CEntrance Ampersand balanced portable headphone amplifier
Jan 18, 2022 at 1:33 PM Post #16 of 131
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Jan 18, 2022 at 5:37 PM Post #17 of 131

mgoodman

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Can this bypass battery when plugged in? Is there is an option to choose wall power or battery?
When running on wall power, the battery is smart -- it is out of the way, unless the charger is wimpy. Then, the battery kicks in to help during loud passages. Otherwise, it's not there. Just remains topped-up.
 
Jan 19, 2022 at 12:08 AM Post #18 of 131

HeadphoneAddict

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I just received a sample of the Ampersand today. I and my son HeadFanatic are both extremely impressed with it! All of our listening today was via the 4.4mm and 4-pin balanced outputs.

I listened to an Alpha version last year and prefer to forget about that one, LOL.

I’m using it with a variety of portable balanced sources - mostly DAC/amps and not pure balanced DACs. That’s including CEntrance BlueDAC, HiFiM8 V2, Palab M1 Mini, and HiFiMan R2R2000. I have NOT tried the Palab and R2R2000 yet, that will come tomorrow. We did also try feeding it SE input from the BlueDAC and Encore Hi-mDAC.

I have a variety of cables to connect any 4-pin, 2.5mm or 4.4mm balanced sources to the 4.4mm input. I’m trying to figure out if I have what I need to connect a desktop DAC with dual 3-pin DAC outputs into a single 4-pin balanced input, but I don’t think I do.

Tje Ampersand’s output sound quality and sound signature matches the HiFiM8 V2 sound perfectly - but this Ampersand has gobs and gobs of power for all of my harder to drive headphones.

It drives my inefficient OG HiFiMan HE-6 better than any other headphone amp in the house, including the HiFiMan EF-6 that was made for them, and a $3000 maxed out Eddie Current ZDT speaker/headphone amp with 8W into 8 ohm (2W into 32 ohm). the Ampersand is pretty close to when I would drive the HE-6 with a 40W Marantz receiver or 55W home theater receiver via the speaker outputs.

If I set the HiFiM8 V2 volume to 80% and used the 4-pin XLR output to drive the HE-6 I would get good everyday listen volumes in high gain. If feeding this 4-pin XLR output into the Ampersand via 4.4mm input, it did not over drive the VU meters on the Ampersand which stayed out of the red zone, and sound was not distorted.

We did some direct comparisons of the M8 V2 output to the Ampersand output with the HE-6, and so the M8 V2 stayed in high gain at 80% volume to get them loud enough to compare to the Ampersand output when setting its volume to 12 o’clock. With these settings we could first listen to HE-6 on the HiFiM8 V2, and then move the HE-6 to the output of the Ampersand - we’d connect the M8 V2 4-pin out to the Ampersand 4.4mm input. It was perfectly volume matched to the M8 4-pin XLR output when the M8 was driving the HE-6 at 80% volume knob.

Turning up the volume from 12 o’clock to 1-2 o’clock got the HE-6 quite loud. Moving to 3-4 o’clock was extremely loud and still hitting solidly, with no sign of running out of juice. We even got the Ampersand up to max volume at 5 o’clock and it was unbearably loud. To listen for audible clipping I will have to put in soft foam earplugs while listening to the HE-6 at maximum volume, because without earplugs I could not focus due to the extreme high volume.

My son’s HD800 and my HD800s sound great with the Ampersand, and I was able to listen to HD800/800s at medium and even low gain. Again, I would pick the Ampersand to listen with my HD800s over any of my current desktop headphone amps (HiFiMan EF2, EF5, EF6, or EF100, Eddie Current ZDT, DACMini, Cavalli Liquid Carbon X, Schitt Magni, Millet Hybrid, Nuforce DAC 100, Nuforce HAP 100).

Back in the day everyone was touting how great the power output of the portable RSA SR-71b balanced amp was; but it could never drive the HE-6 or HD-800 well, and was better with a few planar magnetic from Audeze and HiFiMan, or with the HD600/650. I still have mine but never use it now due to the unconventional input jack (and the SE output was terrible). The SR-71b was the only balanced portable amp with SE and balanced analog input that I ever bought. The RSA F35 Lightning could drive HD800 well (but not HE-6); but it was balanced out only and less powerful. Now there is a better option that is so much smoother and spacious, more versatile, and with more standardized SE and balanced analog inputs and outputs.

The only other amp we have here in the house that comes this close to the Ampersand with HD800 or 800s, playing with such autjoritative bass and authority, is our Pioneer VSXLX303 or VSXLX102 home theater amps with an external DAC (built-in DAC is too grainy), followed closely by the HiFiM8 V2, and then the HiFiM8 v1 (still surprisingly good, albeit better with the bass control turned up).

