Introduction to the Zero DAC and Headphone amplifier.
Posted 09-17-2008 at 01:30 AM by Currawong
Updated 04-06-2009 at 12:47 PM by Currawong (Fixed a couple of things.)
Updated 04-06-2009 at 12:47 PM by Currawong (Fixed a couple of things.)
Tags zero dac
Jan 2009: After the issues people have had receiving faulty Zeros, we have asked the maker of the HDAM upgrade to design an alternative to the Zero. This is now known as the Compass. You can read the Head-fi discussion about the design. This is likely to be available from February and, though it's a bit more expensive than a fully upgraded Zero from Lawrence, it is made to much higher standards.
April 2009 Edit: This guide is merely for information only. It's not a recommendation for the Zero. Due to its poor reliability, buying it is not recommended.
What is the ZERO?
The ZERO is a Digital to Analogue converter (DAC) and headphone amplifier/preamp made in China that has become popular on head-fi.org due to its low price (US$99 for the basic unit) and that it can be upgraded for around the same amount for a huge improvement in sonic quality.
The ZERO's product page from Tianyun100 (in Chinese).
Where can I buy it?
The Zero is available on eBay (click here for a direct search link). People have reported good experiences buying from wsz0304 on eBay. If you don't want to use eBay, the unit from Lawrence. He can be contacted at lawrencechanbig ((%)) msn.com. (Replace the obvious with an @ symbol). As of late October 2008, a few people have reported that their units from Lawrence arrived defective or not with the options requested and difficulty in resolving these issues.
What can it do?
The ZERO, internally, consists of two parts: a DAC, which can convert a digital signal, either coaxial or optical, into an analogue signal, and a headphone amp + pre-amp that can be used with either headphones or a power amp, headphone amp or powered speakers.
Normally, only the DAC section is in operation, with output going straight to the rear RCA jacks. If the Preamp button is pressed, the output goes through the amp/pre-amp section as well, controllable with the volume knob. If headphones are plugged in and the Preamp button is pressed, the ZERO becomes a headphone amplifier.
How can I connect it to my CD player or computer:
You have only two choices of connection to the ZERO: Optical digital, using a plastic or glass TOSLINK cable, or a coaxial digital cable with RCA connections. Many CD players have both of these as an output options. Many sound cards have optical digital outputs, as well as "SPDIF" coaxial digital output. Some improvement in sound quality will result from using a good quality coaxial digital cable, such as from Blue Jeans, or a quality glass optical cable instead of the one that comes with the ZERO. Penchum found a good quality glass optical cable which I need to find the link for.
What upgrades are possible?
To understand this, we have to take a look inside the unit. Inside, you will see three main parts, the large transformer, the large circuit board for the DAC and a smaller circuit board for the headphone/pre-amp.
OPAMP upgrades:
On the larger DAC board is a removable chip known as an OPAMP. On the headphone/pre-amp are two OPAMPs. These chips are essentially the equivalent of a bunch of transistors and amplify the signal. Since they are presumably cheaper, use less power and are more compact to manufacture, they are often found on audio cards, in CD players and other audio devices. The 3 OPAMPs in the ZERO are "dual" OPAMPs, that is, amplify two channels. This is important to know, as there are "single" OPAMPS as well. These OPAMPs can be replaced with better quality ones, resulting in a much better sound from the ZERO.
The current best all-round recommendation from Penchum's testing is to use two Burr Brown OPA627 OPAMPs in the DAC and two LT1364 OPAMPS in the headphone/pre-amp section. WAIT, yes, I did just say "two" OPA627's, as they are single OPAMPs, you'll need an adaptor to use them in the slot, known as a Brown Dog adaptor.
Your OPA627s may be the soldered version and not the socketed version and look like this, with the second chip underneath:
The sound signature of the OPA627 was described by Penchum as being "tube-like". It's gives a rather warm, but still very detailed sound.
Luckily, Lawrence sells an upgraded ZERO for US$275 (including shipping, but note this might vary depending on which country) which includes these better OPAMPS, better volume control saving those of you who just want to buy a nice unit and listen to music without taking off the cover and fiddling an easy option.
Other people have experimented with "OPAMP rolling" - experimenting with many different combinations of OPAMPs in the ZERO, but the purpose of this guide is not to get into that. If you're interested in doing that, there are a great many you can get free samples of and try.
