a short diary of some part of my life.

Posts tagged Sennheiser

Schiit Modi 3, RME ADI2 DAC, Audio-gd Reference 5 DSP

I’ll cut to the chase.

I have the following gears for comparison purposes:
– Schiit Modi 3
Audio-gd Reference 5 DSP
– PS Audio DS DAC (not pictured as it is sitting on my audio rack with lots of cables tied onto the back of the rack, btw the rack is a beauty: Symbol Audio Dovetail)
– Denafrips Ares II (not pictured)

The comparisons were made using my headphone system. The headphones are:
Sennheiser HD6xx
– Campfire Audio Cascade (yep, after so many bitchings about ALO Audio, I hold their first headphones in high regard)
– Grado RS2e

Yes, the last two headphones are very colored. I like them because they are fun to listen to and offer completely different experience from one to another. Unlike DACs which are hard to differentiate, headphones and loudspeakers are not.

Headphones amps used to power headphones above:
– Schiit Magni 3+
Woo Audio 6 SE

My thought process was to use two different amps to basically give some options. The Magni 3+ is a sublime solid state while the Woo is a superb Class A tube amp.

Build Quality

They all offer very solid build quality. There is no product used from bad audio company here. At first, I thought the most attractive was off course the PS Audio DAC. My friend who visited me told me it looks like a Canon printer.

I can’t say I disagree. ūüėÜ
If I want to go down to nitpicking detail, I prefer all jacks to be chassis mounted. My Modi 3 has developed looser RCA connectors.

Chassis Mount Jacks

Sound Quality

To level the playing field, I always use this album as a reference point:

With the exception of PS Audio DS DAC and Audio-gd RE5 DSP, most my DACs sound neutral. This is all you should know really.

Again, if I want to go down to nitpicking details, the RME DAC performs the best out the bunch. It’s incredibly detailed and transparent. The DAC is not fatiguing like some high end DACs can be (I’m looking at you Mytek Brooklyn…).

This RME DAC actually makes my Cascade more listenable. I thought the Cascade was somewhat producing slightly convoluted sound. I was not hearing clear enough passages between notes. There is not a clear sense of space. at least with Modi 3 and Ares II. I can use the Cascade for hours, a very rare case for headphones to me. Cascade becomes more precise in terms of imaging, instruments separations and soundstage. Bass thumps are not so overly boomy anymore. I’d even claim that now, Campfire Audio Cascade has become my favorite headphones.

With Grado RS2e, the German-made DAC does not improve much of Grado’s sound traits or at least as much as it improves Cascade. It does offer similar improvements on sense of space. I love the Grado phones as it is. Actually there isn’t much to improve. Or it could be that this particular Grado is not very sensitive to small changes. To me this is a win.

One interesting find that I very much appreciate is the availability of fine sounding headphone amps in the unit. To keep this short, unless you want to have transformers-coupled tube amp sound signature, you need to daisy chain the ADI2 DAC FS with an amp like my Schiit Magni 3+. Not only if you drive your headphones direct, your headphones will sound better but also the simplicity. I do not favor using a longer signal path in between DAC and amplifier unless a preamp or a separate headphone amp brings something different on the table. So, after I paired it with Magni 3+ and WA6SE, I drove my headphones direct from RME ADI2 DAC FS. You’ll get extra airness and impacts. It’s an audio bliss how this small unit can offer so much and sacrifices nothing in sound quality.

If I want to compare DS DAC and Ares II, I would have to use a headphone amp. There is a small noticeable inferior detail retrievals. Driving my headphones direct is simply superior. Does it fare well against Paul McGowan‘s beloved DAC and Denafrips’ cheapest DAC? Yes, it does. Both DS and Ares II DAC sound warm. This can be a very pleasing for some tracks. DS DAC basically masks imperfections. The next question what Hi-Fi exactly is? RME ADI2 DAC FS is hi-fi.

