Product Description

The Radial Gold Digger is a 4-channel mic selector that enables the engineer to quickly compare the sound of four different microphones while sharing the same preamp. A 'straight wire' passive circuit design is void of any audio buffers or transformers. Instead, the Gold Digger employs military grade gold contact relays to manage the switching process, thus ensuring the pristine mic signal is maintained without introducing color, distortion or artefact of any kind.

Features include four rear-mounted XLR-F mic inputs plus an XLR-m output to feed the preamp. To eliminate bleed between microphones, each channel is equipped with a 'radio style' selector switch that ensures only one mic is on at a time. The external supply provides power for the LED indicators, charges the relays and enables the Gold Digger to generate 48 volt phantom which can be turned on or off for each mic as needed. To ensure an 'honest' comparison between microphones, individual 'set & forget' trim controls let you adjust each mic level so that they produce the same relative output. Once set up, the Gold Digger not only improves workflow, but also gives the artist more confidence with the sound of the vocal, resulting in a better overall performance.

The Gold Digger -- A tool designed to get the very best out of each and every performance.

Gold Digger Development

Today, it is common for studios of all sizes to have a variety of microphones on hand. Comparing them to find the most suitable one to match a particular voice is often cumbersome if not impossible. For instance using a patch bay can slow the process to the point where they no longer remember the sound when switching from one mic to another. And using different preamps or even channel strips can be misleading as each of these can also introduce a degree of personality.

The Gold Digger presents a simple solution that not only makes it easier to compare mics, but also helps tremendously by having the artist participate in the mic selection process. We all know that when the artist is comfortable with the sound, the performance is more relaxed. This usually translates to a better overall recording.

Establishing the feature set

Developing the feature set on the Gold Digger was fairly straight forward. We felt that comparing 4 mics was sufficient as any more mics would cause more confusion than good.

Next they decided to make it so that only one mic could be turned on at a time. In other words, as you select one mic, the previous one is automatically turned off. This is done using a series of logic chips. By ensuring only one mic is on at any one time, this speeds work flow and eliminates the possibility of having two mics on which of course could introduce noise or bleed.

Critical to the design was insisting the signal path be completely passive. In other words, there are no gain stages or buffers inside that can introduce distortion, color the signal, or add any form of artifact. The Gold Digger is 100% pure straight wire. Actual mic selection is done using gold sealed relays. The only thing in between the input and the output is the trim control which is basically a resistor. And with less than 0.0005% distortion and better than 140dB signal-to-noise, the Gold Digger's specs are actually at the threshold of the test equipment. We chose to recess the trim controls in order to avoid their being accidentally touched which could cause one level to be louder than the other which could compromise the comparison or disrupt a recording session.

When phantom power is activated, a series of blocking capacitors are engaged to make sure the 48V phantom will not cause havoc to other equipment or problems with vintage ribbon mics. We decided to also recess the 48V phantom switch so that it would not be accidentally turned on which could harm some older vintage ribbon mics.

As for the mechanical design, they chose to pack everything into the same design as they used with the popular Phazer and the MC3 monitor controller. They felt this works well as it is good and solid, and heavy enough that it will not slide around when five mic cables are attached!

OH, the name. Well -- if you think about it -- most condenser mics employ gold foil of sorts on the capsule. Digging for gold simply made sense. The Gold Digger was born!

Using & Applications

The following sections discusses how to use the Gold Digger. As you will soon realize, it is very easy to use.

Overview
The Gold Digger is a 4 input, 1 output mic selector that has been designed to provide an honest comparison between four microphones to find the most suitable one for a given artist. This process involves the artist right from the beginning which usually results in a more comfortable and confident recording. This improves workflow for the studio. Mic selection is done using front panel 'radio-style' switches that activate the desired mic and automatically turn off the others to eliminate bleed and crosstalk.

Making connections
Before making audio connections, always make sure volume levels are turned down or off. This helps eliminate turn-on transients which could harm more sensitive components such as tweeters from being damaged. There is no power switch on the Gold Digger. As soon as you connect the power supply, it will turn on. If you are using the Gold Digger in a mobile studio or in a high traffic area, you may want to use the power supply cable clamp as extra security.

To start, make sure all of the 48V phantom power switches are in the off position (out) - LEDs off and set the TRIM controls fully clockwise (max) so that there is no attenuation on any of the mic inputs. Connect your microphones to the Gold Digger using standard XLR cables. Depending on what type of microphone you have will determine if phantom power is needed. Most condenser microphone employ phantom. Dynamic mics or ribbon mics do not. Simply push in the 48V switch if needed.

Connect the male XLR out to your preamp. Select channel-1 on the Gold Digger. Talk into the mic as you turn up the volume on your preamp and recording system. It is always best to test at low volumes as this reduces opportunity for feedback or damage due to bad cables or improper connections. Once you have this working, switch to channel-2 and repeat. Once all 4 mics are tested and working, locate the mic with the lowest output level. Using a tweaker or small screwdriver, match each of the other three mics so that the relative output is the same. This will ensure a fair and honest evaluation. Once all of the mic levels have been matched, you are now set to test and record.

Try comparing mics on vocals, guitars, snare drum, kick drum... you can sometimes be surprised at how well one mic may work in a given situation and how the same mic may not in another. You can also compare direct boxes following the same procedure. You would be surprised at how different each DI can sound. In fact you may be surprised to find that just like microphones DIs all have different personalities that can truly flatter certain instruments or render them listless...have fun.

For even more fun, try a Radial Cherry Picker! This lets you compare various preamps to find the best one for a given vocal. Using the Gold Digger with a Cherry Picker lets you find the best mic-preamp combination.

Features:

- Four selectable inputs with trim adjusts
- Straight wire distortion-free signal path
- Will not introduce color or artifact
- Increases artist's confidence when recording zZounds is an authorized dealer of Radial products.

- Audio circuit type: Passive signal path with active relay switching
- Frequency response: 10Hz to 100kHz +/- 0.0dB
- Dynamic range: >140dB
- Equivalent input noise: -115dBu
- Residual noise: -140dB
- Maximum input: +26dBu
- Maximum output: +26dBu
- Total harmonic distortion: 0.0003%
- Phase deviation: < 0.001 Degrees at all frequencies
- Intermodulation Distortion 0.001%
- Input impedance: 600 Ohms (typical)
- Common mode rejection: -92dBu @ 55Hz
- Gain: 0.0dB -- Unity gain device

Features:
- Inputs: 4 x XLR female
- Outputs: Balanced XLR male
- Switches: Individual on/off for each input
- Individual 48V phantom power for each input
- Controls: Variable trim on each input
- XLR configuration: AES standard (pin-2 hot)

General
- Power: +15V DC/400mA power supply included
- Construction: 14 gauge steel chassis & outer shell
- Finish: Baked enamel
- Size: (W x H x D) 4.5" x 2" x 6" (121 x 64 x 147 mm)
- Shipping size: W x H x D: 4.75" x 2.5" x 10.75" (121 x 64 x 273 mm)
- Weight: 2.8 lb (1.3kg)
- Shipping weight: 3.05 lb ( 1.4kg)
- Warranty: Radial 3-year, transferable

Dimensions and Weight in Packaging

Shipping Weight: 3 lbs

Shipping Dimensions: 11 x 5 x 3 in