Volume Pot Upgrade:
The default volume pot in the ZERO is a cheap and somewhat nasty Chinese unit which is known to often be imbalanced at low volumes and even give a bit of hum and hiss. Unfortunately the only replacement known of at this stage is a NOS (New Old Stock) ALPS pot from Japan which Lawrence has a number of. If you've already got a ZERO, replacing the default one will require soldering skills. Otherwise, if you order the upgraded ZERO from Lawrence, you can order the better volume pot for an extra $20.
OPAMP replacement with a HDAM:
Not to confuse the HDAM with what Marantz created, it's a different thing, a HDAM unit replaces an OPAMP altogether with, get this, transistors! That's right, one of the best upgrades you can make to the ZERO is to replace the thing that replaces transistors in the first place, with what it replaced! Confused yet?
The idea came from the Burston HDAM unit that is often used to upgrade CD players in the same way. However, while the Burston unit is a little expensive, the Chinese manufacturer of them, Audio-gd, is not, and you can buy not only the same unit Burston sells, but a newer model with a slightly different sound signature. The older, but more neutral sounding module is known as the Earth. The newer module is called the Sun.
The problem with these units is, as they are vertically-mounted circuit boards (once they are plugged into your OPAMP slot) the cover of the ZERO wont fit back on. As a result, both Lawrence and Audio-gd sell versions that include a 10cm or so long set of wires so that the HDAM can sit elsewhere in the case. Though the units weren't originally designed to be used with extension wires, there have been no reports of problems.
Currently, replacing just the DAC OPAMP with a HDAM is recommended. You can try replacing the pre/hp amp opamps with HDAMs. IMO it's a bit overkill, as the money would be better spent on a dedicated headphone amp, such as one of the Audio-gd models. If you've bought an upgraded ZERO, replacing the pair of OPA627's with a dual-HDAM unit is the go. Feel free to experiment though. All three opamps in the Zero are dual/double opamps.
If you have a soldering iron, connecting the earth wire of the HDAM to the earth leg of the RCA jacks is something I recommend, as it improves the SQ, giving it more accuracy and punch. No soldering iron? You could just use an alligator clip. Edit: This is NOT necessary to do. Also, attaching the ground wire to any of the chassis screws is not recommended as the HDAM becomes quite hot. If it's too much hassle, just leave the ground wire not touching anything.
The unnecessary capacitors:
An interesting find on the web is a site called The Lampizator. In it, the owner does some quite crazy modifications to his Zero in the name of better sound. However, while we aren't interested in the really crazy stuff, one of the mods is quick, easy and only requires a small pair of wire cutter or even strong scissors and is well worth it, scary as it sounds.
As stated on the Lampizator site in the "bad points" about the Zero: "The output RCA are connected to noise killing caps which shouldn't be there at all." If you snip off these caps, the muffled treble of the Zero will clear up considerably, opening up the top end. There is no downside to this modification, except voiding your warranty (though return shipping would probably cost as much or more than the unit itself anyway).
Note: Myriad felt that after snipping these caps, the sound was too bright for him with his Grados. Grado owners might want to keep this in mind as they are reputably bright headphones.
Headphone compatibility:
The ZERO has enough grunt to drive low or high impedance headphones, however remember that the headphone amp built in is very basic. With low impedance cans such as the AKG K701 and Denons, the result is rather good, though not with as much spaciousness and separation in the sound as you'd get with a dedicated amp. If you've been listening out of a crappy PC soundcard and switch to a ZERO, it will be a massive improvement. The ZERO will make do if you have good headphones and haven't yet heard better, but wont in any way compare to adding a good few hundred dollars worth of amp will.
Can I put my amp on top of the ZERO:
It's probably not a good idea unless, like me, you have a slow spinning fan blowing air across the units. The ZERO heated up my Little Dot MKV quite impressively before this.
Summary:
The basic ZERO unit:
US$99
DAC OPAMP: B-Brown OPA2604
HP/pre OPAMPs: ?
