Schiit IEMagni, Monoprice Liquid Spark. Any Differences in their DC Protection?

[Genkishi569]

My only headphone amp since I started this hobby almost a decade ago, the JDS Labs O2 amp, just died recently. Left channel got really weak, and started to cause clicking, buzzing, distorted sounds on my Hifiman HE1000 V2s. I initially thought the issue was with the stock cable cause when I swapped cables around the right channel would get all the problems...little did I know that it was the amp that was going haywire. It really didn't occur to me that it was the amps fault cause that crazy stuff started to happen on the exact same day I got the Hifimans.

Currently, my Chord Mojo is pulling double duty and doing an "adequate" job of it (pretty much at max volume so it's at its limit). I do run into the issue of tripping one of its protections that makes it shut off when songs without negative replay gain are played, and this is really inconvenient cause I tend to use Youtube for most of my listening (Ironic, really). The inconsistent volume levels for the songs force me to lower the volume and then increase it to adequate levels just to prevent the sudden shut down.

Which is why I'm looking for a new amp, and I'm in the market for a small form factor amp with DC protection, and I think the IEMagni and Liquid Spark amps meet the size I want while delivering adequate power. Doesn't hurt that they're really cheap, bang-for-buck amps too. The only thing I want to know to finalize my decision is the kind of protections that both implement. IEMagni doesn't have a lot of documentation so I have no idea what kind of implementation they're using vs the DC Offset protection of the Liquid Spark. So what I want to know is which amp would be better suited to protect the Hifiman HE1000 V2, and the amp from damage?

Any other best practices to take care of amps and headphones would be much appreciated (I already do the turn on amp and wait 10s before plugging in, and plug out before turning off amp). I'd also like to know if plugging an amp to a UPS is a good idea, or whether a surge protector is a better than a UPS mitigating potential sources of damage.

Lastly, if anyone has any suggestions about after market knobs for these amps, I'm all ears. Never was a fan of the rough, scratchy knob of the O2. I hear the Magni knob is more or less the same feeling.

 

[Helicopter]

Not sure how they differ. @JohnYang1997 mentioned in another thread that Monopruce had a good DC protection, Topping the best in the category.

 

[AnalogSteph]

My only headphone amp since I started this hobby almost a decade ago, the JDS Labs O2 amp, just died recently. Left channel got really weak, and started to cause clicking, buzzing, distorted sounds on my Hifiman HE1000 V2s. I initially thought the issue was with the stock cable cause when I swapped cables around the right channel would get all the problems...little did I know that it was the amp that was going haywire. It really didn't occur to me that it was the amps fault cause that crazy stuff started to happen on the exact same day I got the Hifimans.

The O2 has socketed opamps. Have you tried reseating them? As service-friendly as sockets are, they have been known to cause their fair share of contact issues over the years.

Also, does the distortion always occur no matter the volume pot setting? Has to be the gain stage opamp then (the NJM2068D - you can swap with a common NE5532(A), particularly if battery operation is of no concern... perhaps an OnSemi or Fairchild part rather than the cheap TI though; if you have an NJM4580D kicking around, that would be quite alright as well). Otherwise, look at the left channel output driver, U3 (NJM4556AD). You could swap U3 and U4 to see whether the fault moves to the right channel. None of the opamps used in the O2 are expensive by any stretch - that was kind of the point, too. You may end up paying more in postage than for a full complement...

Even if you do end up getting a fancy new amp, it can't hurt to have a spare kicking about, right? If in doubt a working one would sell for more, too...

 

[Genkishi569]

Not sure how they differ. @JohnYang1997 mentioned in another thread that Monopruce had a good DC protection, Topping the best in the category.

Thanks for the info. Chances are, I'll opt for monoprice. I did originally have the topping on my shortlist, but wasn't sure whether I'd get the updated version vs the version that was notorious for damaging headphones if I bought one.

 

[Cahudson42]

Though it isn't popular around here, I have used a Liquid Spark daily for over a year, first with an HE400i, and now with an HE5XX. It has plenty of power for both. And the 18 ohms of the HE5XX doesn't faze it a bit.

The volume knob feels like Japanese of 30 years ago. Solid and firm. A pleasure to adjust.

The 'soft start and power off' have no 'pops or clicks' transients whatsoever.

I have no plans to replace it. It's considerably underrated. IMO.

 

[Genkishi569]

The O2 has socketed opamps. Have you tried reseating them? As service-friendly as sockets are, they have been known to cause their fair share of contact issues over the years.

