Preamp ZP3 thoughts and concerns

[newfosi]

I've ordered a ZP3, which is expected to arrive tomorrow. FedEx consistently gives inaccurate arrival info (it was originally supposed to arrive yesterday), so we'll see.

I checked with Fosi customer support on op rolling. The ZP3 op amps are socketed, so op amp rolling is possible, but unlike the other products in the "Z" line, Fosi is not touting that capability. I believe the case is difficult to open and has a warning about doing so given the interior power supply.

The image of the case construction on Fosi's web page shows the case's side panels are screwed to the case, but the actual product images show the side panels have no screws. I read elsewhere that the panels are glued on. I checked with Fosi and they said the side panels require a special tool to open. Once it arrives I'll ask them to explain what the tool is and how to open it.

I bought two Sparkos SS3602 amps, which I put in my ZD3, but since I am replacing the preamp function with the ZP3 I would like to move them from the ZD3 to the ZP3 if possible.

I agree with criticisms I've read regarding the infinite volume knob, but I don't think it will be a big deal given that I only use one input - the ZD3 to the ZP3. But I liked the ZD3 volume level screen and will miss it.

A bigger issue for me is the ZP3 remote. I will probably go back and forth between the ZD3 and the ZP3 remotes. The ZP3 remote has a ZD3 button that converts the remote to a ZD3 remote to change inputs on the DAC. But the ZD3 screen's input indicators is not legible from a distance. The ZD3 remote resolves that issue with dedicated input buttons. But the only input buttons on the ZP3 remote are "ZD3" and "Mode". I assume once I press the ZD3 button I can cycle through the inputs by pressing the Mode button repeatedly, but selecting a specific input on the ZD3 remote was a better way to do it.

I'll update with further info when the ZP3 arrives.

 

[newfosi]

Just wanted to list the reasons I ordered the ZP3.
1. I have two ZA3s in mono mode connected to a ZD3, and a V3 Stereo amp in a separate room.
2. The Z products are all connected via XLR. I have no idea if that improves the sound but I noticed that a balanced connection provides higher volume at a lower volume setting than RCA for these components. Plus I just like the way XLR cables connect securely to the components.
3. Separation and clarity are excellent. A big improvement over my prior Sonos amp.
4. Fosi prices are very affordable compared with comparable big name brands.
5. Fosi's customer service is good. I've always received rapid responses to my questions.

But as a "nice to have" feature I felt that I was missing a tone control. Finding a tone control that supports XLR is hard to do at a reasonable price point. I could have gotten a Schiit device but that meant switching to RCA.

So I was interested in the ZP3 because of my satisfaction with Fosi so far, the XLR support, the tone control, the HPF and the price after early bird discount. If it turns out I can move my Sparkos op amps from the ZD3 to the ZP3 that would be perfect.

 

[newfosi]

Let’s start with my electronics pre-ZP3

1 Q70 Samsung TV
2 Apple TV connected to the TV by HDMI
3 ZD3 connected to the TV by HDMI ARC
4 ZD3 connected to two ZA3s in mono mode via XLR cables and trigger cables
5 Sparkos SS3602 (2) replaced the stock XLR output op amps in the ZD3

I’ve now added a ZP3 connected by XLR cables to the ZD3 and the ZA3s. The preamp in the ZD3 is bypassed. The subwoofer cable is moved from a ZA3 to the ZP3 and the HPF is set to 80hz.

The good: bass is improved even without adjusting the tone controls.

The bad: overall audio quality seems like a step backward. I suspect the reason is that the Sparkos op amps are still in the ZD3 but the ZD3’s preamp is bypassed. As yet I don’t know the proper way to open the ZP3 case and move the op amps.


Other

1 Volume control with the ZP3 works worse than the ZD3 remote. Volume changes work instantly on the ZD3 remote. Not so on the ZP3. The first press of the ZP3 volume button appears to do nothing. Perhaps it creates a connection to the ZP3. There is no way to prove that other than my own ears but I don’t hear any change on the first press. It creates confusion. The ZD3 remote doesn’t do that. The ZP3 mute button works on the first press, so I don’t understand why the ZP3 remote volume button works differently.

2 The Z P3 remote has a button to convert it into a ZD3 remote and another button labeled Mode. If the remote is used as a ZD3 remote, you can press the mode button to cycle through the various digital inputs in the ZD3. But if you are sitting on a couch a few feet away from the ZD3 you can’t see which input is activated. It’s much easier to choose inputs via the ZD3 remote rather than the ZP3 remote set to ZD3. That means it’sbetter to juggle two remotes.

3 It’s necessary to choose inputs on the ZD3 because my TV is connected to the HDMI input on the ZD3. I use the Apple TV remote to control the TV. But when I use the Apple TV remote to shut off the TV it also shuts off the ZD3 since they are all connected via HDMICEC. There is some quirk between Fosi devices and the Samsung TV that causes the ZD3 to wake up 30 seconds after shut off, and that turns the TV back on. The fix is to change the input on the ZD3 from HDMI to something else, and then shut off the TV. And also shut off the ZD3 separately using the ZD3 remote.

Because the ZP3 remote only has a single mode button, cycling through all of the inputs to get to HDMI to turn my system back on is an annoyance. So I choose to use the ZD3 remote to press the dedicated HDMI button so my TV audio is played through the ZD3.

Also, since the ZD3 preamp is bypassed, the volume button on the Apple TV remote accomplishes nothing. I can tell from the ZD3 volume display that it is changing volume, but the ZD3 volume control is bypassed. The ZP3 controls the volume, but the ZP3 is not part of the CEC daisy chain so can’t be controlled by the Apple TV remote.

4 The end result of the above is that I need a minimum of three separate remotes. The ZP3, the ZD3 and Apple TV remotes.

These various annoyances would be tolerable if I felt that the overall audio quality was meaningfully improved by the addition of the ZP3. But so far that has not been the case other than a noticeable improvement in bass. Perhaps the ZP3 needs time to break in. Or maybe I will see a video online of a brave soul who dares to open the ZP3 case and is willing to share how to go about it.

 

[fester70]

See this other thread about how to open teh ZP3 - you dont need special tools .
https://community.fosiaudio.com/threads/fosi-audio-zp3-disassembling-for-op-amp-rolling.9022/

@newfosi -
>> The bad: overall audio quality seems like a step backward.
I had the ZP3 placed between a ZD3 and Pair of V3 Monos each with dual sparkos and overall it lost some detail and narrower soundstage in this config . Try having the ZP3 in bypass mode , it has more detail in this config.

 

[newfosi]

Thanks fester70.

My understanding of the ZP3 bypass is that it turns off the tone controls, which is one of the two primary reasons I bought the unit.

I also noticed I get a ground loop hum when the ZP3 is installed. No hum when it's disconnected. I haven't identified the source of the problem yet. Might be the difference in ground paths (ZP3 power cord uses a 3 prong plug vs. 2 prong plug for the other Fosi components).

I plan to return the ZP3. Even if I can swap the op amps from my ZD3 (they aren't doing much in the ZD3 when I bypassed the ZD3 preamp to use the ZP3 preamp) there are too many other annoyances.

I didn't realize how much I would lose by subordinating the ZD3 to the ZP3. I like the ZD3 volume level screen, the dedicated input buttons on the ZD3 remote and the ability to control my system with one remote via HDMI CEC. Plus it sounds great.

I read your linked post. Can you describe what was necessary to peel the side panels on the case? Just curious. Are they glued on? Can you put them back on after you're done?