Ares II fares better, although not without its flaws. Ares II somehow lacks punches. It does not have the same surreal listening experience if you play good recordings. It’s far too flat and uninviting. This Ares II will definitely go for sale soon.

Unfortunately, I don’t have a very sensitive IEM. My only IEM is Sennheiser IE8. The IEM headphone jack drives both the IE8, Cascade and RS2e just fine. It’s completely silent. There is no background noise, period. According to, RME ADI2 DAC FS IEM output measures the best, even when compared to the venerable THX AAA 789.

RME ADI2 DAC is feature-packed. I’m a proponent that no speakers sound the same in various conditions. Headphones are not room-dependent but our ears are shaped differently. If micro adjustments are needed, RME has the features to do so.

I won’t cover all the features, they are just too many. You can read the manual, it covers everything. The manual is an interesting read; read it before you decide to buy it:

Even without its’ features and functions, ADI2 DAC FS is a superb sounding DAC. Its’ features are basically the deal breaker. I’d pick RME ADI2 DAC FS over DACs listed above.

Happy listening!

Recently, I visited a prominent local headphone store. I was looking for a portable closed-back headphone for air travel, to replace my in-ear phones, Sennheiser IE8. I no longer feel comfortable wearing in-ear for hours, let alone, a long flight. The IE8 will fall off my ears if I do not constantly reposition it. I have tried various tips but none of them provides the comfort I want up in the air. While I was there, why not try various new & old gears that I have not tried.

The First Setup

The first was the Bottlehead Crack w/ Astell & Kern as DAC, driving Sennheiser HD650. The sound was very lean. The HD650 lost its greatness; imaging, deep bass, soundstage, all gone. Bottlehead turned HD650 into a very thin sounding headphone. After a few minutes, I switched to another setup.¬†Later on, I found out that the culprit is on Bottlehead Crack. The amp just didn’t sound good.

The Second Setup

The second setup was ALO Pan Am w/ Astell & Kern as DAC, driving Sennheiser HD650. Now, this is what Sennheiser HD650 should sound like. It’s not the best amp for it but the Pan Am was a much better amp than Bottlehead Crack. It brought back HD650’s famous imaging and soundstage. The speed was a bit on the slow side but after the hearing the first setup, my ears needed a spa, a spa that Pan Am provided. There was channel imbalance on low volume but still very tolerable.

After listening with HD650, I switched to Audio Technica ATH-ES700. It sounded really bad (bad in every way) that after a few musics, skipped!

Then, I picked up Audio Technica ATH-ES9. Now, this was better, much better than ATH-ES700. This should be the best portable closed-back headphone to replace my Sennheiser IE8. It sounded great with the Pan Am. Wait, I can’t use the Pan Am on an airplane. So I plugged the ES9 directly into Astell & Kern AK100. Although not as great and inviting as HD650, the sound was well balanced, and easy to listen to.

My Conclusions:

  • The Pan Am is a very decent amp for its size but the price puts me off. It’s expensive for the sound quality you get out of it. If I really need a small amp w/ DAC, I’d just get my DACport. It’s even smaller than the Pan Am. If I want to go a just a bit bigger, I’d get one of Schiit’s single-ended amps and you don’t need to worry about running out of battery power or replace the battery unit after a few years.
  • Sennheiser HD650 is as great as ever, it remains one of my all-time favorites.
  • Bottlehead Crack is a bad-sounding amp. Maybe the unit is defective. I don’t know.
  • Audio Technica ATH-ES700 is a very bad sounding headphone. The sound does not sound right. Maybe it’s defective too (by design).
  • Audio Technica ATH-ES9 is a well balanced portable closed-back headphone for the money. This is the headphone I want to replace my Sennheiser IE8. It provides the comfort and SQ. My only concern is its fragile looking cable.
  • Astell & Kern is a great DAP (digital audio player). The sound is surprisingly quite neutral. The freq is very linear. I suspect it should be good for all kinds of music. The user interface is easier to use and not as flaky as iBasso DX50 that I also auditioned. SQ wise Vs. DX50? Better too.

