Quartz Acoustic is now an Authorised Dealer for Holo Audio in Singapore

Hardly there is any product that can sell this well before it has even been listed. Owing to the overwhelmingly positive reviews, Holo Audio May did just that.

Holo Audio has made superbly excellent products that their DACs have garnered over thousands of fave and positive reviews from owners and reviewers worldwide. They are now synonymous with the level of high end and high performance with every ounce of value their products are worth.

This has definitely been an exciting progress for the business of QA to secure the dealership for Holo Audio in Singapore and regions, at the same time furnishing the customers here another excellent choice of options in DACs, especially when R2R is concerned.

Essentially the May DAC of Holo Audio is the flagship of the lineup and it does not really need much introduction because it is such a famed model of DAC. The product listing is here for order with the primary information together with links to some of the major review links attached. What comes below are really more of the technical stuffs of May, especially the L3/KTE, where Holo Audio tries to provide a detailed breakdown of the May’s capabilities.


The May is a DUAL mono DAC. so there is a dedicated DAC Module for each left and right channel. Each channel is individually powered by it’s dedicated O-type FLATWIRE transformer found in all three models. We have found after careful testing this new transformer type outperforms ALL transformers we have ever tested to this date. Near zero leakage, improved dynamics and overall spectacular performance. They are handmade for this DAC specifically and deliver world-class performance you would expect.

May DAC also has a new screen on the front that appears the same as the Spring 2 on initial glance. Font size is bigger than Spring 2 but smaller than Spring 1. CD track-time information is displayed when using S/PDIF inputs! This is done by extracting additional data from SPDIF. This a part of CD red book standard but nobody notices this and often forgets this cool feature or doesn’t know how to extract the data! This will lead a fashion for other DAC developer to support this feature. Customers will surely love this subtle feature. The screen is much better contrast and viewing angles and one of the first things one may notice.

The May also has a front power button now! It’s been a request by many customers and gone are the days of a good old reach around to get the DAC to be turned on. As mentioned before above, the DAC has a soft start circuit. So it takes a moment for it to charge up and pull power without blowing the fuse. It actually uses the same exact value of fuse that our Spring 1 and Spring 2 has but with two transformers in this implementation. Without this soft start, one being a blown fuse can occur from power surge, and there could also be pop noises happening. No chance of these things to happen now as we have carefully designed the circuit to be a zero-compromise design.

DAC “May” is the design of a new generation, it’s HoloAudio’s finest technology all designed by Jeff Zhu, the engineer behind these great products. It’s a full discrete R2R type of audio decoder and does not have off the shelf-DAC chip! This is a bespoke custom-designed core DUAL MONO DAC modules that are truly a breakthrough with technology for any DAC chip today. The May is here to achieve new heights, new dynamics and simply a full spectrum of audio to please the aural senses.

May DAC was carefully implemented with some of the finest components.

More about the May DAC

  • The new generation of linear compensation technology solves the accuracy errors caused by resistor tolerance, after compensation, reaching a variance of 0.00005% tolerance accuracy.
  • Proprietary anti-jitter technology that provides a full amplitude of anti-jitter without increasing noise floor and other undesirable effects.
  • Based on this new generation of technology May “梅” can provide a SINAD of >115dB and a dynamic range of >130dB, which represents the performance limit reached by today’s most advanced R2R architecture DAC.
  • Using the ultimate performance of PLL+FIFO technology, provides 0.1Hz Third-Order low-pass ability to inhibit jitter. It also uses a high-performance femtosecond VCXO as the PLL clock source. Under the premise of being almost immune to the front-end jitter, it can also lock up to 1.5us-2us @ 1KHz signal with high jitter. (It can lock up to 1.5us-2us @ 1kHz signal with high jitter on the premise of almost being immune to front-end jitter).
  • Dual Mono DAC L/R channels are independently powered by their own dedicated transformer in the PSU chassis. This provides better channel separation and more accurate sound stage.
  • Official Support USB and I2S up to DSD1024 and PCM1.536MHz sample rate.
  • The USB interface uses proprietary firmware with ultra-low latency, a highly reliable data transmission, ideal USB eye pattern measurements that contributes to 2-4 times higher performance than official firmware.
  • Two sets of independent HDMI-I2S input interfaces are provided, and each set of I2S has a four-way independent circuit, as opposed to standard LVDS chip, making I2S clock signals subject to lower interference and lower jitter. In addition, each group of I2S inputs can be configured with specific pinout configuration, making it compatible with most of the HDMI-I2S digital devices on the market.