Volume pot: "Song" (China)
The upgraded ZERO: (Lawrence's version)
ZERO DAC
DAC OPAMPs: Burr Brown OPA627
HP/pre OPAMPs: LT1364
Volume Pot: ALPS (Japan)
The upgraded ZERO: (wsz0304 version)
ZERO DAC
DAC OPAMPs: Burr Brown OPA627
HP/pre OPAMPs: NE5532 (original)
Volume Pot: Song (original)
The "as far as you can go without soldering" ZERO:
ZERO plus a HDAM unit with extension wires.
DAC OPAMP: Audio-gd Earth or Sun, or Moon.
How does it compare to other DACs?
April 2009 Edit: This guide is merely for information only. It's not a recommendation for the Zero. Due to its poor reliability, buying it is not recommended.
What is the ZERO?
The ZERO is a Digital to Analogue converter (DAC) and headphone amplifier/preamp made in China that has become popular on head-fi.org due to its low price (US$99 for the basic unit) and that it can be upgraded for around the same amount for a huge improvement in sonic quality.
The ZERO's product page from Tianyun100 (in Chinese).
Where can I buy it?
The Zero is available on eBay (click here for a direct search link). People have reported good experiences buying from wsz0304 on eBay. If you don't want to use eBay, the unit from Lawrence. He can be contacted at lawrencechanbig ((%)) msn.com. (Replace the obvious with an @ symbol). As of late October 2008, a few people have reported that their units from Lawrence arrived defective or not with the options requested and difficulty in resolving these issues.
What can it do?
The ZERO, internally, consists of two parts: a DAC, which can convert a digital signal, either coaxial or optical, into an analogue signal, and a headphone amp + pre-amp that can be used with either headphones or a power amp, headphone amp or powered speakers.
Normally, only the DAC section is in operation, with output going straight to the rear RCA jacks. If the Preamp button is pressed, the output goes through the amp/pre-amp section as well, controllable with the volume knob. If headphones are plugged in and the Preamp button is pressed, the ZERO becomes a headphone amplifier.
How can I connect it to my CD player or computer:
You have only two choices of connection to the ZERO: Optical digital, using a plastic or glass TOSLINK cable, or a coaxial digital cable with RCA connections. Many CD players have both of these as an output options. Many sound cards have optical digital outputs, as well as "SPDIF" coaxial digital output. Some improvement in sound quality will result from using a good quality coaxial digital cable, such as from Blue Jeans, or a quality glass optical cable instead of the one that comes with the ZERO. Penchum found a good quality glass optical cable which I need to find the link for.
What upgrades are possible?
To understand this, we have to take a look inside the unit. Inside, you will see three main parts, the large transformer, the large circuit board for the DAC and a smaller circuit board for the headphone/pre-amp.
OPAMP upgrades:
On the larger DAC board is a removable chip known as an OPAMP. On the headphone/pre-amp are two OPAMPs. These chips are essentially the equivalent of a bunch of transistors and amplify the signal. Since they are presumably cheaper, use less power and are more compact to manufacture, they are often found on audio cards, in CD players and other audio devices. The 3 OPAMPs in the ZERO are "dual" OPAMPs, that is, amplify two channels. This is important to know, as there are "single" OPAMPS as well. These OPAMPs can be replaced with better quality ones, resulting in a much better sound from the ZERO.
The current best all-round recommendation from Penchum's testing is to use two Burr Brown OPA627 OPAMPs in the DAC and two LT1364 OPAMPS in the headphone/pre-amp section. WAIT, yes, I did just say "two" OPA627's, as they are single OPAMPs, you'll need an adaptor to use them in the slot, known as a Brown Dog adaptor.
Your OPA627s may be the soldered version and not the socketed version and look like this, with the second chip underneath:
The sound signature of the OPA627 was described by Penchum as being "tube-like". It's gives a rather warm, but still very detailed sound.
Luckily, Lawrence sells an upgraded ZERO for US$275 (including shipping, but note this might vary depending on which country) which includes these better OPAMPS, better volume control saving those of you who just want to buy a nice unit and listen to music without taking off the cover and fiddling an easy option.
Other people have experimented with "OPAMP rolling" - experimenting with many different combinations of OPAMPs in the ZERO, but the purpose of this guide is not to get into that. If you're interested in doing that, there are a great many you can get free samples of and try.