The HiFiM8 V2 by itself sounds very good with any of the above headphones, but the Ampersand adds some weight and authority to the sound, and certainly more so with the HE-6. Overall, I prefer the HD800s for listening, and with something tiny and low powered like a BlueDAC, DACport HD, or Encore Hi-mDAC, you don’t really have enough power to enjoy the HD800. But you can add the Ampersand to those DAC/amps and gain enough power to do the HD800 justice, even when using a 3.5mm source and feeding that into the 3.5mm input.

When using a small DAC/amp with 3.5mm output as the source, we would turn those up to 100% volume to feed that into the Ampersand. Those devices did not seem to exceed the 2v the Ampersand is expecting, and they did not overdrive the input. Being able to plug this into wall power or computer power via USB is a big bonus. You could leave this plugged in to your computer all the time, and I would like to try it with the ESS DAC built into the front panel 3.5mm output on my desktop PC. I suspect this could be as good as my many USB DAC/amps.

We found that the HE-1000se sound fantastic on the HiFiM8 V2, without the extra amplification of the Ampersand, and the sound basically remained similar to the source when feeding the source into the Ampersand. This is where we started to realize that the Ampersand really does seem to be like “wire with gain.“ It would take on the overall sound characteristics of which ever source we were feeding into it, whether the warmer and euphoric sounding BlueDAC, the well balanced HiFi M8 V2, or the slightly brighter and analytical sound of the encore Hi-mDAC.

With my HD800s I preferred the CEntrance HiFiM8 V2 as my source, but with the original HD800 from 2009 the BlueDAC did help tame the edge that they are so well known for. The Hi-mDAC was not a good match for any headphone until we pulled out the HE-1000se.

When we tried the HIFIMAN HE-1000se we found that any of those 3 DAC/Amp were a good source to feed into the Ampersand. This is such a detailed and spacious headphone, yet so forgiving, that it’s still by far my favorite headphone, followed closely by my HD800S.

My son has his day off tomorrow and the next day, and we plan to spend more time listening to other headphones with the Ampersand like our single ended Grado HF1, and balanced HiFiMan Edition-X V2, HE560 and HE500, our HD600 and HD6XX etc. We will also try using the warmer sounding Palab M1 MINI and HiFiMan R2R2000 as sources, out of their 4.4mm outputs, using my 4.4mm male to male interconnect cable.

Overall, the Ampersand can convert any small portable or built-in computer DAC/amp into a rig that can drive just about any full size headphone. You use the old DAC/amp as source, with the Ampersand contributing a considerable amount of extra power, with NO coloration added to the sound of the source. I can’t even imagine how much better it might sound if I feed my $4000 PS audio Perfectwave Mark II balanced desktop amplifier into it!

This Ampersand is a miracle of modern miniaturization - to get this much clean power out of such a small amp would be unheard of until now, let alone from something running on a battery! We paired it to to a BlueDAC wireless battery powered DAC/amp, and without a full charge on either they both lasted at least 4 hours with almost constant music playback at high volumes. You can’t do that with the huge desktop amp that you would need to match its performance!

I’m more likely to pair something like this with my desktop PC or 16” MacBook while plugged into USB-C full time, but to know that I could use this to fly from Colorado to Miami on a single charge is reassuring. And, the fact that it could replace most people’s desktop amps is even more amazing.
 
Jan 19, 2022 at 12:39 AM Post #19 of 131

HeadphoneAddict

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I would like to add that the sound signature does not seem to change, to my ears, when switching between high gain, medium gain, or low gain. I have experienced sonic changes with some amps in the past when changing to a different gain level, but not this one. The only amp to come to mind right now is my Schitt Audio Magni (OG) which does Not sound as good when you go to low gain, and we prefer to keep that one in high gain.

Also, with HiFiM8 V2 4-pin output at 80% volume as source feeding the Ampersand, the only headphone for which I wanted to use high gain tonight was the HE-6; and I still would never go above 2 o’clock for my personal listening. High gain was fine with the other headphones, but I could not use the last 30-40% of the volume knob with them.

In high gain with the HD800’s and HE-1000se, I usually listened with the Ampersand volume knob at or below 12 o’clock. At medium gain, with these 2 headphones I was not turning the volume higher than 2 o’clock.

I do think it would be quite possible to use the Ampersand in low gain, medium gain, or high gain, with the HD 800 or the HE-1000 SE; but I would not use low gain with the HE-6.
 
Jan 19, 2022 at 12:52 AM Post #20 of 131
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Wow, that's a fantastic set of initial impressions @HeadphoneAddict! :relaxed:

Unfortunately I was out of the office for most of the day today, so I didn't get a chance to run it through its paces yet. However, I did torture it last night in some strange ways, and can verify some of what you mentioned.

