Latest Thread Images

Featured Sponsor Listings

Massdrop x THX AAA™ 789 Linear Amplifier - Impressions Thread

Jan 26, 2021 at 5:53 PM Post #2,326 of 2,619
pbarach said:
There is absolutely no point in using a balanced input cable with this amp. The amp is not truly balanced (i.e., dual mono). Just use a regular, decent-quality single-ended interconnect with the Fiio; I don't know anything about an iBasso and an adapter.
Click to expand...
And then, where is the point to provide inputs and outputs balanced if there aren’t real balanced at all?
 
Last edited:
Jan 26, 2021 at 6:10 PM Post #2,327 of 2,619
iMongui said:
And the where is the point to provide inputs and outputs balanced if there aren’t real balanced at all?
Click to expand...
Convenience

pbarach said:
There is absolutely no point in using a balanced input cable with this amp. The amp is not truly balanced (i.e., dual mono). Just use a regular, decent-quality single-ended interconnect with the Fiio; I don't know anything about an iBasso and an adapter.
Click to expand...

I disagree. Though the amp is not truly balanced in>out, it is quasi-balanced. If you have a balanced DAC, there is no reason not to use balanced in. In real world terms, I hear a positive difference using the XLR inputs (from my balanced DAC). However, if I had a SE output DAC, I wouldn't get adapters just to take advantage of balanced inputs. Also, balanced out is optimal vs SE out and provides double the power output.

From DARKO:

The 789 gives us XLR inputs and a 4-pin XLR headphone out, but is it really balanced throughout? THX engineer Andrew Mason advises:

“The signal path internally is fully differential throughout (per Putzeys), but is NOT truly balanced in a few sections. We preserve the full signal integrity but we avoid increasing the retail price for no measurable benefit.”

Like many other headphone amps, the 789 might more accurately be called “pseudo-balanced”, but that doesn’t mean it isn’t worthwhile. Its 4-pin XLR headphone jack offers double the output of the single-ended for a maximum of 6 Watts into 32 ohms. And the 789’s XLR inputs take full advantage of a DAC’s balanced outputs
 
Jan 27, 2021 at 4:56 AM Post #2,329 of 2,619
Hi all
i thought I’ll chime in on this discussion for what it’s worth. I have owned the THX AAA 789 for two months. I bought it out of curiosity having read / watched all the reviews. My other headphone amp is the Rupert Neve RNHP, itself a well regarded amp. I have 4 pairs of headphones that I’ve used with both amps. Audio Technica M50x, Audio Technica ATH-R70x, AKG K271 mk2 and Beyerdynamic DT990. Firstly to clear up the issue of the Massdrop vs Drop discussion. They are identical apart from the change of branding and the silk screen printing on the casework. Secondly, regarding the question of whether or not the amp is truly balanced and whether there is any value to using the XLR pathway through the amp. As previously quoted elsewhere on the thread, in absolute terms the amp is not a true differential circuit throughout but certain elements of the circuit employ some of those design elements which result in similar benefits in the signal path e.g. lower noise floor, less distortion and higher output voltage via the XLR output. My assessment of this amp in use via its single ended pathway is that it is has a transparent signature and will easily drive easier loads to high levels, using the high gain switch. The XLR output as the specs suggest has a much higher output level than the SE outputs. Output via XLR headphone out when used in conjunction with the XLR inputs is significantly louder and more muscular that that of SE although the sound signature remains the same. The benefit therefore of using the XLR throughput is purely the ability to easily drive more demanding loads and gives the option of reducing the gain if desired. This does leave more headroom on the volume adjustment. Curiously I have also found that when the SE input is used but the headphones are connected to the XLR output the output level is higher than when using the SE output but slightly quieter than if the XLR input is used in conjunction with the XLR output. In absolute terms I find this to be one of the better headphone amps that I have used. It is very linear and transparent and hugely powerful (via XLR). By comparison to the Rupert Neve amp is it more analytical in presentation and less fluid. Instruments tend to sound thinner and uncoloured. Soundstage is narrower than something like the Neve or a tube amp. To my mind headphone choice is important as the 789 will present the headphone’s sound signature as the manufacturer intended. The only criticism that I have is that on high gain with the volume turned right down the sound is still audible, but that’s not an issue for me. Some have commented on channel imbalance on the volume control but my unit is perfect in that respect. I have experimented with different psu’s but they made no difference to my ears. Accompanying equipment is either Quad Artera CDP / DAC or the Artera used as a CD transport into the SMSL SU-9 DAC via a Cardas 50ohm coax cable. My preferred partnering headphone is the ATH-R70x.
I hope that helps.
 
