The following is an excerpt of the LM317 datasheet:

Output Current    500, 1500, 1000 mA
Input Min Voltage    4.2 Volt
Input Max Voltage    40, 37 Volt
Adjustable Output    Yes
On/Off Pin    No
Error Flag    No
Temperature Min    -40, 0 deg C
Temperature Max    125 deg C
RegType    Linear Regulator

What do the 40, 37 volt input max voltage figures mean?  Why are there 2 figures?  Thanks in advance.

LM3886 stereo guitar amp + Phatt passive tone stack + stereo effects loop.  I'm wondering if this is a practical goal.  I need a stereo guitar amp with basic tone controls.  The stereo effects loop is for plugging in my POD XT when needed.  Could I integrate Phatt's passive tone stack in an amp based off of this Non-Inverting LM3886 Stereo PCB Set http://www.chipamp.com/orders.shtml and add a stereo effects loop in the signal path somewhere?

Also, does anyone have transformer recommendations for this build?

Thanks in advance.

How do I find information on the following power transformers taken from different line6 spider III amps?  ON-TECH appears to be the manufacturer but the only match for the product numbers on google yield pages that are in chinese and they error out when trying to get google to translate.  Does anyone have a resource for ON-TECH that is written in English?

Line6 spider III 15 has these numbers stamped in the metal
1X-5730-04H0 and these numbers printed 0826

Line6 spider III 30 has these numbers stamped in the metal
1X-6636-02H0 and these numbers printed 0814

I suspect the power transformer is bad in the 30 watt amp.  It has a 5 pin connector going to the main board.  Measured AC voltage levels are as follows:

red1 = 4.6
red2 = 2.4
blue1 = 7.3
black = 1.6
blue2 = 4.4

Any help greatly appreciated.

I'd like to build a combo 2x12 stereo amp that has balanced stereo sends(to send to the PA).  It doesn't need much(if anything) on it for a tone stack.  The more power the better.  It just needs to be uncolored sound.  I guess what I'm looking to build is very similar to a stereo Tech 21 power engine.  Could any of you point me in the right direction.  I'd really appreciate it.

I'm seriously considering trying this amplifier http://sound.westhost.com/project27.htm 100W Guitar Amplifier Mk II.  Have any of you built this amp?  The only thing I see that it lacks is stereo.  Outside of that it seems to be well documented and I like the way he explained it.