Massdrop x THX AAA™ 789 Linear Amplifier - Impressions Thread
Dec 3, 2018 at 10:35 PM Post #451 of 2,613
1. Yes, with the volume all the way down, you can still hear music playing
2. Crosstalk refers the signal leaking between left and right channels
3. For this amp, the balanced XLR out is more powerful than SE. Depends on the amp.

To be fair I know plenty of amps that can be turned off completely and you can still hear the music even if only faintly, a whole lot of amps actually.
 
Dec 3, 2018 at 10:36 PM Post #452 of 2,613
1. Yes, with the volume all the way down, you can still hear music playing
2. Crosstalk refers the signal leaking between left and right channels
3. For this amp, the balanced XLR out is more powerful than SE. Depends on the amp.

Well I'm guessing any amp with both SE and balanced will have the latter being more powerful. As for the first two points those kind of turn me off to the 789. Maybe Massdrop can fix those in a future update.
 
Dec 3, 2018 at 10:38 PM Post #453 of 2,613
To be fair I know plenty of amps that can be turned off completely and you can still hear the music even if only faintly, a whole lot of amps actually.

My Aune X7S doesn't have that issue.
 
Dec 3, 2018 at 10:41 PM Post #454 of 2,613
My Aune X7S doesn't have that issue.

I am not really sure if it is an issue to be honest. It’s a signal being run through that at times can be transmitted depending on source output, maybe at .25vrms it would not happen but at 2 or more then perhaps more likely.
 
Dec 3, 2018 at 10:42 PM Post #455 of 2,613
Well I'm guessing any amp with both SE and balanced will have the latter being more powerful. As for the first two points those kind of turn me off to the 789. Maybe Massdrop can fix those in a future update.
I don't think #2 is an actual issue. This is one of those things that show up on measurements, but it's low enough to be inaudible.

#1 is a legit preference though. So I understand if this is a dealbreaker for you.
 
Dec 3, 2018 at 10:48 PM Post #456 of 2,613
My Aune X7S doesn't have that issue.

Perhaps I should give a better example, one time I was at a hotel that was next to Jimmy Swaggarts radio station in Baton Rouge LA, my LCD-XC picked up everything that was being said from his broadcast. The IFI Ican SE can’t even tune into radio and I had nothing else plugged in, electricity is a funny thing is all I am trying to get at.
 
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Dec 3, 2018 at 10:51 PM Post #457 of 2,613
I don't think #2 is an actual issue. This is one of those things that show up on measurements, but it's low enough to be inaudible.

#1 is a legit preference though. So I understand if this is a dealbreaker for you.

So is the SE not very good in the 789??
 
Dec 3, 2018 at 10:57 PM Post #458 of 2,613
So is the SE not very good in the 789??

You didn’t ask me but It can power my 70 Ohm LCD-2f to enjoyable levels and sounds good doing it. My opinion is yes, I have had a lot of amps and I think this is the first that was not in balanced or designed to be high output in balanced only that sounded good that way. Beats a Burson Soloist MK2 in my opinion even when not in balanced for more power.
 
Dec 3, 2018 at 11:00 PM Post #459 of 2,613
You didn’t ask me but It can power my 70 Ohm LCD-2f to enjoyable levels and sounds good doing it. My opinion is yes, I have had a lot of amps and I think this is the first that was not in balanced or designed to be high output in balanced only that sounded good that way. Beats a Burson Soloist MK2 in my opinion even when not in balanced for more power.

Well for now I just have the HD6XX and 58X. The Aune X7S has more than enough power for them but someday I want to get some good closed back such as the Fostex ones on Massdrop.
 
Dec 3, 2018 at 11:05 PM Post #460 of 2,613
Well for now I just have the HD6XX and 58X. The Aune X7S has more than enough power for them but someday I want to get some good closed back such as the Fostex ones on Massdrop.

I do not know much about Aune anything to be honest so I can’t comment on its capabilities but for the price the 789 is a ridiculous amount of amp for a relatively small price. The option for balanced from source to headphones is quite nice once you factor in the power. When using either one of my A&K DAP to balanced out XLR and then the balanced out to my headphones I still can’t believe that the 789 was so cheap. Even before I got my cables I was impressed with the sound when not using the power of the 789, it just sounds good, neutral and just an amplification if what you put in with no coloration at all.
 
Dec 3, 2018 at 11:08 PM Post #461 of 2,613
So is the SE not very good in the 789??
My #2 was related to crosstalk. That's an non-issue imo.

#3 was balanced out having more power than SE. I don't think your current headphones require that much power anyway.

The only advantage this amp has over your Aune is the super low output impedance. The Aune is pretty much for high impedance headphones. While I can't find an official number, I think the Aune's output impedance is rather high, so it won't be as good for driving low impedance headphones.
 
Dec 3, 2018 at 11:09 PM Post #462 of 2,613
Well for now I just have the HD6XX and 58X. The Aune X7S has more than enough power for them but someday I want to get some good closed back such as the Fostex ones on Massdrop.

The SE output power is 250mW@300ohm on X7S and 200mW@300ohm on 789. I do heard ppl say sound quality on BAL output is noticable better than SE on X7S and others say on 789 the difference between SE and BAL is only the power.
 
Dec 3, 2018 at 11:09 PM Post #463 of 2,613
I do not know much about Aune anything to be honest so I can’t comment on its capabilities but for the price the 789 is a ridiculous amount of amp for a relatively small price. The option for balanced from source to headphones is quite nice once you factor in the power. When using either one of my A&K DAP to balanced out XLR and then the balanced out to my headphones I still can’t believe that the 789 was so cheap. Even before I got my cables I was impressed with the sound when not using the power of the 789, it just sounds good, neutral and just an amplification if what you put in with no coloration at all.

Okay. I just want to make sure I'm getting my moneys worth cause I have to factor in the exchange from US to Canadian dollar. I'd be paying about $500 + customs fees. I'm using the Massdrop Grace SDAC with my Aune running off my Macbook Pro.
 
Dec 3, 2018 at 11:11 PM Post #464 of 2,613
The SE output power is 250mW@300ohm on X7S and 200mW@300ohm on 789. I do heard ppl say sound quality on BAL output is noticable better than SE on X7S and others say on 789 the difference between SE and BAL is only the power.

Okay. It would just mean I would possibly need to turn the volume up higher on the 789 compared to the X7S. Doesn't balanced headphone out potentially offer a wider soundstage?
 
Dec 3, 2018 at 11:22 PM Post #465 of 2,613
Okay. It would just mean I would possibly need to turn the volume up higher on the 789 compared to the X7S. Doesn't balanced headphone out potentially offer a wider soundstage?
uhhh that I'm not sure, maybe someone can offer a scientific reasoning for that. All I know is these are not truly balanced amps, so they are all converting SE in to BAL out. I mean if you have 6xx its not that hard to get a balanced cable for that.
 

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