own power source. What I have tried is connecting the BH112 speaker to the 8 Ohm slot and the auxiliary into the other 8 Ohm slot. The slots available on the BH112 are: A single 16 Ohm, two 8 Ohm and two 4 Ohm.

Any help would be great.

aja

auxiliary amp? I think you mean cab? Hmmm, I'm confused. Are you trying to build a mini PA?

What is the impedance of the individual speakers? Are they musical instrument speakers or full range hi-fi/PA style speakers?

RayRay

Sorry for confusion, yes like a mini PA.

They are full range hi-fi.

I am not 100% sure what the impedance of the speakers are, but they are 12000 gauss if that is any help.

AlanRatcliffe

However you wire it up it must present the correct impedance to the amp's output. So you have to know your speaker impedance. Being hi-fi, they are probably 8 ohm (but don't assume). If they are, you could wire the two up in parallel to the 4 ohm output or in series to the 16 Ohm.

If you have a multimeter, you can measure the DC resistance of one single speaker (unconnected to the other). The DC resistance will usually read approximately 3/4 of the impedance, so if you get a resistance reading of 6 Ohm, they are 8 ohm speakers.

RayRay

Thanks for the help, I will reply on my findings.