Audio Amp

[pwdrive]

Don't know why I posted this, was doing a routine check on their new listings and noticed this

http://www.surplussales.com/Microphones-...dio-7.html

Lawrence.

[Skywave]

Hmmm . . . 10 kW into 1.6 ohms, eh? Let me think about that for half a mo' . . . that's an RMS current of about 80 amps. So I assume that standard loudspeaker flex is out of the question then!  

Al.

[pwdrive]

Yes Al it's a bit of a lump, bet the circuit is interesting.

Lawrence.

[tiv48]

some 15mm copper water pipe may work for spk wire dont think it will go into 4mm banna plugs
rob t

[Skywave]

Yup, copper water pipe is what crossed my mind too - but that piping had better be well insulated, since the voltage between them is in the order of 125-v or so (and that's RMS, never mind peaks) and with a lot of current available!

Al.

[Paula A]

Quad cooker flex, good for 240A as long as it's not run too far.. And whatever you do unroll it!! Having run 32KW sound arrays it's the stuff we used for the bass end of things, for the tops and mids I just made up 10A mains cable into bundles as required.

Weight being important for equipment which was moved every day or so the amps sat directly behind the stacks, also saved on long heavy cable runs which are lossy and throw out a lot of emf's.

Our big stacks were all 4 Ohm runs.. any less wasn't feasible as cable losses at the low voltages, and the problem of suitable connectors became a real problem.. Sticking in the 100A area standard 3 phase kit was suitable.

Looks to me rather like something you wouldn't want to be lumbered with.. I'll give them a tenner for it sold as seen, as long as they do free delivery

Seriously.. the average price on a used Hill or similar 1200W amp these days is about £350

[tiv48]

i cant belive this is an audio amp not even for cinema use, more like an industrial vibrating m/c
rob t

[Paula A]

I remember having an advert for a Vortexion 500W amplifier in a 1948 Wireless World.. stated uses were variable frequency motor driver and as a modulator for high power transmitters.

More common (as in I have seen one) was a 200W amp they made, similar uses. I have been in more than a few defunct cinemas in my time, and generally the sound equipment is quite basic and using high efficiency horns not as powerful as you might think.. 25-50W was common up until the mid 70's.

Unless you have heard a full on horn system you won't believe how loud 5 watts can be!!