Are luxman integrated amps truly balanced?


Hello,

I have the Luxman L-507z integrated amp. Sounds excellent. There are 2 line inputs on the back that are listed as balanced inputs (XLR). My DAC has balanced outputs (holoaudio spring 3 kte). Am I wasting my time and money getting good xlr cables? Also the DAC puts out 5.8volts. The XLR inputs (according to Luxman) can handle up to 6volts. Using RCA outputs/inputs the DAC puts out 2.9volts and the amp can handle up to 9 volts. Am I in danger of harming my amp using XLR ? The DAC has no volume control. The cable run is very short...3 feet.

paqua123

Thanks! I enjoy the Luxman sound quite a bit. I listened side by side with an AS2200 Yamaha and while the Yamaha house sound is good I preferred the Luxman. My concern about the XLR inputs was that my DAC out puts 5.8volts. The luxman accepts 6volts max ( according to luxman tech guy) I was worried about over driving the amp. I even considered buying rothwell attentuators to lower the DAC output some

As usual there is a lot of speculation going on here. 

Balanced connection is not the same as fully differential amplification. The latter is what you really want from a low noise, high performance amplifier/preamp. One of the main benefits of a differential circuit is noise rejection within the component, it’s not as much about rejecting noise at the signal transmission between components. This doesn’t require transformers in solid state circuits as was alleged above. Lol

If Luxman claims their circuits are fully differential I would be inclined to believe them. However, it may be that their amps merely offer the provision for a balanced connection, and thus noise rejection from cable run interference. I don’t care enough to investigate their designs so can’t say which they are doing.

If you want a fully discrete and differential circuit, Yamaha offers that in their A-S2XXX and 3XXX integrateds. And IMHO, they offer that while looking much better in the process. They don’t have what I consider a neutral voicing, but on balance (no pun intended) they can compete with some separates-based systems costing thousands more. Note that I didn’t say “ALL separates-based” systems. I have to throw that disclaimer in there for those who will invariably get bent and defensive over that claim. Gotta have my legal team standing by with their flame shields in hand. 
 

 


 

 

@mspot

Thanks for the link.

 

I stand corrected. I now see the difference between xlr cable compatible components and truly balanced AES48 compliant ones.
Apologies to @paqua123

Thanks for the article. The XLR is definitely louder than the RCA at the same volume level. The XLR output is 5.8volts the RCA is 2.9

 XLR carries a hot signal on one conductor and an inverted hot signal on another conductor.  A diff amp compares the two signals and amplifies the difference.  A +5 volt compared to -5 volt is a difference of 10 volts.  That's the 6 dB gain.

There should be no gain if Luxman followed the AES48 XLR interface standard, so apparently they do not follow AES48. Read the posts by @atmasphere (Ralph Karsten) in this thread:
https://forum.audiogon.com/discussions/when-to-choice-xlr-over-rca-ics
The consequence of not following AES48 is that some of the benefits of using balanced interconnects are lost. However, XLRs may still provide some benefit and you'll need to compare it with using RCA on your system.

I have some nice RCA cables coming next week. Nothing crazy expensive but on par with the XLR i have. So we shall see. In the mean time has anyone tried inline attentuators to lower voltage output

I have compared balanced and RCA cables on a couple of systems and I cannot tell a difference. My Yamaha studio monitors are quite nisy using RCA cables. Balanced cables make them quite as a mouse. Maybe because the Yamahas are close to my two monitors that cause the noise

It’s too simplistic to say unbalanced or balanced interconnects sound better.  It’s all about the design of the gear and synergy.  I’ve had gear where I hear no difference or unbalanced sounds better but I have had gear that throughout the chain, it’s all been designed to sound it’s best balanced and all the pieces are truly balanced.  I have seen a noticeable sound quality bump on balanced gear that’s designed to be used balanced and truly balanced.  
 

Most of the time it’s easy to tell if gear is truly balanced as the manufacture goes out of their way to call that out, as already pointed out in this thread, a truly, fully balanced piece is more expensive to design and implement.  The manufacture wants you to know.  
 

Let your ears be your guide, good luck. 

Shrug, I havent found it warm at all. Pretty dang neutral and clean. So maybe it's what it's being fed that matters. I'm using a holoaudio DAC. 

No Luxman uses a transformer it is colored and not accurate. On single ended it is also too warm and has a wimpy power supply.

it is Japanese McIntosh.

@audioman58 - his comment is spot on. Luxman also stopped using toroidal transformers as they claimed that they were noisy.

 

 

When i use the XLR connection from the DAC to AMP its 6DB louder than SE. Was my first clue that the Luxman wasnt truly balanced. 

 XLR carries a hot signal on one conductor and an inverted hot signal on another conductor.  A diff amp compares the two signals and amplifies the difference.  A +5 volt compared to -5 volt is a difference of 10 volts.  That's the 6 dB gain.  

I think a company called Rothwell makes inline attenuators. Like -10db etc. That would lower my DACs output to like 1.9volts...wonder if they change the sound at all.

Ya, I think thats beyond me hah. Ill just test SE and go with it, so long as the quality is still there. When i use the XLR connection from the DAC to AMP its 6DB louder than SE. Was my first clue that the Luxman wasnt truly balanced. 

These little Jensen transformers are normally used. They also add a little gain, making "balanced" louder which is whey some people think it sounds better.  They are about $100 each and you need 2 per amp.

 

I use SE for everything. --Jerry

Ya I dont think Luxman has those transformers. Ill try with RCA and XLR see what sounds better. Do you guys think the 5.8Volts into XLR input is dangerous for the Luxman? Since it can handle 6volts?

True balanced is Differentially balanced input to output meaning it needs 

a separate transformer per channel to isolate it ,it is more $$ expensive 

and more complex in design. , it is not common though. 

OP,

You are right to ask the question. But one can simply sound better because of the way it was designed and built, and the component you are connecting it to. Whether the design is fully balanced is unlikely to guarantee the correct choice. The  correct answer is you have to try them both to be 100% sure. 
 

I own ARC equipment which is balanced, and they recommend XLR… but I tried both and if there is a difference I can’t tell. They spent a lot of effort to make sure they sounded the same. With my equipment I am able to hook up to equalize the volume and switch back and forth. 

This is why I was using the XLR cable as well. But the run is so short and Luxman seemed to think the DAC output was too close to the max input level of amp. So was considering switching to RCA to mitigate the issue. Just didnt want to lose sound quality.

I use balanced for noise and shielding.  In most cases you can't hear a difference, but just in case I use balanced between my DAC and integrated.  I imagine some users near radio towers are going to be the one's who can most hear a difference.

No, the Luxman is not true balanced. Stay with RCA single-end interconnects. No benefit at 3 feet! XLR cables are for 50/100 ft distances where hum can be a problem.