Tje Ampersand’s output sound quality and sound signature matches the HiFiM8 V2 sound perfectly - but this Ampersand has gobs and gobs of power for all of my harder to drive headphones.

Yup, pretty much. In fact, I discovered some unexpected synergy here.

I think that many people, upon hearing about the new LCD-5, expected it to sound exactly like an LCD-4, but way more resolving. I also think that a lot of those people were a little disappointed that it wasn't quite the above, in that the LCD-5 sounded much more mid-centric than they wanted it to be.

However, when I drove my LCD-5 with a HiFi-M8 + Ampersand pairing, and engaged the HiFi-M8's bass and treble boost, I was immediately rewarded with exactly that: a tonal signature that was reminiscent of an LCD-4, but with all the resolution of an LCD-5. I'm hesitant to post this in the LCD-5 thread just yet because it's: (a) just an initial impression thus far; and (b) I don't want to prematurely cause a riot that will surely result in a lot of extra moderation work that I don't have time for right now. But yeah, holy smokes, that was pretty amazing!

I’m trying to figure out if I have what I need to connect a desktop DAC with dual 3-pin DAC outputs into a single 4-pin balanced input, but I don’t think I do.

I just happened to have such an adapter, and I immediately decided to do something silly with it... :stuck_out_tongue:

I can’t even imagine how much better it might sound if I feed my $4000 PS audio Perfectwave Mark II balanced desktop amplifier into it!

So, I fed it with the XLR line outs of a Chord Dave. 🤣

In my case, I did notice some coloration changes over that of the Dave's built-in headphone amp. Most notably, there was a non-trivial increase in bass slam. It was like... like Dave grew a pair.
 
Jan 19, 2022 at 1:15 AM Post #21 of 131

mgoodman

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I and my son HeadFanatic are both extremely impressed with it! All of our listening today was via the 4.4mm and 4-pin balanced outputs.

I listened to an Alpha version last year and 1prefer to forget about that one, LOL.
Thank you Larry. Coming from you this means a lot!

Thank you also for your honest and relentless feedback about the earlier prototype. I had to redesign the whole thing pretty much from scratch to address your suggestions, and while I hated myself during that process, it came out much better in the end! :wink:
 
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Jan 19, 2022 at 1:22 AM Post #23 of 131

HeadphoneAddict

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Wow, that's a fantastic set of initial impressions @HeadphoneAddict! :relaxed:

Unfortunately I was out of the office for most of the day today, so I didn't get a chance to run it through its paces yet. However, I did torture it last night in some strange ways, and can verify some of what you mentioned.



Yup, pretty much. In fact, I discovered some unexpected synergy here.

I think that many people, upon hearing about the new LCD-5, expected it to sound exactly like an LCD-4, but way more resolving. I also think that a lot of those people were a little disappointed that it wasn't quite the above, in that the LCD-5 sounded much more mid-centric than they wanted it to be.

However, when I drove my LCD-5 with a HiFi-M8 + Ampersand pairing, and engaged the HiFi-M8's bass and treble boost, I was immediately rewarded with exactly that: a tonal signature that was reminiscent of an LCD-4, but with all the resolution of an LCD-5. I'm hesitant to post this in the LCD-5 thread just yet because it's: (a) just an initial impression thus far; and (b) I don't want to prematurely cause a riot that will surely result in a lot of extra moderation work that I don't have time for right now. But yeah, holy smokes, that was pretty amazing!



I just happened to have such an adapter, and I immediately decided to do something silly with it... :stuck_out_tongue:



So, I fed it with the XLR line outs of a Chord Dave. 🤣

In my case, I did notice some coloration changes over that of the Dave's built-in headphone amp. Most notably, there was a non-trivial increase in bass slam. It was like... like Dave grew a pair.
So I caught a typo in what you quoted from me that I’m not gonna go back and fix.

But I also caught where I mistakenly said dual 3-pin into single 4-pin, and I actually meant to say dual 3-pin into 4.4 mm male, which is the input into the Ampersand.

I have adapters to let me use 4-pin XLR headphones on a 2.5 mm balanced or a 4.4 mm balanced headphone out jack. And I have cables to connect a 4-pin headphone jack to a 2.5mm input or 4.4mm input. And other to connect 2.5mm or 4.4mm headphones to a 4-pin XLR.

I just have nothing to connect a desktop DAC-only to a portable balanced amplifier’s input, except for a dual 3-pin to RSA cable to feed the RSA SR-71b and F-35 Lightning amps.
 
Jan 19, 2022 at 1:33 AM Post #24 of 131
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So I caught a typo in what you quoted from me that I’m not gonna go back and fix.