Volume Pot Upgrade:
The default volume pot in the ZERO is a cheap and somewhat nasty Chinese unit which is known to often be imbalanced at low volumes and even give a bit of hum and hiss. Unfortunately the only replacement known of at this stage is a NOS (New Old Stock) ALPS pot from Japan which Lawrence has a number of. If you've already got a ZERO, replacing the default one will require soldering skills. Otherwise, if you order the upgraded ZERO from Lawrence, you can order the better volume pot for an extra $20.
OPAMP replacement with a HDAM:
Not to confuse the HDAM with what Marantz created, it's a different thing, a HDAM unit replaces an OPAMP altogether with, get this, transistors! That's right, one of the best upgrades you can make to the ZERO is to replace the thing that replaces transistors in the first place, with what it replaced! Confused yet?
The idea came from the Burston HDAM unit that is often used to upgrade CD players in the same way. However, while the Burston unit is a little expensive, the Chinese manufacturer of them, Audio-gd, is not, and you can buy not only the same unit Burston sells, but a newer model with a slightly different sound signature. The older, but more neutral sounding module is known as the Earth. The newer module is called the Sun.
The problem with these units is, as they are vertically-mounted circuit boards (once they are plugged into your OPAMP slot) the cover of the ZERO wont fit back on. As a result, both Lawrence and Audio-gd sell versions that include a 10cm or so long set of wires so that the HDAM can sit elsewhere in the case. Though the units weren't originally designed to be used with extension wires, there have been no reports of problems.
Currently, replacing just the DAC OPAMP with a HDAM is recommended. You can try replacing the pre/hp amp opamps with HDAMs. IMO it's a bit overkill, as the money would be better spent on a dedicated headphone amp, such as one of the Audio-gd models. If you've bought an upgraded ZERO, replacing the pair of OPA627's with a dual-HDAM unit is the go. Feel free to experiment though. All three opamps in the Zero are dual/double opamps.
If you have a soldering iron, connecting the earth wire of the HDAM to the earth leg of the RCA jacks is something I recommend, as it improves the SQ, giving it more accuracy and punch. No soldering iron? You could just use an alligator clip. Edit: This is NOT necessary to do. Also, attaching the ground wire to any of the chassis screws is not recommended as the HDAM becomes quite hot. If it's too much hassle, just leave the ground wire not touching anything.
The unnecessary capacitors:
An interesting find on the web is a site called The Lampizator. In it, the owner does some quite crazy modifications to his Zero in the name of better sound. However, while we aren't interested in the really crazy stuff, one of the mods is quick, easy and only requires a small pair of wire cutter or even strong scissors and is well worth it, scary as it sounds.
As stated on the Lampizator site in the "bad points" about the Zero: "The output RCA are connected to noise killing caps which shouldn't be there at all." If you snip off these caps, the muffled treble of the Zero will clear up considerably, opening up the top end. There is no downside to this modification, except voiding your warranty (though return shipping would probably cost as much or more than the unit itself anyway).
Note: Myriad felt that after snipping these caps, the sound was too bright for him with his Grados. Grado owners might want to keep this in mind as they are reputably bright headphones.
Headphone compatibility:
The ZERO has enough grunt to drive low or high impedance headphones, however remember that the headphone amp built in is very basic. With low impedance cans such as the AKG K701 and Denons, the result is rather good, though not with as much spaciousness and separation in the sound as you'd get with a dedicated amp. If you've been listening out of a crappy PC soundcard and switch to a ZERO, it will be a massive improvement. The ZERO will make do if you have good headphones and haven't yet heard better, but wont in any way compare to adding a good few hundred dollars worth of amp will.
Can I put my amp on top of the ZERO:
It's probably not a good idea unless, like me, you have a slow spinning fan blowing air across the units. The ZERO heated up my Little Dot MKV quite impressively before this.
Summary:
The basic ZERO unit:
US$99
DAC OPAMP: B-Brown OPA2604
HP/pre OPAMPs: ?
Volume pot: "Song" (China)
The upgraded ZERO: (Lawrence's version)
ZERO DAC
DAC OPAMPs: Burr Brown OPA627
HP/pre OPAMPs: LT1364
Volume Pot: ALPS (Japan)
The upgraded ZERO: (wsz0304 version)
ZERO DAC
DAC OPAMPs: Burr Brown OPA627
HP/pre OPAMPs: NE5532 (original)
Volume Pot: Song (original)
The "as far as you can go without soldering" ZERO:
ZERO plus a HDAM unit with extension wires.
