McIntosh MHA200 Impressions
- Thread starter warrenpchi
- Start date
ABQ2
New Head-Fier
The balanced output of the DAC and the balanced inputs of the 200 don’t match. How are you doing that?
TSAVJason
Sponsor: The Source AV
I tried a few tests on ours in our showroom and on my personal amp. I can only duplicate something similar by introducing a bad tube or a device that is improperly shielded.
I also checked to see if on any portion of the chassis is there a ground that would change to a mutual group. There isn’t.
I typically don’t point people to other components but I think your noise is likely coming from your dac or something close by with significant radiated interference
I also checked to see if on any portion of the chassis is there a ground that would change to a mutual group. There isn’t.
I typically don’t point people to other components but I think your noise is likely coming from your dac or something close by with significant radiated interference
Haven't tried RCA yet, don't actually have such a cable right now. What do you mean the balanced don't match?
Thank you for your input, it helps narrow it down. I feel as though I'm getting closer.
ABQ2
New Head-Fier
The DAC has a single balanced output but the 200 has two inputs, at least that’s what my research shows. If that’s true you would need a special custom cable. Is that what you have?
Yes. 4.4mm balanced to dual xlr. Shouldn't be an issue, I hope.
ABQ2
New Head-Fier
I assume that the sound from the DAC headphone jack is clean? That’s an unusual cable. For comparison could you find a set of standard RCA’s?
How come? Are you sure?
I have connected the DAC (Eversooo DMP-A8) to the MHA200 using the XLR cable.
That’s the way to go.
I am running a seperate ground wire to the mains socket. An otherwise I have a hiss when I touch the MHA200
ABQ2
New Head-Fier
It seems to me that what we’re trying to avoid here is sending the 200 back. The cheap alternative is to try standard RCA’s. Just because a cable looks good doesn’t mean it’s good on the inside. I have driven myself nuts trying to discover a problem elsewhere when the headphone cable was the problem. Just saying.
Well I've made some discoveries now.
From the wall to the MHA200 the power looks like this now:
From the wall it goes into an IFI DC blocker+, then into IFI Ground Defender, then into the MHA200 with a separate spade for the ground.
Before today, I used a simple adapter between the MHA200 and the IFI units. However, it turned out this adapter didn't properly connect the ground anyway, so the spade before wasn't actually connected to anything on the other end.
Notice that the ground spade isn't attached to anything. Apparently, when it's connected to any of the screws on the MHA200 a loud and annoying hiss sounds is produced. When it's just dangling like that there is no hiss, but a hum as always. The hum is amplified when I touch the unit and turn up the volume past noon.
Any combination of the IFI units being connected or disconnected doesn't make any audible difference in any regard, disappointing.
I noticed that the MHA200 only produced any hum or noise of any kind when the XLR connectors from my DAC were plugged in. I guess the unit mutes it self when nothing is plugged into it?
I've orded a set of RCA cable in hopes they will do something for me. I'm thinking of getting another DAC to test with as well. One that isn't powered via USB or DC this time.
I'm running out of ideas and hope soon. I appreciate any sort of enlightenment.
From the wall to the MHA200 the power looks like this now:
From the wall it goes into an IFI DC blocker+, then into IFI Ground Defender, then into the MHA200 with a separate spade for the ground.
Before today, I used a simple adapter between the MHA200 and the IFI units. However, it turned out this adapter didn't properly connect the ground anyway, so the spade before wasn't actually connected to anything on the other end.
Notice that the ground spade isn't attached to anything. Apparently, when it's connected to any of the screws on the MHA200 a loud and annoying hiss sounds is produced. When it's just dangling like that there is no hiss, but a hum as always. The hum is amplified when I touch the unit and turn up the volume past noon.
Any combination of the IFI units being connected or disconnected doesn't make any audible difference in any regard, disappointing.
I noticed that the MHA200 only produced any hum or noise of any kind when the XLR connectors from my DAC were plugged in. I guess the unit mutes it self when nothing is plugged into it?
I've orded a set of RCA cable in hopes they will do something for me. I'm thinking of getting another DAC to test with as well. One that isn't powered via USB or DC this time.
I'm running out of ideas and hope soon. I appreciate any sort of enlightenment.
My next idea would be to try the iFi AC iPurifier together with the iFi Groundhog+.
The fact that there is a noticable hum, and that it's amplified when I touch the unit, makes me believe I'm still dealing with a ground issue.
But the fact that my previous efforts to solve this didn't work has me perplexed...
The fact that there is a noticable hum, and that it's amplified when I touch the unit, makes me believe I'm still dealing with a ground issue.
But the fact that my previous efforts to solve this didn't work has me perplexed...
Well I've made some discoveries now.
From the wall to the MHA200 the power looks like this now:
From the wall it goes into an IFI DC blocker+, then into IFI Ground Defender, then into the MHA200 with a separate spade for the ground.
Before today, I used a simple adapter between the MHA200 and the IFI units. However, it turned out this adapter didn't properly connect the ground anyway, so the spade before wasn't actually connected to anything on the other end.
Notice that the ground spade isn't attached to anything. Apparently, when it's connected to any of the screws on the MHA200 a loud and annoying hiss sounds is produced. When it's just dangling like that there is no hiss, but a hum as always. The hum is amplified when I touch the unit and turn up the volume past noon.
Any combination of the IFI units being connected or disconnected doesn't make any audible difference in any regard, disappointing.
I noticed that the MHA200 only produced any hum or noise of any kind when the XLR connectors from my DAC were plugged in. I guess the unit mutes it self when nothing is plugged into it?
I've orded a set of RCA cable in hopes they will do something for me. I'm thinking of getting another DAC to test with as well. One that isn't powered via USB or DC this time.
I'm running out of ideas and hope soon. I appreciate any sort of enlightenment.
I have tried both RCA and XLR and still had a hum when touching the amp. This used to drive me crazy. The hum has gone as soon as the amp was properly grounded. I did not use any extra product (like IFi Ground Defender etc). Just a simple wire to ground the amp.
Could you show me exactly how you've done it with pictures? I'm at the point where I really need to be handheld I feel.
