Muzishare X7 KT88 Class AB Push-pull Integrated Tube Amp in details

Muzishare X7 KT88 Tube Amp has attracted vast attentions since QA has moved into a shopfront to allow the audition of this wonderful amplifier. Our bad for taking so long in getting the details of the amp into writing as there just too many stuffs to settle in setting up of the shop. So let go straight into a better detailed introduction of the X7 for more accurate information instead of hearsays and misnomers being fed to our customers and misinterpreting the facts.

Above: Video of the sound demo with Muzishare X7

As the official dealer for Muzishare in Singapore, tube amps sold from QA will always be the latest version of what Muzishare has to offer, make no mistake about that. We can understand that due to the lack of recognition and information of Muzishare in Singapore, some details being posted from unofficial routes or channels not from QA may not be the most updated ones. So in any case, please just seek us out for any clarifications.

Reason for saying this being that the current X7 QA is selling is the latest model since beginning of 2022. Yes, now is already 8 months into 2022, but we do have customers comparing cheaper X7s out there when they were the older models WITHOUT the balanced inputs and better optimization of the circuits within. By getting Muzishare products from QA, you are making your spending worthwhile with official support and warranty for the updated models.

To clear another doubt about whether the balance inputs in X7 are truly balanced – yes, they are. The higher end models, but still considerably affordable in comparison for now, of Muzishare tube amps are getting balanced inputs as a future-proofing design consideration. More DACs are getting balanced outputs nowadays, as the number of DACs exploded into scenes for consumers in the past few years. It should not really be a surprise to see tube amps getting such inputs for a more improvement in dynamics and noise reduction in connections when digital music is concerned. What is surprising is some other brands of tube amps are still not making balanced inputs available. Which is why such spec being available in Muzishare tube amps is what makes the price performance ratio exceptionally high.

Above: back panel of the X7 detailing the phono, balanced and pre inputs

The balanced inputs are followed by 2x line in inputs, 1x phono input and 1x pre in. Generally 2x line ins and 1x balanced in for this price range of the amps should be suffice for most users. The presence of the phono input is another bonus for some users who may have just starting into vinyl playing can consider playing with that. We always manage the expectation to our customers and with regards to the phono input, an external phono stage will always triumph any build-in phono pre amp most of the time. We should just treat this presence of a phono input as a bonus good-to-have feature, which can come in handy in anytime of troubleshooting future external phono stage – who knows? Such feature is not available in many other amps while still costing less, so why not?

Pre-ins are not getting uncommon in Muzishare tube amps too. By connecting to a pre-amp one may have, all volume control will be ceded to that, and Muzishare tube amps, the X7 in this case, will be acting as the power amp. Again, another misinformation floating around was that preamps tubes will not be used when pre amp is connected via pre-in – they do. Caveat of using pre-in will be the restriction to using single-ended RCA connection instead of any possibility of using balance connections. However, balanced pre-in is really a niche in tube amp. It will no doubt raise some cost of it on such implementation, but this is definitely a feature QA will hope to see in future Muzishare integrated tube amps as well.

Going to the front of the unit, from the left, we are greeted with something familiar for users who have seen it in the X5. And that is the toggle switch to change between triode and ultralinear modes. Basically triode mode has less power output, at 25W per channel while ultralinear mode produces the maximum power from the 4x KT88 tubes at 45W per channel. 45W per channel is aplenty of power in tube amps specs, rivalling and equivalent to 200-250W per channel of solid state (SS) amps. Hence there is really no issue of X7 not able to drive certain speakers. They are definitely able to drive most speakers out there as low of a sensitivity as 82-83dB no problem.

Above: a pair of toggle switches and a pair of VU meters

Ultralinear mode unleashes to the speakers in its maximum capability, providing the juice and power if ever the speakers need. High dynamics in the frequency spectrum, crisps highs, engaging mids and importantly, deep and tight bass. The wide stereo imaging X7 gives make music listening a truly enjoyable experience, and we are not even talking about the merits of tube-y sound yet.

The clean and precise sound signature of KT88s is the reason why QA always mentioned that they are the best tube type for any one entering or transitioning into tube amps from SS amps. They can almost sound like one, even by any reason if they do not (which is not a deficiency of tube sounds), the tube sounding characteristic will carry you over into another form of enjoyment – emotional enjoyment. Vocals will sound magically sweeter and more realistic, for which we are no longer hearing into the technical part of music listening (some of you will understand what this means), but just purely enjoying music. This literally should be what it is. Even for Classical/Ensemble fans, the lack of vocals will still be up to the treat in that the level of details KT88s can bring to pick up the various instruments is playing is just fascinating.

