Acoustic 136 head..Anybody know what Ohms it runs?

The 136 was a bass combo, so someone must have pulled the amp section and put it in a case. The corresponding head was the 140 (electronics identical to the combo sibling AFAIK), rated 125 W RMS @ 4 Ohm. I've heard of 140:s surviving 2 Ohm loads, but that wasn't supported officially back in the day. At 8 Ohm you run into clipping pretty quickly.

 

It's very possible that new caps would indeed fix those problems. But unless you know what you're doing (and honestly, if you're asking, you probably don't), take it to a tech, lest the caps kill you. I had a 136 combo for years and it absolutely was loud and clean.

 

From what I've seen there are two 136 combos. A vertical one resembling Acoustic's other models, and a horizontal one with a different look. Found the latter at Guitar Center the other day and was wondering if it's a smart buy. $329 used and looked like it was in great condition.

 

Zombie thread resurrection...just found this searching GC and it appears to be the same amp mentioned above...to weird not to post.

Acoustic 136 Bass Amplifier (1971 Vintage) Amp Cabinet. Bass Amp Head

 

I literally just got back from (trying) to play through this head and cab. All the pots were extremely scratchy and I could not get it to play a clean signal through any of the four inputs at any volume. Even with the volume pots all the way down it would only pass intermittent signal and produced really LOUD crackly noises. Disappointed, I really wanted to pull the trigger on this one.

 

I was scoping that one out as well.Sorry to hear that its in such bad condition.

 

I have a 126, which is the slightly later version of the 136. I like it well enough, but there's no way I would pay $200 for it now. There are better amps out there.

 

I have an Acoustic 136 that my Dad bought me in May, 1971. Acoustic had just released this model. A rep from Acoustic was there asking me how I was going to use the amp. I told the rep the amp was going to get put on a school bus a lot. The label on the cabinet said 8 Ohms. The owners manual indicated the amp ran at 150 watts at 4 Ohms. I figure it runs at 100 watts. The cabinet is a 1x15” cab that is “horn loaded” with a vent to the side - Not downward. This gave the cabinet a “stereo wide” sound that got bigger and louder the farther away you were from the cab. The amp has a mid-range sound that isn’t “boomy”. If I wanted “boomy bass” that I could feel, I would flip the cab on it’s side with the vent downward. This would double the volume and boost the lows. The hassle with that was flipping the cab moved the on/off switch right next to the ground. The combo weighs 80 lbs. That didn’t feel like much when I was 15, It feels like a lot more now that I’m 61. It was my “70’s amp”. Even though I fixed the amp in 2010 (the motherboard cracked thru the center, “killing the amp”), I mainly use the cabinet with different amp heads because of the “stereo wide” sound I get. Right now, I use a MarkBass Nano-Mark head that puts out 200 watts into 8 Ohms with this cabinet. The nanoMark puts out massive “boomy” bass tone, so I don’t have to flip the cabinet.

 

Wow, never saw a 136 that looked like that before! Mine was the more vertical one (not mine...I sold it in the 90's):

 

My 126 looks exactly like Jimmy's 136 did. It works just fine still. As long as the PCB doesn't break, the amp may live forever.

 

I really get a chuckle when we gab away about something started by someone who has not visited the site since September 2009. He joined stayed nine months and was gone like a wisp in the wind! <sigh> Who says I ain’t a bit poetic like?

 

I just landed here doing a search for the same problem. (Anybody still around?)

Someone recently gifted me an Acoustic 136 combo. It was super quiet and scratchy sounding and I'm sadistic enough to tinker with the thing, so ...

Trentonswartz -- did you ever come to any conclusion as to what was causing your problem? I'm having it too.

As mentioned above, the service manual says it's rated at 125W @ 4 ohms. I just measured the existing speaker (not sure if it's original) at 4.3 ohms.

 

Also, as to the wide vs. tall Acoustic 136 configurations... as best I can tell, the first year (1971) had the wide side-ported configuration, and 1972 forward had the tall (bottom-ported) configuration. They probably got tired of flipping the thing on its side. ;-)

 

FYI

unofficial acoustic control corp forum: 136 amp

 

I built a head case for a 136 and used it for club gigs for years. It was a little shy in the lows (into a 4-ohm 402 cab) but a 10-band MXR EQ pedal solved that nicely.