Photo by adiputraryan

Reviews of Sennheiser HD650 have probably been written thousand times. That speaks a lot about its popularity. It’s one of the most well regarded audiophile headphones and it’s been around since many years ago in the form of HD580. Since the introduction of planar phones, its popularity as one of the best performing is waning. But I feel like it’s not waning at all in term of overall sound quality.

This headphone was my first audiophile headphone and is certainly one of my long time favorites along with my Grado RS1i. They complement each other. Even if compared with the HD800, I still choose HD650. Why?

  • HD800 is astronomically expensive, considering very little performance gains you are getting with HD800.
  • HD800 is not a comfortable-sounding headphone. I prefer listening to RS1i. A lot of people consider Grado uncomfortable but the HD800 is more uncomfortable. I feel more comfortable listening to HD650 for hours.

I don’t know what Sennheiser is thinking about pricing the HD800 that high. Maybe that has something to do with it being assembled in Germany where labors are more expensive than in Ireland where HD650 is made.

Comfort-wise, HD800 is more comfortable than HD650 but it’s not a huge improvement. The look itself will attract people asking about it, especially spouses who will definitely ask what kind of headphone that is. Build quality-wise, HD800 is entirely made of plastic. It feels cheap for a very expensive dynamic headphone.

Since my exposure to speakers, I have significantly reduced my investment in headphone. I don’t feel the need of having a balanced headphone setup or a very high performance headphone setup. The fund for those setups will likely eat my budget for my speakers. It’s not going to be fun as well as I won’t be able to share headphone with my wife. So the priority is to get the best sounding speakers setup. Headphone is not going away, but the priority needs to be set right. I want a headphone that sounds like speakers. I want a headphone amp that is reasonably priced, made in the USA, and high performance. I got the amp and I have reviewed it.

HD650 is the only headphone that I find sound like speakers. It does not have all the speakers superiorities over headphone. What it has, is the the trait of imaging of speakers. No headphone does it as well as HD650. I understand now why people who owned HD800, go back to HD650.

The sound is also surprisingly well balanced for a headphone. It has a few weaknesses but the imaging alone worth considering over other headphones. Since I’m concentrating my budget more on speakers and less on headphone, I consider the price to be also one of the most crucial factors. At US$500, it’s almost a no brainer. You will be hard pressed or in fact next to impossible to find similar headphones at this price. A headphone setup does not have to be super expensive to be enjoyable.


Like everything else, a journey may end at some point. I just didn’t expect this would end so soon. I was an advocate Head-Fi reader – not a frequent poster. I have gradually but surely, walking away from Head-Fi. It has become a place where I buy and sell my headphone gear. There are only very few respected Head-Fi members whose comments/replies are worth reading. To make it even worse, most if not all of them are Head-Case members (they provides better users’ impressions due to their vast knowledge about audio electronics in general and anti-hype approach). Head-Fi user interface has also become dreadful (did I mention that Head-Case interface is MUCH better than Head-Fi’s?). A prominent Head-Fi member have summed up the problems, he too decided to leave.

Head-Fi’s Major Issues

There are many other major (disturbing) issues that prompted me to say good-bye. Issues like their over-protective approach over their site sponsors, post deleted without any notice (I have seen this myself, several times. I refreshed the page after 5 minutes and some posts were gone), users’ idiocies (of defending their purchases, users’ incompetencies… make the forum very uninformative, unfriendly, and useless. There is another issue (another issue and another issue?) about sponsors trying to make easy money. Head-Fi is going to be a much worse place for those who cheer good sound if the admins decide not to do anything about those issues. Many have left, many have not posted useful posts for some time.

Head-Fi DGAF about Regular Folks

Even after issues after issues are exposed, Head-Fi still do not give a crap about us regular folks who spend countless hours on honest jobs. If I were to run a forum, read by millions of unique visitors per month like Head-Fi, I would make sure that the vendors are always kept in check, especially after vendors are caught lying or making very questionable products at extraorbitant price. They could have made the forum much safer for users with a bit more effort but they don’t.

