AccessoriesSiglent probesProbe adapters
Oscilloscope probes

Probe adapters

Keep the active probes you already own when the oscilloscope changes. Two adapters put LeCroy ProBus and Tektronix TekProbe Level II probes onto a Siglent SAPBus input, powered and offset-controlled by the scope, with no external supply.

4 GHz
Adapter bandwidth
2
Interfaces supported
None
External power needed
SAPBus
Scope-side connection
Siglent TPA10 active probe adapter

An active probe is a large investment. An adapter protects it.

A modern active probe carries its amplifier in the probe head, so it needs power, and it needs the oscilloscope to know what is attached — the attenuation ratio, the offset range, the calibration constants. That handshake happens over a proprietary interface: Teledyne LeCroy call theirs ProBus, Tektronix call theirs TekProbe, and Siglent call theirs SAPBus. The connectors are not compatible and neither are the supply rails behind them.

That is what makes changing oscilloscope brand expensive. A pair of differential active probes and a current probe can easily be worth more than the instrument they plug into, and none of it moves across. The LPA10 and TPA10 sit between the two worlds: the scope end is SAPBus, the probe end is ProBus or TekProbe Level II, and the adapter generates the supply rails that the foreign probe expects. The oscilloscope powers the whole assembly — there is no separate brick to find bench space for.

Both adapters pass 4 GHz, so they are not the limiting element in front of any probe likely to be connected to them. Note the difference in what they carry: the TPA10 also passes an offset command of −1.2 V to +1.2 V through to the probe, so scope-side offset control keeps working. The LPA10 supplies power only.

Specifications side by side

Every model in this family, on one row each.

ModelBandwidthProbe interfaceRails suppliedOffset to probeTypical probes
LPA104 GHzLeCroy ProBus±12 V (±2%)ZD1000 · ZD1500 · CP030 · AP033 · AP034
TPA104 GHzTekProbe Level II±15 V (100 mA)
±5 V (200 mA)
−1.2 V to +1.2 VTekProbe Level II active and current probes

When an adapter earns its price

Changing oscilloscope brand

The scope is replaced but the probe set is not. One adapter per channel keeps a five-figure probe inventory in service instead of on a shelf.

Cross-checking a result

Measure the same node with the probe that produced the original data and with its Siglent equivalent. If the two disagree, the difference is in the probe, not in the instrument.

A probe with no modern equivalent

Some older ProBus and TekProbe heads — unusual geometries, specific current ranges — have no current replacement. The adapter keeps them usable.

Questions we are asked

Which oscilloscopes do these adapters work with?

Any Siglent oscilloscope with a SAPBus probe interface — the SDS5000X, SDS6000A, SDS6000L and SDS7000A series. The adapter draws its power from that interface, so no external supply is required.

Does the adapter reduce the probe's bandwidth?

Both adapters are specified at 4 GHz, which is above the bandwidth of the probes normally connected through them, so in practice the probe remains the limit. The usual caution applies: the bandwidth you actually get is set by the slowest element in the chain — probe, adapter or oscilloscope.

Will the oscilloscope read the correct attenuation ratio automatically?

The adapter passes the probe's identification through to the scope where the probe interface provides it. Where it does not, set the attenuation ratio manually in the channel menu — and check it before trusting an absolute voltage reading.

What is the difference between TekProbe Level I and Level II?

Level I carries power only. Level II adds the communication that lets the oscilloscope read the probe and send it an offset command. The TPA10 is a Level II adapter, which is why it can pass −1.2 V to +1.2 V of offset through to the probe.

Not sure which one fits your measurement?

Tell us the instrument, the signal and what you are trying to see. We are the official Siglent distributor for the EU and we will point you at the right part — including when the right answer is a probe from another family, or nothing at all.