Technical information about May custom PLL circuit

Now the May is implemented with femto clocks, and also new discrete ultra high performance voltage regulators. It has an advanced PLL (phase lock loop) circuit that is completely custom built for ultra high performance anti jitter performance. Even the highest levels of jitter are near eliminated which delivers world class performance. Using Crystek VXCO clocks that will take any incoming digital signal and reclock it to perfection! This feature can be enabled or disabled to test and prove it’s performance is truly spectacular. Note: this is NOT an off the shelf PLL, but it’s truly the most powerful PLL found in a DAC. Or at least to our knowledge it’s the most powerful PLL ever. S/PDIF usually is a not a good protocol because it’s very old and dated! It was designed in 70s together with CD with Sony and Philips. As you may know, It encodes the data signal together with clock signal so it can be transferred by a one-core cable. It makes the cable easy to source, but to encode the data to clock at the transmit side and decode the clock from data at the receiving side, creates jitter. Toslink is a fiber glass version of S/PDIF. So Toslink adds even more jitter while doing electronic to photon and photon to electronic translation. So people will see clearly that I2S is usually better than S/PDIF because I2S has 4 separate signal, 3 clocks 1 data. So it does not have encoding-decoding stuff and thus having a better jitter performance. This is important to know.

A common technique to improve the clock signal from SPDIF is PLL. A PLL is to use a local clock generator to track the source clock. You know jitter is actually a time deviation problem. For example, the first period frequency is 44101Hz and the following second period is 44099Hz. Thus it has 2/44100 jitter. A PLL is to smooth the time deviation of clock. So after the PLL, it can be 44100.9-44099.1(this is a weak/poor performing PLL). Or it can be 44100.1 – 44099.9 (this is a strong performance PLL). Usually, a S/PDIF chip, like AK4118A, has an internal PLL. AK4118A is good chip compared to other S/PDIF receiver chip and it marks 50ps jitter. It’s the best we can get from a commercial chip. But it’s far from ideal, and definitely not enough for a HiFi standard we are implementing in the May DAC. So we need a significantly stronger performing PLL. If the PLL is strong enough, it can smooth the 44101-44009 source clock to 44100.00001-44009.99999(very close to ideal 44100-44100)

But to make a stronger PLL is not easy, it’s actually incredibly difficult. First you need a powerful local clock source. A fixed clock can’t be used because it need to be adjusted to follow source clock rate. A common solution to use a VCO (voltage controlled oscillator). VCO is made by resistors, capacitors and inductors. The cost is low but performance is not so great. So, a better solution is to use VCXO(Voltage controlled crystal oscillator), it uses crystal as oscillator and crystal is a far better oscillator. The VCXO we used in May is Crystek’s CVHD-957. This the best VCXO we can get now.

The second hard problem is, the data need to be synchronized with clock. For example, the source has 44101-44099 clock from S/PDIF and that also means it has 44101 samples in first period and 44099 samples in second period. So a good local 44100-44100 clock will have to throw away one sample in first period and lack one sample in second period. An easy fix to it is to use digital filter to smooth the data and it calls ASRC, but ASRC actually modified the data. So after ASRC, the data is modified thus not bit perfect anymore. And digital filter can also generate time domain problems like ringing artifacts. So, a digital filter is not a good way to solve this problem, or you can say, it solves a problem by introducing another problem.

