sound city bass 150

I'm pretty sure the 100v / voltage regulator allows you to use both American 110 and British 220 volt wall service.

The slave in is for using the amp's power section only. Plugging something into this jack bypasses the preamp section. The slave out send a signal from the preamp for use by another slave head.

The 600 ohm output should be your direct out jack.

I think the telephine looking thing was meant to be a headphone jack. Not sure though. You may want to ask the guys here:
http://vintageamps.com/PlexiPalaceUBBcgi/ultimatebb.cgi?ubb=forum&f=9

 

i've just got a sound city bass 150 amp head second hand, in really good condition, but i've got a problem.

on the back i've got 2 speaker outputs (obviously) but theirs some other stuff on their and i don't know what it does.

1 the ohm selecter, i know what it does, there's 4, 8, and 16 ohms, but theirs something else called a 100 v line or something, what does this selection do?

--------That's for an old system called 100V line, or in most cases it was for 70V line, which was a way to distribute sound to a whole lot of speakers, like in an office building, without ending up with like a .01 ohm impedance. Transformers were needed, and you selected the appropriate impedance taps on the transformers so that each speaker only got a portion of the power. In other words, don't use the 100V line.

also theirs a thing called a slave in/ out, what does this do.
----------basically, it is a point at the output of the preamp and the input of the power amp. So you can pick your preamps "signal out" out of that jack, or you can input signal into the power amp input right there.

i also have a 600 ohm output, anyone know what this does?
----------600 ohms is what microphone balanced XLR systems are designed for. It could be used for direct lining into a PA or recording board.

lastly, theirs another output thing, it says something to do with a battery or radio, what does this do.
----------I have no clue.

the last three things don't have sockets on them but i can get them fitted, i just don't know what they do.
----------If there is no socket, the necessary guts are probably not in the amp to make the sockets work. Just something to know. Most manufacturers used standard nameplates, so all the options are listed, but not all are actually implemented.

Hopefully that helps.

Chris

 

I'm with Throbbinut. What he say's is exactly right.

There must be something else to help us sort the "radio" thing.

More info please.

John

 

My guess is those last three jacks that are not wired up were for a PA version of that amp. Not much use for a 100v line in a bass amp!

 

Why you'd need such a facility on a bass amp puzzled me, too. But I should really have thought it over like Brianrost. It's not that uncommon for makers to use the same chassis for a few different types of amp, but it certainly has the potential to mislead the punters!!

John

 

The British amp makers were famous for using a standard chassis for all of the models. If you look at a Hiwatt 100W head it will have 2 or 3 "extra" preamp punches with no socket. Those Sound City heads are interesting since many times they used "active" EQ circuitry that would boost the signal rather than just "cut" like most all of the other amp makers used. I've heard complaints about noise from the SC heads though; are you hearing a lot of hum or buzz when cranked up?

The really cool thing about the SC heads is that most of them used Partridge transformers (same as a Hiwatt) and these are coveted even in the HIFI world. Look through the top vents and see if you see a little yellow sticker that says Partridge.

tapp

 

Did you try the guys in the Sound City forum that I posted? They will probably be more helpful.