Acoustic 140
 

Hey. I just picked up and Acoustic 140 head for $100 bucks... Couldn't pass in up. I've had a little trouble finding specs and what not on it. So if anyone has got some info please let me know. Most specifically what is the booster speaker and the output 2 for? Are the powered outs? I'd also like to know how old the thing is roughly. What cabinets were meant to be paired with it? And why is it so much louder than my Ampeg SVT 3Pro with a quarter of the watage? Thanks ya'll.
--Chris

As far as why it is louder than your 3PRO is because it was rated at a time when SS amps were rated in watts equivellent to TUBE amplifiers. "the good old days" Tube amps can clip and compress signal overload, an SS amp cannot. So the SS amp has a 3-4X power overhead built in to safely pass the signal peaks without destruction.

Somewhere along the way the marketing department decided to take this amplifier headroom and publish it as the amp's max power. Why did they do this? Because the amp can pass that power; it just cannot continuously operate at that level.

So if you were to rate the 140 in modern BS power it might be rated up to maybe 560 watts... I prefer the orignal system of comparing apples to apples we would then not have all this confusion and power disparity between Tube and SS amplifiers.

SO which system is actually BS watts? or marketing watts? You could say it was either way!... Because if you sit down and measure up the output of your 140 in a single tone test, it will probably top 500 watts... Can you play it like its 500 watts? NO... and an SVT 300 watt tube head will still smoke it.... The confusion goes on.

BOB

Thanks Bob... I knew about that a bit but have yet to wrap my head around it. I know my 3PRO is loud enough for me so this amp will probably be too...

The 140 has two parallel speaker outputs (1 and 2) and a "booster" output, which is the same signal as the speakers get but attenuated down to a level where it can be used to drive an external power amp. It's similar to a line out.

That amp was intended to be paired with the Acoustic 106 cabinet, which was a 2x15 cab. Those old Acoustic cabinets are very good-sounding cabinets. Later Acoustic also made a similar cabinet called the model 402. A model 404 1x15 cabinet would also work well with that amp. Of course the bigger model 406 cabinet (2x15 in a bigger box) would also be good, although tougher to move around. You couldn't go wrong with any of those (106, 402, 404, 406), really. I don't have personal experience with the new Acoustic cabinets that they sell now at Guitar Center (B115, B410, B810), although they tend to get good reviews and would match your head in general appearance. The B115 and B410 are 8 ohms, and the older cabinets are 4 ohms, so if you're running just one cabinet, you'll get more power out of the head into one of the old cabinets, unless you go with the B810. Although, it's surprisingly loud for its very conservative power rating, even into 8 ohms. You could always get two of the new cabinets to run it into a 4 ohm load. :-)

For more information, check out the Acoustic Wiki at

http://acoustic.homeunix.net/twiki/b...oustic/WebHome

There's lots and lots of information about Acoustic gear there, particularly the "original" series of Acoustic amps and cabinets.

Thanks Chuck great info....

Your amp is 105 watts and regardless of what Bob just wrote- it's still just 105 watts. Oh and BTW, it's a VERY VERY loud 105 watts. While it will not smoke a tube SVT, it will make it feel very ashamed for weighing sooo much and for having so many costly tubes that need replacement. And just to dig the knife in a little deeper - try plugging a guitar into your new head and ten into a couple of nice guitar cabs... THAT will send the SVT back to where it came from with defeat smeared on it's 90 pound face!!!

They performed well, for what they were.
 

I bought one new in late 1974. It was marginal for power for use in the typical bands of the era. The unit sounded much better with the addition of another powered enclosure. (361) It was a durable, nice sounding amp, just not that loud. You'll enjoy it!

I didn't look up the specs. If it is a 105 watt amp then it is a 105 amp. But I stand by my statement that it was rated when SS amps were compared straight across the board to tube amps.

105 watts is 105 watts and that's not a lot of power. I gigged with both a 50 watt Bassman and a VOX foundation, they made music but didn't blow rooms apart like the 300 watt amps of the day.

I wouldn't walk around saying the 140 is a 500 watt amp for sure, just as I'm not happy saying an SVT-4PRO is a 1200Watt amp. I wish they were still rating SS amps like the tube amps then they would call the 4PRO a 375 watt amp which it is more reasonable.

BOB