We are proud to announce our newly developed headphone/speaker booster RJ-1 for use with a wide range of metal detectors. Its compact and lightweight design makes it a winner. In quiet remote areas where a headphone is not crucial you will experience the benefit of a speaker system with superior detection rate. No objects will be missed with this remarkable and sensitive built-in amplifier.

Our field tests prove that even the smallest objects can be detected without the need for a headphone.

We have designed this booster for optimum comfort. The minimum weight is a welcome feature that many metal detector operators will appreciate. The booster can be attached to your belt or jacket using e.g. Velcro clips. Or it can simply integrate in our protective control box cover (see pictures). Here we even made room for a small but heavy gauge Li-ion battery pack that will deliver up to 8 hours power for your metal detector.

For those prospectors who stick with the original metal detector battery we have provided an optional connection cable (see pictures) that can be purchased separately.

Below I will explain some features of the booster. We always kept in mind that the design should be easy to use.

From right to left we have a volume control knob for adjusting the output level for either the built-in speaker or the headphone output.

Next we have a switch to select between the speaker or headphone mode.

Then we have the on/off switch sitting together with a LED indicator.

At the left we have the output cable that connects to the combined input cable for the Minelab GPX-series control box.

Also at the left side of the box we see a headphone output socket to plug in an optional headphone. (first picture)

Please note that the pictures shown below are pre-sales models. The retail box may be slightly different.


RJ-1 side view


RJ-1 top view

Connection cable


Below we can have a look inside the booster.

The booster has its own battery supply that will last for about 100 - 200 operating hours. (A lithium battery will give you maximum power).

When the battery life comes to an end, simply open the box and exchange the battery (Preferable use an alkaline or lithium 9V battery). Do not use a rechargeable battery!

The internal speaker does a good job. It gives a loud and clear signal when detecting an object.

The amplifier itself has been carefully selected after hours of field testing and comparing against other models.

We are pleased with the result. We are sure that this all-in-one solution will bring a smile on the face of any metal detector operator!


RJ-1 open view

Picture that shows a Minelab GPX-4500 control box together with the RJ-1 and a Canon Li-ion battery pack. All safely packed in our custom designed control box cover.

RJ-1 operational

Combined set for outdoor use. The heavy external Minelab battery was left at home.


An optional Canon Li-ion battery pack BP-970G (7,2V 7800mAh) + connection cable is not available through our website, but can be found here:




Available in kits with 1 or 2 batteries + mains charger + car charger.

Prices : AU $150,00 or AU $220,00

Our web shop will not be operational before spring next year. Till that time we will offer our headphone/speaker booster + accessories for sale on eBay.

A direct link to eBay can be found here:

Please return to this page again to check for the link.


Price RJ-1: AU $95,00 + postage

Price optional connection cable : AU $13,00 + postage

Price GPX-Series control box cover: AU $39,00 + postage

You can order a single item or a set. A set will save you postage costs.


Wishing you all the best,


Jean-Pierre .