Loxjie P20 Balanced 6N3 Tube Hybrid Amp for under $100


#82

I personally own the AAA 789 and Loxjie P20. I can’t exactly rate them on 1 to 100 as they aim to do different things.

The 789 provides neutrality, details, and power – so on a technical basis it’s very close to what a neutral amp can be. The P20 intentionally distorts/warms the tone, but does that function very well – it achieves this with a tiny bit of high-range ring or hiss (factory tubes). But, it’s intentionally only 90% neutral or accurate as an amplifier.


#83

If I own a neutral/bright headphone (HD800) and warm headphone (HE-400S), which do you think would be a better match?


#84

Honestly it isn’t a good comparison. I would say purely based on price the P20 is a heck of a deal but the 789 is still better overall.


#85

I personally use my 789 with both neutral or warm headphones and reserve the P20 for bright headphones or genres that benefit from warmth:

THX AAA 789 preference

  • Audeze LCD-2C (gets too bassy/warm with a tube amp)
  • AQ NightHawk Carbon (needs all the clarity it can get)
  • Music that relies on details and reproduction (e.g., classical, acoustic)
  • Music that was heavily tubed in production (e.g., blues, husky vocals)

Loxjie P20 preference

  • Grado headphones (but mine are rarely used)
  • Music that had the bass cut off (a lot of pre-1990s rock and pop)
  • Music with thin, harsh, or flat production (e.g., 2nd tier vocalists, pre-1990s independent studios)
  • Electronic music that lacks organics or internal variation (from the 1980s to current)

Headphones that work well with both per musical source

  • Focal Elex
  • Sennheiser HD-600
  • HiFiMan HE-560

#86

I agree with @generic comments. Warmer headphones may become too warm on the P20.

For example, I really enjoy the Focal Elex and Elegia and even the HE560 on the P20 as well as my Monolith THX-AAA, but the HD58X does not sound right to me with the P20. The HD58X sounds a lot better out of the Monolith THX-AAA amp. I don’t have the Massdrop THX-AAA so I can’t comment on it but impressions seem similar enough.

When I have some time I’d like to measure these headphones with the P20 as source and see how much change occurs. I posted the Elegia before/after earlier in this thread.


#87

SE/SE 60
Bal/SE or SE/Bal 92 Different but rating the same
Bal/Bal 100
All with Clear and relative to each other


#88

Personally I think that the HD800 benefits from a warmer Amp/Dac. If I use my Topping D50 with the HD800 it can become over analytical at times. With a Warmer setup it can smooth out any edginess you may perceive. Just my personal thoughts.


#89

New tubes for the Lox…

needs burn in…but initially it is brighter and feels/sounds “quicker” to my ears. More detail, a little wider, Tone is off though…hopefully some burn in will do them good…

Ok forgot to hit send it has been 10 minutes of listening and the tone is getting better…I am liking it more…I think with a couple dozen hours of burn in they will be great.


#90

Incredible thread going on here!

Thanks to all of you for the thread!

I’m not an audiophile. I was formally trained as PA/Studio audio engineer, though went the IT route early. I tend to favor no frills pro equipment, or solid/interesting designs, and love DIY and Chi-Fi gem hunting.

Of course like all of you, I’m after that “ideal” sounding rig. I tend to favour using my ears than measurement equipment.

I was involved into DIY on mid 2000’s, but with the advent of Chi-Fi I chose to hunt instead… and this find is a gem! A diamond!

I’ve built variations of several DIY hybrid amps (SOHA, WCF with tons of variations (OTL), Millett Hybrid Max, Bijou, and Nuhybrid. Some all SS stuff too, had a mini3 and a JDS Labs C421. Got a DarkVoice336 too (no frills Chi-Fi OTL WCF).

Several DIY and Chi-Fi DACs too: GrubDac, DDDAC 1543MkII, ES9023 HifiMeDiy DAC2, and a Wolfson Dugood WDAC-1. Pro equipment: Behringer Ultramatch Pro SRC2496, Audient id22.