May uses a fifo buffer to store the extra one sample in first period and release it in second period. So it has no harm to data. The difficulty for this design is how to manage fifo buffer. It can be a problem when you have a long-term jitter. And long-term jitter is actually called low frequency phase noise in a frequency domain point of view. To explain it easily, let’s take a example, a long term jitter can be like this, 44101-44102-44103-44104-44105-44104-44103-44102-44101-44100-44099-44098-44097-44096-44095-44096-44097-44098-44099-44100. So you see, it will have 25 extra samples in first ten periods, so the fifo buffer need to able store enough of them and release it in next 10 periods.

So, as a result, May’s PLL’s corner frequency is set to 0.05-0.1Hz in 3-orders. Than means it can reduce a 10s long term jitter by 90%, 1s period jitter by 99%, 0.1s period jitter by 99.9%. That maybe the most powerful PLL in this industry. And the most important is, it won’t lose data, it can still lock the source while huge jitter comes in. When you compared other similar PLL in the industry, you can see it simply unlocks the signal when huge jitter comes in. So, in that way, it simply stops you from listening, it tells you there is a problem but does not solve it. Compared to other competitors PLL. They won’t remove the jitter so clean, and simply unlock the signal for more than 10ns jitters.

May’s input and output interface:

  • Digital input interface includes
  • Enhanced USB (ground isolation) + Titanis 2.0 circuit + KYCON industrial High retention USB Connector (improved impedance spec) – Proprietary inhouse firmware w/ ultra low latency performance. Ultra low noise voltage regulation
  • RCA coaxial
  • BNC coaxial
  • AES/EBU
  • optical fiber/Toslink
  • I2S (HDMI) – improved ultra high performance 4way custom circuit (NOT traditional LVDS chip anymore) backwards compatible
  • I2S-2 (HDMI) – improved ultra high performance 4way custom circuit (NOT traditional LVDS chip anymore) backwards compatible
  • All digital input interface supports DSD (DOP mode).
  • Analog Output interface: single-ended, balanced.

May DAC R2R structure and design + Input/output Stage

Modern and popular delta-sigma type DAC differs from R2R within one clock analog value can recover a sampling point, and the delta-sigma is used to represent an analog signal after passing through oversampling and high-speed digital switching 0 and 1. In comparison, the conversion structure of R2R is most direct and pure, but delta-sigma is essentially a digital chip, high-speed digital signals 0 and 1 switch to the low-pass filter to process the analog signal and this process is prone to various problems, produce digital sound (digititus) and also in the super-sampling process will inevitably cause some ringing and distortion. But DAC R2R structure requires high-precision resistor network which the cost can be very expensive. And the digital delta-sigma DAC chip in comparison is very low cost.

Patented R2R technology. 

This is the first discrete DAC that has Linear compensation and this allows for ultimate music reproduction accuracy. Dual R2R ladder network with advanced architecture for PCM, and Dual Resistor Ladder network with optimized architecture for DSD!

I/O stages: There is an Op Amp used for input stage and discrete component used for the output stage. The discrete output stage is working in pure class A.  It’s BiPolar Junction Transistors, direct coupled.

A common question we get…” Why do you use an Op amp at the input of the DAC?”

The input stage with an opamp is a good choice. It has a paired transistor input by the nature it is manufactured. But an opamp for the output stage is limited due to it’s size and the thermal capability. Also, no one will offer an opamp with class A output as it’s efficiency is so low. So an opamp used as input and discrete output combined together will have an advantage. It doesn’t mean that all discrete is not good. Actually, if we need to achieve enough low distortion. It needs at least 30-40 transistors. Which not only will it be huge and waste of space but it will also be too costly. To beat the opamp’s performance, a simple discrete architecture is not possible, although an all-discrete design looks beautiful.

