Geekvape Z50
Cheap & cheerful, has a con or two, but packs an amazing punch & somehow seems to perform adequately in TC mode for emesh, and also dimitri sub ohm use.
Intro
For emesh and sub ohm d-juice exploration, I believe the original Geekvape Solo/Mini is unbeatable for value & performance. But sadly, having been discontinued we can now expect supplies to gradually dry up. Here I evaluate the Z50 as a cost-effective replacement for dimitri emesh and 'sub ohm', and in particular the temperature controlled operation that many continue to prefer.
Note TCR of 92 for TC-SS default on earlier Z50s
Features
Menu screens are stock Geekvape Aegis (Power, Bypass, VPC, TC-TCR, and TC-SS), but without the (largely redundant) TC-NI and TC-TI.
Notice earlier Z50s (inc firmware YK2021 0319 V01) have a default TCR value for the TC-SS setting of 92, compared to 105 for the Solo and later models of Z50 (inc firmware YK2022. 0214 V01) Theoretically, this means that for a correct reading of 200°C on a Geekvape Solo, a setting 225.4°C would theoretically be needed on the earlier Z50 to achieve the same actual temperature with an identical coil. Of course, by switching to TC-TCR mode with a TCR of 105, this removes the need to add this offset. (For workings to these calculations, see bottom of this page)
So if your Z50 is an earlier model with the 92 TC-SS you'll likely need to raise the temperature by 25°C or so above the "usual" Solo emesh temperature setting in order to generate optimum vaporization, as in I'm finding out myself from intial emesh testing.
TCR of 105 for TC-SS default on later Z50s. Many thanks to Zed for reporting & providing the pic
Ohms law in action During a "Fire Cycle" Volts x Amps = Watts
Performance
Max power rating is 50W, which appears fully warranted. From a fully charged battery, I continously chain-vaped an entire 3ml tankful of PG/VG in Power mode at full 50W. The Z50 became warm, the tank got hot, and dense vapour filled the entire room, but throughout, the indicated power stuck almost entirely at 50W with intermittent short dips to around 48.5.
Afterwards, the battery level indicated only 1 pip down, and it was still cheerfully throwing out what felt like a very punchy 50W.
In an identical comparison to my Geekvape Solo, the Solo felt a noticeably less lively until I realised it's tired battery was only managing 50W for a second or two before dropping to mid 40s.
The Z50 is also capable of reaching its full power in TC modes, with about 48.5to 50W visible on the display during a hard blow onto the mesh. Thankfully, there is no sign of the L200 TC defect.
Temperature Control Testing
The all-important coil reset procedure is a little different to the Solo/Mini, but works perfectly when performed as described here.
During "empty mesh" testing, the Z50 inspired little confidence in both "no toke" & "standard toke" tests (see the emesh update/troubleshooting video). However several live tests with 15mg loads actually felt quite smooth. At I write, I've conducted many runs with TC-SS settings of 180 to 215°C. These felt very slightly softer than the expected equivalent from my GeekVape Solo, but nevertheless produced a very agreeable experience. It was only afterwards that it dawned on me about differences in TCR as mentioned above, so there's still scope for further tests with slightly higher temperatures. Edit 20 Jan 2023: I've now tested upto a setting of 235°C, which felt moderately hot and appeared to supercharge the intensity considerably
So the Z50 really does appear to be a genuinely viable mod for emesh in both temperature control and fixed wattage mode.
For 'sub ohm' temperature controlled operation, tested on my ZeusX Mesh, the temperature control performance seems perfectly adequate.
"No Toke" Test
The Z50's "no-toke" test usually shows much greater inconsistency & wider variance than the Original Solo/Mini's fairly constant 4-6W. Here is a video of my own Z50's typical "no toke" test. If yours looks anything like this then it's probably performing as-expected and will be fine to try the "standard toke" test.
Z50_NoToke.mp4"Standard Toke" Test
Just like the Z50's "No Toke" test, this typically has far less accuracy than the Original Solo/Mini's 14-16ish Watts. Here is a video of my own "Standard Toke" test for reference.
I emphasise once again that despite the discouraging-looking excursions from the expected ~15W and not ideal by any means, somehow the Z50 in the video provided a smooth emesh dimitri experience just after the video was shot.
Z50_StdToke.mp4
Conclusions
So far I'm very impressed by this pretty little mod for dimitri use. It's definitely no Original Geekvape Solo, but a low price (which of course includes a quality internal battery), delightful ease of use, plus it's general performance makes it a truly incredible bargain.
It's physically small, so much that the Mesh Pro RDA (overhangs it by a mm or two) gives it a slighty top-heavy look & feel. It would certainly appear odd with larger sub ohm tanks, but who cares for dimitri use.
Some may be discouraged by the 50W maximum power, but be assured that at least on my own Z50, it's effortlessly achieved and apparently sustainable throughout chain-vaping without cut-out. For my own dimitri vaping, this capability is way more than adequate.
Despite emesh temperature control tests appearing erratic, the live TC vaping experiences so far suggests adequate performance. And I'm perfectly happy using it in either TC or power mode for 'sub ohm' atomisers.
I haven't dismantled for build quality inspection, but the external appearance of the 510 connector plate would suggest a stronger fixing arrangement than the painfully feeble design of the latest Aegis models. Let's hope Vapey Mcgyver features one on his VMG Testing channel soon.
If you're looking for an inexpensive, easy-to-use mod for general Dimitri use, IMO it's definitely worth a closer look.
Workings From The Above TCR Calculations
Using TCR 105, assuming resistance at 20°C= 0.2Ω, find R2 (i.e resistance at genuine 200°C)
R2 = (R1 x ∆T x TCR) + R1 R2 = (0.2 x (200-20) x 0.00105) + 0.2
R2 = 0.2378Ω
Now find non-genuine temperature T2 of same material when it undergoes equal resistance change calculated using TCR of 92
∆T = ∆R /R1(TCR)
∆T = 0.0378/(0.2 x 0.00092) ∆T = 0.0378/0.000184 = 205.435
∆T = 205.435 T2 = T1 + ∆T
∴ T2 = 20+205.435 = 225.435°C
T2 = 225.435°C