[cirodts]

A few posts up the thread...

https://www.head-fi.org/threads/lox...nformation-on-this-thing.903733/post-16554259

thanks, quantity 1 means 1 valve or a couple of valves?

 

[rprodrigues]

thanks, quantity 1 means 1 valve or a couple of valves?

This listing is for a pair (2 units):

https://www.ebay.com/itm/USSR-Russi...1980-NOS-2-pcs/133598278899?item=133598278899

 

[cirodts]

does anyone directly compare the loxjie to the xduoo t20? if yes i'd like to read the sound impressions of him.

 

[trollchu]

I see a lot of people in this thread have modified the opamps on their p20. Currently, does a tutorial exist breaking down how to do this?

 

[DBaldock9]

I see a lot of people in this thread have modified the opamps on their p20. Currently, does a tutorial exist breaking down how to do this?

1.) Unplug Power
2.) Remove Tubes
3.) Unscrew front panel
4.) Unplug 2 flat ribbon cables from front panel circuit board
5.) Set aside front panel
6.) Unscrew back panel
7.) Slide main circuit board, with attached back panel, out of the case
8.) Carefully unsolder the 4x through-hole 8-Pin op-amps
9.) Carefully solder in 4x 8-Pin DIP sockets - noting which end is Pin 1
10.) Find and install 4x Dual op-amps that can work with ±18VDC rails
11.) Reverse Steps (7 - 1), to reassemble and use the P20 Amp

 

[troyoz]

Hello, everyone! Brand new poster here, and I just bought my first ever DAC+amp combo in the form of the Loxjie P20 and the SMSL Sanskrit. The Sanskrit sounds excellent on its own, but it's not as loud as I think it could be with the amp.

Cliffnotes on my issues with the Loxjie P20 amp on Day 1:

- The problem is that on top of the amp being a pre-owned unit from Amazon, I finally received some unbalanced connectors for the amp and they sound quite horrible.

- When I plug in only one of the two RCA cables into the input of the P20 amp, I get a much better soundscape, but I never get a proper output when both of the RCA cables are plugged in. Everything sounds distorted and good chunks of the sound seem to be omitted entirely.

- I got an aftermarket power supply for the Loxjie P20 amp, rated at 12V and 5A of power. Neither it nor the original power supply seem to have any influence on the problem I am experiencing.

- I wish I knew how to properly use the balanced output on the P20 amp, but have no idea whether it will work with either my Razer Blackshark headphones which I own now, or the Beyerdynamic DT 900 PRO X's I just ordered a few weeks ago for that matter.

Any advice or feedback from the regulars on this thread would be greatly appreciated! I'm still very happy with my DAC, but I am considering refunding or exchanging this amp as I suspect that it's defective but I cannot diagnosed the balanced connections so that I can be sure.

 

[DBaldock9]

Hello, everyone! Brand new poster here, and I just bought my first ever DAC+amp combo in the form of the Loxjie P20 and the SMSL Sanskrit. The Sanskrit sounds excellent on its own, but it's not as loud as I think it could be with the amp.

Cliffnotes on my issues with the Loxjie P20 amp on Day 1:

- The problem is that on top of the amp being a pre-owned unit from Amazon, I finally received some unbalanced connectors for the amp and they sound quite horrible.

- When I plug in only one of the two RCA cables into the input of the P20 amp, I get a much better soundscape, but I never get a proper output when both of the RCA cables are plugged in. Everything sounds distorted and good chunks of the sound seem to be omitted entirely.

- I got an aftermarket power supply for the Loxjie P20 amp, rated at 12V and 5A of power. Neither it nor the original power supply seem to have any influence on the problem I am experiencing.

- I wish I knew how to properly use the balanced output on the P20 amp, but have no idea whether it will work with either my Razer Blackshark headphones which I own now, or the Beyerdynamic DT 900 PRO X's I just ordered a few weeks ago for that matter.

Any advice or feedback from the regulars on this thread would be greatly appreciated! I'm still very happy with my DAC, but I am considering refunding or exchanging this amp as I suspect that it's defective but I cannot diagnosed the balanced connections so that I can be sure.

Does the sound of the amp change when you switch either the cable or the input you're using?
Have you tried swapping the tubes from one channel to the other?

 

[troyoz]

I've tried swapping the tubes to no avail. I'll have to order a cable in order to use the balanced input, so I'm forced to use the unbalanced input for now.

 

[Arum16]

I've tried swapping the tubes to no avail. I'll have to order a cable in order to use the balanced input, so I'm forced to use the unbalanced input for now.

I've never used my P20 on unbalanced configuration. From day 1, I've always used it fully balanced, from my DAC to my headphones.
By the reports on this thread, with no further enhancements to the P20, fully balanced mode is how you get the best out of this amp.
I'd suggest, a close watch on Amazon's return deadline for defect items.

 

[intoitreviews]

Okay so there is really not much out there on the Loxjie P20. There's a few out there that have given really high regards to this thing, and i feel like it deserves a good discussion. (TL;DR: just read the bold stuff)

The main thing i want to know is regarding the balanced in/out. I DON'T want this to descend into a balanced argument thing. The point is that nearly every reviewer has mentioned how the balanced is noticeably better on this thing. I personally don't care about balanced - it's not something i need or care about. HOWEVER. It seems like the circuitry/electronics/whatever in this specific amp is somehow better than the unbalanced.

