PJuddery
Well-Known Member
So, as the title suggests, I'd like to have a discussion about line level attenuation and volume dial position. Apologies if this has been discussed before. I did have a search, but didn't see anything specific.
So here's some background that has prompted me to want to discuss this subject and what I've found so far.
This is a new subject for me, that I only came across yesterday, for the first time. I've just restored my Sansui 6060. I rebuilt the power and driver boards first, testing again after each board was rebuilt. After recapping the pre-amp/ tone board and also fitting a replacement for the fuse resistor, I suddenly found there was a huge jump in volume. At first I was impressed, but then I quickly noticed a lot of sibilance in vocals and that the whole top end was hugely bright, harsh and fatiguing. I did quite a bit of further testing, with various sources and with different styles of audio. What I found was that even at low volumes, the audio was distorted slightly and that only got worse with higher volumes.
Prior to the volume jump, I'd been listening with the volume control set to around the 10:30 - 11:00 position, but after wards it was more like 08:30 - 09:00 position.
I did some research on the subject and eventually found articles that discussed line level attenuation and how it's often necessary and really important for good, clean audio, to reduce the level of input sources, prior to entering the audio amplifier/ receiver/ pre-amp, because otherwise, by the time the signal gets through all of the amplification stages and depending on the original source level, it can already be clipping and therefore distorted, even at low listening levels. This is often evident by the user being unable to turn up the volume beyond around the 8 or 9 o'clock position. From what I've read, the higher the volume control position can be turned without it becoming too loud for comfort, the cleaner and better sounding the resulting audio will be.
So, armed with that information, I decided to test it out. I'm using an rca source selector switch, because my Sansui only has a single aux input and I need at least 4 and as it happens, that switch box has a volume control. So I experimented with turning it down more and more with various sources, while simultaneously turning up the volume control on my receiver.
The more I turned down the switch box volume control and turned of the receiver volume control, the cleaner and cleaner the audio became, until it began to sound absolutely amazing. The harsh brightness is gone, most of the sibilance is gone and the distortion seems to be gone too. The volume control on my receiver is now sat at the 11:00 position and that's giving a nice comfortable volume level.
However, I've never had to do this before. My Kenwood amp that I've been using for years until now, has always just had the input rca connections plugged in and has never even had a hint of distortion, so I wanted to have this discussion, to see if this is quite normal for vintage receivers, if other people have experimented with line level attenuation and what sonic differences were gained or not gained by doing so.
So here's some background that has prompted me to want to discuss this subject and what I've found so far.
This is a new subject for me, that I only came across yesterday, for the first time. I've just restored my Sansui 6060. I rebuilt the power and driver boards first, testing again after each board was rebuilt. After recapping the pre-amp/ tone board and also fitting a replacement for the fuse resistor, I suddenly found there was a huge jump in volume. At first I was impressed, but then I quickly noticed a lot of sibilance in vocals and that the whole top end was hugely bright, harsh and fatiguing. I did quite a bit of further testing, with various sources and with different styles of audio. What I found was that even at low volumes, the audio was distorted slightly and that only got worse with higher volumes.
Prior to the volume jump, I'd been listening with the volume control set to around the 10:30 - 11:00 position, but after wards it was more like 08:30 - 09:00 position.
I did some research on the subject and eventually found articles that discussed line level attenuation and how it's often necessary and really important for good, clean audio, to reduce the level of input sources, prior to entering the audio amplifier/ receiver/ pre-amp, because otherwise, by the time the signal gets through all of the amplification stages and depending on the original source level, it can already be clipping and therefore distorted, even at low listening levels. This is often evident by the user being unable to turn up the volume beyond around the 8 or 9 o'clock position. From what I've read, the higher the volume control position can be turned without it becoming too loud for comfort, the cleaner and better sounding the resulting audio will be.
So, armed with that information, I decided to test it out. I'm using an rca source selector switch, because my Sansui only has a single aux input and I need at least 4 and as it happens, that switch box has a volume control. So I experimented with turning it down more and more with various sources, while simultaneously turning up the volume control on my receiver.
The more I turned down the switch box volume control and turned of the receiver volume control, the cleaner and cleaner the audio became, until it began to sound absolutely amazing. The harsh brightness is gone, most of the sibilance is gone and the distortion seems to be gone too. The volume control on my receiver is now sat at the 11:00 position and that's giving a nice comfortable volume level.
However, I've never had to do this before. My Kenwood amp that I've been using for years until now, has always just had the input rca connections plugged in and has never even had a hint of distortion, so I wanted to have this discussion, to see if this is quite normal for vintage receivers, if other people have experimented with line level attenuation and what sonic differences were gained or not gained by doing so.