It’s not fair to leave without saying anything, so here is a few bits of my story:
During my time searching for the right headphone, amps, and sources, I have learnt a lot. This headphone journey led me to speakers system which I think sounds superior to any headphone systems on the planet. I’m grateful for my experiences on Head-Fi. Without it, I would not know how to start looking for the right system. For those who have the funds, the space, and the time to set up a speaker system, but you are still using headphones, I urge you to try a good speaker system. It will blow you away!

I figured, it will be fair to list what headphones and amps that I have owned and tried. So, you’ll know how far I have gone. Here are the lists:


  • JH Audio JH16 Pro
  • Sennheiser HD650
  • Sennheiser HD800
  • Grado RS2i
  • Grado HF2
  • Audeze LCD-2 Rev.1
  • Beyerdynamic T1
  • HiFiMan HE-5
  • HiFiMan HE-6
  • Shure SE535
  • Grado HP2
  • Sennheiser HD600


I think I have had a few more amps but I can’t remember the names.

Which headphone and headphone amp are the best and the worst?

From the owned lists above, I consider Audeze’s LCD-2 and AMB B22 as the best headphone and the best amp. The worst are Sennheiser HD800 and Audio-gd Phoenix. Although I did not own them all at the same time, I can definately tell you that HD800 and Phoenix are my least favorite headphone and headphone amp.

I dislike HD800 due to its’ artificial-like sound signature. Anything that comes out from HD800 do not sound right to me.¬†Audio-gd Phoenix sounds too smooth, is not as transparent as other top-tier amps, and has its’ own sound signature. My only requirement for a good amp is complete transparency. Its’ sound signature masks almost everything and changes my source’s sound signature. A reference amp must be transparent to the source, otherwise, you are better off settled with a tube amp like I once did with a Woo Audio 6 SE. AMB B22 and HeadAmp GS-X are much better amps than Audio-gd Phoenix, they are much more dynamic and transparent. I can easily do DBT on what source is used with AMB B22 and HeadAmp GS-X but with Audio-gd Phoenix, the differences between sources are very subtle. Even with ACSS, the Phoenix sounds soft and dull compared to AMB B22. I’m beginning to think, Audio-gd is not good at designing headphone amps. I have also briefly auditioned their Compass and C-2C and found them to be mediocre at best. A small headphone amp like AMB M^3 and HeadAmp Gilmore Lite are also much better alternatives than the big honking space heater Phoenix.¬†Audez’e LCD-2 should pair well with any top tier amps like the GS-X. It is a very transparent headphone, I think it’s a better headphone than HiFiMan HE-6 which is quite piecing on the ears. I sold the LCD-2 because I simply wanted a retro headphone and I was also disappointed with LCD-2 build quality. It’s gone now and I don’t miss it at all.

Portable Amp (w/ DAC)

There are a few things that I want to talk about portable amps. If you really need portability and you are using a notebook computer, look no further, get a CEntrance DACport. It has a superb DAC and a superb Class A amp for its size. Don’t bother buying portable DAC/amp from various unproven manufacturers, they are all inferior. Most general DAC/amp combo use battery and they need to be recharged. This is not the case with DACport, DACport only needs a USB cable to connect it to your laptop or your iPad because it does not have a battery. It draws its power from your computer’s USB port. You don’t even need to install any driver. It’s that easy. Oh yes, you can use a DACport with an iPad. If you are using a portable music player, don’t bother buying a portable amp. It adds bulk and weight. You may also end up spending too much money on LODs, interconnects… Look at this set-up:¬†Cypher Labs AlgoRhythm Solo. Honestly, I think it looks rather stupid. If I have to use a portable music player like an iPod, I greatly prefer to use my old trusty iPod Mini (that’s right, iPod Mini) without an external amp or DAC. Sometimes, audiophiles may turn into audiphools. They are willing to sacrifice everything for one thing called sound quality. I bet CEntrance DACport offers much better SQ than that bulky set. That bulky set is NOT a portable setup. Instead of wasting your hard-earned money for silly things like LODs for an external amp or DAC, get yourself a nice pair of headphone. You will be much more satisfied in the long run.

