Official THX Measurements of the Massdrop x THX AAA 789

[amirm]

Fascinating that he would use the word "we" in there. Did THX design and get this unit manufactured themselves?

 

[Sythrix]

View attachment 16803

Fascinating that he would use the word "we" in there. Did THX design and get this unit manufactured themselves?

I think "we" in this instance, could be referring to THX + Massdrop. It's not really specified.

I wouldn't be surprised if Massdrop had comparatively less to do on this drop though. THX is a bigger company that may have had the lion's share of the actual work, with Massdrop simply hosting and distributing.

 

[Veri]

View attachment 16803

Fascinating that he would use the word "we" in there. Did THX design and get this unit manufactured themselves?

Andrew speaks for THX, he comments on both the Massdrop and the Monoprice products. From what I gather it's on him that the products are made towards the companies' credit, rather than embarrassment. LinkedIn tells me he is "Staff Engineer, Product Development at THX Ltd".

 

[andymok]

https://www.massdrop.com/buy/53162/talk/1982062

 

[FunctionalDoc]

I got mine on Tuesday this week and loving it using 300 ohm ZMF Auteur's balanced or running pair of IEM on low power I tried using the XLR balanced outs of my DX7S and got lot ground him / buzz . I am trying another pair of other interconnects to run balanced out to the THX .

Any suggestions to solve the noising connection going XLR out to the THX?

I like the amp a lot dead quiet and powerful and seems to be put together very well for $349 .

 

[Veri]

I got mine on Tuesday this week and loving it using 300 ohm ZMF Auteur's balanced or running pair of IEM on low power I tried using the XLR balanced outs of my DX7S and got lot ground him / buzz . I am trying another pair of other interconnects to run balanced out to the THX .

Any suggestions to solve the noising connection going XLR out to the THX?

I like the amp a lot dead quiet and powerful and seems to be put together very well for $349 .

It seems you and others receive hum through the balanced input. Which is weird since I thought balanced supposedly protects against noise over longer cable runs.

Maybe it's a ground issue in the source box.

 

[mi-fu]

I got mine on Tuesday this week and loving it using 300 ohm ZMF Auteur's balanced or running pair of IEM on low power I tried using the XLR balanced outs of my DX7S and got lot ground him / buzz . I am trying another pair of other interconnects to run balanced out to the THX .

Any suggestions to solve the noising connection going XLR out to the THX?

I like the amp a lot dead quiet and powerful and seems to be put together very well for $349 .

But it works without problem on single ended output?

 

[Sythrix]

It seems you and others receive him through the balanced input. Which is weird since I thought balanced supposedly protects against noise over longer cable runs.

Maybe it's a ground issue in the source box.

I’d find it a little hilarious if they have an assembly line AP testing setup for every unit, but nobody bothered to actually listen to it and realize there was a hum on all the balanced jacks.

God I hope this isn’t a universal thing.

@amirm I know you said you were looking, did you/will you get balanced headphones for the upcoming 789 review?

 

[andymok]

Not if there's a ground loop. This is called the "Pin-1 Problem"

Try get a cable with ground lifted / pin-1 NOT connected

 

[amirm]

@amirm I know you said you were looking, did you/will you get balanced headphones for the upcoming 789 review?

I will be making a balanced cable for my HD-650s.

 

[Sythrix]

I will be making a balanced cable for my HD-650s.

Sounds good! I’m going to make one for my M1060s, because of this amp.

 

[andymok]

Jensen Transformers has written an excellent guide on troubleshooting ground loop problem.
http://www.jensen-transformers.com/application-notes/

Rane has some excellent notes as well

Grounding and Shielding Audio Devices
https://www.rane.com/note151.html

Sound System Interconnection
https://www.rane.com/note110.html

 

[FunctionalDoc]

But it works without problem on single ended output?

Yes single ended no problem.

 

[FunctionalDoc]

New Interconnects no more noise so the custom cables have a ground issue. I am glad that my amp is working perfectly since 3-4 people have reported dead units on their amps.

 

[Veri]

New Interconnects no more noise so the custom cables have a ground issue. I am glad that my amp is working perfectly since 3-4 people have reported dead units on their amps.

What kind of cable did you use? Did it not have proper shielding? This really shows again that a cheap but well built cable is all you need, I guess

 

[amirm]

New Interconnects no more noise so the custom cables have a ground issue. I am glad that my amp is working perfectly since 3-4 people have reported dead units on their amps.

I too had custom balanced cables once that were wired incorrectly and caused hum. I built my own and all was well.

 

[Rod]

I received mine and with the factory balanced cables and the HE-560 I have no hum. I have not heard any on single ended or balanced.
Tried RCA and xlr between the RME ADI 2 Dac and the 789 and no noise either. Sounds fine.

 

[Rod]

I received mine and with the factory balanced cables and the HE-560 I have no hum. I have not heard any on single ended or balanced.
Tried RCA and balanced between the RME ADI 2 Dac and the 789 and no noise either. Sounds fine.

Next I will try the dac in the Monolith. This is fun guys.

I received mine and with the factory balanced cables and the HE-560 I have no hum. I have not heard any on single ended or balanced.
Tried RCA and balanced between the RME ADI 2 Dac and the 789 and no noise either. Sounds fine.

Listening to Windham Hill Chill "Miserere" with the balanced He-560's. Sounds really good actually.

 

[amirm]

My review is up for people monitoring this thread: https://www.audiosciencereview.com/...easurements-of-massdrop-thx-aaa-789-amp.5001/

 

[Veri]

New pictures of the monoprice one https://www.monoprice.com/product?c_id=120&cp_id=12008&cs_id=1200801&p_id=24459&seq=1

Looks like the DAC filter is fully configurable, for the tinkerers

Can someone tell me if this thing can power a HD650 at least?