Jan 27, 2021 at 8:51 AM Post #2,331 of 2,619
Jan 27, 2021 at 11:01 AM Post #2,332 of 2,619
RStdik said:
Hi all
i thought I’ll chime in on this discussion for what it’s worth. I have owned the THX AAA 789 for two months. I bought it out of curiosity having read / watched all the reviews. My other headphone amp is the Rupert Neve RNHP, itself a well regarded amp. I have 4 pairs of headphones that I’ve used with both amps. Audio Technica M50x, Audio Technica ATH-R70x, AKG K271 mk2 and Beyerdynamic DT990. Firstly to clear up the issue of the Massdrop vs Drop discussion. They are identical apart from the change of branding and the silk screen printing on the casework. Secondly, regarding the question of whether or not the amp is truly balanced and whether there is any value to using the XLR pathway through the amp. As previously quoted elsewhere on the thread, in absolute terms the amp is not a true differential circuit throughout but certain elements of the circuit employ some of those design elements which result in similar benefits in the signal path e.g. lower noise floor, less distortion and higher output voltage via the XLR output. My assessment of this amp in use via its single ended pathway is that it is has a transparent signature and will easily drive easier loads to high levels, using the high gain switch. The XLR output as the specs suggest has a much higher output level than the SE outputs. Output via XLR headphone out when used in conjunction with the XLR inputs is significantly louder and more muscular that that of SE although the sound signature remains the same. The benefit therefore of using the XLR throughput is purely the ability to easily drive more demanding loads and gives the option of reducing the gain if desired. This does leave more headroom on the volume adjustment. Curiously I have also found that when the SE input is used but the headphones are connected to the XLR output the output level is higher than when using the SE output but slightly quieter than if the XLR input is used in conjunction with the XLR output. In absolute terms I find this to be one of the better headphone amps that I have used. It is very linear and transparent and hugely powerful (via XLR). By comparison to the Rupert Neve amp is it more analytical in presentation and less fluid. Instruments tend to sound thinner and uncoloured. Soundstage is narrower than something like the Neve or a tube amp. To my mind headphone choice is important as the 789 will present the headphone’s sound signature as the manufacturer intended. The only criticism that I have is that on high gain with the volume turned right down the sound is still audible, but that’s not an issue for me. Some have commented on channel imbalance on the volume control but my unit is perfect in that respect. I have experimented with different psu’s but they made no difference to my ears. Accompanying equipment is either Quad Artera CDP / DAC or the Artera used as a CD transport into the SMSL SU-9 DAC via a Cardas 50ohm coax cable. My preferred partnering headphone is the ATH-R70x.
I hope that helps.
Click to expand...

Really nice post, thanks.

I have owned my 789 for a few days, having moved from a Metrum Aurix. I agree with almost all of your presentation comments. Detailed but not bright. Your observation about the narrow soundstage is spot on; I was trying to put my finger on what it was. Spot on.
 
Jan 27, 2021 at 1:29 PM Post #2,333 of 2,619
RStdik said:
Hi all
i thought I’ll chime in on this discussion for what it’s worth. I have owned the THX AAA 789 for two months. I bought it out of curiosity having read / watched all the reviews. My other headphone amp is the Rupert Neve RNHP, itself a well regarded amp. I have 4 pairs of headphones that I’ve used with both amps. Audio Technica M50x, Audio Technica ATH-R70x, AKG K271 mk2 and Beyerdynamic DT990. Firstly to clear up the issue of the Massdrop vs Drop discussion. They are identical apart from the change of branding and the silk screen printing on the casework. Secondly, regarding the question of whether or not the amp is truly balanced and whether there is any value to using the XLR pathway through the amp. As previously quoted elsewhere on the thread, in absolute terms the amp is not a true differential circuit throughout but certain elements of the circuit employ some of those design elements which result in similar benefits in the signal path e.g. lower noise floor, less distortion and higher output voltage via the XLR output. My assessment of this amp in use via its single ended pathway is that it is has a transparent signature and will easily drive easier loads to high levels, using the high gain switch. The XLR output as the specs suggest has a much higher output level than the SE outputs. Output via XLR headphone out when used in conjunction with the XLR inputs is significantly louder and more muscular that that of SE although the sound signature remains the same. The benefit therefore of using the XLR throughput is purely the ability to easily drive more demanding loads and gives the option of reducing the gain if desired. This does leave more headroom on the volume adjustment. Curiously I have also found that when the SE input is used but the headphones are connected to the XLR output the output level is higher than when using the SE output but slightly quieter than if the XLR input is used in conjunction with the XLR output. In absolute terms I find this to be one of the better headphone amps that I have used. It is very linear and transparent and hugely powerful (via XLR). By comparison to the Rupert Neve amp is it more analytical in presentation and less fluid. Instruments tend to sound thinner and uncoloured. Soundstage is narrower than something like the Neve or a tube amp. To my mind headphone choice is important as the 789 will present the headphone’s sound signature as the manufacturer intended. The only criticism that I have is that on high gain with the volume turned right down the sound is still audible, but that’s not an issue for me. Some have commented on channel imbalance on the volume control but my unit is perfect in that respect. I have experimented with different psu’s but they made no difference to my ears. Accompanying equipment is either Quad Artera CDP / DAC or the Artera used as a CD transport into the SMSL SU-9 DAC via a Cardas 50ohm coax cable. My preferred partnering headphone is the ATH-R70x.
I hope that helps.
Click to expand...

Wall-of-Text2.png
 
Jan 27, 2021 at 2:53 PM Post #2,334 of 2,619
NickT23 said:
Aesthetics
Click to expand...
You mean the tiny-ass little Massdrop logo changed to a tiny-ass little Drop logo? :rolling_eyes:

pbarach said:
I know what the instructions state, but this amp is not truly a balanced amp. You do get more power using the balanced outputs. See this review for some information from the amp's designer:
https://darko.audio/2020/08/starting-points-drop-thxs-aaa-789-linear-amplifier/
Click to expand...
I'm not disputing that. But it is quasi-balanced. My comment was to your 'no benefit to using the XLR inputs'. I disagree. It still makes sense to use the balanced inputs if you have a balanced DAC. But to each their own. the quote I cited in my last post was taken from that same article.

cel4145 said:
Click to expand...

What is this about?
 
Last edited:
Jan 28, 2021 at 3:26 PM Post #2,339 of 2,619
NickT23 said:
No ! The logo, branding, fonts/wording and the overall arrangement at the front and at the back. While front thick bold 'DROP' is eye sore.
Click to expand...
The front and back layout and chassis are literally the same. The only things that changed are the logo, font style and volume knob. Talk about OCD

Old:
1611865149351.png
1611865385984.png

New:
1611865165313.png
1611865399804.png
 
You must log in or register to reply here.

Users who are viewing this thread

Total: 6 (members: 0, guests: 6)
Back
Top