Also, does the distortion always occur no matter the volume pot setting? Has to be the gain stage opamp then (the NJM2068D - you can swap with a common NE5532(A), particularly if battery operation is of no concern... perhaps an OnSemi or Fairchild part rather than the cheap TI though; if you have an NJM4580D kicking around, that would be quite alright as well). Otherwise, look at the left channel output driver, U3 (NJM4556AD). You could swap U3 and U4 to see whether the fault moves to the right channel. None of the opamps used in the O2 are expensive by any stretch - that was kind of the point, too. You may end up paying more in postage than for a full complement...

Even if you do end up getting a fancy new amp, it can't hurt to have a spare kicking about, right? If in doubt a working one would sell for more, too...

The entire problem does actually move to the right channel since I have dual 3.5mm connectors for the hifiman...I basically just swapped the cables around and the all the problems went to the right channel (lower volume, loud crackling, buzzing, clickling). Also, yes, distortion is present on every volume setting for the channel with the issue. It was quite mild but jarring, at first. The busted channel sounding like it was lagging behind, and there was just enough distortion for the headphones to sound bad and wrong. I'll see what happens if I swap U3 and U4 though

I figure the postage will be the larger part of the cost for these parts than anything else too. As long as they're readily available through southeast asian channels I should be able to get expedited for about a dollar or two. China would be the next option and the cost would probably balloon to anywhere between 5-10 dollars if I opt for expedited.

I really appreciate the advice, and I'll see if I can't get ahold of the parts and get it troubleshooted and fixed once I get it back. I'm having it looked at, as we speak. Sadly, the guy isn't too well-versed in audio repair cause we have a pretty non-existent audiophile market here so there are obviously no readily available professionals for this job.

 

[Genkishi569]

Though it isn't popular around here, I have used a Liquid Spark daily for over a year, first with an HE400i, and now with an HE5XX. It has plenty of power for both. And the 18 ohms of the HE5XX doesn't faze it a bit.

The volume knob feels like Japanese of 30 years ago. Solid and firm. A pleasure to adjust.

The 'soft start and power off' have no 'pops or clicks' transients whatsoever.

I have no plans to replace it. It's considerably underrated. IMO.

That's good to hear. Great feeling volume knobs are underrated as hell (Too bad that youtube channel that reviews audio equipment knobs isn't active anymore). The sentiment probably comes from my exposure to so many sublime watch crowns. People don't ever talk about the winding and setting action (understandably), but those really contribute to the whole experience of operating something with analogue controls so it's generally an irrationally large part of my decision to take one amp over another.

and yeah, I'm definitely sure that the liquid spark has enough power for the HE1000 V2s. If the mojo can get it to listenable levels (with a very tiny bit of room to fine tune) at less than half the power of the liquid spark @ 35 ohms then the liquid spark should just have enough power for me to skip through channel imbalance, but not enough power for me to blow my ears off should I accidentally move the pot. I also shortlisted the IEMagni for that same reason though I definitely have no clue as to how drastic its negative gain is (not a bad option to have either).

Currently, heavily leaning towards liquid spark just cause it gets the fundamentals right while balancing design and feel at an incredibly competitive price. It might not measure the best, but it's well above the baseline where I'm going to get audible problems so I can sacrifice the number porn to get more of what I want in other areas at a hyper competitive price point.

 

[JohnYang1997]

Not sure how they differ. @JohnYang1997 mentioned in another thread that Monopruce had a good DC protection, Topping the best in the category.

I am not sure about Liquid Spark. The good protection circuits are the THX ones.

 

[Genkishi569]

I managed to revive the O2 though my confidence in its stability has taken a hit. Swapped out the U3 and U4 op amps as advised and things seem to be okay. I'm pretty sure that the damage was caused by my Final Audio Design FI-BA-SST iems when I hooked them up to the O2->Mojo out of curiosity (this was a day or two before receiving the hifimans). I felt like I was being used as the "ground" for the iems cause it would occasionally send static electricity up my ear, and if I lifted myself off the chair to re-adjust everything from the audio chain going up to the tv would just shut off abruptly.

Ended up buying a Monolith THX 887 and Liquid spark. I'll shelve one up as a back-up depending on which ends up being more convenient to use. Should've probably bought a back up DAC too, but I'll cross that bridge when the mojo decides to croak (removed that terrible battery they put in there...was bloated to high hell).