We use opamp+discrete architecture for the amp parts of May. Opamp is used for the input stage, discrete is used for the output stage. All the transistors in the opamp are in the same die, then it is matched by nature. This is key because by now, there are few choice for low noise matched pair transistors but an opamp has plenty of them inside. The Output stage is discrete because it generates a bit of heat. We need a class A output stage. So you can see May is very hot compared to other DACs. An opamp output simply can’t handle that power.

The true balanced DUAL MONO circuit design

XLR is using all of the circuit and RCA is just using half of them. The balanced output has better performance (THD, noise) and also better common mode rejection rate. If you’re listening environment contains interference, either from AC power or from EMI/RF then you will find a full balanced system can really help significantly.

With diverse and flexible sampling mode conversion mode

1: NOS mode: has no digital oversampling, the raw data is directly converted to analog. Because digital oversampling will produce time-domain distortions, such as ringing, NOS avoids these problems.

2: OS mode: PCM is over sampled to PCM at a higher frequency, DSD is over sampled to DSD at a higher frequency, and then digital is converted to analog.

3: OS PCM mode: in either PCM or DSD the data will be oversampled to PCM and then digital is converted to analog.

4: OS DSD mode: in either PCM or DSD the data will be oversampled to DSD and then digital is converted to analog.

 

35% lower in Worldwide Shipping Rates for ALL Muzishare Amps with FREE Aucharm Fuse!

In order to further expand the reach of Muzishare tube amps to wider parts of the world, for they are more deserving to be enjoyed by more of the audiophile community, QA has managed to seek out lower worldwide shipping rates by DHL/FedEx up to 35%* cheaper! In some instances, these savings could be as much as close to S$500!

For those who have previously enquired but are held back by the higher shipping cost, we hope you can find comfort in knowing the substantial amount of savings you can have now. Feel free to chat with us again to get an updated shipping fee now!

Do note that the warranty covers the unit, but not the shipping service – insurance from DHL/FedEx will cover that. Although 1-year warranty for all Muzishare tube amps is valid and covered by QA Singapore no matter where the region it was purchased from, customers will still need to bear any shipping fees if it was decided for the unit to be sent to Singapore for support coverage as well as for any subsequent return sending back to customers.

To sweeten the deal further, any purchase of our X7, X9 or R100 amps will include 1x popular Aucharm highest performing audiophile fuse for FREE! If you are going to be amazed by the stock models of our Muzishare tube amps, you will be in awe how spectacular the upgrade to Gustard fuse is going to be. It is easily one of the worthwhile and excellent performance upgrades one could do to push the potential of these tube amps.

Enquire now! Email or WhatsApp us.

*This savings rate will remain for as long as until further adjustment from logistics.

Do not worry about the voltage difference. The units can be used in either 220-240V or 110-120V covering most regions. We will set it for you so there is no need to do that on your part.

Introducing our Star Series Cables

A few months in the making and testing, QA is excited to announce a new lineup of high-performance cables, the Star Series.

Star Series is born out of the symbolism of excellence, like how children stand to understand from their first grading system since young. At the same time, it is also paying homage to the five stars on our Singapore national flag, where the country Quartz Acoustic proudly calls home.

There is no end to the best in hifi, so the thought of naming the best lineup of a brand as ‘reference’ like many others do is not QA’s ideal of thought. Surely our best is below the mark of the truly best one out there, if there really is one, categorically speaking. But in using the higher echelon of parts and components with similarly high-end craft of termination, our Star Series is no way hovering at even the upper midrange, but way more above that. With our Star Series cables, you are guaranteed a star of greatness high up in the vast openness of sky amongst others, and definitely also a platform not far away in your journey in search of reaching out to the next or more stars.

Prices of cable lineups in Star Series may look extraordinarily expensive in comparison to similar cables from the general DIY masses, but only because QA Star Series is not those average ones out there. Until one realises the true cost of the connectors/plugs we hand-picked to be used as terminations for our Star Series cables will then the value be fully understood. Using selections from Furutech, Oyaide and KLE to name a few, there is no one critical component of the Star Series cables being a counterfeit or inferiorly-made one, because the quality of the connectors/plugs are that crucial in ensuring these cables will be right down the long list of upgrades after getting them.

