# Singxer SA-1 with DC bypass mod - what's the risk? **URL:** \ **Category:** Amplifiers\ **Created:** [October 26, 2026, 11:40am UTC](https://forum.headphones.com/t/singxer-sa-1-with-dc-bypass-mod-whats-the-risk/27503 "2026-10-26T11:40:01Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![MichaelJames](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.headphones.com/michaeljames/32/58530_2.png) [@MichaelJames](https://forum.headphones.com/u/MichaelJames)\ **Post date:** [October 26, 2026, 11:40am UTC](https://forum.headphones.com/t/singxer-sa-1-with-dc-bypass-mod-whats-the-risk/27503/1 "2026-10-26T11:40:01Z")
Hi all, hoping someone might know the answer a few questions about my Singxer SA-1. The TL;DR is: 1. What is the risk of getting DC through my Singxer SA-1 with DC offset bypass mod (fed by my PC connected to my Chord Mojo 2)? 2. If there is more than marginal risk, is there a way to mitigate it without reinstating the DC offset protection circuit in the Singxer? 3. If the answer to 2. is that there isn’t, is there another amp that is similar to the Singxer (balanced circuit, discrete, with single ended inputs and a volume knob without steps) but which doesn’t need to involve electrical risk to sound good? The source chain at my study desk is my PC connected to my Chord Mojo 2, which feeds the single ended inputs on my SA-1. I love how the Mojo 2 sounds, but the lack of a volume knob drives me mad. I bought the Singxer early last year to solve that problem, and to provide enough power to drive high impedance, insensitive headphones with negative pre-gain for EQ (I mostly use my HD800S with EQ, running negative pre-gain of -9). It excels in that role. However, there’s a catch. When I first set up the SA-1, the sound I got from my headphones was disappointing. It’s hard to describe, but it was as if instrument transients, or the edges of instrument tones, were slightly dulled or muted, or perhaps decayed a little too quickly. I would maybe call it dark, or perhaps foggy, in the sense that this left some musical details missing or being harder to perceive. I wonder if this is what reviewers like Zeos were describing as “that warm Class A sound”, and I could see how someone might consider this as “smooth”, but I didn’t like what I heard. I tested it against my other sources (the Mojo 2, my XDuoo TA-26S, my Fiio K5 Pro), and I confirmed this experience was unique to the SA-1. Now, I’d watched a number of YouTube reviews, and several of them talked about the DC-offset bypass mod. This involves installing four small jumpers (or shunts) inside the amplifier to bypass its DC offset protection / surge circuit, which consists of a number of capacitors. I’d bought my SA-1 second hand and out of warranty, so I decided to give it a go. It was easy enough to do the mod, and afterwards I tested the DC on the outputs, which showed as safe. I tested on my HD560S first, and yep, no problems. Lo and behold, it was just as the reviewers described. That “dark” character was gone, and from that point on the amp has been everything I want it to be. My headphones sound full, weighty, punchy, energetic and _driven_, but with all the details and transients still there and presented beautifully. And it has all the power I could ever want. I’ve enjoyed playing with ridiculous EQs on my HD800S without ever worrying about volume. I have to stop myself from turning it up too much, it’s so damn good. In the last week, I had a bit of a scare. I was playing a song with some deep, deep subbass (Sickick - Intro (Infected)), and the right channel of my HD800S started cutting in and out and sounding staticky. The timing was poor - this was just before I went away for a long weekend, and I wasn’t able to fix it before I left, so at the back of my mind the whole weekend I was worried I’d bricked my best headphones, possibly by having DC go through them because of the mod on the amp. Thank God I hadn’t bricked them. It turned out that my wife had sat her laptop on the desk on the XLR adaptor attached to the SA-1, and also moved the amp itself, and after re-seating all of the cables I worked out it was a physical connection issue. Again, very glad about that. But now I have _the fear_ that there might not be anything to stop DC from ruining my headphones. I also have no real sense of how big of a risk that actually is, and whether I should be worried enough to do something about it or not. I understand the general concept of DC offset, but not the specifics - is there a real risk that I could accidentally send DC through my headphones? Would the Mojo 2 prevent this? Is there a way to know if particular songs would do this? (I’ve heard songs with deep bass can do this, I think @listener mentioned on a Noise Floor one time there’s a Radiohead song that outputs pure DC). And if there is a risk, does anyone know if there is another headphone amp with a similarly excellent sound, but that doesn’t present this same risk? ---
**Author:** ![Loomynarty](https://avatars.discourse-cdn.com/v4/letter/l/e0b2c6/32.png) [@Loomynarty](https://forum.headphones.com/u/Loomynarty)\ **Post date:** [October 26, 2026, 11:17pm UTC](https://forum.headphones.com/t/singxer-sa-1-with-dc-bypass-mod-whats-the-risk/27503/2 "2026-10-26T23:17:48Z")
There can be a risk of outputting DC to your headphones but it depends heavily on your setup. If the Mojo 2 has input/output filtering which rolls off sub-sonic frequencies, your amp will never output DC unless something catastrophic happens inside the amp which is unrelated to your source. You can also easily ensure this never happens by using a high-pass filter in your eq at ~10Hz. If you really want a different amp I think the closest thing would be a Schiit Jotunheim.