Allnic Audio L-8000 DHT Preamplifier Review

Audio Reputation AwardsTo many audiophiles and audio enthusiast, a well-executed pure DHT circuitry is the holy grail of the preamp design. Only a few high-end manufacturers can implement Directly Heated Triode circuitry and make a unit that can achieve a true audiophile performance. Today, we are reviewing one of those units. Allnic Audio L-8000 DHT preamplifier could easily be the best DHT preamp in its price range. 

Allnic Audio is a high-end audio equipment manufacturer, based in South Korea. The company was founded in 1990 by Kang Su Park. Before founding Allnic Audio, Kang Su was the cofounder of Silvawed, a company known for its high-end single-ended-triode and transformer-coupled tube designs. At first, Allnic Audio made only tube amps but today, they manufacture all kinds of audio equipment including tube preamps, phono stages, phono cartridges, DACs, headphone amps, cables, etc. Some of the finest, most unusual, and most sophisticated tube designs in the world come from the Allnic Audio. They do things that are too difficult or too expensive for other manufacturers. 

The first thing you have to know about the Allnnic Audio L-8000 DHT preamp is that it has a pure DHT circuitry – all the way from the signal input to the signal output. Numerous manufacturers tend to place directly heated triode stage after one or two stages of indirectly heated triodes. However, this approach is a compromise and doesn’t result in pure DHT amplification – the output stage is DHT but it only amplifies the signal determined by the indirectly heated triodes. Allnic Audio didn’t want to make compromises – instead of implementing indirectly heated triodes, Kang Su Park opted for pure DHT circuitry. The result is a pure class A pre-amplification with very low distortion.

The manufacturer implemented a few more advanced technological solutions. They used transformer-coupled line output circuitries instead of much simpler and cheaper capacitor coupling, which resulted in low and constant output impedance (120Ω). One of the most common issues of DHT amplification is the microphonic noise and it was solved through the implementation of the Allnic Audio’s proprietary tube damping technology (Absorb GEL tube damper). Quiet and dynamic operation was achieved by using advanced tube technology voltage regulation. 

The result of such a careful and methodical designing and manufacturing procedure is pure class-A (pre)amplification with a fully balanced output stage and perfect channel balance at all volumes. 

The only downside that we can think of is the price. Depending on the distributor, the price can go up to $23,000. That’s very expensive for a single piece of audio equipment. If you want to achieve the right match (high-end audio sources, high-end power amp, high-end cables, and high-end speakers) and make a true audiophile setup, you will have to spend more than $100,000 (maybe even over $200,000). 

Allnic Audio L-8000 DHT Preamplifier

UPSIDES 

  • Pure DHT (directly heated triode) circuitry 
  • Transformer-coupled line output circuitry
  • The output impedance is constant and low (120Ω)
  • No negative feedback (0dB)
  • High-speed tube voltage regulation
  • Fully balanced output stage with a perfect channel balance at all volumes
  • Pure Class A pre-amplification

 
DOWNSIDES 

  • Very expensive

 
VERDICT

Allnic Audio L-8000 DHT preamp is a holy grail of the DHT preamp design. It is top-of-the-line DHT preamp and it’s the answer to your audiophile prayers. If you’re one of those people who would rather buy a piece of audio equipment than a new car, or if you’re lucky enough and don’t have to think about the money, L-8000 DHT preamp is a perfect choice.

When paired with the right amp and right speakers, L-8000 has the ability to deliver every tone smoothly and transparently. It’s a truly magnificent audiophile-grade DHT preamp and it deserves our high recommendations.

What’s in the box?

Inside the box, there’s your Allnic Audio L-8000 DHT preamplifier, power cable, remote (batteries included), manual, and a warranty card. There’s also an Allan key included – you have to use it to take the top of the chimneys off and to remove the Styrofoam cushioning material protecting the tubes.

Specs

Allnic Audio L-8000 DHT Preamplifier Specifications 
DIMENSIONS
Width16.93in
Height8.3in
Depth15.75in
Weight45.2lbs
INPUTS
XLR Balancedx2
RCA Unbalancedx3
PERFORMANCE
Frequency response20Hz-20kHz (FLAT)

16Hz-75kHz (-3dB)
THD (@ 1kHz)0.3V OUTPUT – 0.06%

1V OUTPUT – 0.16%
Input impedance10kΩ (Balanced and Unbalanced)
Output impedance120Ω (constant)
Gain+18dB
S/N Ratio-90dB
Max. Output20V RMS
TUBES
1st Gain Stage3A/110A x2 (equivalents - MR0 PT8, MR0 TS8)
2nd Output Gain Stage3A/109B x2 (equivalents - CV1671, 4021a)
Rectifier7233 x2 (no equivalent)
Voltage Regulator5654 x2 (equivalents - 6AK6, A4361, CV1762)
ADDITIONAL FEATURESIR remote

Design

Allnic Audio L-8000 DHT preamplifier has a strong aluminum chassis without the top plate (to provide better airflow and better ventilation). You can see all the internal components – there’s a beautiful array of tube chimneys, transformers with permalloy cores and anodized casings.

On the back, there’s a series of inputs and outputs, divided into left and right channels. You have 2 balanced XLR inputs and 2 balanced XLR outputs. Also, there are three unbalanced RCA inputs and one unbalanced output. Right in the middle, there’s a switch used to select a balanced/unbalanced output.

On the front, you have a large volume wheel, right in the middle. Below the volume wheel, there’s an array of input buttons (dedicated button for each input) with an LED indicator for each input. Also, there’s the power button and the operate/mute button. On the left and right ends of the front panel, you have two current meters (tube health meters). Based on the needle position, you will know if all the tubes are working properly. 