Many makers and resellers seemingly market their cables to only the affluent group, actually leaving the majority of users in the audio community totally devoid of chances in hearing what ‘really good authentic’ cables can sound like. This is the reason why we do not say Star Series is only for those who can afford it. Affordability is not true at all in hifi, because enthusiasts and audiophiles like us can afford anything we want – we will go to great lengths to get it, only sooner or later – if we are honest.

And that makes everyone the possibility be the rightful owner of Star Series cables if one fully appreciates how the sum of all parts will be a greater equivalent. Nothing beats owning a cable knowing it can bring significant improvement to their system whilst been safe in the knowledge craftsmanship quality is assured and warranty support is enabled. These are values proving to be monumentally worthier than considering any justification of prices for cables, or worse yet, comparing apples to oranges and still decided based on whichever is the cheaper one. This is only doing a disservice to the outstanding products of the brands involved, who have stood out amongst the rest and have already marked their presence in many truly top-of-the-line industry cables over the years.

And before we left out the reason for Star Series creation – QA believes in the potential of these cables and simply, they deserved to be paired with few of the best connectors/plugs in hifi audio to becoming a more common option of choices for all audiophiles and the community in powering and linking their equipment up.

All Star Series cables come with extended 2-year warranty from QA.

Our Commitment to Corporate Social Responsibility

From the month of March onwards, QA will be donating a small percentage of our proceeds to the Community Chest in Singapore on a monthly basis.

I have always believed in contributing back to the society in any way possible. While the field of industry in my work does not engage in the mass community to directly impact them positively, I hope a small monthly donation is the least I could make a difference.

While QA is nothing of big-earning entity, being registered as company should fulfill a corporate social responsibility, no matter how small, in the capacity as an official business.

All transactions made in March (even for back-dated ones before this announcement) will be attributed towards the donation for the month by beginning of April, with the subsequent months following the same pattern of contribution.

I thank you for your support of QA, from all customers old and new, and thank you for your contribution to the society. Every little amount counts.

Regards,
Jordan

A little backstory of Muzishare R100

Our Muzishare X5 was the first full-fledge branded factory-made tube amp we brought in around 3-4 years ago in bid to increase its exposure to the general audiophile community in Singapore and the region. A tube amp so well-made and beautiful has no reason not to be considered for anyone seriously into getting his/her first, second or third tube amp.

Muzishare over these years has consistently improved on the quality further, both on the aesthetic front as well as the worksmanship and most importantly, audio quality. Their increasing popularity in China are slowly bringing much awareness outside the region and to the global scene. It is imperative such exposure could do a lot of good to have a focus here in Singapore. And as outlined in our previous post, QA’s effort has finally paid off to have secure the official distributorship of Muzishare tube amps in Singapore from November 2019 onwards.

In recent months, Muzishare has been building a flagship model in order to refresh their tube amp lineup, which has been consistently hovering in these respective tube series – EL84 of X3T, EL34 of X5, KT88 of X7 and 300B of X-300B. While KT88 tube amps are traditionally the onset of big boys, for those graduating from a EL34 tube amp, it is no longer a tube series of amp that holds the charm. Many other manufacturers have come out with various KT88 tube amps and begin saturating the market. The once-powerful and rather exclusive KT88 tube amp is now quite a dime a dozen. Not to undermine KT88 tubes at all for I am still a huge fan of the fat beam tetrode, but above this class is another league that just dwarfs the KT88s (as can be seen in the photo below), big triode tubes, 211/845/805.

From left to right: EL34, 5881, 6L6GC, KT66, KT88 & 845. The first four belongs to the same tube type and are interchangeable in most EL34 amps. Currently using the 5881 Brown base from RCA. But 6L6GC remains my all-time favourite which I could not even bear to use, similar to my reverend 6L6GC Blackplates from RCA that are preciously stowed away.