Do I keep any headphone and headphone amp?

Now, I’m settled with Schiit Asgard (3/16 /11 – oops, got a Lyr now, purely for the tubes)¬†and Grado RS1i. I consider both of them to be the best in their price ranges. Surprisingly, I find Asgard superior to Audio-gd Phoenix (yep, a $250 made in USA amp Vs. $1200 made in China amp). Grado RS1i is a very fun pair of headphone. It excels with rocks. Guitar strings sound superb. It’s just magical with rock genre. The¬†RS1i fits better on my head, LCD-2? not as good and very heavy. You may question why I decided to scale back a bit. Well, the reasons are:

  1. I no longer listen to headphone that much.¬†I listen to headphone ¬Ī¬†1 hour a day.
  2. I don’t feel comfortable wearing headphone for hours.
  3. My fear of hearing impaired.
  4. Speakers are superior in every way. Headphone cannot resolve the same level of resolution and imaging as a good pair of speakers.
  5. I could have splashed a chunk more for a GS-1 which had always been my number one preference for a single ended solid state amp. It’s been well known that GS-1 and GS-X are the most transparent headphone amps in the market. My reason is simple, sometimes, good enough is good enough. Asgard Lyr is good enough. ūüėÄ

Now, I’m obviously a headphone lover, but the truth is, as much as I love headphones, they will always be secondary to speakers in my life, because speakers are just that much more dimensional, natural, and convenient to listen to; there’s nothing on your noggin that could fall off, or prevent you from hearing important audio cues like phones, doorbell, neighbor screaming for help, and it’s much easier to share music with others.

Schiit Asgard Lyr and Grado RS1i are my last headphone system. I will likely not going to add a headphone, unless it is broken. That Schiit amp will likely outlast me, so there you go, a long-lasting headphones system. And this is where I stopped: A Happy Ending (Hi-Fi) ~ [I also explained a bit about how you should spend your money, where to spend it on, and various issues about audiophile in general]

Head-Fi users’ impressions and reviews…
I think it will be wise for those of you who are reading reviews to make sure that the reviewer has considerable knowledge about various amps in the market. A review like¬†this is pointless IMHO… The reviewer did not compare his gear with top-tier amps and DACs or even worse, the reviewer has little to no experience with top-tier amps and DACs. I imagine the reviewer will be completely floored with an AMB M^3 or a HeadAmp Gilmore Lite .

From those many reasons above: Head-Fi is no longer a useful place and headphones are inferior to speakers, I decided to leave Head-Fi world. It’s been a fun experience. Thank you Head-Fi!


Update (3/19/2011): ~ read links on the top of this page:
Looks like Head-Fi has become¬†extremely hostile towards NwAvguy, links to his blog have been deleted. Let’s wait and see what will be deleted next… This is not the first time I have seen this happened on Head-Fi. I just didn’t expect them to be super protective of their sponsors. I have all the print screens and PDFs of the deleted posts if anyone wants to read them. No wonder there are more and more¬†bad guys roaming free on Head-Fi. ūüė¶ I guess,¬†a farewell to Head-Fi is a good thing after all…

About two years after the introduction of the original Pico amp (with or without DAC), Justin introduced his latest creation, the Pico Slim.¬†The new Pico Slim is primarily designed to drive IEMs (in ear monitors) ~¬†It’s not designed to cater larger portable amp market.¬†It’s small and slim form factor is meant to attract those who want to carry a portable amp that doesn’t consume too much space. There are many portable amps in the market but none of them has the design prowesses or the form factor of the Pico Slim.

HeadAmp has been building their reputation based on their extreme attention to details and superior designs. Justin Wilson, the man who is running HeadAmp all by himself is one of the most respected headphone amp designer in the industry. HeadAmp is a one man shop. So, please bear with him if he has not replied your emails or phone calls.