This little dude (P20) sounds incredible goind fuly balanced, and for the SQ and features it simply cannot be beaten pricewise.

Sources
Defintely, Balanced in/ balanced out is the way to go.

What I have found is the P20 is incredibly transparent while keeping all the “good stuff” tubes can provide to enhance (make enjoyable). Just suit your cans to the source :smile:

Due to this, I find the most noticeable difference being imparted by the source (DAC).

If you don’t have any balanced out DAC, you can get this gem of pro equipment, Behringer SRC2496 for 99€ new from any reputable dealer.

If you already have a dac use it’s SPDIF out, otherwise a PCM2704 based (TCXO if possible) USB/SPDIF card can be had for less than $20, or go for a XMOS208/Amanero USB/SPDIF, will be a good investment.

My SRC2496 is stock (didn’t mod a bit), set as Sample Rate converter to 24/96.

My rig:
Audirvana -> USB ESS9023/TCXO DAC SPDIF -> UltraMatch Pro <=balanced==> Loxjie P20 <=balanced=>HD6XX

I’d say you’ll need to go into 5-10x this budget to find gear sounding as incredibly good.

Made me to finally re-rip all my CD collection and sparkled interest on HD sources… incredibly revealing while making everything sound great, really share @generic comments regarding production/mastering styles/years!

@generic The RME Dac got my interest… I’m very fond of AKM DAC chips sound, SRC2496 uses AK4393.

I see the RME uses two AK4490, I’m currently in the hunt for a balanced out AK4490 or preferrably AK4497EQ Chi-Fi / DIY DAC, some interesting kits on aliexpress for much, much less.

Tubes
I collected tubes, specially russians, during the 2000’s. I’m pretty sure the ones I received (comments lead me to think so too) or are included in the amp (Shuguang) are “selected” tubes.

I had a look at my 6N3P collection: 6N3P, 6N3P-E (two different sources) and 6N3P-DP (Reflector NOS) and I can assure you included tubes are new production, with some sort
of QC.

6N3P-E virtually identical to some fake NOS russians whose stamping are recent… and the innards (micas, heaters, plates…) are all identical but from slight different materials on the pins.

The tubes take several days to reach optimal performance, but so far the stock ones are almost identical performing than the fake NOS one I have, fake NOS ones may be a even tad worse (gritty highs with some sources).

Will test the definitely different true NOS 6N3P-DP next week, and a pair of GE5670 once I receive them but I suspect there’s already a lot of tweaks/sinergy in this design, and tube/opamp rolling will make marginal difference, I’d focus on the source DAC for improvements…

Definitely looking forward this Brand future releases.

Love the PCB of the P20, IMO lots of love went to it design, is a great example of Chi-Fi t its full glory: careful component selection without going unobtanium, and polished design with price in mind. Sure, you may tweak it with some exotic parts or mods, but will get marginal enhancements in return and ROI will go down the drain.


#91

Hi Pukkita - Great first post! Lots of good info. Thanks!

Would be great to hear any impressions you have on some of the DIY kits you’ve built. I want to make a new amp or dac sometime this year as a project, so very interested to hear what some good ones to go after are.

I agree, this sounds much better with Balanced out than it does through SE. I found negligible differences using balanced input and RCA input though, but I haven’t done A-B of that set up in a while, and currently do not have capability of it anymore.

I am using mine in my living room now where it’s a headphone phone for a network streaming Pioneer device.


#92

Where’d you get the silver one? All I see is red and black online. I’d like to get a silver so it fits nice beside my Focal Clears, Schiit Vali, and Modi.


#93

The box shows silver but it’s black. I would buy a silver one of they made it available. As far as I know, there is no silver model. I looked on their Ali Express official store too


#94

@antdroid is correct mine is black.


#95

I was afraid that would be the answer. Weird the box shows a model that does not exist.


#96

Thanks @antdroid!

I will… latest one was a NuHybrid

Really easy and safe project, low distortion and sweet tube sounding, but… want to compare oranges to oranges and apples to apples, the Loxjie made me think on building a balancer preamp so that I can compare a given DAC with the amps.

