portable V4

OldNewSound review:

Been really burning in this amp with Jlabs burn in track. It is finally starting to open up at the frequency extremes and wow does this amp have presence. Singers pop out of a black background and just sound so much more solid. The sense of air and space is improving now and the bottom end is gaining in snap and kick as well but is the way both male and female vocalist just sound like they are there with you. We are up to about 60 hours of burn in now. Can't wait for 100+ hours on it. This amp is so quite with such a low noise floor as well. Detail just emerges with a wonderful sense of integrated musicality and flow...
...3 hours of listening and I can't stop...most involving sound I believe I have ever had...this amp is just evolving beyond what I have previously experienced...I have never heard a pair of headphones sound this!...
...sound is huge and extended bass keeps getting tighter and more extended with ridiculous pace and drive and absolute pitch clarity. Pace rhythm and timing are completely addictive. I can crank the volume and the phones completely hold amp. Live albums are so amazingly like being there. The venue is huge and deep and i can hear the audience around me in the recording. Orchestral Manuvers in The Dark's latest live albumn. Awesome 80's dance electronica. Sooooo.....soooo goood Neco. How do you this in such a small package.
...completely effortless. It's clobbering the V3 as much as I loved that.


Hi Neco,
I have received your amp the day before yesterday, all is well. Thank you so much...
I've put my pair of AD797 in my new amp because I didn't trust the impression I reported recently, and what can I say: my hearing must have been impaired, because they suddenly don't sound so "grizzly" anymore. In fact, they sound wide and precise but a bit less detailed compared to my OPA 627s. I can confirm what the testers on the forums said about these chips.
There is no such thing as an optimal opamp, obviously. Most of the time it seems to depend on my mood, stress level, environment, etc., how these amplifiers modulate what I'm listening to.
Anyway, I'm very happy that I've found your little headphone amp workshop. Thanks again.

Best regards,



Absolutely great sound, and I believe I know what I'm talking about. Got an Ami Musik DDH 1, which is connected to a Little Dot I + equipped with a MUSES02 (and AEG tubes) after experimenting with millions of other OpAmps and tubes. I'm using an AK 100 as a player. Up to now, I've been using a modded iBasso Anacona D12 or a Teak HA P50 as mobile devices for listening with my Hifiman HE-560 or my Ultrasone Signature Pro (as well as other headphones and in-ears such as Sennheiser IE 800s).

I replaced the AD OpAmps with OPA627s though because the ADs don't make sense in my chain; they're very detailed and analytic - that's great but with analytic headphones they're rather harsh most of the time. They should be perfect if you're a Sennheiser or a Shure addict.

As you can see from the attached image, I've replaced the screws with black pill-style ones. And I've ordered a thinner but longer volume knob.

This headphone amp is made with love to music reproduction. Thanks, Neco Soundlab!

Hey Neco... I've basically just bought the V...ze pure amp ii, amazing piece of kit meant to be one of the best ! But comparing it to your amp leaves it sounding less amazing. Doing an A & B comparison I think your design is something quite special...

Kind regards


...still loving my amp definitely one of the best sounding amps on the market...Thanks.

I thank you for everything...
 like the amp a lot; it drives my headphones with ease and its already marvellously before the burning period is over :-))
André S.

...Great amp by the way! I have a feeling this amp can be my final portable amp! Now I have to go buy opamps...

...With each listening the amp sounds stronger and Senns brighten up...I did let it burn two days so maybe closer to 100. The sound continues to become richer with each listen! Like!
Best to you,  

Hi Neco
I’ve had your amp for a few days now, and I must say I think it’s fantastic. The impressions I read from your other customers weren’t understating the build and sound quality of the piece at all. You’re clearly very good at what you do.

Hi Neco,
Please find attached a few lines on the ADA4627 with the Neco4. These notes refer to testing of the V4 with two portable setups using HD650 and IE8’s
a) Neutron Player (Android) + Neco v4 with ASA4627 with MP3’s @ 320
b) JPLAY Mini + ODAC + Neco v4 with ASA4627 with FLAC
The Neco v4 partnered with the ADA4627 makes for the perfect match. The 20v Dual-Mono design of the Neco v4 allows for the ADA4627 to be driven without clipping or distortion for a sound signature that similar but more refined than opa627/opa637. The ADA4627 delivers richness with great transparency without treble glare; it’s very agile and articulate offering a wide, deep, and taller soundstage with solid bass/ note weight and smooth dynamics.
Kind regards
Mark I had an epiphany a Revelation, after the gain was increased, something else happened too, it has become beguiling involving, musical, Impossible to ignore. On Marvin Gayes what's going on the track save the children now the V4 brings me very close to tears as it should, the whole album is Marvin pleading for us to make a better world. Tears for fears woman in chains Oleta Adams vocal makes the hairs stand up on the back of my neck. what has happened to the v4? it is not just gain, its come alive
..I am not saying that I don't find it a little sharp at times with the AKG it still does, but now I am far less bothered I don't care, now I just want to listen and listen and listen. The detail is awesome piano stools squeak before people play, I can hear ray brown pick up his bow to play his double bass. why didn't they oil the kick drum pedal when Hendrix was recording. Steve ray Vaughan's valve amp buzzing away in the background awesome!