I’m using the Pico Slim almost everyday. It’s small, err… it’s tiny…! It doesn’t add much foot print to my already large iPod 5.5G. There are portable amps that add their own sound signatures. It’s not necessarily a bad thing, I just prefer a more transparent amp.¬†Unfortunately, most portable amps do have their own sound signature. Pico Slim is no exception.¬†Given how bad the iPod is and channel imbalance issue in most amps, Pico Slim is a revelation. It is silent (silent in HeadAmp term means completely silent at any reasonable listening level; I can’t detect any audible noise at normal listening levels), more transparent than most portable amps and tiny.¬†I ended up not liking my iPod 5.5G, it sounds congested if compared with the highly regarded AMB Gamma 2. This is a bit disappointing because the reason why I bought the Slim is to pair it with my iPod, now it’s also serving its’ duty as a transportable computer rig.¬†In my experience, a separate DAC is always better than an iPod. Apart from being tiny, it’s a cute amp.

Although it has 255 steps attenuation, I find half of the volume range useless. I find myself always go pass 12 o’clock to get reasonable listening volume level. Finding the sweet spot is quite troublesome as well, I wish Justin could have made it to have fine volume adjustment throughout its’ volume pot. BTW, the sweet spot is somewhere around 1 o’clock. Oh and, the volume knob itself isn’t as sturdy as the original Pico. It feels quite fragile.¬†Other than the volume control and the volume knob, I don’t have anything else to complain.

For those who care about the chassis work, it is simply the most gorgeous portable amp that I have seen. Justin has always amazed me with his work. This one is no exception, the chassis was milled from a single piece of aluminum, CNC cut, and laser engraved. Even the tiny volume knob is a solid aluminum.

If you are looking for a portable amp to drive your IEMs, this is it, the near-perfect portable amp.

Here are of Justin’s posts to get some glimpses on how he designed the Pico Slim:

I have not announced a price yet, but I have said it will be in line with my other portable amps – despite the much higher cost of parts of the Pico Slim, and time spent designing it. I would say it sounds a little warmer than the original Pico, but I am focusing on the experience of using this amp with IEMs and other sensitive headphones.

The prototype finished running with a battery life of 72 hours. That’s a significant increase from the original 40-50 hours, while the enclosure is also now 20% smaller. This isn’t due to changes in the circuit, it still uses the same amount of power, just changes to the layout that allowed a larger battery to fit. ‚Ķ

The battery pack will cut off automatically when the voltage gets too low, so I wouldn’t worry about that.
As for battery leakage, after about a year of non-use you can expect the charge to be about 2/3 full. 1 week without use is nothing
I really don’t think there’s much you can do to increase the life of the battery, so don’t worry about how you use it and charge it. They are rated for 500 cycles, which means the battery is expected to be at 70% of its original capacity after that usage. At 8 hours use per day, that would be 12 years. So that rating is only useful for devices like cell phones that might only have 2 hours of talk time, because batteries like this only last about 3 years whether you use them or not. All the MacBooks and iPhones have internal batteries and they are far more taxing on the batteries, and you can’t replace any of them easily. Hasn’t hurt their sales, so they don’t care. At least I’m honest about this and I’ve made it extremely easy for the battery to be changed. Remove 4 phillips screws, unplug battery, plug in new battery, put screws back in. That’s it. I guarantee to offer new batteries for at least 10 years, and beyond that there are hundreds of other battery cells that can fit. By that time the latest technology will probably get several hundred hours of life in a Pico Slim.

Noise level will be higher than the regular Pico. All digital volume controls add noise. But it’s insignificant and well worth the advantages. With ES3X, my most sensitive IEM, I can’t hear anything until it’s past the level I would ever want to listen at.