What i want to know is this - can i still take advantage of this "better" balanced sound by simply using something like RCA --> XLR adapters and running them into the Loxjie P20 inputs? The balanced output thing is relatively cheap/easy, but i'm definitely not spending balanced DAC money anytime soon. Is it just the balanced OUTPUT that gives this benefit? Do i need to even run balanced into it to benefit?

Question 2: [Loxjie P20 owners ONLY] - does this make a good first real amp for the HD6xx? I know that a JDS Atom is a "safer" choice, but i kind of want something interesting and different, which leads me to...

Will this still give me SOME amount of the benefit of tube despite being hybrid? The warmness, light distortion, and soundstage/reverb type of effect that people talk about? Reviewers seem to think that it.

It would also give me an upgrade path if i DID want to eventually buy a balanced DAC.

can i still take advantage of this "better" balanced sound by simply using something like RCA --> XLR adapters and running them into the Loxjie P20 inputs? Not really. Balanced DACs have a higher output than non-balanced, and the circuit of the amp would need a balanced line level (using an adapter cable would not change this). There are cheaper balanced DACs like the Khadas Pro, ifi Zen DAC, and others that will all out perform what you have.

Question 2: [Loxjie P20 owners ONLY] - does this make a good first real amp for the HD6xx? Yes, I would take it over an atom any day, just run it balanced. Atom is not as good as this thing with 6xx. Only better "cheaper priced amp" with 6xx is the iFi Signature 6XX amp, but that's over double the price.

Will this still give me SOME amount of the benefit of tube despite being hybrid? Yes, experiment with different tubes for different flavors. The stock tubes are relatively flat.

 

[ShaolinGrump]

I've tried swapping the tubes to no avail. I'll have to order a cable in order to use the balanced input, so I'm forced to use the unbalanced input for now.

I had this problem with a Bravo Ocean amp. That only has one tube. I tried about six different tubes. Several worked fine. The rest had exactly the problem you're experiencing. I haven't had this problem with my two Loxjie P20 units.

You have a circuitry problem in your amp, or you have tubes that aren't working correctly in the amp. The best test is to try a bunch of P20 compatible tube pairs that are well matched to each other. But that kinda defeats the purpose of a nice cheap P20.

 

[troyoz]

I had this problem with a Bravo Ocean amp. That only has one tube. I tried about six different tubes. Several worked fine. The rest had exactly the problem you're experiencing. I haven't had this problem with my two Loxjie P20 units.

You have a circuitry problem in your amp, or you have tubes that aren't working correctly in the amp. The best test is to try a bunch of P20 compatible tube pairs that are well matched to each other. But that kinda defeats the purpose of a nice cheap P20.

I'll most likely be returning it, although to get one from outside Canada could be a potential nightmare -- I was given an ETA of August 10th by Amazon if I were to buy a new one instead of the pre-owned I did buy. I do have a pair of tubes that I bought from AliExpress as well as a balanced-to-3.5mm adapter which are both on the way now. If those do not work, then I'll most certainly be returning this unit and buying a new one instead.

 

[Arum16]

Hello, everyone! Brand new poster here, and I just bought my first ever DAC+amp combo in the form of the Loxjie P20 and the SMSL Sanskrit. The Sanskrit sounds excellent on its own, but it's not as loud as I think it could be with the amp.

Cliffnotes on my issues with the Loxjie P20 amp on Day 1:

- The problem is that on top of the amp being a pre-owned unit from Amazon, I finally received some unbalanced connectors for the amp and they sound quite horrible.

- When I plug in only one of the two RCA cables into the input of the P20 amp, I get a much better soundscape, but I never get a proper output when both of the RCA cables are plugged in. Everything sounds distorted and good chunks of the sound seem to be omitted entirely.

- I got an aftermarket power supply for the Loxjie P20 amp, rated at 12V and 5A of power. Neither it nor the original power supply seem to have any influence on the problem I am experiencing.

- I wish I knew how to properly use the balanced output on the P20 amp, but have no idea whether it will work with either my Razer Blackshark headphones which I own now, or the Beyerdynamic DT 900 PRO X's I just ordered a few weeks ago for that matter.

Any advice or feedback from the regulars on this thread would be greatly appreciated! I'm still very happy with my DAC, but I am considering refunding or exchanging this amp as I suspect that it's defective but I cannot diagnosed the balanced connections so that I can be sure.

Just making sure: You've double checked your setting on the Input and Output menus? Via the multi-function volume knob.
I'm asking because I've made a mess out of those settings, on my own P20, on day .

 

[troyoz]

Just making sure: You've double checked your setting on the Input and Output menus? Via the multi-function volume knob.
I'm asking because I've made a mess out of those settings, on my own P20, on day .

The only settings which will respond correctly are "ou2" and "in2," which would be consistent with where the unbalanced inputs and output are located on the device. I don't have anything balanced plugged into the amplifier, so I'm fairly certain I adjusted the settings correctly.

 

[Ufanco]

Decided to buy one of these to dip my toes into tube amplifiers. Bought one on classified and ordered the balanced cables from amazon. Going be using a M6 pro 21 as source and going be using with iem and a bit concerned with independence of them adding noise is signal.
Well researching thought I read somewhere that there are tubes that work better with low independence iem? Read a lot reviews and the forum here but can’t find where I read that, any thoughts concerning this would be much appreciated.