[dadozen]

Jan also takes payments in USD. I've always paid him in this currency. The only thing that happens is that sometimes he drops the price of his amps due to better EUR/USD exchange rates.

 

[hawat]

I should probably post in the source section but since there is already a huge thread about this dac/amp in this section, I ll post here.

I was interested in this for the look and the dac fuction mostly but I' d take sound over look

, anyone have have heard the symphony compared to the recent benchmark dac1 usb/pre or to the lavry da10 ?
I have seen some comparison of the opera with those dacs but the symphony dac seems to be upgraded compared to the opera.

The headamp function would be a plus of course if it beats the hd53r but I am already quite happy with the cec.

 

[Richter Di]

Quote:

Originally Posted by hawat /img/forum/go_quote.gif I should probably post in the source section but since there is already a huge thread about this dac/amp in this section, I ll post here. I was interested in this for the look and the dac fuction mostly but I' d take sound over look , anyone have have heard the symphony compared to the recent benchmark dac1 usb/pre or to the lavry da10 ? I have seen some comparison of the opera with those dacs but the symphony dac seems to be upgraded compared to the opera. The headamp function would be a plus of course if it beats the hd53r but I am already quite happy with the cec.

I can only refer to the AQVOX USB 2DA DAC and for me it is a step up. As the AQVOX was also developed by Carlos Candeias and I owned different Candeias devices (HD53, CD-player) I can only say that it strongly depends on your sound taste. Candeias' devices do produce a very special sound. Jan Meiers has a less strong house sound - the older Corda, the Opera and the Symphony sound all different. For me personaly the decision was easy as the CEC HD53 sounded best with the AKG 701 and the HD650 - which I both sold - the HD 53 had to go too. I would also state that from the Opera onwards Jan Meiers amps sounded cleaner, more detailed and controlled as competitor devices.

 

[hawat]

Thank you Richer Di.
I' ve read that comment from Iron Dreamer in one of his review about a clicking noise in the opera, is that true for the symphony as well?

Quote:

Originally Posted by Iron_Dreamer /img/forum/go_quote.gif The choice to use a muting relay in the DAC where most companies use a potentially sound-degrading muting transistor does result in a clicking sound (from the unit itself, not in the signal) whenever the digital input signal drops to zero (on the gaps in between CD tracks, for instance). While using headphones, I usually didn't even notice it, but it could be an issue when using speakers.

 

[hawat]

Can someone with the symphony check please?
I'm not sure I would appreciate being distracted by a clicking sound between each track.

 

[Jan Meier]

Dear Hawat,

Please don't worry. The DAC-chip in the SYMPHONY allows for a soft-mute and thereby does not require any external muting circuitry. It does not have a relais.

Cheers

Jan

 

[Richter Di]

Quote:

Originally Posted by Jan Meier /img/forum/go_quote.gif Dear Hawat, Please don't worry. The DAC-chip in the SYMPHONY allows for a soft-mute and thereby does not require any external muting circuitry. It does not have a relais. Cheers Jan

Right, as Jan said there is no clicking at all. Regards, Reiner

 

[Jan Meier]

Dear Revenge,

Today I finally got some time looking into your problem with the lights.

“ switching on the lights in the house (neon lights) causes droppouts and distorsions and you can actually see the blue leds blinking on the DAC side.”

I did connect a neon light to the same power bar as my own SYMPHONY and thus was well able to reproduce this effect.

A more close inspection using a digital oscilloscope revealed that the switching of the light caused very short and very strong multiphase voltage peaks, not only on the powerlines but also on the groundwires. Typical frequencies of these peaks in my situation were around 8 MHz (but I expect these to vary depending on the specific situation of one’s home, as the multiphase peaks do indicate reflections inside a wire of approximately 12 meters length which is approximately the length from my wall connection to the central distribution station in my house).

A frequency of 8 MHz is very close to the typical bit frequency of CD playback (5 MHz). Since the peaks are very strong and the typical digital input signals are very low (around 0,5 V peak-peak) they result in loss of data tracking. Part of the digital audio signal simply can not be detected by the input circuitry.

I tried using a power-filter (actually I did have two in series) but that didn’t work at all. The reason probably is, that the ground wire is also strongly contaminated. Thus filtering is ineffective.

Why do other DACs not suffer from these interruptions?

