Are you a vinyl enthusiast who’s been scratching your head over why your receiver sounds better on Aux than Phono?
You’re not alone.
It’s a common question among those who are new to the world of vinyl. The answer lies in understanding the difference between the two inputs and the role of a preamp in amplifying audio signals.
In this article, we’ll dive into the technical details and explain why your receiver might be producing better sound on one input versus the other.
So, sit back, relax, and let’s explore the world of vinyl sound quality together.
Why Does My Receiver Sound Better On Aux Than Phono
The first thing to understand is that the signal strength of audio signals transmitted from phono outputs is very weak. The output voltage of phono outputs is about 2.5 millivolts, which is much lower than the output voltage of an AUX connector, which can reach as high as 1 volt.
This means that audio signals from a phono output need to be amplified by passing it through a preamp. The purpose of this preamp is to boost and strengthen the weak signals into a line-level signal transmitted from phono outputs. This boosting enables us to hear audio signals transmitted by a phono output.
However, if you have an amp between the turntable and line-in other than a phono pre-amp, this can cause issues with sound quality. This is because a phono preamp is a specific-purpose device that raises the signal level from the cartridge to line-level, at the same time as rectifying the tonal balance to RIAA standards. This is necessary because the sound signal has been altered by lowering the bass signal and raising the treble amplitude before cutting the record. Without this, the bass would take too much of the record, and the small treble signals would be lost.
When you have a preamp housed within the body of an integrated unit, such as a turntable with a built-in preamp, the device’s internal noise will almost certainly impact the sound quality of the signal that’s being processed by the preamplifier. Generally speaking, all preamplifiers add noise to the weak signal, but with an internal preamp, you’re most likely to have more noise than you would with an external unit.
Additionally, manufacturers looking to integrate preamp functionality into turntables will almost surely use cheaper components. This means that the capacitors, resistors, and circuit boards won’t do as well of a job amplifying your turntable’s signal to line level as one with better internal components.
So, while an integrated turntable with a built-in preamp may be more convenient and cost-effective, it’s not necessarily going to produce better sound quality than an external preamp.
Understanding The Difference Between Aux And Phono Inputs
When it comes to connecting your turntable to your receiver, you’ll likely come across two different types of inputs: phono and aux. The main difference between these two inputs lies in the signal strength and frequency response.
As mentioned earlier, phono outputs have a much weaker signal than aux outputs. This is because the audio signals transmitted from a turntable’s cartridge are very low-level and require amplification to be heard. A phono input includes a built-in preamp that boosts the signal and applies RIAA equalization to recreate the original sound of the record. On the other hand, an aux input is a clean input that doesn’t have any built-in amplification or equalization.
Using an aux input for your turntable may sound better in some cases, especially if your turntable has a built-in preamp. However, if you’re using a turntable without a preamp or an external preamp, using an aux input will result in a very weak and trebly sound. This is because the signal needs to be boosted and equalized before it can be heard properly.
The Importance Of A Preamp In Vinyl Playback
The preamp plays a crucial role in vinyl playback, as it is responsible for boosting the weak signal produced by the turntable cartridge to a level that can be processed by the amplifier. Without a preamp, the signal produced by the cartridge would be too weak to produce any sound, and the music would be inaudible.
The amount of gain added to the signal by the preamp is significant, as most turntable cartridges produce an output of only 3-6 millivolts, which is nowhere near the strength of other audio components like a CD player. A basic preamp can boost this signal to an output of 300 millivolts, which is about 75 times stronger than the original signal.
In addition to amplifying the signal, a preamp also corrects for the RIAA equalization curve that is applied to vinyl records during production. This curve helps to improve sound quality and reduce record wear, but it also means that the signal produced by the cartridge needs to be equalized before it can be processed by the amplifier.
When it comes to choosing a preamp, it’s important to keep in mind that cheaper models may not be as accurate in correcting for the RIAA curve and may introduce noise into the signal. Investing in a high-quality preamp with better internal components can help to ensure that your vinyl playback produces warm and rich sound quality without any distortion or noise.
How A Preamp Impacts Sound Quality On Aux And Phono Inputs
It’s important to note that the impact of a preamp on sound quality differs between AUX and phono inputs. AUX inputs do not have a built-in preamp or EQ, which means that the audio signals transmitted through them remain clean and uncolored. This results in a pure and unadulterated sound.
On the other hand, phono inputs require a preamp to boost the weak signals from the turntable’s cartridge to line-level signals. As mentioned earlier, the preamp introduces coloration into the audio signals passing through it, which can negatively affect the purity of the sound. Additionally, since preamps amplify audio signals, they also introduce noise into the signal. This can impact how clean the audio signal is and affect sound quality.
It’s worth noting that some turntables come with built-in preamps, which can be convenient but may not offer the best sound quality. External preamps are generally considered to offer better sound quality than internal ones because they use higher quality components and produce less noise.
Troubleshooting Tips For Improving Phono Input Sound Quality
If you’re experiencing issues with the sound quality of your phono input, there are a few things you can try to improve it.
Firstly, check all connections to ensure that they are properly plugged in and secure. It’s possible that one of the leads may be connected to the wrong input, such as the record inputs on the tape loop.
If all connections seem fine, it’s possible that your amp may have a fault. In this case, it’s recommended to invest in a dedicated phono stage/preamp. There are many options available on the market, but the Cambridge Audio 640p is a great budget-friendly option.
It’s important to note that if your turntable doesn’t have a built-in phono stage, you’ll need a separate phono preamp to properly channel the signal. A good preamp offers adjustable settings that can help you get the most out of a top-notch cartridge.
Another possible cause of poor sound quality could be a mismatch between your cable outputs and inputs. Ensure that if you have a built-in preamp, it is set to “phono” with the RCA cables plugged into the “phono” input on your receiver. If you have RCA cables plugged into an AUX input, then you would put the built-in preamp on the “line” setting.
It’s also worth noting that line and phono signals have different frequency responses and levels. Phono inputs on hi-fi equipment are specifically designed to handle the low-level signal output from a turntable’s phono cartridge, while line inputs are intended to handle higher-level signals from other audio sources such as CD players or tape decks.
Conclusion: Finding The Right Setup For Your Vinyl Playback
In order to get the best sound quality from your vinyl playback, it’s important to have the right setup. This means ensuring that your turntable is properly grounded, and that you have the right preamp and receiver to amplify your signal.
If your turntable has a built-in preamp, you may be able to connect it directly to your receiver’s phono input. However, keep in mind that this may not always provide the best sound quality, as the internal noise of the preamp can impact the signal.
For the best results, consider investing in an external preamp, which can provide better amplification and reduce noise. Additionally, make sure that you have a receiver with multiple inputs, so that you can easily switch between different audio sources without having to rewire your setup.
Finally, don’t forget about the importance of grounding your turntable. A grounding wire can help reduce humming and improve overall sound quality. Many turntables come with a grounding wire included, so be sure to use it if yours does.
By taking these steps to optimize your vinyl playback setup, you can enjoy high-quality sound from your records for years to come.