Line Magnetic is one brand of the Chinese-made amps that have enjoyed stellar reputation worldwide for its indisputable quality. They are one of the early adopters in Chinese tube amp manufacturing to use these giant triode tubes. Their 845 and 805 series of amps are parked at the higher end range of the tube amp chain in many rooms, providing a sound output of the higher echelon.

Muzishare’s flagship model of R100 is heading towards this direction – a hefty tube amp that branches into three different versions of 211/845/805 tubes respectively, allowing customer to choose one that they are most comfortable with. It may seem like a challenging feat for Muzishare in building the R100 as it is only a recent development and lack of previous big triode tube model to back as portfolio. Truth to be told, amps from both Muzishare and Line Magnetic come from the same factory estate in Zhuhai at Guandong, China. Connecting the dots, Muzishare does has a wealth of expertise in building a big triode tube amp, confidently and remarkably, as we are to find out in the next post, where I will dive in details on the Muzishare R100.

Quartz Acoustic is now the official distributor of Muzishare tube amps in Singapore

This news came way earlier but the festive period and orders have been preventing us from announcing!

We are pleased to announce that Quartz Acoustic is now the official distributor for Muzishare tube amps in Singapore!

As some of the customers know, we have always been huge admirers of Muzishare amps. They are just very well-built, fantastic quality in performance and are some of the more beautiful tube amps manufactured from China. Their specifications often edged out amps of the same tube types from competitors which gives their amps an excellent value for money.

Muzishare has a strong following in China, where it is considered relatively high-end for a tube amp brand with extensive features and solid workmanship. Manufactured in Zhu Hai, Guandong, China, the components and parts in Muzishare tube amps consisted of high quality, audiophile-grade of materials, build together with remarkable point-to-point exquisite soldering. External chassis are all well-machined and sand-blasted to a posh exterior, resulting in Muzishare tube amps to be heralded as one of the more beautiful and refined tube amp brands in China. A lesser-known fact is that Muzishare amps are manufactured in the same production factory as the remarkable Line Magnetic.

QA will provide all official queries, sales and support of Muzishare amps through all official channels of contact. 1-year official warranty, as with all our other products, will be provided. We will see to your issues and rectify them, if any, before extending the support to China factory if that need arises, even if your warranty has unfortunately expired. Terms and conditions of warranty and returns still applied. All warranties and supports are only applicable to customers of QA and units purchased from QA. Grey and/or imported sets will not be honoured.

Other than the modded and upgraded version of the X5, we also carry:

X3T – EL84 small-scale tube amp that works very well as a headphone amp as well at S$850

X7 – KT88 tube amp with balanced and phono inputs at S$1,850

R100 – 845 tube amp with plenty of power with balanced and phono inputs at S$3,050

Our journey

It was then a part-time sideline to satisfy the ever-growing interest in audiophile myself. Who knows serving the customers of this sideline can be an even growing satisfaction?

While there was a year and a half break in between this period to serve a greater need in my main job as a Photographer, QA was well-rested in the same duration, always having the intention to come back when a time can be right.

It was in 2017 when QA was relaunched with the entire makeover of the brand and website, with internet security high on the list of priorities. SSL was thus introduced site-wide. But more importantly, payment gateway is processed on the side of Stripe, offering even more protection to customers’ credit credentials. These infrastructures serve as a crucial foundation to build upon the trust of customers.

Yes, these are signs of growth and QA aims to grow. For those who follows QA close enough, the stop-gap period when these new infrastructures are being implemented after the break, QA was engaging in the buying service of products from various e-commerce platforms. It was a great platform tapping into consumers’ interest in the growing market then. The availability of choices and options given to consumers were immense. Too immense, though, that QA was not able to leverage on a focus group of products as well as the target audience.


