GCD does not display sample rate

Hi all, am I missing something? I have a MacBook Pro via usb to the gcd and the display of the gcd does not show sample rate. Is there a button I’m missing?


You probably have an older unit. They did a firmware upgrade that corrected the issue. Contact support and the will send out a new PIC chip.

I just went through the same process. Super easy to replace yourself they send tools and instructions.

I just purchased it. I’m still in the trial period. In fact I had to send it back because of a buzz, which they did fix. The support sheet in the box also said they updated the firmware. This should be totally new.

CPU version is
Fpga is 1.04


Well dang. I am not sure then.

Ok thanks. So to be sure, laptop plugged in via usb should show sample rate? No special button or option to turn it on or off etc.?

It is automatic it will show without you having to do anything.

Howdy @lmerino,

Thanks for posting this. I spoke with our engineering team and it looks like you’ve found a small bug as a result of a recent change.

Specifically, we’ve updated to a new version of USB handler that handles some things a bit differently than the previous generation. Performance is identical between the two chips, though as you’ve found the sample rate doesn’t show over USB.

Our engineering team is currently looking into the matter and will be developing a fix for this bug. I’d be happy to update this thread once I have more information from engineering.

How are you liking the Gain Cell otherwise?

Thanks for the feedback.

TBH, I’m a bit back and forth on the Gain Cell Dac. Maybe it’s my setup, maybe it’s my room, but when I A/B against my Marantz receiver using the pre-outs into the S300, it’s hard to distinguish a difference. All my music is streaming. Most times I’m streaming Spotify, the highest quality will be Tidal via Roon. I pass the Marantz through a GCD Home Theater input and switch between that and a computer via USB playing the same thing. When I switch back and forth they sound pretty much identical, and the fact that the Marantz is basically a streaming pre-amp is really hard to ignore.

I also find both the GCD and S300 have a rather audible noise floor. Using the S300 with the Marantz I can hear a slight hiss compared to a couple other power amps I have, nothing too loud, but it’s there. With the GCD/S300 combined, the noise floor is rather apparent.

That being said, I think the S300 itself is really good. Right out of the box I heard a really nice sound with solid low end that my other amps did not have. I certainly had that “oh that’s nice” moment on the first track i played.

Listening to Paul’s podcast, perhaps one could say my system is not resolving enough to hear the differences inherent in the GCD vs the Marantz as a pre-amp, but I’ll keep listening.

That’s my .02 cents since you asked, not sure if you wanted that much of an answer. :wink:

Thanks again.

What speakers, cables and interconnects are you using?

I really appreciate the detailed answer.

Your comment on the noise floor in particular catches my interest - I ran the Gain Cell and S300 in my home system for several months and the pair was dead quiet.

What speakers are you running?

My main pair are Kef LS50’s, but I also have several pairs of DIY speakers and some vintage Dynacos.

As per cabling, I use quality cables, but nothing fancy. Hosa HMIC xlr, Monoprice’s premium RCA’s, plus DIY as well. For speaker cables I currently have DIY twisted pairs made from 14 gauge OFC.

I’ve read some other posts about the noise floor with these units, so I figured it was just inherent in this gear. The other amps I’ve tested are the amp built in to my Marantz, an emotiva a-300, a couple diy Pass class A amps, and some older NAD amps (2200 and 7240pe). Those are all silent.

The only other time I’ve heard a hiss like this is from a cheapo SMSL class D amp from amazon that was known to have a really high gain to begin with, but even still it was not as loud as the GCD/S300 combo. I’m not comparing the S300 to that amp, but if I would have to take an uneducated guess, it would be that both the GCD and S300 were designed with a much higher gain than this other gear I’m testing. At least the specific units that I have feel like the gain is high. This makes me wonder if something is up with my particular units?

How far away from the speaker can you hear the noise floor?

When I get back home tonight I’ll try to do some more accurate measuring, but certainly at least 2-3 feet away. I don’t have a listening room, it’s just set up in the living room, so there is general house noise that does mask it from the listening position

I’ve definitely had the thought that if I actually had my own listening room it would probably be too audible from the listening position. But again, I’ll try to do some measuring this evening.

My Stellar GCD/S300 were dead silent, as are my M700s with the same pre. My DS Sr, GCD, and M700 combo is also dead silent.

I’ve got a relatively new GCD and S300 and if I put my ear near the tweeter I can hear some hiss, but from the listening position in a dedicated room, its silent

So did some testing tonight. I wasn’t able to get the house totally quiet, but if anything that helps in the matter… I think in bullet points so…

  • The GCD and the S300 have their own “amount” of hiss. Combined they add to each other.
  • the amount of hiss increases as the volume on the GCD increases. I suppose this makes sense because the Gain Cell is a way to increase volume by increasing gain, right? So as the gain goes up, so does the noise floor?
  • When the GCD is muted, it sounds the same as when it’s powered off. Tested this by turning it on and off with my ear to speaker
  • When the GCD is at 1 or above there is hiss, which rises as I increase volume. I can power the GCD on and off, and hear the hiss go on and off.
  • The hiss is louder with digital inputs than the analog inputs

Now something I find interesting… as I was testing I was thinking to myself “I hear the hiss, but i remember it being louder than this.” And then I switched to input 3 which I have set for Home Theatre bypass. Boom, there was the level of hiss I remember, and realized that HT bypass sets the volume to 76. With any line source this would be crazy loud, but as a bypass for another pre-amp or AVR it’s controlled. So yeah, noise floor is very noticeable when the volume is at 76.

That being said, I probably identified this after I was watching tv, I would walk up to my system to shut it off and I heard the hiss while in HT Bypass mode. I would hope that mode would basically sound identical to plugging my speakers directly into the AVR… or at least the power amp the AVR is using.

At volume level 1-20’ish I can hear it about a foot away.
Once i get to 30 i can hear it a couple feet away, but I wouldn’t normally listen to levels this loud.
At 76 (HT Bypass) i can hear it about 4 feet away.

I can say with certainty that my units are not “dead silent” as tensor9 says above. If I plug in my speakers to my marantz AVR and turn it all the way up (+12db) I don’t hear any hiss, I would call that dead silent.

Are these just my units? Can anyone share similar experience?


You likely have very sensitive speakers. Indeed, there’s likely hiss in every preamp to some extent and the GCD is no different. I would suggest that an audible hiss 1 foot from the speakers is pretty normal.

The default of 76 for HT bypass can be adjusted to whatever you want in the setup menu. Obviously, that level in your system is too much, so just turn it down to solve the problem.

BTW, the reason we chose 76 is because that is unity gain or, put another way, that is without any amplification. That said, it’s still pretty loud for most systems even of medium efficiency. Imagine plugging your CD player directly into your
power amplifier. It would be pretty loud n most systems.