DAC OPAMP: Audio-gd Earth or Sun, or Moon.
How does it compare to other DACs?
Quote:
Originally Posted by Ben Diss
I have a Zero with just an OPA624 upgrade. I've compared it to a DIYEden Great March II and to a Lavry DA10.
On a 100 scale, if an iPod rates a 5 and the Lavry a 95, then my Zero is about a 60 and the Great March II is about 85.
On a 100 scale, if an iPod rates a 5 and the Lavry a 95, then my Zero is about a 60 and the Great March II is about 85.
Total Comments 64
Comments
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Total: US$152 (basic model + HDAM) to $220 (Lawrence's completely upgraded version) I guess I don't know what completely upgraded means?Posted 11-07-2008 at 05:18 AM by les_garten
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To clarify my comment/question above...wsz confirmed that the ebay q/a I saw was a mistake, but he couldn't figure out how to remove it. In other words, his unit has the original headphone opamp, not the upgraded one (1364).
Sorry for any confusion.Posted 11-10-2008 at 02:46 PM by brady7
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Hi,
No problems mate! I read all 780 pages of the Zero thread and am now up to speed. Thanx for the quick answer!Posted 11-10-2008 at 03:55 PM by les_garten
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Hey guys! I need some help here. I have issues with the ZERO (Earth HDAM + LT1364):
- Sound is way is way too unbalanced and more ponouced in the right ear. How can I fix this? By soldering a new volume pot? How can I do this if I have never soldered? What do I need beside a soldering iron? Can you guys give me all the setps to follow with pictures?
- How do I ground the Earth HDAM to the RCA jacks? I have a loose white cable attached to the module, what is that for?
- Volume knob not well seated it scratches the chassis when I turn it. How can I fix this?
- Have to turn in the headphone plug in the jack to the point where I can hear sound in both ears. This is bad! How can I fix this?
- Power led faints. How can I fix this?
ThanksPosted 11-11-2008 at 02:39 AM by punk_guy182
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Error: double post
Error: double postPosted 11-11-2008 at 02:42 AM by punk_guy182
Updated 11-11-2008 at 02:43 AM by punk_guy182 (Error: double post) -
I have just received my Modded Zero DAC from Lawrence.
And I'm very disapointed :
It should be with HDAM, Alps pot and LC1864.
I have opened it and there is only the LC1864, no HDAM and no Modified Pot.
very very sad....
I suggest other people t buy the standard one and to mod themself...Posted 11-25-2008 at 11:01 PM by ads2
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Awesome. I think I will try and swap the DAC OPAMP with an HDAM Moon. Thanks!Posted 11-26-2008 at 01:46 AM by Garret Jax
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Woa! Ask a refund, that's outrageous!Quote:I have just received my Modded Zero DAC from Lawrence.
And I'm very disapointed :
It should be with HDAM, Alps pot and LC1864.
I have opened it and there is only the LC1864, no HDAM and no Modified Pot.
very very sad....
I suggest other people t buy the standard one and to mod themself...Posted 12-09-2008 at 06:04 PM by oldschool
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He have sent me a second parcel with the the HDAM and the pot, but I will have to do the modd myself...Posted 12-10-2008 at 08:21 AM by ads2
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Very nice writeup Currawong, really helps the noob head-fier's like me. Do you think it will still be worthwhile in getting an HDAM upgrade for the Zero if you plan on using a dedicated amplifier? If the Zero serves as a dedicated DAC will it still receive the benefits of the op-amp/hdam upgrades?Posted 12-14-2008 at 10:51 PM by dwong
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The HDAM will improve the sound output of the DAC whether you're using the inbuilt HP/pre-amp or a separate amp. If anything, since a separate amp will improve the SQ of good headphones, then any upgrade to your source will be worth it.Posted 12-15-2008 at 05:41 AM by Currawong
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EDIT: Found what I was asking through the Zero MOD thread. Removing my dumb comment
Posted 12-16-2008 at 09:23 PM by dwong
Updated 12-17-2008 at 12:51 AM by dwong -
Thanks for this. This is a great summary. Much nicer than trying to read through the 800+ page thread just to get the basic info about the zero.Posted 12-23-2008 at 06:59 PM by broodwich
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Cutting the 4 brown caps works perfect for me Sound is clean and bright now, just what i like.Posted 12-30-2008 at 07:16 PM by domzz
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Should be getting the OPA-Earth soon.
