[mgoodman]

Hello everyone. I bought Centrans and it pisses me off that it does not connect the first time as a DAC. it connects, but there is no sound. you need to reconnect it each time or turn on the bluetooth and change the output again so that the sound appears. I want to break it.

Hi Yasick, please contact us at { info at centrance dot com }. We may be able to help.

 

[ssriram2791]

@mgoodman

I am interested to know more about the stacking of Centrance HiFi-M8 V2 + Centrance Ampersand

1. Does the 3.5 mm and 2.5 mm ports on Hifi-M8 function as Phone out (Pre-amp out) and Line out ? It is quite difficult for me to visualize how I could operate in line out mode (FIXED VOLTAGE MODE in AMPERSAND) if my source does not operate as line out.

2. If the answer is yes to #1, I should be able to connect Hifi-M8 as a DAC Pre-out/Line out to other higher powered external amplifiers correct ? This is pretty common with DAPs that I have used in the past.

 

[mgoodman]

By the way, this coming weekend, Sept 25-26th CEntrance will be at Can Jam in Irvine, CA. We will demo our brand new Ampersand, as well as HiFi-M8 V2, DACport HD and DACport Pro. Please come say hello if you are at the show!

 

[mgoodman]

I am interested to know more about the stacking of Centrance HiFi-M8 V2 + Centrance Ampersand

1. Does the 3.5 mm and 2.5 mm ports on Hifi-M8 function as Phone out (Pre-amp out) and Line out ? It is quite difficult for me to visualize how I could operate in line out mode (FIXED VOLTAGE MODE in AMPERSAND) if my source does not operate as line out.

2. If the answer is yes to #1, I should be able to connect Hifi-M8 as a DAC Pre-out/Line out to other higher powered external amplifiers correct ? This is pretty common with DAPs that I have used in the past.

We will demo this at CAN JAM this weekend. Yes, you can choose either 3.5 mm single-ended output or 2.5 mm balanced output to feed the Ampersand. The headphone outputs on the HiFi-M8 function as line outputs if you don't connect the headphones. And since you will not need the high power amp on the HiFi-M8, you can turn on the STAMINA mode to get longer battery life. Ideally, you want to feed full-level signal from the source into the amp and use the amp's volume control knob to control the level. So in this case, you would need to max out the volume on the HiFi-M8 and use the Ampersand's big volume knob.

 

[ssriram2791]

We will demo this at CAN JAM this weekend. Yes, you can choose either 3.5 mm single-ended output or 2.5 mm balanced output to feed the Ampersand. The headphone outputs on the HiFi-M8 function as line outputs if you don't connect the headphones. And since you will not need the high power amp on the HiFi-M8, you can turn on the STAMINA mode to get longer battery life.

Awesome ! Thanks for quick response. I hope someone in this thread would probably meet up at your booth at Canjam 2021 and provide us some impressions on the "Ampersand" coupled to Hifi-M8 V2. Also, the specs at this point seems to indicate 3W per channel, though it is not clear what impedance that power is measured at.

With Hi-Fi M8 V2, we could see that 1.6Wpeak@ 75 ohm translates to about 400mWpeak@300ohm and 3750mWpeak@32ohm (which is already phenomenal for portable system with XLR output)

Is there an estimated timeline on the spec sheet release, so it helps us with purchase decision. Would actually prefer to move away from desktop systems if it can power headphones (with sensitivity less than 90 db/MW) with larger headroom than Hifi-M8 V2.

 

[newworld666]

By the way, this coming weekend, Sept 25-26th CEntrance will be at Can Jam in Irvine, CA. We will demo our brand new Ampersand, as well as HiFi-M8 V2, DACport HD and DACport Pro. Please come say hello if you are at the show!

Does this mean we can expect delivery of our preorder somewhere mid October ?

 

[mgoodman]

Does this mean we can expect delivery of our preorder somewhere mid October ?

