Acoustic 126 resurection

[wrnchbndr]

I just acquired an Acoustic Model 126 that is in mint cosmetic condition. I paid nothing for it. Unfortunately, someone has taken a pair of scissors and cut the wires to the power amp CCA and removed the power amp entirely -- it is gone. The preamp and graphic EQ work perfectly if I run the preamp out to the input of another amp.

Back in the day... I know a lot of manufacturers utilized common components to produce a model line of different amplifiers. Since I need an entire power amp section, I want to see if there were higher output models that utilized the same power supply. Looking at the diagrams, it is within my capabilities to fabricate a clone CCA for the original 100 watt 126 power amp as long as the transistors can still be found. But it would be great if a higher output CCA could be employed. Are there any Acoustic enthusiasts who can speak to this issue??

[johnk_10]

AFAIK, a 126 combo and a 220 head share the same preamp. they might share the same power amp too.




but you might ask that question on the unofficial acoustic amps forum.

[BassmanPaul]

You could think about dropping a Class D module into the amp. Hypex make a small 180W module that might just fit your bill. It will need some kind of a heat sink.

[Mr. Foxen]

I'd be interested in doing something like this as I have a 120 heads with a distorting power section. You need to figure the voltage swing from the preamp to match it to a power module though. I'd go for one of the higher power class D ones for no heat troubles. And also inappropriate unexpected bottom end form what is apparently a vintage head.

[seamonkey]

You could Frankenstein it with a Class-d module, but most all modules don't have built in limiters. It's going to be pricey.

It would not be conserving the head if that's important to you.

I'd say it's not worth it.

Get a good power amp. Keep using this as a pre-amp.

Keep an eye out for other 126's that maybe you can part out.

[BassmanPaul]

Originally Posted by Mr. Foxen

wing from the preamp to match it to a power module though. I'd go for one of the higher power class D ones for no heat troubles. And also inappropriate unexpected bottom end form what is apparently a vintage head.

The limitation is going to be the original power supply designed to operate a 100W SS power section. The other option is to redesign the power supply (new bigger transformer etc) to supply the needed power. The 180W module is around $150 plus shipping.

[wrnchbndr]

Yes, I understand about the PT but on occassion, some manufacturers just employ an overkill powersupply section on their smaller output units for the economy of utilizing common parts and being able to make larger bulk purchases of transformers from their suppliers -- I'm hoping that this might be the case although its unlikely -- just wishing I suppose but you never know and it doesn't hurt to ask. I think I may have a line on a 126 power amp section from a local guy with lots of junk in his basement but he's not yet sure of which acoustic model he's got.

[wrnchbndr]

I've just ordered the full service manual for the amp ($20). I'll see what is involved in cloning the original CCA. I have CCA etching cabability and few generic heat sinks. Another 100 watt amp is not exactly unwanted and this amp has a pre-out so I can alway plug it into something bigger if I want.

[wrnchbndr]

Total cost of all parts on the CCA is $42 from Mouser. They are on order.

[BassmanPaul]

Originally Posted by wrnchbndr

Total cost of all parts on the CCA is $42 from Mouser. They are on order.

Then , for one, wish you fortune and a successful resolution to the project.