Any DAC derives an internal clock signal from the incoming digital data. For this it uses a circuitry that is called the PLL. This clock signal is used to set the “pace” by which the digital data are converted to analog signals.

Normally the PLL is able to adapt relatively fast to changes in the effective sampling rate of the incoming data. This has advantages when multispeed applications are required (DJ-applications) but it has disadvantages with respect to jitter reduction. Since the PLL adapts so fastly it is not capable to reduce jitter very effectively. It can not separate jitter from other variations in speed.

With the SYMPHONY the PLL was made much stiffer than normally is the case. It can not adapt fast to changes of the incoming sampling rate. Therefore its DAC can not be used with multispeed applications. However, the advantage is that the clock signal derived now is much less dependent on speed variations caused by jitter. Jitter is strongly reduced.

When the SYMPHONY was designed a prototype was made that allowed a direct comparison of different settings for the PLL and it was found that the strong reduction really did result in sonic benefits. Sound simply became more fluent and less raw. That’s why I gave up multispeed applications and made the PLL as stiff as it is.

When the digital data stream is interrupted, a conventional PLL is able to react very quickly when new data are present. The conversion process from digital data into analog data can be resumed very quickly (normally within 1..2 ms). When the interruptions are small then they may well stay unnoticed.

Because the PLL of the SYMPHONY is very stiff it can not react very quickly to interruptions of the data stream and the DAC has to wait before data conversion can be resumed. My tests have shown that it takes the SYMPHONY around 20 ms before it can output analog data again. Such interruptions are much longer and therefore clearly noticable.

Possible solutions:

The only thing that really may help to prevent interruptions is to connect all lights to a wall socket that itself is connected to a different electrical “group” than the audio setup.

Alternatively the PLL of your SYMPHONY can be changed to more conventional settings. Thus interruptions become very small. However, in my opinion sound quality will suffer. Depending on the quality of the digital source the effect of jitter can be very noticable, as my own experiments have learned me.

Just send me an e-mail when there are more questions.

Cheers

Jan

 

[Richter Di]

Hi Jan, thank you for taking the time to investigate the phenomenon and to clarify where it comes from. I can only speak for myself but I rather like to keep the extraodrinary sound quality of the Symphony and live with a short "interruption" when I switch off my bedside lamp still listening to the music.

I think everything is in itself a trade off. Your customers gain from the decision you took by enjoying the super sound quality for an extraordinary "low" price. I know that "low" might be misunderstood but honestly, I invested today some thousand dollar in a new CD-Player (AudioNET ART G2) not knowing wether it will realy beat your Wolfson Chip WM8471 implementation. Still I felt that even a Hoerwege modified Cambridge CD-player is no longer good enough in my little hifi temple. So if the Symphony's DAC might be actually better, I still would enjoy the top loading of the ART G2

Last comment: My recommendation would be to put your description above on your website since it is fair to inform customers in advance about this phenomenon.

My feeling is that your fans will from now on demonstrate there friends your jitter-free implementation by switching the lights off and on.

 

[anoobis]

Just to show my ignorance once again

I was under the impression that peaks in music may require more than 13V (which the specs indicate the symphony can provide), especially for high impedance cans.

I understand that Meier amps are high quality and high SQ, so how does this equate? Or am I completely wrong about the voltage peaks?


Secondly, what's with the holes on the top of some of the Meier amps? I don't get it!

 

[Skylab]

Quote:

Originally Posted by anoobis /img/forum/go_quote.gif Secondly, what's with the holes on the top of some of the Meier amps? I don't get it!

This I can answer - ventilation!

 

[anoobis]

woohoo, an easy, non-subjective, no caveat answer on Head-Fi

 

[onocentaur]

I thought my Symphony sounded better when I covered the ventilation holes with some medical grade air filter mesh. Definitely improved the soundstage.

[size=xx-small]Wait. Has this joke been done before?[/size]

 

[Kees]

Quote:

Originally Posted by onocentaur /img/forum/go_quote.gif I thought my Symphony sounded better when I covered the ventilation holes with some medical grade air filter mesh. Definitely improved the soundstage. [size=xx-small]Wait. Has this joke been done before?[/size]

No, it's a new one.
Has anybody laughed yet?

 

[woof37]

Quote:

Originally Posted by Kees /img/forum/go_quote.gif No, it's a new one. Has anybody laughed yet?

I did.

There are some anal-retentive nutjobs in the audiophile world who'd actually do something like this and swear they could hear a difference.