You are talking about the direction of the polishing. You’d have to polish forever to remove everything.¬†The owner of the company that does this work has said I am the most demanding customer he has ever had, and that’s probably true.¬†Many of the metal finishes on mass market electronics are created with processes that are illegal in the United States and most western countries as they are known to cause cancer or are very bad for the environment but they’re OK in China. This makes things more difficult. Accept that these are hand polished and may have small imperfections that would not be found with an aggressive chemical process.

The coupling caps are Niobium Oxide and PPS film.

It appears that the Pico Slim will be the only USB-charging headphone amp on the market that follows the rules for USB charging.¬†A USB device must request permission from its host before charging. Charging can be done at up to 100mA or 500mA, or be denied any current such as when the computer is asleep.¬†Most USB devices simply try to charge at 500mA at all times by “stealing” power from the USB port without permission. This is the cheap and easy way to do it. There are risks and problems with this.¬†Risk of damaging a low power (100mA) USB port, or charging won’t work at all because the computer will shut down the USB port.¬†While most new computers and full-size laptops only have high power (500mA) ports, low power ports are increasingly common in portable devices like netbooks, UMPCs, and PDAs that will have the ability to charge another device in this case a headphone amp.¬†The Pico Slim will find out if the USB port is a low power (100mA) or high power (500mA), and then charge appropriately. This means it will be compatible with all USB ports and all devices that can act as a USB host.¬†Find out if your USB charging amp does this, if not, you are risking damage to a computer/other host device, or you won’t be able to charge at all.

Clipping ~ Was looking at some specs last night and realized another area where the digital volume control in the Pico Slim does extremely well.¬†It has the ability to accept audio inputs that are far larger voltage than the voltage that powers the digital volume control (in the case of a li-ion/li-poly battery, usually 3 to 4V).¬†With most other digital volume controls, audio inputs at higher voltages than the battery voltage will be clipped.¬†Does your source output more than 3-4 volts / 1-1.4Vrms? If you are using an iPod or other portable DAP, you should be OK — most of the time. If you use a home CD player or DAC, chances are you will be in the clipping range. Many USB DACs will also output above this level.¬†Clipping will become a significant issue especially with recent CD pressings being made with almost no headroom. The Pico Slim can accept an input signal far greater than necessary from any kind of source.

the whole point of the digital volume control was because regular analog pots had poor left/right matching at low volumes, and they were also limited in how quiet they could go.¬† so with many IEMs, you could be at a listening level even with the volume knob all the way down.¬† turn it up slightly and it could be very loud, and still have left/right imbalance.¬† this way you have far more range.¬† about every 1 degree of rotation is a 0.5dB change.¬† sure you may find that leaves a 20 degree range with a particular headphone/source setup, but its going to be compatible with all combinations you throw at it, and you’re going to be able to hit every 0.5dB adjustment with slight turns of the knob.¬† the alternative would have been to have an infinitely rotating knob, which would have required resetting the volume to 0 at power off, and there was no room for any kind of display to indicate volume level.¬† I wanted to duplicate the experience of the analog pot, just with much more attenuation and way better channel matching.

THIS FEATURE HAS BEEN CANCELLED ~ Here are some ideas. These are all things that could be added later. Right now, the priority is just getting the Pico Slim finished.¬†– Left/right balance adjustment. I have seen several people ask about this recently. It could be adjusted through the USB port.¬†– Change the volume control. You probably don’t want to do this, since the Pico Slim already has 255 steps, 0.5dB between each one, and 110dB attenuation and nothing comes close to that kind of precision adjustment. But if you wanted to, you could change it so it only has 23 steps, and set it up so that it emulates a DACT Stepped Attenuator exactly. Or maybe you find even though the Pico Slim has so much adjustment, you still only ever use the area between 10-12 o’clock. Well you could customize it so that 10-12 o’clock becomes the entire 300 degree rotation of the volume control.¬†– Scare your friends by making the volume go full blast 1 minute after power on. Not recommended.¬†– Count the number of times the battery has been charged.

Here is a link to the “Q&A” about the Pico Slim that Justin posted on the original Pico Slim thread: HeadAmp Pico Slim portable headphone amplifier