I would ask Nik why it isn't there. I would put one in, it can't hurt anything and you can always remove it.

I built a Weber 5F6A kit about 3 years ago. Very cheap components compared to Ceriatone BTW. Nice speakers though and it sounded great. I originally used the electronic rectifier WZ34 Copper Cap. I now have a JJ GZ34, OK but not as good. I have used a variety of power tubes, including Tung Sol 5581s (Sovtek makes a 5881, as well), Winged C 6L6, Sovtek 6L6GC WXT+, TAD 6L6WGC-STR (supposedly "vintage" tone), and JJ 6L6s. My favorites in the Bassman are the JJs, by far.
It sounded exceptional with the Weber WZ34 rectifier and JJ 6L6s. The TADs were disappointing in the Bassman but sounded killer in my'66 Super Reverb. The 56FA is the most sensitive amp to tube changes, that I have. When switching tubes you must rebias to get the bets tone and tube longevity

I smoked the Weber power transformer in the amp after about 6 months due to a bad (shorting, cheap, crappy, weber, chinese) on/off switch. I replaced with an OEM Fender PT ($75) and it worked just fine. That WZ34 only lasted about a year, unfortunately. The JJ GZ34 has been going for 2 years now. I have a NOS Mullard GZ34 in my Super Reverb that has been in there for at least 12 years.

Bob at Eurotubes is a great reference for tubes and sells retube kits for the 5F6A for a reasonable price. His tube matching is impeccable.

Values sound about right. Keep in mind that ohmage is not a 100% accurate way to tell when your pick ups will cause break up.

I am familiar with that chart. I built a Weber Bassman kit about 3 years ago. I would still check with someone knowledgeable before I started running KT88s in my OTS. 

Thanks for the feedback. I burned out 2 sets of the TADs in my Super Reverb over the course of about year. But they sounded great in that amp. I am going to get some for the OTS.

I agree about the effect of the pre-amp tubes when going from really bad tubes to good quality tubes. I have about 30 spare pre-amp tubes, and about a dozen NOS tubes, including Mullards. But I still find myself going back to the JJ ECC83S all the time.

These look like a pretty good deal. This guy custom winds here locally, and has a top reputation right up there with WCR, Holmes, Lollar, Fralin etc. They have the right impedances.

http://cgi.ebay.com/PAF-WOLFTONE-DR-VINTAGE-NECK-BRIDGE-HUMBUCKER-PICKUPS_W0QQitemZ260386084323QQcmdZViewItemQQptZGuitar_Accessories?hash=item260386084323&_trksid=p3286.c0.m14&_trkparms=72%3A1205|66%3A2|65%3A12|39%3A1|240%3A1318|301%3A0|293%3A9|294%3A50

6550s and KT88s are equivalent. Also after sending the post above I read the link for Eurotubes in one of Hywel's posts on biasing. In there, Bob was talking about substituting 4 KT88s for 6L6s in a Twin and how good it sounds. I think if you email Bob at Eurotubes and give him the amp specs he can probably provide some  valuable guidance on this subject.

I think I mentioned that I set up my super reverb to run EL34s. If I want clean headroom at high volume with that amp I use JJ KT77s (amazing tubes) and a 12AT7 in the PI. The amp breaks up at about 4 with a 12AX7 and humbuckers, but stays clean up to 8 with the AT7.

How are the TADs working in your OTS?

I would give Bob at Eurotubes a strong recommendation. His tube matching is consistently impeccable. His recommendations have always been right on. I have spoken to him in person a couple times and believe tubes and customer service are this guy's life. He is so busy that the last thing he would do is mislead somebody to sell more tubes. That said, I can see no reason to bias that hot, even if Bob says its OK.

You are referring to power tube biasing, I think. If so, then I can say that the Tung Sol 6L6s that Nik supplied, sound the same to me anywhere from 25 to 35. I keep them at 30 based on my amp tech's advice. I am currently running Tung Sol 5881's at 35-36mA. They sound fine, I think I like them a little better than the 6L6s. I have been wanting to try some TAD 6L6WGC-STRs  (short bottle like the 5881s). They were my favorites in my super reverb, very musical, nice sparkly natural overdrive, not the most clean headroom. I biased them at about 35mA in the SR but it was running close to 500 volts (and they only lasted about 6 months). I would try them at 30-35mA in the OTS. My experience that that bias does not effect tone except near the extremes of the range and if you operate out there you are burning up tubes or damaging other components.

I don't think it would be a good idea.  The KT88 is designed to operate with a plate voltage of 600-800 max. I believe the OTS is 425-450. The current output transformer, etc. would not support KT88s.

Also my personal experience is that there is little reason, other than to satisfy your curiosity, to do a conversion. Several years ago, I did a fairly major overhaul of a '66 Super Reverb (this is before I knew that they would be such a collectors item). Since I was replacing most of the components I decided to upgrade the output transformer (50W vs. 40W),  etc. to support EL34s. The net result was a much louder amp, that still sounded like a Super Reverb. Contrary to what most people think, output tubes do not change the tone of an amp that much. On the Super Reverb, changing brands (e.g., JJ to Sovtek) seems to change the tone as much as 6L6 to EL34.     

1.) The JJ ECC803S (balanced) is an upgrade to the Sovtek LPS,  http://www.eurotubes.com/

2.) There is a lot fussing compared to a Super Reverb, for example. But it is sooo worth it when you do get it figured out.

Well if you decide to go that way, here is a link you may find interesting: http://www.tonebone.com/tb-headbone-vt.htm

Thanks for the feedback on the TR vs OTS.

I have a '59 RI Les Paul with Burstbucker 1 & 2 pickups. It is the loudest guitar I have ever played, but the impedances are only about 8-8.5 (go figure ). I have played guitars with overwound humbuckers (12 ohms+) that are not nearly as loud. Also have a Heritage Les Paul w/Duncan '59s(nearly as loud)  and a '74 Les Paul w/ full size OEM HBs (7.5 ohms). I like the old, "well behaved",  70's humbuckers the best.

The Duncan Alnico II pro pickups are better behaved than the '59s.

With Volume at 4.5 and Master at 5 my OTS w/humbuckers is too loud for anything but a fairly large venue. I can use single coils at that volume.  I'll be a t 2.5 -3 max with HBs.

My general set up is similar to yours as far as OD and Ratio (my trimmer is at 10 o'clock).

My switches are as follows:
Rhythm P.U.  Bright on , Deep off, Rock
Bridge P.U.  bright off, deep off, Rock

Occasionally, I will use deep with the Bridge P.U. but EQ is pretty much always Treble 3, Mid 7, Bass 7, Presence 5. I don't use a Klein.

I do think lower output HBs are better with the OTS. You don't need to add distortion with the pick ups. With those Burstbuckers my Super Reverb starts to break up at 4!, it will stay clean up to 7-8 with Fralin Vintage Hot SC's.

I am sure there will be many other opinions on this.

Thanks. It is a special amp. I have been gigging with it for almost a year now and any time there is a knowledgeable guitarist in the crowd they will come up, check it out and tell me how good the amp sounds.  How do you compare it  to the Two Rock?