Improved Connectivity, Disappointing Radio Tuner
The TStak Connect is the brand new for 2018, more compact counterpart to DeWalt's ToughSystem Music which was released in 2015. The TStak is compatible with the modular dockable toolbox systems including the VersaStak sold by parent company StanleyBlack&Decker. At the time of this writing, both are current products so I will be making comparisons between the two.
In short: If you're looking for a device to charge high-capacity FlexVolt batteries, and use primarily as a wireless or auxiliary speaker, you'll enjoy the multiple device capability as well as the 2-way control via Bluetooth on the TStak Connect. If you are looking for an excellent AM/FM radio tuner, and use regular 12 or 20V MAX batteries, I feel the ToughSystem Music is still a better choice.
The TStak Connect has a redesigned storage compartment that is now a single release handle instead of the 4 latches on the ToughSystem. This makes it much easier to access - and now the battery, mobile device, and power adapter storage is all located in the same space. Some rugged phones or cases do not fit, and the USB is for charging only, with no media support. This compartment has a seal to provide the IP54 weather resistance rating when closed. The battery compartment is larger, to support the dimensions of the high-capacity FlexVolt battery packs, which do not fit in the ToughSystem Music. There is a revised clip to retain the battery pack rather than using adhesive foam bumpers as on other DeWalt radio models. From a user interface perspective, it has a full colour graphical display which automatically rotates depending on if you have the unit laying flat or standing up. There are 6 context-sensitive soft keys and the jog dial doubles as the power button, along with home, back, and the dedicated seek up/down buttons that were missing from the ToughSystem. Volume settings are remembered per input.
Even with all these many more pixels on the screen however, there is no more 8-segment battery state of charge icon as with the ToughSystem, instead it is replaced by a tiny multi-colour LED to indicate 3 states going from green, to yellow, and then red as it discharges, and then flashing red for charging or error. I feel like the high-resolution colour graphical display could be put to much better use by retaining the "status icon tray" that many people are familiar with in consumer electronics these days. Display brightness and auto-dim can be selected in the menu.
The mobile app is functional, but needs refinement at this time. I tested both Android and iOS variants of the TStak Connect Radio app, released in May 2018. The app allows for remote control of the TStak's volume, standby/power, and you can also control a TStak that is receiving streams from another Bluetooth device, which is a big plus for some audio accessories that can't run apps (such as standalone Bluetooth audio senders. DeWalt no longer claims a wireless range for the TStak (it was 100ft for the ToughSystem) but it is expected to be a Class 1, maximum allowable by the specification - but difficult to guarantee as it really depends on the chipset specifications and implementation of the corresponding paired device. In practice - real-world differences in range between products were negligible. The TStak's Bluetooth chipset offers 3.0 (audio) and 4.0 BLE (control) capability to paired devices. BT 3.0 reveals A2DP and not HSP, so phone call audio won't accidentally get blasted across site.
There is also a very basic media player built in to the app that attempts to index supported local media files on the device, but you can also use the media player or platform of your choice (including streaming apps) of course.
This model was originally released for the European market first, so the app defaults to settings catered for that market's model - which includes a DAB+ digital radio tuner as well as 50kHz FM tuning step. The North American model we are reviewing here does not have a DAB+ tuner (nor does it have any iBiquity IBOC or "HD Radio" features which is the prevalent digital broadcast format in the USA, Mexico, and Canada) and the front panel offers a 100kHz FM step, but the app often gets confused and shows a DAB option and allows for tuning to 50kHz which is not relevant to this market and could cause confusion. In addition, FM presets can be recalled and modified from the app interface. Meanwhile, AM tuner control capability appears to be completely absent from the app interface, and can only be adjusted from the device front panel.
