Anode Acoustics #4 Solid State Headphone Amp

General Information


  • Full class A operation, BJT power transistors on the output
  • Power output 1W
  • 5ohm to 1k ohm load (and beyond) operation
  • 30v peak to peak maximum voltage output
  • RCA inputs and 6.3mm Headphones output
  • Built-in regulated 25w linear power supply. The amp is 230v mains operated
  • Dimensions: 21 x 13 x 6 cm, weight: 1.5 KG
  • Well tried and tested with these headphones and more: Sennheiser HD600, Beyerdynamic T1, Sennheiser HD650, ATH R70X, Hifiman Sundara, Audeze LCD 2C, Hifiman Ananda etc.
Anode Acoustics's latest solid-state Class A headphone amplifier. Price 22000 INR(Approx 300$).



Latest reviews


100+ Head-Fier
Anode Acoustics #4 Solid-State AMP: Natural, Powerful!!
Pros: No coloration to the sound, natural and organic amplification with excellent dynamics.
Solid, heavy build.
Clean & Powerful, powers my headphones super easily.
Cons: No pre-amp out.
Soundstage is kind of intimate.

Anode Acoustics is a Hi-Fi Indian brand that makes some brilliant hand-crafted audio amplifiers and other studio-related gears. Anode Acoustics have a history of manufacturing high-quality studio equipment mainly consisting of tube and solid-state amplifiers. But a few years back Nitin Ji from Anode Acoustics also started making headphone amplifiers with their very first Anode Acoustics #1 tube headphone amplifier. I personally have a short experience with the #1(with HD600) that I got to try at an audio meet in my city a year back. Since then Anode Acoustics has added a few more additions to the headphone amplifier range with three more products, #2, #3, and #4. #3 is an OTL tube amplifier while #2 and #4 are both solid-state amplifiers but both working on different technologies.

According to Nitin Ji #2 is built on MOSFET Technology and #4 is built on BJT Power Output Transistors. Ever since I tried the Anode #1 back at the audio meet, I was interested in making a headphone setup. But was limited to portable use. When I got able to make a decent enough desktop stack, I could not order a #1(Budget issues) and got myself a Cayin HA-1A MK2 that ended my cravings for a decent tube amplifier. But a place in my heart still left empty that craved for a decent enough solid-state amplifier. In this search, I ended up buying a Topping L30. L30 made my HD600 sound like a damn toy, lean, no dynamics, no weight, nothing. It felt only good for IEMs at best or with HP’s other than HD600, Like Hifiman Sundara. Though powering the Sundara with it took almost full power out of it. So my search for a decent solid-state amplifier was still on.

A few weeks back Nitin Ji approached me, he asked me whether I would like to try the #2 and #4 for myself? Without any hesitation, I instantly said yes and received both the amplifiers on the same day itself(He lives in the same city as me). So today, I am going to share my take on Anode Acoustics #4.


The unit was sent to me by Nitin Ji, I am in no way getting paid or any other benefit in return for a positive/negative review. All these impressions are my own based on my own usage with the amplifier over the past few days. The Anode Acoustics #4 is available to purchase at 22,000 INR(approx 300$). Check it out on Anode Acoustics website:-

Build Quality:-

Anode Acoustics products are hand-crafted with a simple design and plain metallic chassis. They are not as compact as the products available in the market but they are built with great strength. The #4 here weighs in at about 1.5-2Kg, has a simple form factor with a volume knob and single-ended 6.35mm headphone socket on the front. On the back, we just have the power socket, power button, and a power switch. There’s also a space at the back that according to Nitin Ji is left for adding a DAC in the future that he is planning on.

The Chassis has ventilation holes on three sides of the chassis(on the top and both sides). The RCA connectors here are of very heavy quality, they don’t look like simple RCA ports usually found on devices such as L30. Despite being very simple looking, the amp has a solid build quality.

During my usage, I kept the amplifier on continuously for several hours(up to 6-8 hours during a single day), I never felt the chassis getting hot or anything. The amp runs perfectly cool even after long usage hours.

