systemshock
Member
- Joined
- Mar 30, 2019
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- 26
Hello!
I am currently facing a challenge with my setup and would be grateful if I can get an advice on the issue. The post came out quite long. That's because I tried to describe the situation as accurately as possible. Coming from an engineering background (albeit a software one), I understand that there are no absolute solutions and unless the context of the situation is known, a question usually results in an "it depends" answer
My question is about finding an effective way to lower the output level of my DAC, without sacrificing quality. I did a research on the subject and I think I have found a workable solution, but would be grateful if I can get an advice on whether I am on the right track here.
What I have is the Khadas Tone Board, connected to a JDS Atom amp. Connected to the Atom I have a pair of JBL 305 active monitors (connected to the pre-outs of the Atom) and Alessandro MS-Pro headphones. The MS-Pros are a modified version of the Grado RS-1 and are manufactured by Grado for Alessandro.
Like other Grado headphones, the MS-Pro is really easy to drive. In fact, so easy, that in order to be able to listen to them at all (without damaging my hearing), I usually have to bring down the volume all the way down. This is true on any device, e.g. on my phone, computer, etc.
In this particular case, this means that I have to bring down the volume of the Khadas board (on my PC) to just 20-30% or less and also to have the volume on the Atom at about 7-8 o'clock. It stays basically just a few millimeters above the point at which the device turns on. If I turn the dial even a little bit back, I go to that state of the amp, where the sound of the headphones gets distorted (e.g. you can hear something on the right, but almost nothing on the left).
Listening to the headphones with this setup is quite problematic. On one hand, the volume cannot be finely controlled at all. Even a slight rotation of the dial increases or decreases it way too much. One way to counter it is to set the volume on the computer to a very low value, e.g. 7%. This allows me to operate the Atom volume dial properly. However, at this level, it should be resulting in a significant loss of bit-depth. Whether this is objectively degrading the sound quality in a perceptible way or not, is another question. To me it seems so.
For reference, I had a similar issue with the JBL 305s before purchasing the atom, although not at that extreme level. I had to turn their sensitivity down (they have a switch, which lets me drop it from -10db to +4) and their amp at volume of 4/10, while keeping the software volume of the Khadas at 70% on the computer. Now with the Atom, this problem is solved and I can finally get the Khadas at 100% on the computer and I can also set the monitors, to, say 5/10.
Unless I am missing something here, it seems that to fix the situation, I have to somehow reduce the output from the Khadas Tone Board. I did some research on what can be done and came with three possible solutions:
1. One that was pretty obvious from the start was to look for a way to reduce the volume on the Khadas board itself. There is a thread on the Khadas forums about that. The good news is that controlling the volume in hardware is, in fact, possible. There is (although a very rudimentary) demo of how to do it and back in November they wrote "We will make an accessory for this hardware volume control, which will probably be completed next month." Unfortunately, as of the time of writing of this post, there is still no info on when/if such an accessory will be released. Also, the mod in question seems to be far from being applicable to general daily use. Also, it has not been stated how the volume level is being controlled. E.g. is it a "proper" hardware control, or is it similar to how the Windows volume control works and the bit-depth gets reduced.
2. To use In-Line Attenuators, like this one from Rothwell. However, from what I have found from different reviews, they tend to distort the sound and also they are not cheap. For quite a similar price I can go for the third option, which is:
3. To use a passive attenuating pre-amp. After doing a bit of research, I came down with two options, which seem to be able to solve the problem and both promise to be pretty nearly transparent (I understand that with a passive attenuator some distortion may be expected):
- JDS Labs Ol Switcher;
- JBL M-Patch 2.
So, to sum things up: Am I missing something in the big picture? Is there another, more simple solution, which never occurred to me? Also, if someone has experience with the Ol Switcher or the M-Patch 2, can you share your thoughts on the device?
Thanks in advance for any help provided!
I am currently facing a challenge with my setup and would be grateful if I can get an advice on the issue. The post came out quite long. That's because I tried to describe the situation as accurately as possible. Coming from an engineering background (albeit a software one), I understand that there are no absolute solutions and unless the context of the situation is known, a question usually results in an "it depends" answer
My question is about finding an effective way to lower the output level of my DAC, without sacrificing quality. I did a research on the subject and I think I have found a workable solution, but would be grateful if I can get an advice on whether I am on the right track here.
What I have is the Khadas Tone Board, connected to a JDS Atom amp. Connected to the Atom I have a pair of JBL 305 active monitors (connected to the pre-outs of the Atom) and Alessandro MS-Pro headphones. The MS-Pros are a modified version of the Grado RS-1 and are manufactured by Grado for Alessandro.
Like other Grado headphones, the MS-Pro is really easy to drive. In fact, so easy, that in order to be able to listen to them at all (without damaging my hearing), I usually have to bring down the volume all the way down. This is true on any device, e.g. on my phone, computer, etc.
In this particular case, this means that I have to bring down the volume of the Khadas board (on my PC) to just 20-30% or less and also to have the volume on the Atom at about 7-8 o'clock. It stays basically just a few millimeters above the point at which the device turns on. If I turn the dial even a little bit back, I go to that state of the amp, where the sound of the headphones gets distorted (e.g. you can hear something on the right, but almost nothing on the left).
Listening to the headphones with this setup is quite problematic. On one hand, the volume cannot be finely controlled at all. Even a slight rotation of the dial increases or decreases it way too much. One way to counter it is to set the volume on the computer to a very low value, e.g. 7%. This allows me to operate the Atom volume dial properly. However, at this level, it should be resulting in a significant loss of bit-depth. Whether this is objectively degrading the sound quality in a perceptible way or not, is another question. To me it seems so.
For reference, I had a similar issue with the JBL 305s before purchasing the atom, although not at that extreme level. I had to turn their sensitivity down (they have a switch, which lets me drop it from -10db to +4) and their amp at volume of 4/10, while keeping the software volume of the Khadas at 70% on the computer. Now with the Atom, this problem is solved and I can finally get the Khadas at 100% on the computer and I can also set the monitors, to, say 5/10.
Unless I am missing something here, it seems that to fix the situation, I have to somehow reduce the output from the Khadas Tone Board. I did some research on what can be done and came with three possible solutions:
1. One that was pretty obvious from the start was to look for a way to reduce the volume on the Khadas board itself. There is a thread on the Khadas forums about that. The good news is that controlling the volume in hardware is, in fact, possible. There is (although a very rudimentary) demo of how to do it and back in November they wrote "We will make an accessory for this hardware volume control, which will probably be completed next month." Unfortunately, as of the time of writing of this post, there is still no info on when/if such an accessory will be released. Also, the mod in question seems to be far from being applicable to general daily use. Also, it has not been stated how the volume level is being controlled. E.g. is it a "proper" hardware control, or is it similar to how the Windows volume control works and the bit-depth gets reduced.
2. To use In-Line Attenuators, like this one from Rothwell. However, from what I have found from different reviews, they tend to distort the sound and also they are not cheap. For quite a similar price I can go for the third option, which is:
3. To use a passive attenuating pre-amp. After doing a bit of research, I came down with two options, which seem to be able to solve the problem and both promise to be pretty nearly transparent (I understand that with a passive attenuator some distortion may be expected):
- JDS Labs Ol Switcher;
- JBL M-Patch 2.
So, to sum things up: Am I missing something in the big picture? Is there another, more simple solution, which never occurred to me? Also, if someone has experience with the Ol Switcher or the M-Patch 2, can you share your thoughts on the device?
Thanks in advance for any help provided!
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