Sure,

The basic 18 watters are a simple two channel amp with a vibrato channel with tone and volume controls and a normal channel with a separate volume and tone. 

The TMB version has a treble, middle, bass tone stack in place of the vibrato.

The TMB EF86 has a separate ef86 pre amp tube feeding the normal channel.  The tone pot on the normal channel is also subbed out for a 6 way tone selector.

The EF86 pre-amp tube is a little more aggressive, has a little more gain than the 12ax7. It was made famous in the original Vox AC15 & AC30/4 amps in the late 50's,early 60's. If you get a chance, plug into a new Vox AC 15 or 30 "Heritage" amp. They have resurrected the old EF86 circuit in these amps. But be forewarned, the EF86 tubes had/have a habit of going microphonic. I believe this was the main reason Vox dropped them 40+ years ago.
        P.S. - I own a Vox AC15 "Heritage" head & I just bought the 18 Watt EF86 kit from Nik so you could consider me a fan of the EF86 sound.

I have the DC30 and I use a Dario Miniwatt EF86 tube.  Superb tube...spend money here it is worth it!

In fact if you are going for EF86 type amp go for a DC30 as it can be used at half power (15w) and is a superior amp in every way to the 18W. The cleans are out of this world and it is way more versatile.

The 18W does have that nice grinding Marshall crunch at low volumes. The DC has a good crunch but that Marshall crunch is sweeter i think.