Driving Power:-

There’s no gain switch but the amp adapts the output according to the connected IEM/HP. I tried the #4 with my Unique Melody Mirage and Sennheiser HD600. Mirage has a 26-ohm impedance while the HD600 has a 300-ohm impedance. It powered both the sets very easily never going above 40% even for the 300-ohm headphone. My listening was done with Mirage at about 10% volume and HD600 at about 35% volume.

#4 is a pretty clean amplifier, there is no noticeable background hiss or noise that might affect the output even with IEMs.

Sound Quality:-

Now comes the most important part for an amplifier. To be very honest when I tried my HD600 with Topping L30, I lost all future mood to ever connect HD600 with any solid-state amplifier. It was so lean, made my HD600 sound like a toy. HD600 lacked body with the L30. Even though it was good with Sundara and IEMs, but it just couldn’t provide HD600 what it needed.

But then came the #4 at my doorstep, changing my opinion about solid-state amplifiers. The #4 has a natural tuning presenting the sound without any coloration. Senn HD600 has a full-bodied presentation with the #4. It no longer sounds lean, rather has a great sense of weight to the instruments. Please don’t get me wrong I still consider HD600 pairs the best with a tube amplifier, but this #4 right here is a gem. It brings the best out of HD600 without making it sound artificial or lean.

Another great aspect of the #4 here is its mid-range performance. HD600 has lovely mids, the #4 enhances them with a natural tonality and accurate presentation. Listening to Hotel California from Hell Freezes Over album by Eagles is a brilliant experience. The acoustic intro has a brilliant presentation, everything from the acoustic guitar to the bongo sounds amazing. Vocals sound rich and precise, they have a natural tone, and don’t get shouty even at louder volumes. But I personally feel that Female vocals have a more forward presentation than male vocals here.

Sub-bass has a well-detailed, rumbles presentation with the #4. The lower end feels more emphasized on the sub-bass portion. Mid-bass shows its presence for a quick while whenever called upon. The lower end has good airiness too.

Treble portion has good extensions but lacks a slight bit of air in this portion. Though instruments sound well-separated they are placed close to each other. The imaging of instruments is very good with the amplifier.

Pairing an IEM like the UM Mirage also enhances its performance. UM Mirage has a powerful bass response with lovely mid-frequencies, the #4 brings the best out of such an IEM complementing its signature with clean power. There is no noticeable background hiss here.


Soundstage is kind of intimate with the #4. It has average width but good height and depth. I personally love such a presentation, though a little bit of width would’ve made this an even better one.

Comparison With Other Amplifiers:-

I have a long-time experience with Topping L30 that is priced at around 150$. So I will put up a comparison about how big of an upgrade is #4 over it.

>L30 sounds way too lean in front of the #4.

>#4 has much better dynamics in the sound, transients and layering is top notch.

>#4 has a natural sound with no coloration at all, L30 has more of an analytical sound tuning.

>L30 produces a wider stage presentation but instruments and vocals lack weight when compared with #4. #4 might not have such a wide stage presentation but it has a better sense of height and depth.

>Instruments, Vocals, the overall presentation has a much better sense of weight with the #4.

>#4 has a lot of power, L30 even at high-gain(+9dB) had to push to full volume for HD600, but the #4 powers it easily at 30-35% volume only.

Some Cons that I noticed with #4:-

>There is no gain switch(Though not required as such the other amplifiers in the market have this).

>No pre-amp out.

>Stage width is intimate and a slight bit of extra width could’ve been better.

A Few Final Words:-

I loved the #4, I loved it to the extent that I got myself one. Yes after auditioning only during the first few hours I knew this is the solid-state amplifier I need in my chain. It has a natural, non-colored sound that brings a pure sound out of the connected IEM/headphones. Even with a lot of power to even power 300-600ohm cans, it is suitable for IEMs too. With the #4, I will be closing my search for a good solid-state amplifier, I was actually looking for one around the 15-20k range and this one fell right into my category. It will be complementing my stack right next to my Cayin HA-1A MK2 now :)


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