But so far, the best sounding rig is the one I posted, with the Loxjie P20. The level of detail it brings, without making things harsh is unmatched by the rest of rigs.


#97

@pukkita you are a dangerous fellow for my desire to try my hand at these things lol…this could easily be another rabbit hole to “fall” into …(pay no attention to the man running and diving into that hole over there…)


#98

@DarthPool :laughing: sorry about that! birds of feather flock together! :wink:


#99

@antdroid: as promised… hope it doesn’t derrail the thread, but I think it provides certain perspective for those looking into any of these amps.

Pmillett Hybrid Maxxed
So far I see myself favouring the P20, NuHybrid and DarkVoice over the pmillett Hybrid Max.

The Hybrid Max was tuned, uses JFET diamond output buffer. But is actually the one receiving less usage as is the less euphonic, harsher sounding with dubious sources to me. Was tuned to a pair of lower Zo AKG 701… I may finish it and give the combo away for my eldest one. HD6XX sounded much, much better on it, no longer can stand the thin sounding hollowness of the K701, though sadly they’re heaps more comfortable that the Senns.

DarkVoice 336SE

The DarkVoice is interesting.

I’ve built dozens of White Cathode Follower OTL variations in the past, and harassed pmillett and other knoledgeable people to no end (thanks!!!). I tried different drivers (6SN7, 6H8C, 6N32-P, ECC88, 6922, 6H30-DP) and single/dual 6080/5998/6H13C/6AS7G for the outputs; used no frills SS PSU, and tried also one no frills, tube rectified choke loaded, and a brutal CLC one using 5U4C, this was years ago with the K701 and I end up dismantling the beast.

So going back to a no frills circuit like the DarkVoice was interesting, specially with the HD6XX.

Definitely, the sound really engages, and never fatigues; coupled up with the DDDAC the sound is dark, (NOS sound) but mellow, and detailed (70% of P20), never fatiguing. Signature is mostly imparted by driver, Russian metal base 6H8C being my preferred one so far. Wanna try also sylvania 7N7 on it (requires adapter).

I will be doing some typical enhancements next (cathode bypasses, etc).

I already had Chatham (TungSol?) 5998’s, so one went there. Marginal changes (fatter bass), but definitely and absolutely not worth the expense versus the included Shuguang 6N5P.


pmillett NuHybrid

Been following Pete Millett designs since early 2000… Headwize and Chu Moy days. Rest In Peace.

When saw this new design, I had to try it!

Uses the Korg developed, Vacuum Fluorescent Display technology based NuTube 6P1 as driver:

nutube_small

The NuHybrid… was assembled in a couple hours, was my Xmas project. I wholeheartedly advice this project for anyone wanting to step into DIY tube sound safely and cheaply.

I just upgraded the BOM to WIMA MKP caps (+$2, fit perfect) and the TKD pot, as the weak spot on most DIY/Chi-Fi amps (specially the DarkVoice) is the potentiometer. Only mod done was grounding the TKD metal case to the PCB ground.

Use a typical POE brick (24V 2A) from a mikrotik router to power it. Tried a linear PSU, saw zero enhancement, so back to the switched one.

Its sound… it’s incredibly transparent, while adding just the proper amount of euphony, keeping pace and decay without losing slam… I was more blasted after hearing the NuHybrid than after my last 70W WFC monster iteration.

One of the reasons I love the P20, is the use of the encoder to precisely set volume… wild dreams of building a unbalanced to balanced hybrid or tube preamp using this NJM Volume/relay source control switch, then making my DIY amps potless…


#100

BTW, took out the 6N3P-EBs I was trying for a week, original Shuguangs went back in… and are smoother.

Where did you get your 6N3P-E @DarthPool?

Will have a detailed look at mine, so far I only noticed the getter posts being different on their internal construction, Shuguang having two, and the -EB ones I tried (fake NOS) having just one.


#101

I picked them up from a seller on Amazon… I just searched for paired 6N3P