The goal is to plug as many headphones as possible into the Ampersand prototypes at the show, so that we can finalize the output power. It's a tight balance between output power and battery life. If we pump more power out, battery would last less on a full charge. But too much power is not needed. We think we have found a happy medium, but need to verify that. As we don't have every headphone at the lab, the show will be the proving ground. After that, we will make production. Parts are ready and waiting at the factory.

 

[mgoodman]

Awesome ! Thanks for quick response. I hope someone in this thread would probably meet up at your booth at Canjam 2021 and provide us some impressions on the "Ampersand" coupled to Hifi-M8 V2. Also, the specs at this point seems to indicate 3W per channel, though it is not clear what impedance that power is measured at.

With Hi-Fi M8 V2, we could see that 1.6Wpeak@ 75 ohm translates to about 400mWpeak@300ohm and 3750mWpeak@32ohm (which is already phenomenal for portable system with XLR output)

Is there an estimated timeline on the spec sheet release, so it helps us with purchase decision. Would actually prefer to move away from desktop systems if it can power headphones (with sensitivity less than 90 db/MW) with larger headroom than Hifi-M8 V2.

Having evaluated a large list of hungry cans, 6W total may be overkill. We are considering something like 4W total, which is 2W per channel. That would give you 4-5 hours on a fresh charge. 6W would give you less run time, so it's a tight balance. The show should deliver all the answers. We are measuring with 50 Ohm and 100 Ohm loads. Realistic planar headphones range from 32 to 100 Ohms, so we will have to figure out how to spec the output power, as it's not possible to list power per every headphone model

 

[newworld666]

The goal is to plug as many headphones as possible into the Ampersand prototypes at the show, so that we can finalize the output power. It's a tight balance between output power and battery life. If we pump more power out, battery would last less on a full charge. But too much power is not needed. We think we have found a happy medium, but need to verify that. As we don't have every headphone at the lab, the show will be the proving ground. After that, we will make production. Parts are ready and waiting at the factory.

For sure ... I already own the LESS BX2+, and battery life is actually less than 4 hours .. which makes it really uncomfortable for a daily use, or even long travels by plane or train. This portable amp must be almost be plugged all day long (which can't be good for the battery)
I don't know if it's possible, but 6 to 8 hours should be a nice target.

Then, concerning power, I would think that the M8V2 is falling short quite often with some of my headphones when I need significant PEQ adjustments (HEDDPhone, Sony Z7M2, ..), so I really hope the Ampersand will produce a sustain juice at a minimum 2x2W to 2x2.5W at 32ohms.

 

[mgoodman]

For sure ... I already own the LESS BX2+, and battery life is actually less than 4 hours .. which makes it really uncomfortable for a daily use, or even long travels by plane or train. This portable amp must be almost be plugged all day long (which can't be good for the battery)
I don't know if it's possible, but 6 to 8 hours should be a nice target.

Then, concerning power, I would think that the M8V2 is falling short quite often with some of my headphones when I need significant PEQ adjustments (HEDDPhone, Sony Z7M2, ..), so I really hope the Ampersand will produce a sustain juice at a minimum 2x2W to 2x2.5W at 32ohms.

Yeah, 2x2 or 2.5x2.5 is realistic from both power and battery life standpoints. Although 8 hours will be possible with an external power bank (they are getting quite small).

Our charging circuitry allows the unit to be plugged in indefinitely. We don't charge the battery when it's full, so it's safe to leave it plugged in.

What other hard-to-drive headphones do you have?

 

[newworld666]

Yeah, 2x2 or 2.5x2.5 is realistic from both power and battery life standpoints. Although 8 hours will be possible with an external power bank (they are getting quite small).

Our charging circuitry allows the unit to be plugged in indefinitely. We don't charge the battery when it's full, so it's safe to leave it plugged in.

What other hard-to-drive headphones do you have?

That's an excellent feature, which actually makes a Cayin C9 almost unusable for normal office use, I don't mind using a powerbank for long trips (intercontinental flights or so).
On trip, I use a lot an Ultrasone Ed 15 Veritas .. though it's basically 96db with 40 ohms, to enjoy it fully, I use some PEQ which needs nearly -8db preamp, so with some DSD or old stuff, even the Centrance M8 V2 can be falling short with power.
I expect to stack sometimes M8V2 or Sony WM1A with the near to come Ampersand.

