Dynavox Gold-Plated Banana Plugs with Expansion Pins – Set of 4 (2× red / 2× black)

Audio accessories · Banana plugs

Bare cable ends that work loose in the binding post, stray strands that risk a short circuit, and plugs that sit loosely in the socket after just a few weeks: the connection between amplifier and loudspeaker is often where more gets lost than necessary. The Dynavox banana plugs with expansion lock put an end to this – with a design that holds both the cable and the plug connection securely for the long term.

At the heart of the design is the expansion pin: it is screwed into the plug from the rear and spreads the slotted contact pin as it goes. This lets you set the contact pressure in the socket precisely – for a firm, play-free connection that does not wear loose even with frequent plugging and unplugging. The cable is clamped without soldering by two grub screws, and the 24K gold plating protects the contact surfaces from oxidation. Supplied as a set of four with red and black colour coding in a blister pack.

Simple banana plugs rely on the spring tension of their contact pin. This weakens over time – especially with frequent re-plugging or when sockets from different manufacturers vary slightly in size. The result is a plug that wobbles and only makes contact at isolated points. Speaker connections carry comparatively high currents, so every well-seated contact surface counts here.

The expansion lock of the Dynavox banana plugs solves this mechanically: the expansion pin pushes the slotted pin apart from the inside – exactly as far as you screw it in. If a plug sits too loosely, a small turn is enough to fit it snugly to the socket again. Instead of fading spring tension, you get a defined, adjustable contact pressure – for a connection that still sits firmly after years.

On the cable side, too, the plugs rely on a solid mechanical connection. The stripped cable end is pushed into the plug and clamped by two grub screws. Two clamping points spread the pressure over a larger area and hold the conductor more securely than a single screw. Cables up to approx. 4.5 mm in diameter are accepted – no soldering iron or solder required.

The 24-carat gold plating completes the design. Gold does not oxidise, so the contact surfaces stay clean even if the system goes unchanged for a long time. The contact resistance between plug and binding post therefore stays permanently low, and creeping contact problems caused by corrosion do not stand a chance.

Assembly takes just a few minutes. Strip the speaker cable to the insertion depth of the plug, twist the strands tightly and push them into the plug so that no individual wires stick out. Then tighten both grub screws evenly. An important tip: do not tin the strands. Tinned wire gives way under the pressure of the screws over time and the clamp loosens. Bare, neatly twisted strands hold much better under screw pressure.

Then screw in the expansion pin until the plug slides into the socket with a noticeably firm fit, but without force. Observe polarity when connecting: red goes to positive, black to negative – on both amplifier and speakers, otherwise the speakers work out of phase and the bass sounds thin. It is advisable to retighten the grub screws after a few weeks, as copper strands settle slightly under pressure.

Banana plugs are the most convenient way to connect speaker cables to amplifiers, receivers and speakers: instead of threading cable ends into binding posts and screwing them down, you simply plug them in. This makes it easier to swap connections when trying out different components and to set up the system in tight spots behind the rack.

A set of four covers a stereo pair of speakers at one end – i.e. both cables on the amplifier or on the speaker side – or a single speaker cable at both ends. For a fully terminated stereo pair of cables you need two sets. Note: some amplifiers leave the factory with plastic plugs in the binding posts, which must be removed before inserting banana plugs.

How does the expansion lock on banana plugs work?

On the Dynavox banana plugs, an expansion pin is screwed into the plug from the rear. It spreads the slotted contact pin and so increases the contact pressure in the socket. If the plug sits loosely, the grip can be adjusted at any time by turning the pin further.

Do I have to solder the banana plugs?

No, the Dynavox banana plugs with expansion lock are fitted without soldering. The stripped speaker cable is clamped in the plug by two grub screws.

What cable size fits the plugs?

The Dynavox banana plugs accept cables up to approx. 4.5 mm in diameter. With very thick speaker cables, it is advisable to measure the conductor beforehand.

How many banana plugs do I need for a pair of speakers?

Two speaker cables with plugs at both ends need eight banana plugs, i.e. two sets of four. One set is enough if only one side – for example the amplifier – is connected with banana plugs.

What do the red and black markings mean?

Red marks the positive terminal, black the negative. Consistently connecting red to positive and black to negative on amplifier and speakers avoids reversed polarity, which makes the speakers work out of phase and costs bass power.

Should I tin the speaker cable before fitting?

No, strands should not be tinned for plugs with screw clamping. Tin gives way under the pressure of the grub screws over time, which can loosen the clamp. Neatly twisted bare strands hold more firmly in the long run.