LM3886 amp from (mostly) recycled parts

[Ripthorn]

Hey, I just found this place and have a couple questions for you guys who have more experience.  In my office there was an old Dean Markley kb-20 practice amp that apparently went defunct.  As far as I know the power section in it is still good, so I took it (they've been trying to get rid of it for 2 years) thinking I could at least use the transformer and rectifier and some of the other parts like large caps, etc. 

The only problem is that I am unable to figure out what kind of transformer it is.  The amp is based around two tl072's, so I am guessing that the power section all together is putting out +/- 18V, which is in the operable range of the lm3886, as I understand it.  I am just wondering if I can use the same power section virtually component for component, or if I will be running into risks with things such as current supply, voltage sagging, etc.  I just want a decent power amp for running different low-power preamp sections into.  If anyone can help me with the transformer identification, it would be greatly appreciated.

[teemuk]

The power supply will work with LM3886 like any other power supply but the output power will be limited to that what the supply can provide. In other words, you will indeed run into problems with sufficient current supplying capacity, which will then lead to supply rail voltage sagging etc. The output power you can get from the LM3886 chip will be pretty much limited to the current output power of the KB-20 (or is it K-20B?).

I'd say it would be more worthwhile to try to fix the defunct amp as is and get a (I assume 20W) practice amp - instead of trying to modify the amp to house a LM3886 chip - and in the end still end up with a 20W practice amp. If you need an amp with higher output power then the power supply must be rated for the job.

[Ripthorn]

Yes, it is a k-20b it looks like.  Thanks for the info regarding the power supply issue.  That makes total sense now that I think about it.  I'll see what I can do with it.