Quick question about the HDAM grounding and the recent "Edit". So is it still best to ground the HDAM or does it make no difference to the sound quality if I leave the ground wire disconnected?! A bit confused...
As for the earth leg of the RCA jack, is that the middle piece sticking backwards in some of the photos?
Thanks!Posted 01-19-2009 at 06:59 AM by Archimago
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I bought one last week from Lawrence fully upgraded ($220 + Free Ship) and it arrived today. I inspected it, and it appears that it does definitely have the HDAM and LT1364 op-amps, and the pot is different than the default (you can tell by the elongated shaft that doesn't quite suit the depth of the default volume knob), but it is not an RK27. While I realized that wasn't specified in the auction or anywhere here, I was hoping that the specific ALPS pot put into the upgraded version would be the RK27. Seeing as it was as described, I can find no complaint however. I went ahead and purchased an RK27 from the parts page over at TangentSoft and I'll put it in myself sometime next week. Initial listening tests have me very impressed moving from a rig that is just my computer connected directly to a headphone amp via standard stereo patch to having the DAC in between, much less noise in the background at high gain, much cleaner source.
I plan to do an extended burn in and will post my experiences with installing the RK27. I anticipate having to move the board for the pre-amp back by about an inch from where its currently positioned in the case in order to fit the RK27 properly, but I believe it is doable.
EDIT: My god this is magical. I don't know why I never invested in a DAC and preamp before this. Having the extra amplification has given my HD280s some balls in its bass for once, I could almost swear I was listening to some Grados. Which, now that I fixed my noise issue I think it's time to start looking for some more headphones. I've got a pair of HD280s and a pair of HD555s, I'm wanting something with more bass and a better sound stage, something more appropriate for rock and metal (I bought the HD555s originally for listening to opera and classical on my portable player through a pocket amp, and they do sound marvelous for that). Any recommendations? I'm thinking a set of Grado SR-225s, but I'm not sure if I want to spend that much right off the bat.
EDIT2: Decided not to put in the RK27, the Alps pot that was in it is actually pretty decent so I'll save the RK27 for another project. Ordered some Alessandro MS1s and the supplies to recable them and both of my Sennheiser cans with Canare Star-QuadPosted 02-03-2009 at 11:51 PM by Tristor
Updated 02-06-2009 at 01:17 AM by Tristor -
Buying Mod Parts from Chan Lawrence
Hey guys,
I would like to share my modding experience with everyone.
I recently upgraded my stock Zero to this:
DAC OPAMPs: Burr Brown OPA627
HP/pre OPAMPs: LT1364
Volume Pot: ALPS (Japan)
I ordered all the parts from Chan Lawrence. You can reach him here:
eBay My World - biglawhk
I received all the parts I payed for. Everything was well packed.
All the parts worked out of the box and the seller kept in touch via email. A tracking number was provided for my order.
I have read bad things about this seller but in my case I have no complaint whatsoever.
I have no relation with Mr. Chan Lawrence other than this transaction.
So, here's my (very positive) feedback...
Oh yes... and de Zero?...
Well, let's just say that while writing this I'm listening to some Bliss and man... this thing just sounds amazing. The mods were worth every penny. This thing just puts a big grin on my face. :-)
Regards.
JohnPosted 02-05-2009 at 11:44 PM by jmcl
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Just wanted to say, you should not cut the 2 brown caps at the headamp section......those caps are there for dc offset protection.......if anything they should be replaced with higher quality ones, but definitely don't remove them all togetherPosted 02-06-2009 at 04:44 AM by Rick
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Too lateQuote:Originally Posted by fsma
Just wanted to say, you should not cut the 2 brown caps at the headamp section......those caps are there for dc offset protection.......if anything they should be replaced with higher quality ones, but definitely don't remove them all together
But... without them, i don't have to use any EQ, now the highs are perfect (just i like).Posted 02-07-2009 at 10:47 AM by domzz
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Are you talking about the ones at the RCA jacks? or the opamps?Posted 02-07-2009 at 11:04 AM by Rick