If the absence of AM from the app is any indication that the feature is basically an afterthought, I was disappointed to find that the excellent tuner electronics from the ToughSystem Music did not carry over to the TStak Connect. The internal electrical noise makes the AM tuner deaf to all but signals with the highest field strength, ie. if you are in the broadcaster's primary 25mV/m contour region. Furthermore, there are several frequencies across the range where the TStak generates internal "birdies" or products of internal mixing, which severely impact receiver performance within its operating band - in fact, while reviewing the two DeWalt radio models side-by-side, merely bringing a TStak switched on in close proximity to the ToughSystem would wipe out both of them. This was noted when the device was operating on battery pack, as well as by its power adapter, with the noise getting even worse when the unit was in charging mode. There is no graphical signal bars meter displayed as with the ToughSystem. Finally... the AM tuner section does not remember the last tuned frequency between power/standby cycles, and always defaults to the bottom of the band at 520kHz when powered on. Using a preset would be a workaround to this.
The FM tuner is more immune to the noise issues described earlier, and is otherwise functional. The auto-scan is very fast and there is a search function to populate all preset slots in the order they are discovered. Stereo is fully automatic when 19kHz pilot tone is detected, with no mono override.
RBDS, or Radio Broadcast Data System, is partially implemented on the TStak Connect and it decodes the PS (Program Service) field up to 8 characters maximum. Oddly enough, it does not reset the PS when changing frequencies, meaning if you tune from a station that has an RBDS subcarrier, to a station that does not, it will still retain the last decoded message on screen. If you then subsequently save that preset, you'll end up with the wrong label for the station. In comparison, the ToughSystem decodes both PS and RT (Radio Text) fields and displays them both simultaneously.
Moving on from my critical review of the radio functions, the sound on both devices is otherwise very good and there is no audible apparent differences between the TStak and the ToughSystem audio systems, even if the TStak has a slightly smaller pair of active subwoofer driver and passive resonator. This part is very well done, and the TStak continues to offer the 3-band equalizer, although with fixed Q and it is global across all sources (eg. no way of setting different EQ per source type). For the intended market and application, these are designed to be loud but not necessarily a flat response. In that theme, there appears to be a loudness contour that is always enabled, which further boosts low frequencies at low volume levels and then weans it off as the volume is increased, this is also to manage internal amplifier power. The internal DSP processing introduces a very slight delay, in the range of milliseconds to the audio, which is not an issue with Bluetooth but may be noticeable or distracting if you have the radio operating with others tuned to the same program, in the vicinity.
Powering the TStak is still accomplished by a 24-volt DC adapter, and the only visible change is the right-angled strain relief connector to allow the new adapter to fit snugly into the TStak's storage cubby. Although I would have preferred this to be an internal power supply with a male NEMA 5-15P recessed in the chassis to attach any commercially available extension cord (like their area light and outdoor equipment products), I understand the use of an external power adapter allows the product to be easier adaptable to worldwide markets. Time will tell how durable the DC connector is with repeated use.
Recharging certain battery models like the DCB203 and DCB120 on the TStak turned out to be hit-or-miss on my particular unit. It would often show the 'faulty battery' symbol on the display and fast flash red until the battery was re-seated, and/or the DC power cord detached and re-connected. The same batteries charge without any issue - every time - on the ToughSystem, DCR015, DCB113, and DCB101.
In conclusion, evaluating this product as the next evolution of toolbox radio products from DeWalt, I feel there were some important improvements with the TStak while some other features were poorly implemented, or not necessarily thoroughly tested before going to market. This product is brand new for the North American market at this time, and so there may still be running improvements along the way. I noticed the app had implemented a device firmware update capability, which allows software upgrades to be implemented after sale by the user without sending back to depot or an authorized service centre. Most of my commentary revolves around improvements to the product that could be easily implemented in software, so this could very well change in the future, should they devote some resources towards it. StanleyBlack&Decker has just recently submitted an FCC regulatory application for the Craftsman-branded counterpart to this TStak Connect, apparently virtually identical except for the colour scheme, so I feel they are actively working on this model yet.