Arbiter Solo RTA (Genuine)

Intro

Although I'd hesitate to recommend this tank to complete newbies, I believe that this little tank has impressive potential to demonstrate enhanced effects of the "Thundercastle Effect", (i.e. slower toking/higher temperature & more concentrated Dimitri vapour) in a controlled & repeatable way to a much wider audience.  And the comparison can be done by simply changing settings rather than having two otherwise identical setups.  Its enabler is an ingenious two-position control (used in conjunction with the usual standard airflow ring) allowing precise airflow control in two modes as follows

1. Restricted Direct To Lung (RDL) - provides an airflow range slightly more restrictive to regular Direct To Lung tanks like the Zeus X, Destiny, etc. In this mode, the standard airflow ring (see pic below) is designed to expose one larger inlet hole, or several simultaneously. 

2. Mouth To Lung (MTL) - provides a much more restricted airflow (tighter draw).  In this mode, the standard airflow ring (see pic below) is intended to be adjusted to select airlflow in just one of several different size holes.

The MTL/RDL control works by rotating the inner aiflow chamber, causing alignment of specific internal holes which guide airflow under and around the coil to optimise vaporisation in each selected mode. The standard airflow ring operates independently of this MTL/RDL control allowing a range of single inlet holes of various sizes, or alternatively the airflow ring can be set to expose multiple holes, presumably for the RDL setting.

If you're unsure what is meant by MTL/RDL/DTL airflows, see the explanation at the top of this page, "Airflow Restriction Types"

Note in Dimitri vaping, although we may choose to use MTL airflow tanks, our actual vaping is far better performed in a direct to lung manner - i.e. the (slow) flow of vapour directly into the lungs but without pausing to accumulate in the mouth. Feel free to try otherwise but expect sore mouth, wickedly harsh vapour and very weak effects.

Why the "Thundercastle Effect" is a big deal

You may already appreciate the effect of slower toke rate/duration.   Slower & longer tokes result in higher vapour temperature/stronger Dimitri vapour/air mixture concentration, often dramatically increased potency, reduced d-juice consumption, and (subjectively) more euphoric effects. The tradeoff is normally a potential increase in vapour harshness plus a reduction in predictability, meaning trips can become unexpectedly intense very quickly. However, the wide and finely controlled airflow of the Arbiter Solo so far looks very promising to partially offset this second disadvantage.

Airflow in Regular "Sub Ohm" DTL tanks

For my regular direct to lung tanks, hitherto I've tended to control airflow with lung action alone, setting the airflow control ring wide open (little or no airflow restriction).  This has been quite effective, but error-prone because even a slight change of driptip suction creates a relatively large change in airflow.

Of course, closing off the airflow ring on DTL tanks improves slow-toke precision to a degree.  However, from testing with dedicated MTL atomisers like the Aston 22 and FEV4.5S, it's obvious that smaller tanks with smaller coils, and purpose-designed smaller internal air channels results in far superior predictability and overall better effect for restricted airflows. In short, to maximise benefits from the "Thundercastle Effect", a regular DTL tank (even if the airflow ring is set to create a tigher draw) is unlikely to be our best option. This is where the Arbiter Solo steps in.

Results FromTesting So Far 

At the time of writing, I've only performed limited testing with 1:3 60/40 PG/VG, and 4 turns of 2x26+36 SS fused clapton i/d 2.5mm.This is a DTL wire so not traditionally expected to be ideal for the MTL setting, but despite this I've been utterly delighted with its performance on a mere 20W with two or three 6(ish) second tokes. 

And although I've barely scratched the surface of possibilites, already I'm finding this to be a thoroughly intriguing tank and just can't wait explore its potential further. Based on my impressions do far I'd enthusiastically recommend it to any curious experimenter to test out it's many possibilities for Dimitri juice.

Conclusions

I believe this RTA to be potentially noob-friendly, but perhaps not for Mr Average noob who just wants the easiest/quickest rebuildable to get up and running with a smooth vape. Sure it can be set to RDL and provide a vaping experience in the same rough ballpark as standard DTL tank, but handling and vaping from smaller coils may take a little practice to get the best from. Plus the build deck is suited only to clockwise coils (see this page for the difference). It might not be easy to find ready-made coils to fit this deck (most are anticlockwise) so you may need to wind your own.

However, for the curious experimenter who would like to explore variables for Dimitri juice vaping, it forms a versatile test bed.  I'll update this review when I've done more testing, but so far I've been totally blown away.  It has earned a permanent place in my toolbox.

Pros

• Ingenious airflow restriction setting that works extremely well with Dimitri juice, this is no gimmick

• I believe this tank to be an great demonstrator for the "Thundercastle Effect", having considerable transformative educational potential.

• Unparalleled versatility, many different setup options for the Dimitri experimenter

• Generates the "ThunderCastle" effect extremely well on the MTL setting, with airflow ring set to max airflow, 6-7 sec tokes as described above (hanging onto tokes a bit longer can result in an unexpected & dramatic potency boost)

• Definitely the very best build quality build I've ever seen on any tank, genuine or otherwise.  Remarkable finish throughout, and depite the usual close scrutiny with a x40 magnifier I haven't found one single fragment of manufacturing swarf anywhere

• For my own preference, pretty much ideal juice capacity for Dimtri (see pics below)

• M3 terminal grubscrews rather than the smaller (and imo inferior) M2.5 that are common on most RTAs

Cons

• Deck suitable for clockwise-wound coils only, which may be tricky to source as pre-wound. Coils may have to be self wound which may not be the preferred option for some.

• Has a 510 driptip fitting. This is expected for a non-DTL tank, but I'm just not keen on them. My Aliexpress 510 curved glass driptips are a wobbly loose fit, needing tape packing to render them acceptable

• Like most RTAs, it has a base-resident hidden juice pool, although less than the usual DTL RTAs.  Of course, some may not regard this as a disadvantage

• The MTL/RDL control is a little easier to turn than I'd prefer. If an extended curved driptip is fitted, swivelling it around can unintentionally change the MTL/RDL control position. So far this hasn't been a problem, but something to bear in mind

• The gap between build deck terminals is extremely narrow (only 4.5mm).  Again this is acceptable for a restricted airflow tank, but it means that options will be limited if your toolbox is full of thicker gauge DTL multi-cored wires.

• Very limited space for coil diameter, max recommended 2.5mm i/d (I just about squeezed in a 3.0mm i/d coil when using fine MTL wire) and less margin for error for avoiding side-contact.  I'd suggest using a coil winding tool (see pic) to achieve the best possible accuracy.

• A bit strange to disassemble.  Can appear reluctant to unscrew, seems stuck.  The remedy is not to overtighten it, and when disassembling grip the base and the standard airflow ring to unscrew, not the main body/glass 

• The usual issue - spare O-ring kits for this tank are hard to find or unavailable (I cannot find any despite much searching)