- - Our Most Frequently Asked Questions - - -

-How To Choose the Correct Stepped Attenuator Value. General Rules and Considerations: 1. When upgrading from a potentiometer, use the same value stepped attenuator. (5K, 10K, 20K, 25K, 50K, 100K, etc.) 2. Choose the value to match the input impedance (of what the stepped attenuator will be controlling). This applies to both preamplifiers and power amplifiers when the stepped attenuator is to be installed at the input. If necessary, check your owner's manual to find the the rated input impedance of your unit. Or contact the manufacturer. 3. When choosing the stepped attenuator value for an in-line level control or "passive preamp" (such as the Goldpoint  Level Control Boxes), the attenuator value is chosen to match the input impedance of whatever it will be controlling. example: If the amplified monitor speakers or power amplifier you will connect the output of your your passive preamp to has an input impedance of 20K, then order a 20K stepped attenuator for that application. 4. You can usually use a level control value which is LESS than the rated input impedance of the gear it will be controlling. So, if your amplifier has a rated input impedance of 100K, instead of using a 100K level control, you could use a 50K, 25K, or even a 10K level control. (Avoid using a level control value which is HIGHER than the rated input impedance). 5. Vacuum tube equipment usually uses 100K or 50K level controls, due to the higher input impedance of tubes. Solid-state gear usually has 50K, 20K, or even 10K level controls.  6. You typically begin to have high frequency roll-off beginning to appear with attenuator values above 100K. If you don't have an engineer handy, or just can't decide, 25K is usually a good choice for both vacuum tube and solid-state equipment, especially for passive line controls.

-Which Type of Goldpoint Stepped Attenuator Sounds Best? All Goldpoint stepped attenuators improve sound quality and provide much better channel-to-channel signal level matching compared to potentiometers. I highly recommend our new Mini-V attenuators with the low noise, high precision resistors already installed. (0.1% tolerance, 25ppm, thin film, SMT (Surface Mount Technology)  Our new 0.1% resistors are SO good, that we no longer hear any advantage to producing Ladder or Shunt type stepped attenuators. These resistors are SO "quiet" you can string dozens of them together and that will still sound like a single individual resistor! You are welcomed to try this for yourself... You can use our Mini-V Custom stepped attenuator switches and install your own chosen brand of thru-hole resistors. This can result in various (usually slight) sonic differences, due to different characteristics of different resistor types.

-How Much Attenuation is Right for Your System? The word "attenuation" means the opposite of amplification or gain. It is "reduction in the amplitude of an audio signal"  or  "how much the volume level is turned DOWN". On all stock Goldpoint stepped attenuators, turning the knob fully counter-clockwise is OFF, (= infinite attenuation). Turning the knob fully clockwise is zero attenuation, (= full ON). The chart below shows the size of the steps we use. Our modified audio taper has larger steps for the first six positions, and then -2dB per step up to full ON. Our off-the-shelf stepped attenuators supply the correct amount of attenuation for most audio systems. But with some systems which have relatively low overall gain, you might have to turn the knob up past the 12 o'clock position to achieve normal listen levels. And some systems with relatively high gain cause the volume level to be too loud after turning up the knob to only the 4th or 5th position. These conditions are easy to remedy, however, as explained below. The graph shows standard and modified stepped attenuator tapers. The blue line is the standard Goldpoint taper. 1) "Does not get loud enough soon enough". This would mean that your system has relatively low gain available. There would be a large number of silent knob positions before you could hear anything. One fix for this is to add a resistor as shown (at left). The green line above shows the results of adding a resistor to the ground terminal of the stepped attenuator. In this example, we made the stepped attenuator start at -42dB, instead of OFF, so the volume level will be "louder sooner". Sample resistor values are shown on the page titled: "Modified Attenuator Tapers". 2) "It gets too loud too soon". This could mean that your system has relatively high gain. The sound level would be too loud after turning the knob up only a few steps - and there would be lot of unusable positions higher in the knob rotation because they would all be too loud. This is easy to fix by adding a pre-attenuation circuit (two resistors per channel), as shown at left. The red line above shows the results of adding this pre-attenuation circuit. In this example, we gave the stepped attenuator -20dB more attenuation at every knob position. Sample resistor values are shown on the page titled: "Modified Attenuator Tapers".

-Which Stepped Attenuator Values Are Stocked? Mini-V stocked values include: 5K, 10K, 20K, 25K, 50K, and 100K.  These are all available in mono, stereo, quad (4 channel or balanced stereo), and 6 channel.  Note: Normal Stereo "single-ended" attenuators are used as monaural attenuators for Balanced Input applications. Single-Ended quad attenuators are used as stereo attenuators for Balanced Input applications.

-What Kind of Switches Are Used ----and What Are their Dimensions? Goldpoint stepped attenuators employ ELMA, 24-position, precision switch components. They have smooth turning torque, great for audio applications.  All current models employ thick, hard-gold plated switch contacts on PC boards designed (with high precision) by Arn Roatcap. They are fabricated in the San Francisco Bay Area by a leading PC board fabrication facility. Click here for Attenuator Dimensions

-Which Attenuators Come In Kit Form, and Can I Get a Custom Value? Currently, there are no kits being offered, but we do offer blank switches  (MVC type) which accept any 1/4 watt or 1/2 watt through-hole resistors of your choice. If you want any special taper, attenuator value, or special type of resistor, the Mini-V Custom switches are for you. These attenuator switches come fully built but without resistors. You can use our resistor lists if you wish, or make up your own.  If you want an attenuator value which we do not stock, or one with a special taper, contact us to work out your custom resistor list - we will get onto your project typically within a couple of days. Sometimes we have the time to install your resistors for you, but we do charge extra for that.

-How About Some Knobs? The shafts on all Goldpoint attenuators are 6mm (.237"). This size is close enough to 1/4" (.250") to allow you to use of knobs designed for 1/4" shafts. However, if you are using knobs designed for 1/4" shafts, we recommend wrapping a few layers of tape, such as Kapton or common Scotch tape onto the attenuator shaft to create a better fit. We sell custom machined aluminum knobs designed specifically for 6mm shafts. To see our knob page, click here or on photo >>

-Recommended Stepped Attenuator Panel Mounting Hole Pattern

The 0.1" notch is for the protruding key at the front of the rotary switch. This keeps the rotary switch from turning when the knob is turned, even if the front panel nut is not tight.  A notch MUST be filed into the mounting hole or the stepped attenuator could become warped when the hex nut is tightened on the front panel.  Alternatives:  1) You can skip filing a notch into your front panel IF it is thin enough for you to mount the attenuator with two hex nuts - one on the front and one on the inside of your panel. 2) The protruding key on the switch itself could be filed off. (But it is better to mount the attenuator with two hex nuts).

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-How to Determine if Your System Will Sound Good With a Passive Preamp. In-Line Volume Control (only one channel is shown) - Use a stereo audio taper potentiometer for building an In-Line Volume Control. Split some audio cables in half and wire them to the pot as shown above. An audio cable is required for each of the stereo potentiometer sections, (one for the Left channel, and one for the Right channel). The inexpensive stereo pots and audio cables from Radio Shack work well for making this "Passive Preamp Tester".  If using this In-Line Volume Control still yields you enough "headroom" (meaning you can still turn the system up loud enough to suit you), then you can get even better performance by using a Goldpoint Level Control box (passive preamp).