Adapter advisor: The right adapter for every task

Adapters make incompatible formats match. They range from simple USB plugs to audio cables to PCIe plug-in cards for SCSI, M2 or eSATA.

What does not fit is made to fit. With the right adapter, you can get almost all connections in the format you need. We show how you can expand USB almost at will, how to convert the Lightning connector on the iPhone or how to connect old hard drives to the PC. We’ll show you a few ways to operate old hardware such as eSATA or IDE with current systems.

Since even the new iPhone 12 (guide) does not have a USB-C socket, Lightning adapters remain relevant for Apple fans. Most are looking for one of two variants: Either the Lighthing plug should end in a USB variant or in a 3.5 mm jack socket. Alternatively, there are adapters that can do both, jack socket and charging connector. When converting Lighthing to USB-C or USB-A you have a wide selection of products, from cheap to Apple. The multi-adapters are particularly clever. These consist of modular plugs so that you can switch between Lightning, USB-C, USB-A or Micro-USB with a cable. So you can easily charge or control a wide variety of devices.

It is a little more difficult with the Lighthing variant on the jack socket. Apparently, the number of those who connect high-quality headphones to their iPhone via jack has declined sharply in recent years. The official Apple adapters are available on the web from around 7 euros. Alternatives are often more expensive. Adapters that separate the Lighthing connection into data and audio are particularly clever. So the iPhone can be charged and at the same time you can listen to music via the jack socket.

The Universal Serial Bus has one task: to connect external devices to the PC as easily as possible. That also works wonderfully, albeit with restrictions. They are mainly due to the bandwidth. For example, USB has problems with the transmission of visual content. Apart from that, there is little that USB cannot do. Regardless of whether it is a data carrier, WLAN dongle, data cable, LAN connection, sound card or TV receiver: Almost everything that can be built into a PC internally can be retrofitted via USB.

USB-to-LAN is not a problem, but usually you can only create a 10/100 connection.

In most cases, you can only add one function at a time, such as a USB to LAN adapter or a WLAN adapter. However, there are USB hubs that share the available bandwidth between all connected devices. In other words: the more the LAN adapter pulls, the less there is for the USB stick. But since very few devices run permanently, it doesn’t hurt to have a cheap hub in your backpack.

USB-C is significantly more versatile. This is not only due to the higher bandwidth, USB-C manages at least 5 GBit / s, the Thunderbolt 3 variant is even 40 GBit / s. This not only ensures a fast connection to external data storage, you can also easily connect external monitors or external graphics cards (eGPU advisors). But you shouldn’t let yourself be dazzled. Many smartphones have a USB-C socket, but only achieve speeds of USB 2.0 (around 40 MB / s in practice). Still, most notebooks and current desktop PCs often have at least one USB-C port, which in the best case also supports Thunderbolt 3, recognizable by the small lightning symbol.

Four of the USB-C docks we tried for our guide.

It’s almost a shame to use a 1-to-1 adapter on such a port. We therefore recommend using a passive or active USB-C dock. This not only gives you important interfaces such as LAN or HDMI, most of the devices also provide several USB-A sockets as a bonus. So you can continue to use older devices without any problems.

We show more on this topic in the article USB-C docks from 30 €: Conveniently connect monitors & Co.

USB-C has the disadvantage that not every PC can handle the standard. It is therefore worth taking a USB-C to USB-A cable or a suitable adapter with you. USB-C is compatible with older standards, but then loses speed. This is especially blatant if you insert a USB A-to-C adapter incorrectly. As we show in the guide: The right data storage device for on the go, in the worst case scenario, you lose two thirds of the speed. So if the external hard drive is too slow, maybe just turn the USB-C adapter, stupid as it sounds.

If you want to remove hard drives and then read or delete them, you can easily address them via USB. Basically there are two different approaches: Enclosures in which SSDs or HDDs can be installed and used as a mobile device, or adapters in which hard drives are clamped. The latter are more there to read data from an old or possibly defective hard drive.

Such HDD docks can be used to connect old hard drives to another computer, for example to save the data.

These docks have a simple structure: They offer one or more bays, usually the respective hard drives are inserted from above, the necessary connections for power and SATA or IDE are integrated in the docks. The docks support 2.5 or 3.5 inch hard drives; many devices support both formats. It is important here that the docks are switched off when inserting or removing the hard drive. The docks usually have to be supplied with electricity themselves. On the PC side, the devices are easy to use. They register as USB mass storage devices and can be used like an external hard drive without a driver. Some have the option to clone or erase the hard drives directly.

We found a big surprise in our article Retrofitting NVMe cheaply. We originally assumed that a PCIe adapter card should be slower than an M.2 slot on the mainboard. In fact, the opposite was true. It is probably related to the better cooling, after all, the PCIe card is not located between the CPU cooler and the graphics card. In this respect, we can recommend this approach to anyone who wants to upgrade their mainboard with an M.2 NVMe.

Such adapters combine M.2 slots with PCIe connections.

