Preamplifier Compatibility Mode - Video Tutorial
If you are using a separate preamplifier with your Benchmark DAC, then this video is for you!
All Benchmark DACs Can Be Used Without a Preamplifier
Most Benchmark DACs include preamplifier functions such as a volume control and audio input selection. These DACs are designed to directly drive virtually any audio power amplifier without the need for a separate preamplifier. This is important, since most preamplifiers will rob some of the transparency that we have built into the Benchmark DACs. But, when it comes to system transparency, the Benchmark LA4 and HPA4 preamplifiers can actually improve the system performance by a few dB while adding other convenient features. Some of our customers choose to insert a non-transparent tube preamplifier between their Benchmark DAC and their power amplifier in order to modify the sound of their system.
All Benchmark DACs Can Be Configured for use with External Preamplifiers
All Benchmark DACs include special functions to make it easy to integrate a separate preamplifier. The DAC volume control, DIM function, and MUTE function can be bypassed collectively or individually, according to the needs of your system.
Add a Preamplifier to Increase System transparency
Benchmark makes two preamplifiers; the LA4 and the HPA4. These feature pure analog relay-controlled volume and relay-controlled input switching. These preamplifiers can actually improve the end-to-end signal to noise ratio of your system while also allowing your DAC to operate at its optimum output level. These two Benchmark preamplifiers can be added to increase the transparency of your system.
Add a Preamplifier to Modify the Sound of Your System (Decreased Transparency)
Other preamplifiers, especially those containing tubes, can be added to create a particular sound that is decidedly not transparent. This choice is a matter of personal preference.
Watch this Video to Learn How to Configure Benchmark DACs for Compatibility with an External Preamplifier
Also in Videos
How Loud is the Distortion from Your Power Amplifier?
In this video, John Siau extracts the data from the published test results of 7 top-rated audiophile power amplifiers. Hidden within the THD+N vs. Power graphs are the answers to two key questions:
- How loud is the noise produced by my power amplifier?
- How loud is the distortion produced by my power amplifier?
Your Amplifier THD+N may be Louder than a Washing Machine!
Don't take our word for it! The evidence is captured in the hundreds of test reports compiled by Stereophile Magazine. Unfortunately, we cannot see this information when looking at traditional THD+N graphs. We need to extract the raw data from the Stereophile graphs and do a bit of math.
John Siau shows that the distortion produced by some of these top-rated amplifiers is louder than the noise that would be produced by having a washing machine in the middle of your listening room!
You wouldn't put a major appliance in the middle of your listening space, so you may want to take a careful look at your power amplifier.
Traditional THD+N Measurement Units Hide the Truth!
THD+N is usually plotted in terms of percent. This is a problem because percent is not a measure of loudness, nor is it a logarithmic unit. If we plot THD+N in terms of loudness (dB SPL) at the listening position, we can easily visualize the noise floor of the amplifier, and we can read the loudness of the THD directly from the graph.
Amplifiers are the Weak Link in the Electronic Chain
In most systems, the power amplifier will generate more THD+N than all of the other electronic components combined. It is time to take a fresh look at amplifier perfomance measurements. The evidence is hiding in Stereophile's test reports!
Feed-Forward Correction Explained!
Feed-Forward Error Correction
Don't look back, the future is here!
Benchmark's AHB2 power amplifier has a unique feedforward error correction system that cancels distortion before it reaches the speaker terminals. In contrast, global feedback systems attempt to correct the distortion after it reaches the speaker terminals.
Feed-forward correction is fast, precise, and inherently stable.
Benchmark's AHB2 blends feedback with feed-forward correction to leverage the best characteristics of each.
Listen to Gene and John as they discuss this revolutionary technology.
- How does the feed-forward system know what correction to send?
- Does it predict the future?
- What makes feedback unstable when driving capacitive loads?
- Why is feed-forward stable when driving capacitive loads?
Take a few minutes to learn how feed-forward error correction works:
- Watch as John provides an easy-to-understand analogy for feed-forward error correction.
- Join the discussion.
- We reserve the right to limit negative feedback.
What is the Purpose of an FFT in Audio Measurements?
The FFT … an Audio Microscope.
An FFT analyzer is like an audio microscope. It allows us to easily measure the frequency and amplitude of tones that are below the level of the noise. Traditional audio meters fail when the signal is lower than the noise level, but with an FFT, we can accurately measure tones that are 30 to 40 dB below the level of the noise.
In many ways, our ears behave like an FFT audio measurement system. Our ears can detect the frequency and amplitude of tones that are as much as 30 dB below the ambient noise. This means that our ears are 30 dB better than traditional audio meters! This is why we can carry on a conversation in a noisy room, and this is why we can hear individual instruments within an orchestra. This is also why small defects need to be detected and corrected when designing top-quality audio gear.
John Siau, Benchmark’s lead Engineer, will explain the “magic” of the FFT analyzer without the use of advanced mathematics. He will show an FFT analyzer in action, and he will measure a complete Benchmark chain to determine if it produces audible noise or distortion. Learn how to read an FFT plot and learn what to look for when selecting audio components.