Vacuum tubes. I got to bring that essence of personal belief back in. The glowing beauty of these hot glass bulbs caught my eyes and love the very first time I saw them personally. They were a marvel in decades before, and they are still a marvel now. A vintage product in the ever technology-exploding field of audio definitely should have its place now, at least in Singapore, like how the turntables are turning tables.

Too many great Audiophile products are out there in the world with superb potential yet to be discovered by a larger group of consumers, and they often lack the outlet to get hold of as well. QA is turning towards to be a source for products well-curated that can provide a positive listening experience to audiophiles. You will find audio tubes and tube amps high in our emphasis as that is what I want to be when QA is being thought of.


In 2019, our inventory had undergone some refresh, to cater to the advancement of technology, market prices and most importantly, customers’ varied choices. Performance and value were still the two factors high on our prerequisite list our products must feature in order to be profiled and offered. And we had realised our growing knowledge and experience should now value-add to serve up even more efficient and improved products.

Rising to be one of our USPs, we have begun providing modification upgrades to components in both internals and exteriors of products to push their performances even higher. Stock components can never make it in this perfection-chasing hobby/past time/profession, whatever you called it. For QA, there is no snake oil or placebo on these deemed ‘insignificant’ upgrades; we have done enough experiments to be sure to say different capacitors DO sound differently, as much as a 15-35% change in sound in relation to a tube/opamp change.

Hence there was no reason for QA not to polish gemstones further that are already unearthed when their potentials have much room to scale up. In some instances, we are confident our upgrades will even be comprising of full/re assembly and branding here fully in Singapore.


In 2020 we have successfully become the sole distributor of Muzishare tube amps from Zhuhai, China. For the first brand which we could proudly carry as our product line, it had since garnered wide interests, both locally and abroad, on the superior quality of Muzishare tube amps which shone on its high performance and affordability in compared to other brands on similar specs.

Not long after, R100, a flagship model that was offered in the choice of 211, 845 and 805 SET tubes make its way into our demo sessions. Almost all who have heard it had only positive things to say. By 2021, the improved model of R100 which included the remote control and better-included tubes was making waves in the community, while on their end, Muzishare was bringing on a EL84 tube amp for the headphone user crowd.


2021 was an incredibly busy year despite the unfortunate global pandemic. There was wider recognition for Gotham cables which QA has always been confident that they will make a stronghold for most of the audiophiles who have given them the opportunity. Positivity and surprises were the various feedback that will propel QA to populate more cables types from Gotham in the coming days ahead.

TeddyPardo then became the 3rd brand QA was pleased to have dealership with, as we sought to bring their stable and high quality LPS, not just primarily for the Naims, but also basically any other equipment that require DC votlages to the greater audience in South-east Asia. One can be definitely sure through QA is where you will be getting on hand one of the finest LPS made entirely in the Middle East with extensive warranty and sales support.


Mid 2022 is when things being planned earlier in the year materialised. Not only is Muzishare X9 finally be available for auditioning now, which keeps up the continuity in the confidence of tube amps QA had placed in Muzishare ever since, but having a dedicated space in the form of a retail shop is probably the biggest statement for that!

Having a retail store open is definitely one of the greatest milestones thus far in the history of QA, enough said. Not only has this underlined the commitment QA has placed in providing for the audiophile community, it also meant a great deal from the support QA has gathered from its customers and we fully appreciate that. So please, feel free to drop by the shop, have a chat and I hope you can enjoy a wonderful listening experience too.


There will definitely be a lot more things to look forward to but execution of plans will take time. Things change, but providing warranty support is our beliefs on the quality of products we carry and it will continue to be true. Competition is still inevitable, but we know we have more than what figures can be counted for.

8 years in and counting, it is an evolution of how QA has become, but it is always a growing phase for QA. Newsletter subscription is not in QA’s current plan, so do follow us on the various social media to keep up to date what we are busy at in giving you more performance and value for all the music we love!