The power input is located on the left side, which is a little bit weird, in terms of aesthetics. Luckily, the manufacturer includes an angled power cable, which minimizes the visual impact.

Aesthetically pleasing design with an open-top chassis

Aesthetically pleasing design with an open-top chassis

Features

We have already mentioned some of the most important features in the introduction. Now, we will discuss those features in detail and explain the benefits that each of the implemented components and technologies brings.

The manufacturer insists on is the transformer coupling, which is not that common when it comes to tube amp/preamp circuitries. Most manufacturers use capacitor coupling for the line output stage. This method is easier and costs less. However, this method doesn’t transfer any real energy (it transfers voltage and only 10% of the wattage). Transformer coupling, on the other hand, transfers much more energy (90% of the wattage is transferred). So, transformer coupling is a significantly better method, but only when using high-quality transformers. Allnic Audio makes its own transformers and it uses Permalloy, which is considered the best transformer core material. Thanks to the use of their own high-quality transformers and to transformer coupling, L-8000 DHT delivers a wide frequency response with very low distortion.

Another benefit of transformer coupling (aka LCR coupling) is the low and constant output impedance. This is a critical thing when it comes to preamp design. The output impedance is kept at 120Ω at all frequencies. Tube amps featuring capacitor coupling usually do not have constant output impedance because they need special mechanisms (so-called cathode follower circuits) to lower the impedance. These mechanisms tend to have a negative effect on distortion and they also can’t keep the impedance at a constant level.

Transformer coupling keeps the output impedance at a constant level

Transformer coupling keeps the output impedance at a constant level

 

In order to control the voltage and provide quiet operation, this preamplifier uses an advanced tube technology and an automatic voltage regulation circuits that consist of vacuum tubes. For this purpose, L-8000 DHT uses two 5654 vacuum pentodes. These pentodes protect the power tubes from the AC line supply changes

The most common problem with DHT tube amps is the propagation of the microphonic noise. In order to prevent this problem, Allnic Audio uses its proprietary ‘’absorb gel tube damper’’. Thanks to this patented technology, the output audio signal is perfectly clear and transparent.

L-8000 DHT also has a proprietary precision attenuator volume control. The sophisticated attenuator provides constant impedance and perfect L/R balance at all volumes.

61-step precision attenuator volume control

61-step precision attenuator volume control

Like always, Allnic Audio used high-quality and low-noise driving circuitry. In the case of L-8000 DHT preamp, the manufacturer employed two 3A/110A triode tubes for the first gain stage and two 3A/109B triode tubes for the output gain stage. 

This Allnic L-8000 DHT also features two backlit analog current meters for the tube health monitoring (one meter for each channel). They can indicate the damage or failure of the tubes. When everything is working fine, the needle inside the current meter is between the two parallel lines, slightly left of the center. If the needle moves to the left on either channel, it means that the gain tubes (3A/110A or 3A/109B) for that specific channel are failing and have to be replaced. If the needle moves to the right, it means that either voltage regulator tubes (5654) or rectifier tubes (7233) for the specific channel are failing and need to be replaced.

Setup and Performance

Setting up the system doesn’t take too long, but you have to think about the placement and connection cables. In the manual, there’s a whole chapter called ‘’LOCATION, LOCATION, LOCATION’’ with the instructions on what you can and cannot do. It’s recommended to place it on a stable shelf/stand and to provide good ventilation (preferably, you should put it on a top shelf).

The manufacturer also recommends using high-quality cables. For connecting sources with balanced outputs and amps with balanced inputs, you can use Allnic Audio’s MU-7R XLR cables ($2,300/1m). For connecting sources with unbalanced outputs and amps with unbalanced inputs, you can use their MU-7R RCA cables ($2,300/1m). For connecting the speakers, it’s recommended to use ZL-3000 ($2,500/3m) or ZL-5000 cables ($3,800/3m). All the Allnic Audio’s MU cables use Mu-metal shielding which protects from both electrically induced and magnetically induced noise. They also eliminate any audio signal loss. 

One thing to remember is that L-8000 preamp doesn’t have a phono stage and if you want to connect your turntable, you have to buy a phono preamp.

Our recommended setup would look like this (assuming that you already have a turntable, other digital/analog audio sources, and DAC):

Mu-7R Phono Cable ($1,700/1.5m)

Phono stage – H-5000DHT (approx. $32,000)

Preamp – L-8000 DHT (approx. $23,000)

RCA and XLR Cables – Mu-7R XLR and Mu-7R RCA ($2,300/1m)

Power amp – M-3000 MK2 monoblock x2 (approx. $18,000/pair)

Speaker Cables – ZL-3000 ($2,500/3m) or ZL-5000 ($3,800/3m)

Speakers – Focal Kanta No 3 (approx. $14,000/pair)

The price of this crazy setup (without the audio sources and DACs) reaches $100,000 and it’s definitely not for everyone. Then again, if you are already interested in the Allnic Audio preamp, it would be stupid to use sub-par power amp, phono stage, or cables.

Once you connect everything, you can start enjoying the magnificent performance of this beautifully crafted preamp. To turn it on, select the input, and control the volume, you can either use the buttons and volume wheel on the unit or the included remote.

The unit, as expected, delivers a very sophisticated performance with incredible clarity, transparency, dynamics, and musicality. Combined with the right audio equipment, L-8000 DHT preamplifier will provide you with such a life-like listening experience – you will most definitely admire the accuracy and purity of the sound.

Final Thoughts

If you forget about the price, there’s nothing not to like about the Allnic Audio L-8000 DHT preamplifier. But, even at this price point, L-8000 is arguably the best DHT preamp in its class. If you are a true audiophile who cares more about high-end audio components than about other fancy stuff (especially if you are into tube amps/preamps), this is the right preamp for you. 

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