Apollon Purifi 1ET7040SA ST / Parasound P6 - Bad combination?

[Glarioo]

Connecting a Parasound P6 preamp to an Apollon Purifi 1ET7040SA ST with Sonic Imagery 994 op-amps.
A problem surfaced...
While switching between different sources, an annoying ‘tick’ can always be heard. With the volume at zero, that ‘tick’ is also there.
I first connected the preamp balanced and then single-ended. With both there was the problem with those ‘ticks’
At first I thought the problem was with the P6 and I went back to the shop where I bought the P6. Got another P6 but the problem with that ‘tick’ was also there.
Again back to the shop and connected both P6 preamps to a Class AB power-amp, here that ‘tick’ was not there.
The shop gave me another class D power amplifier, a Gato DPA-4004, to try. No ‘tick’ with this power amplifier either.
Anyone have an idea what causes those ticks?
I am a bit worried that it will end badly for my speakers.

In the attached zip file a video, nothing connected to the preamp, just the Apollon poweramp...

 

[proux]

Connecting a Parasound P6 preamp to an Apollon Purifi 1ET7040SA ST with Sonic Imagery 994 op-amps.
A problem surfaced...
While switching between different sources, an annoying ‘tick’ can always be heard. With the volume at zero, that ‘tick’ is also there.
I first connected the preamp balanced and then single-ended. With both there was the problem with those ‘ticks’
At first I thought the problem was with the P6 and I went back to the shop where I bought the P6. Got another P6 but the problem with that ‘tick’ was also there.
Again back to the shop and connected both P6 preamps to a Class AB power-amp, here that ‘tick’ was not there.
The shop gave me another class D power amplifier, a Gato DPA-4004, to try. No ‘tick’ with this power amplifier either.
Anyone have an idea what causes those ticks?
I am a bit worried that it will end badly for my speakers.

In the attached zip file a video, nothing connected to the preamp, just the Apollon poweramp...

how did you like the Gato sound compared to Apollon?

 

[Glarioo]

how did you like the Gato sound compared to Apollon?

To my hearing, there was no audible difference in sound, both top quality. I was not able to test them side by side, it was always swapping cables from the Apollon to the Gato.
Edit: That's why I kept the Apollon, and not the much more expensive Gato.

 

[proux]

really useful, thanks!

To my hearing, there was no audible difference in sound, both top quality. I was not able to test them side by side, it was always swapping cables from the Apollon to the Gato.

any other views on the Gato power amp 4004? Looks beautiful, apparently runs warmer than other class D, offers 4 channels, so can biamp if one is that way inclined...

 

[Glarioo]

really useful, thanks!

any other views on the Gato power amp 4004? Looks beautiful, apparently runs warmer than other class D, offers 4 channels, so can biamp if one is that way inclined...

”apparently runs warmer...”
Indeed, the Gato gets “noticeably” warmer than the Apollon.

 

[DVDdoug]

A guess...

The preamp may "need" a "DC current path" (a resistive load) and the power amplifier might have a DC blocking capacitor at the input (so there's no DC load). When there's also a capacitor on the preamp's output and there's no path to discharge it the blocking doesn't work perfectly and get DC on the preamp's output. You can't hear DC (zero Hz) and the capacitors will keep it out of your power amp & speakers, but you can get a click or pop when it's switched in-and-out.

If that's the problem, I blame the preamp. But the same thing can happen with a power amp... You can get sometimes DC leakage on the input when nothing is connected (or when there's no DC path). The capacitor keeps it out of the amplifier's active electronics but when you suddenly connect something, the DC is discharged and you hear a click or pop.

As an experiment you can get an in-line attenuator to give it a DC load, and you can turn attenuator volume to maximum so it doesn't do anything to the signal/sound. And that should work whether the DC is coming from the preamp or power amp.

BTW - This can be difficult to measure because when you connect a multimeter you've provided a DC path to discharge any DC voltage.

I am a bit worried that it will end badly for my speakers.

A little tick is unlikely to hurt anything.

 

[Glarioo]

A guess...

The preamp may "need" a "DC current path" (a resistive load) and the power amplifier might have a DC blocking capacitor at the input (so there's no DC load). When there's also a capacitor on the preamp's output and there's no path to discharge it the blocking doesn't work perfectly and get DC on the preamp's output. You can't hear DC (zero Hz) and the capacitors will keep it out of your power amp & speakers, but you can get a click or pop when it's switched in-and-out.

If that's the problem, I blame the preamp. But the same thing can happen with a power amp... You can get sometimes DC leakage on the input when nothing is connected (or when there's no DC path). The capacitor keeps it out of the amplifier's active electronics but when you suddenly connect something, the DC is discharged and you hear a click or pop.

As an experiment you can get an in-line attenuator to give it a DC load, and you can turn attenuator volume to maximum so it doesn't do anything to the signal/sound. And that should work whether the DC is coming from the preamp or power amp.

BTW - This can be difficult to measure because when you connect a multimeter you've provided a DC path to discharge any DC voltage.


A little tick is unlikely to hurt anything.

Thanks for the advice.
I have tried DC-Blockers, on both preamp and power amp, but to no effect.

https://www.amazon.com.be/-/en/iFi-SilentPower-DC-Blocker-Connector/dp/B08XWHJRZ1/ref=asc_df_B08XWHJRZ1?mcid=4a135280d03e379ba1576d759c65f53c&tag=begogshpadde-21&linkCode=df0&hvadid=712655811307&hvpos=&hvnetw=g&hvrand=15178350377017194840&hvpone=&hvptwo=&hvqmt=&hvdev=t&hvdvcmdl=&hvlocint=&hvlocphy=9195617&hvtargid=pla-1211837079319&psc=1&language=en_GB&gad_source=1

 

[Glarioo]

By the way, I'm looking out for a new preamp. Problem is that I need four analogue inputs and a “rec” out. Only Anthem STR preamp has that, and the Parasound.