In addition to the simple cards, there are also PCIe adapters that accommodate multiple M.2 memories in one device. In that case, however, the mainboard should support the PCIe bifurication (or PCIe splitting) function. This ensures that a PCIe connection can be split up, for example a PCIe x16 connection could control either two PCIe x8 or four PCIe x4 cards. This is currently only available in a few mainboards for end customers. If you are not sure that a mainboard offers this function, you should use two separate adapters.

In addition to USB-C, the DisplayPort and HDMI are widely used to transmit content to monitors or TVs. Very few notebooks have both connections. Adapters would be ideal, but they repeatedly led to problems in the test. An example: While you can usually bend DisplayPort to HDMI without additional hardware, an HDMI port often wants an additional power supply to control DisplayPort devices. It is important to know that adapters can only be used in one direction. In other words: A DisplayPort-to-HDMI adapter cannot be used for HDMI-to-DisplayPort. Another potential problem is HDCP copy protection. When using an adapter it can happen that the copy protection works or fails completely. This can cause problems when using consoles or Blu-Ray players, for example.

It’s easier if you go from digital to analog. That sounds outdated, but if you are out and about in companies, you will find a VGA connection more often than you think. Old projectors or, for example, connection distributors in conference rooms are the usual suspects. HDMI to VGA is usually not a problem. Retro gamers who find their NES or SNES console in the basement may want to hook them up to the latest TV. This works, but if there is no longer a suitable SCART connection, it can be expensive. There are converters that translate the analog SCART for HDMI, but not many. In terms of price, they are as expensive as the Raspberry Pi, which you can use to build a retro console yourself.

Couplings for HDMI are an exciting area. This allows you to put the connection down, for example, and lay the cable neatly behind the TV. However, you have to make sure that the coupling meets the same specifications as the cable, the player and the TV. Because if, for example, an HDMI 2.1 player is routed via an HDMI 1.3 coupling, the entire system falls back on this standard. Everyone who wants to put HDMI to DVI should be careful. This only works with a passive adapter to single-link DVI, not to dual-link DVI.

In most cases, DisplayPort is probably about converting a mini DisplayPort connection (e.g. on a Macbook) to another format. There are numerous adapters with sockets for HDMI, DisplayPort or VGA. If you want to display presentations or images on external projectors or monitors, you usually have no problem. The reproduction of sound can be a bit more problematic: Switching from DisplayPort to HDMI can lead to restrictions and errors, and the HDCP copy protection may also be problematic here.

Displayport is much more flexible when it comes to DVI. Here you can go from DisplayPort to single-link DVI (with passive adapter) and to dual-link DVI (with active adapter).

The 3.5 jack is not to be found dead, as much as the smartphone manufacturers want it to be. Not everyone wants to switch to Bluetooth so that they can continue to use old hardware. Since the analog connection is an old and proven format that has no integrated DRM or even copy protection, there is pretty much every adapter for the jack plug. This includes jack sockets with USB-A or USB-C connection. Alternatively, the jack can be split to cinch, for example to connect headphones or the player to a system. Hobbyists can split the signals from a jack plug into a 3 or 4 port terminal and use it for their own projects.

If the breakout cable is lost, you can buy it for little money.

But it is probably much more important to split the plug of a headset into the headphones and microphone, for example to connect a headset like the Sennheiser GSP 300 (test report) to a sound card. These breakout cables are cheap, but tend to get lost or broken. Replacements are available for less than 2 euros.

Here we are slowly getting deep into the history of the desktop PC. For more than 14 years, SATA has been the de facto standard for controlling hard drives in PCs. But it could be that you dig up an old hard drive from a PC in the attic, or you just want to continue using an old tape drive or burner. Suitable adapters are available for less than 10 euros. When buying, you have to pay attention to whether the IDE connector is 2.5 or 3.5 inches wide and what the PIN assignment should be.

Another ghost from the past. But even now there are still users of SCSI devices. No problem, but SCSI cards for PCI Express are expensive. Almost 400 euros should be budgeted for here.

If eSATA says little to you, you shouldn’t be ashamed of it. The connection was intended to quickly connect external hard drives to the PC. Or, as the colleagues at c’t wrote in 2013: “For a long time, eSATA was the only interface for external hard drives that did not slow down data transfer.” That has changed fundamentally, eSATA hardly exists any more. But if you can find such a hard drive somewhere, you can retrofit the right interface for little money.

You can redirect almost anything to anything. Technical problems usually arise when copy protection spits in the soup. Thanks to USB-C, this is also much easier – and, above all, cheaper. Solid USB-C docks are available from around 30 euros, as our guide to USB-C docks shows. We’d recommend anyone with USB-C to have at least an inexpensive passive dock in their laptop bag. You never know when you may need it.

The other side are adapters for special applications. Here you can dig deep into the Internet and find a way for almost every standard, no matter how old, to connect it to a current system. This is not always cheap (SCSI) or practical, but if you find an old IDE hard drive with the first family pictures or something similar, it is probably worth the work. We recommend that you work as little as possible on the original, especially with old or potentially defective hard disks, and that you make a copy immediately. That shouldn’t be a problem thanks to the storage capacities of current data storage devices.