How we test our vacuum tubes

We do our testing of preamp triode tubes with the Tube Imp tube tester specifically on their mutual conductance (or transconductance as some say), measured in the unit Gm. Mutual conductance is a common way of measuring, to be it simply, how much life is left in the tube, by measuring the change in plate current across the change in grid voltage. With operating characteristics from tube data widely available, we chart the readings according to what a specific tube type typically shows.

Every single tube type has their own operating characteristics; hence 12AU7’s Gm rating is different from a 12AX7’s Gm. Looking at different readings of Gms across different tube types may be difficult. So to put it simpler for you, we converted the readings into a percentile. It instantly allows the gauge of the tube’s lifespan to be so much easier. A reading of 92% simply means, theoretically, it has still up to 92% of lifespan.

The two percentage readings you see is because a preamp triode tube is actually comprised of 2 individual amplifying sections. So the reading is for one of each.

There are many talks and hearsays on a pair or quads of tubes got to be balanced/matched to sound the best. Matching only applies to the power tubes like EL34, 6L6GC, KT88, 6550 tube types; basically tubes at the output stage of the amp where current draw of the tubes are kept in similar range. Even so, amps with biasing features are totally not reliant on matched tubes to sound their best. Our tube amps like Yaqin MS-110B and Muzishare X5 have their biasing adjustment built into the amps, so unmatched power tubes are never a problem operating in such circumstances. What are the advantages then? Money is saved! Probably too much mark-up is done to tubes being sold just because they are matched. We are not saying that is not important, but if your tube amp has easy bias adjustment, there is certainly no need to spend an extra premium on power tubes being matched which we can only trust some seller to really do the matching.

With matching not applicable to preamp tubes, we then talk about them being balanced. As previously mentioned, a preamp triode tube has 2 amplifying sections in each tube. So a balanced preamp triode tube means the 2 readings within it is very close to each other. So how much of a variation is considered balanced? Well, the good news is this ‘balanced’ attribute of a preamp triode tube is actually not that a big issue in determining the good from the bad. Still, a range of not more than 15% difference between the two readings of a preamp tube is more than fine. And our tubes listed are definitely within that range.

In conclusion, do take precautionary note on getting tubes from sources that advertised their preamp triode tubes are matched, as there is no need for that as far as preamp triode tubes are concerned in audiophile devices. While balanced preamp triode tubes are desirable, if the extra premiums are paid just for them being balanced, the cheaper alternative with some slight variation is probably the better deal.

Warranty Service is our Top-Most Priority

One particular comment from potential customers which I got very often is that they could be getting the same item online themselves at a cheaper price.

Anyone can buy things easily online nowadays, and as an online shopper myself, I can definitely understand that in terms of price comparison.

However, striving to be a responsible online retailer and provide trust to customers, we place as much emphasis in our service and after sales support as in making prices attractive.

With our products imported from legitimate suppliers, we took out the guesswork that you may have in confronting with so many variations you see in sites like Taobao and Aliexpress. There is no need to worry about getting unreliable or mismatched item in the process of choosing one that is the cheapest. We took our own product photography; so what you see in pictures is what you get.

While you may still be getting the exact same item cheaper online by yourself, any problem you may encounter on the product later can leave you by yourself too. Even in the case of your online merchants allowing you to ship back defective items for servicing, the shipping fees incurred for that may just add up to what could be a good deal from the start becoming a costly deal at the end.

That is why one of the most important service from us is to provide warranty, for ALL of the items. Big or small, cheap or expensive, new or used (some tubes), every items we sell have got to be covered.

No worries of not able to find the person to speak to, no worries of not able to find an email to send, no worries of expensive overseas shipping fees and finding out where to ship to. Our warranty given to you is meant to just give you a simple and effortless process; just leave it to us. As long as the defect is under the scope of warranty and within the warranty period, you will get it back fixed.

At the end of the day, these are savings in our prices that will be counted in days to come. After all, values come in many forms not just quantified by figures alone, and we are always confident in that what we provide can be priceless.

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Peninsula Shopping Centre
#03-19, Singapore 179804

UEN: 201706979E

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