Typos reflect frank and candor in the moment, and a lack of polish and dressing do they not? :relaxed:

But I also caught where I mistakenly said dual 3-pin into single 4-pin, and I actually meant to say dual 3-pin into 4.4 mm male, which is the input into the Ampersand.

I have adapters to let me use 4-pin XLR headphones on a 2.5 mm balanced or a 4.4 mm balanced headphone out jack. And I have cables to connect a 4-pin headphone jack to a 2.5mm input or 4.4mm input. And other to connect 2.5mm or 4.4mm headphones to a 4-pin XLR.

I just have nothing to connect a desktop DAC-only to a portable balanced amplifier’s input, except for a dual 3-pin to RSA cable to feed the RSA SR-71b and F-35 Lightning amps.

Ah, yes, forget to mention a few things. In addition to the dual 3-pin to single 4-pin adapter (which I presume all of us old farts have, and yes probably some Kobiconn connectors too lol), I picked up a 4-pin XLR to Pentaconn adapter a little while back. This one. I also have a short Pentaconn-to-Pentaconn connector that I picked up from somewhere, but I can't remember where at the moment. That Frankenstein assortment was enough to get the job done. Though, at this point, I'm very tempted to ask Peter to DHC something specific for me. :smile:
 
Jan 19, 2022 at 1:36 AM Post #25 of 131

HeadphoneAddict

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Thank you Larry. Coming from you this means a lot!

Thank you also for your honest and relentless feedback about the earlier prototype. I had to redesign the whole thing pretty much from scratch to address your suggestions, and while I hated myself during that process, it came out much better in the end! :wink:
I certainly will not forget all the late night sessions we spent chatting on the phone and in messenger, to make sure that this product was perfect when completed. I have to tell you it’s a job well done and I can’t think of any way to make it better.

Well, except maybe if it also had tone controls for people who are not using a source with tone controls. But the tone controls would not be to correct any flaws in this amplifier, but rather to correct flaws in someone’s headphones.

I like that it’s possible to get a finger nail in there to change the gain without needing to use a pen or pencil to poke inside the switch slot. But it’s so flexible that most people can set it and forget it for the majority of their headphones - the gain could be mostly to match it to your source’s output level.
 
Jan 19, 2022 at 1:43 AM Post #26 of 131

HeadphoneAddict

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Typos reflect frank and candor in the moment, and a lack of polish and dressing do they not? :relaxed:



Ah, yes, forget to mention a few things. In addition to the dual 3-pin to single 4-pin adapter (which I presume all of us old farts have, and yes probably some Kobiconn connectors too lol), I picked up a 4-pin XLR to Pentaconn adapter a little while back. This one. I also have a short Pentaconn-to-Pentaconn connector that I picked up from somewhere, but I can't remember where at the moment. That Frankenstein assortment was enough to get the job done. Though, at this point, I'm very tempted to ask Peter to DHC something specific for me. :smile:
So I’m pretty sure that I have a dual 3-pin to four pin adapter, but I would need gender changers, because it lets me plug a headphone cable with dual 3-pins into a 4-pin headphone amp.
 
Jan 19, 2022 at 2:25 AM Post #27 of 131
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I have to tell you it’s a job well done and I can’t think of any way to make it better.

lol, I just thought of something. But since it's too late now, I should just :zipper_mouth:.
 
Jan 19, 2022 at 4:46 AM Post #28 of 131

ruffandruff

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When running on wall power, the battery is smart -- it is out of the way, unless the charger is wimpy. Then, the battery kicks in to help during loud passages. Otherwise, it's not there. Just remains topped-up.
thats good to know....so it can be kept plugged in 24/7 as a desktop unit without harming the battery.
Could you confirm if this is Class-A like the website states. Is it completely Class-A. If that is so, that would be an incredible feat of achievement for a such a small device that too considering the amount of power this thing is outputting.
 
Jan 21, 2022 at 1:20 PM Post #29 of 131
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Could you confirm if this is Class-A like the website states. Is it completely Class-A. If that is so, that would be an incredible feat of achievement for a such a small device that too considering the amount of power this thing is outputting.

I had a chance to chat with Michael Goodman yesterday, and he confirmed that the Ampersand is in fact Class AB. :relaxed:
 
Jan 21, 2022 at 1:27 PM Post #30 of 131

SDBiotek

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I had a chance to chat with Michael Goodman yesterday, and he confirmed that the Ampersand is in fact Class AB. :relaxed:
Pure Class A and battery powered don't mix, lol. Maybe it could be done, but either a massive battery pack would be needed ( making the device barely portable) or it would provide a very limited amount of amplification. I do have another portable amp that has a Pure Class A mode, but it can really only work with iems and easy to drive headphones. Even many mains-powered "Class A" amps really only stay in Class A for just a small percentage of their total rated output, then switch to AB as the load demands.
 

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