Hi, just got my OD-100 after going through Fedex hell for a nearly a MONTH!!! :x So I have a few questions... 1) Is it an OD-100 or OD-100+? Is a serial number check possible? It came with a printed out manual from Custom Audio Electronics, rather than from Suhr. I don't see it refered to as a + at any point, but at a glance it looks identical to the amp advertised on the Suhr website. What are the obvious (and not obvious) differences between the original and the (+) version? Is there any reason the original would be desirable in a different way, or is the (+) simply an objective improvement? 2) Somewhere in this month of being reshipped THREE times with lottts of Fedex drama in between, a power tube dissapeared. I'm guessing it just shattered and is somewhere loose in the amp... Frankly, I'm dying from allergies and can't take a look until they settle down. Now, according to this manual, the amp can run on the two inner tubes. Is this accurate? Will I experience any changes in tone from running it with all four tubes? I guess there will be less headroom, right? 3) Can I just replace that one tube or do I have to replace the pair (inner? outer? how are they paired?) or is it necessary to do the whole quartet? Which tubes does it come with from the factory (power and pre)? These power tubes in the amp look like Tung-Sol 5881's but I'm not sure. I'll take a look tomorrow when the allergies die down. Is it possible to retube with different tubes? What kind? I'm assuming I have to stick in the 5881 category, but is it possible to use different brands like Groove Tubes or something else? How about 6L6's, are those fair game/ 4) Now that I've stepped outside of the happy world of Mesa's fixed bias, I have a whole new problem on my hands... BIASING!!! Hell, I don't even know WHAT biasing is, just that I never needed to think about it with Mesa amps... Can someone give me a quick explanation on what biasing is, how it affects me, and can I make these adjustments myself or should I leave it to a tech? 5) Can the channel selecting & boost be controlled via external switching like a Ground Conrol Pro with GCX switcher? I don't know anything about interfacing all of this stuff, but it'd be great to get a headstart. I assume this equipment would communicate with it in the same way that the footswitch does - via stereo cable? While we're at it... why no footswitchable Ch. 1 boost? That seems like it would make things a hell of a lot more convenient, no? 6) About the Ch. 2 boost... WHAT is an "internal trim pot"? Is this an adjustment I can do myself or should it be left to a tech? Well, thats about it for now. I'm looking forward to a very rewarding experiencve with this amp as soon as I'm feeling better! Thanks!