New SGCD loud pop/thump when changing to/from HT input?

Yeah, I looked at it earlier and it is nasty. I can’t use the Home Theater input in my PS Audio/Sony/Bose setup. Because I hacked 5.1 fixed level true balanced outputs out of my Sony AVR, it bypasses the AVR’s internal volume control but not any of it’s other audio functions. With some other DIY hacks (see my posts in the “Do It Yourself” category), I have a very nice sounding, clean, psuedo true balanced interconnect layout, and no noise (other than the odd thumps…but I don’t believe in my case it’s a PS Audio issue. I adjusted the center and surrounds using the AVR’s internal amp’s to match the dB level produced by the Stellar Stack. I can actually dial the same volume “number” on both the SGCD/Preamp & the Sony STR-DN1080 and everything blends together nicely. 5.1 SACD’s, DSD files, DVD & BluRay Audio Discs, Concerts, and movies all sound so much better after carefully integration of everything mentioned above.

After a month I got my SGCD back from the PS Audio. They changed everything they told me, but the problem still exist. So there is a problem with the hardware. I have tested 3 different SGCD’s now and all have the exact same problem - a loud thump from the right speaker when switching to Home Theater passthrough mode from digital input.

Found one more case like this:

Sorry to hear you are still having issues. They should have been resolved before sending your SGCD (or replacement) back to you. I don’t use the HT setting. However, I have a similar, but much smaller, issue happening with my SGCD.

Probably unrelated - I get a small thump from the right speaker whenever I pull my headphone plug out of my SGCD. My headphones are very efficient so the SGCD volume is very low (usually under 10). The thump is very mild.

Weird that both issues create a thump only in the right speaker.

@JRSBat Can you please test your SGCDs HT passthrough?

  1. Just enable HT pass from the menu with volume set to 76
  2. Let any digital input play for 15 minutes at volume 10-15
  3. Switch to HT pass enabled input
  4. Do you hear a loud thump from the right speaker?


spezwend YUP - definite thump in the right speaker when switching to HT bypass! The thump was about as loud as in the above video. I put the speaker covers back on a few days ago so I could not see what happened to the speaker drivers.

The thump was louder than the right speaker thump I hear when I unplug my headphones.

Thanks @JRSBat! The thump goes louder every minute you play the music. After about 30min it is the loudest as it gets.

At the moment I have tested 3 different SGCDs and all of them have this problem.
+1 @JRSBat’s SGCD New SGCD loud pop/thump when changing to/from HT input?
+1 @lcouplinverizon-net’s SGCD Stellar DAC/Pre Home Theater switching
+1 @Rudolf_Appel’s SGCD Stellar Gain Cell DAC Experience

So total 6 faulty units I know of.

I wanted share a Paul’s e-mail to me that there is nothing wrong with the SGCD’s. :open_mouth:

On Fri, 31 May 2019 at 01:39, Paul McGowan wrote:

I have gone through all the engineering documents, the three units you sent us, the programming changes made to make it better, and the test results. From all I can see, there’s nothing wrong with the units.

Thus, the problem is something we cannot solve for you. It may be simply an incompatibility with your system, which is odd because we have never encountered this in any of the hundreds of units in the field.

I wish there was more we can do, but alas, there is not. We are at a dead end.

Unbelievable! Paul always says to use your ears to judge equipment but now he uses his eyes and documents only. :frowning:

If anyone reads this post and owns a SGCD - please test it and post the results here.

  1. Just enable HT bypass from the menu with volume set to 76
  2. Let any digital input play for 15…30 minutes at volume 10-15
  3. Switch to HT bypass enabled input
  4. Do you hear a loud thump from the right speaker?

Hi @spezwend, please allow me to correct, I encountered the thump inserting the headphone jack.

I will test the HT input switching with the Audio Quest silence caps on the RCA inputs and report back.

I’d like to add, my unit sounds very good, I am happy how it makes my Yamaha active speakers sing.

Maybe, you tried this already, please do not take this offensive:

  • Plug the SHCD into the same power bar as the HT receiver
  • Having Dome the above, reversing the power plug of your HT receiver / controller.
  • Another option could be, in case that receiver has no ground wire in it’s power supply cable, to consider to add a ground lead from your receiver chassis to the earth where the power plugs are connected.

Since you assume that a DC voltage is building up, which I imagine is a plausible cause, since the thump tends to get louder, it might have to do with the power supply of any of the apparatus.

Anyway, I’ll test my SGCD as mentioned above and report back to this thread.

Absolutely yes Rudolf, my SGCD sounds very good also but it’s about the HT bypass and preamp. It seems to me that the only option is to use two different sets, one for stereo listening and one for Home Theater. You can not use SGCD in the chain! I’m considering to buy another real preamp and use SGCD only as a DAC. A working preamp that has input relays, no input crosstalk, no pops on volume control and working HT bypass.

This thump happens even with AVR/HT Receiver disconnected. I have one “audiophile” power strip where all my gear is connected. I’m not assuming about the DC voltage, I have measured and made a video while measuring. If you are interested check my videos linked above. I have tried many different players also and one at the time for testing and the result is the same.

Please Rudolf test your SGCD, I’m just trying to prove that this is a larger problem probably hundreds faulty units out there not just with couple of SGCD’s I have tried.

I saw the video. I will test my SGCD and let you know. Still I would not exclude software issues, everything is Micro Processor controlled.

Excellent plan Mr S!!

A real pre-amp that has volume recall per input. Just set the volume of the input that will be assigned as a HT bypass to 0.0 dB, and every time you select that input it will be in HT bypass mode. With no thumps in the speakers to cause any aggravation.


Actually SGCD does have kinda same feature but only for one analog (1-3) input and it’s the main reason I bought it on the first place and second I already had M700s.

Your PS Audio device has been like this since brand new, and now it’s over one year old. Whilst I admire your patience, I think it’s time to look somewhere else for peace and happiness.

Why would you guys ever change inputs or connect or disconnect cables without turning the volume level down to zero or muting the output? You have a remote so how hard can it be if you know a problem exists to just avoid it instead of continuing on.

Are you serious? You have got to be kidding.

I can change sources with my Yamaha all day long and plug in my head phone anytime without even a glimpse.

Even the Sony IPod docking station ten years old of my son takes any switching of sources and sudden docking / undocking without a glimpse.

Everything without muting.

A pre Amp is a switching device that is supposed to make this work without manually muting.


Not sure if you are aware, but the source switching and switching the speakers of when inserting the headphone jack-plug, is performed digitally controlled.

The source select dial is a multi purpose input device for the digital control unit.

So all issues reported could potentially be resolved by a firmware update, the unit could even be programmed to mute before switching.

Best regards, Rudolf

Mute does not resolve the issue. I have the latest firmware at the moment (mute -> HT input -> unmute) and still there is a loud thump when it unmutes. Large amount of DC voltage builds up on the output and when the relay connects the output you can hear the thump from the right speaker. Left channel is dead silent at the same time. So this is definitely SGCDs fault or design flaw. :frowning:

Are you using XLR or RCA for input 1?

Sorry Brodric, I should have addressed the question to @spezwend,

1 Like

The reason I ask is that XLR is shared with input 1 RCA.