As for 25W per channel triode mode, the reason of its existence is the flexibility of sounds X7, like the X5, can give. This lower powered mode is useful for higher sensitivity speakers like horns and full range speakers, where the sound signature is also more midrange focused. Listening to Jazz or Oldies where the warmth of tube sound is so desired will appreciate the triode mode available for toggling. The more laid-back and mellow harmonics from triode mode can never make listening on the X7 a fatiguing experience, especially on lower volumes on some late-night music relaxation.

Above: single-ended headphones with 6.35mm plug can enjoy the powerful KT88 driving headphones while another pair of precisely-CNCed msooth knobs are on display showcasing top-notch quality.

KT88 tubes for headphone usage tend to be a bit overkill in all honesty but still can be done with the presence of a 6.35mm single-ended headphone jack. Admittedly not being marketed as a headphone amp, the TRS connection is still available for compatible headphones to be plugged in and be driven with great power in melodic sweet nature of the tubes.

X7 employs a dual VU meter for each channel and as the grooves play, the needle will dance beautifully in the warm, orange back-lit glow of the meter, giving one a sense of nostalgia in a modern-designed amplifier outfit. The VU meter is also crucial for biasing adjustment for the KT88 power tubes, which is made very easy in all Muzishare tube amps with just a simple switch of knobs and trim pots-turning with a small flat head screwdriver.

Turning the knob at the top of the amplifier near the tubes to the respective power tube V1 to V4 (two to each knob, one of each side), the needle will show that particular tube biasing current. The needle should be pointed to 40mA – that is the correct biasing current for KT88 and 6550 tubes in X7. New X7 owners should have no need to adjust anything as it was already done accurately right out from the factory in most cases. There is no harm to switch the knobs to check for it, even when music is playing. However, do take note any future bias adjustment should be done at least 30 minutes in after the amp is switched on, just so the electricity and heat has stabilised the tube for a more accurate reading without much drifting.

Above: turning the biasing knob to the respective tube allows adjustment of its bias through reading of the VU meter

Contrary to some myths, please understand only power tubes need biasing. Preamp tubes do not need biasing. Both tube types, however, will need matching in order for the specs of the tubes in their pairs or quads to be as close and similar to one another in order for the two channels to run exactly the same as much as possible. Still, each and every tube is different. A perfectly identical spec matched tubes may over time drifted and aged at different speeds. That is perfectly normal. Hence it is a good practice to check on the bias reading every few months because the tubes may be drifted higher or lower from the ideal range. Again, that is normal. Just adjust them back.

A single rectifier tube is present in X7, which makes this tube a very likely first to be rolled, in QA’s opinion. As with all mentions to our customers, QA firmly believes the merit of a rectifier tube in tube amps and Muzishare so far is upholding that ethos too. As much as the rectifier being a simple function of converting AC to DC which can be easily done by a small transistor chip, having a rectifier tube doing this job in a tube amp speaks volume in Muzishare tube amps as a true tube amp in this regard. Some, if not most, brands have chosen not to use rectifier tube(s) and that is totally fine. For our case, rolling the rectifier tube(s) in Muzishare tube amps give users an additional avenue of play, of fun, and chance to further improve the sound – yes, rolling rectifier tube(s) affect the sounds in Muzishare tube amps too! And we highly recommend that.

And at the topic of tube rolling, KT88 tubes may not be the cheapest tube to roll. But there are still options nonetheless where 6550 and KT90 are some alternatives users can consider. If not, swapping out the smaller 2x 12AU7s and 1x 12AX7 can be great starting fun! 12AU7 alternatives, vintage or reissues, are not very expensive afterall. And while although 12AX7 will cost more, at least the X7 only requires one of it, so a good investment in an improved 12AX7 can go a long way definitely.

In an overall package, the Muzishare X7 is an absolute bargain of a highly capable and great performing KT88 tube amp. It is only just a few years ago when many other more established tube amp makers are marketing KT88s as their highest end of tube amp models. Muzishare, along with a couple of Chinese-made tube amp manufacturers, have over these few years been producing very well-designed KT88 tube amps like the X7 without a hefty price tag, lowering the barrier of entry in financial terms for those who yearn for a KT88 or for the matter, any tube amp. Muzishare’s continual improvement to their amps has allowed X7 to punch way above their weight in recent times as the more affordable price does not relate to a lesser representation of sound. Anyone who have seen the X7 in person will know and understand the quality of the construction is unbelievable for a high-end equipment costing just slightly over two grand Singapore dollars. If you have not, you are more than welcome to make an appointment with us and come down to our shop front to see and hear for yourself why it makes perfect sense, as well as a sound investment (we can jolly well keep it a secret in all honesty but Muzishare and QA have no qualms of sharing that Muzishare amps will only cost more as time goes) to own and enjoy a X7. So why wait. Muzishare X7 listing here.