 

[ssriram2791]

@mgoodman

Thanks for all the responses ! So, at this time, Hifi-M8 V2 provides 1.6 W per channel @ 75 ohm. With this new dedicated amp, it hovers about 2 W per channel, based on battery constraints. Why don't we have a larger capacity battery to handle this extra power driven battery consumption ?

What volume level is the battery tested at ? If you say 80 dBA average (which occurs at half the volume dial), low gain and battery only lasts for 4-5 hours, could be quite concerning. It is not just about the loudness, but how certain regions in the audio spectrum (bass specifically requires lot more power because impedance curve is non-linear) are being properly excited with enough headroom.

ATH-R70X is classic case for this.

 

[ssriram2791]

That's an excellent feature, which actually makes a Cayin C9 almost unusable for normal office use, I don't mind using a powerbank for long trips (intercontinental flights or so).
On trip, I use a lot an Ultrasone Ed 15 Veritas .. though it's basically 96db with 40 ohms, to enjoy it fully, I use some PEQ which needs nearly -8db preamp, so with some DSD or old stuff, even the Centrance M8 V2 can be falling short with power.
I expect to stack sometimes M8V2 or Sony WM1A with the near to come Ampersand.

Actually you could buy a Cayin C9 spare module and having 18650 batteries charged overnight and stored inside that. The time it takes to remove a module and insert the spare module is 10-15 seconds. I would much prefer no cable hanging of my portable amp. In that sense, Cayin C9 is more portable than Hifi-M8.I have a spare module that I carry with me fully charged always. I can get 8 hours of battery with Class A, tube mode, balanced or about 12 hours with Class A, solid state, balanced.

However, I also agree from a power standpoint, C9 is weaker than Hifi-M8 V2 or Ampersand for driving low sensitivity headphones. Balanced XLR is unique feature that makes Centrance stand out from others. Kudos to them for that and hence makes me interested to see more power with their dedicated amp.

 

[newworld666]

You are right, the main issue of C9 is the lack of power for the very low sensitivity HEDDphone ... Not being able to just plug in to an USB power when I arrive at my office, is not convenient, but I could have deal with it if it could really amp my HEDDphone.
As I own a LESS BX2+ I already know and M8V2, that it's already uncomfortable when the external power stops when battery is fully charged.
I hope Ampersand will work on external power supply and not only battery, though I know that some prefer 100% battery powered amp or DAC (Sony DMP-Z1).
It sounds strange as there seems to be only a little 5V 2.4A USB-C input on Ampersand, so I doubt it works from the external power supply/bank without passing through the battery and discharge it if more than 800mw is needed.

 

[ssriram2791]

You are right, the main issue of C9 is the lack of power for the very low sensitivity HEDDphone ... Not being able to just plug in to an USB power when I arrive at my office, is not convenient, but I could have deal with it if it could really amp my HEDDphone.
As I own a LESS BX2+ I already know and M8V2, that it's already uncomfortable when the external power stops when battery is fully charged.
I hope Ampersand will work on external power supply and not only battery, though I know that some prefer 100% battery powered amp or DAC (Sony DMP-Z1).
It sounds strange as there seems to be only a little 5V 2.4A USB-C input on Ampersand, so I doubt it works from the external power supply/bank without passing through the battery and discharge it if more than 800mw is needed.

I think if you have Class A amps, the power supply to them is quite critical to ensure that they can work optimally without switching over to Class AB or Class B modes. I think that is why some of the portable amps like Cayin C9 have 18650 high drain batteries (totalling 12000 mAh) for pure Class A optimization. At the same time for portability considerations, you cannot make them work like desktop Class A system which can work on linear power supply and hence we end up compromising on power requirements for hard to drive headphones.

I view Centrance Ampersand as a portable equivalent of desktop Class A system, which I can carry around and hence making sure I get as much power out of it (R70X can sing if properly driven - though people like to call it neutral)