Apos x Community Gremlin Tube Amp - Pre-order Now on Apos

[Nemesis9]

The Fiio K3 is an DAC/AMP combo so that may be an issue. Is the high gain on on the K3? Also, do you happen to have a DAP that you can with a 4.4 output that you connect to the amp? That may help with troubleshooting your issue.

I saw reviewers online using dac/amp combos and worked great for them.

 

[Nemesis9]

Hi @Nemesis9, we asked the technical team and they advised a few things that may resolve the concern.
Did you mean you are using a K3 or the K35 by FiiO? If you bought it brand new recently, it may not be the K3.
if it is a FiiO K35 with 2.5 balanced output, try these steps.
- Use a 2.5mm to 4.4mm adapter cable with a ground wire connected, otherwise there may be humming.
- The general 4.4 balanced cable only connects L+, L-, R+, R-, without connecting GND. However, these two units must be connected to GND.
We hope this helps.

It is in fact the k3. I'm not following what you mean mean by 2.5mm to 4.4mm adapter with a ground wire connected. Also I'm using a 2.5mm to 4.4mm cable so I wouldn't need adapters (I thought). Are we saying the 2.5mm balanced may be the issue?

 

[Evldice]

I saw reviewers online using dac/amp combos and worked great for them.

For sure - a couple of notes though; I use the Q15 and ensure that I set it to LO and not PO, this adjusts the output voltage. Also, on the Q15 it is 4.4mm to 4.4mm on the Gremlin, direct connect. Never had any issues with hum or noise with this set-up.

 

[Nemesis9]

For sure - a couple of notes though; I use the Q15 and ensure that I set it to LO and not PO, this adjusts the output voltage. Also, on the Q15 it is 4.4mm to 4.4mm on the Gremlin, direct connect. Never had any issues with hum or noise with this set-up.

The key part to trying to dial this down is that it hums without a dac plugged in. If it's powered on and I simply plug in a 4.4mm to 2.5mm balanced cable in the back it hums extremely loud immediately. Just the cable.

 

[Evldice]

It is in fact the k3. I'm not following what you mean mean by 2.5mm to 4.4mm adapter with a ground wire connected. Also I'm using a 2.5mm to 4.4mm cable so I wouldn't need adapters (I thought). Are we saying the 2.5mm balanced may be the

The key part to trying to dial this down is that it hums without a dac plugged in. If it's powered on and I simply plug in a 4.4mm to 2.5mm balanced cable in the back it hums extremely loud immediately. Just the cable.

It is a cable issue, Apos is saying that you must have cables that utilize the grnd. See the images. One for the ground and one without.

 

[Nemesis9]

Thanks. Looks like the 4.4mm and single ended are only one's that have use ground? What do you recommend I use to make this work? My k3 only had a 2.5mm balanced out. I'll buy whatever cable/adapter I need to make this work correctly.

 

[Evldice]

Thanks. Looks like the 4.4mm and single ended are only one's that have use ground? What do you recommend I use to make this work? My k3 only had a 2.5mm balanced out. I'll buy whatever cable/adapter I need to make this work correctly.

I'm not an expert here, but I believe that you have to find a cable that wires in the ground for both connectors. I learned today that some 4.4mm don't have grounds wired to the connector, I never knew that. The cable I use is 4.4mm to 4.4mm and I never checked to ensure it is wired to ground, but it works without issues. Maybe try a 4.4 to 4.4 with an adapter to 2.5mm that wires ground?

 

[Nemesis9]

I'm not an expert here, but I believe that you have to find a cable that wires in the ground for both connectors. I learned today that some 4.4mm don't have grounds wired to the connector, I never knew that. The cable I use is 4.4mm to 4.4mm and I never checked to ensure it is wired to ground, but it works without issues. Maybe try a 4.4 to 4.4 with an adapter to 2.5mm that wires ground?

Thanks ill try that. I just figured it would have to be a balanced 2.5mm connector only, but the ones with ground are single ended.

 

[Nemesis9]

Seems like maybe I should go with xlr to the gremlin because I don't see how I can tell if there is ground on any of these 4.4mm or 2.5mm balanced cables.

 

[Evldice]

Seems like maybe I should go with xlr to the gremlin because I don't see how I can tell if there is ground on any of these 4.4mm or 2.5mm balanced cables.

That may be a good option too

 

[jsabini1]

Listening to Gremlin with Mullard tubes, and Verite Open Blackwood, what a great combo! This amp has no business sounding as good as it does, really nice. The smoothness and nice tonality the Mullards bring slightly softens the sound of the Verite, while still keeping the overall speed and resolution that the Be coated drivers have.

 

[emdeevee]

This little baby is the perfect bedside companion!

 

[ch1525i]

Listening to Gremlin with Mullard tubes, and Verite Open Blackwood, what a great combo! This amp has no business sounding as good as it does, really nice. The smoothness and nice tonality the Mullards bring slightly softens the sound of the Verite, while still keeping the overall speed and resolution that the Be coated drivers have.

So glad to hear this! I'm running Mullard reissues in my Gremlin and I'm eagerly awaiting my ZMF November VO rarity!

 

[BS5711]

Seems like maybe I should go with xlr to the gremlin because I don't see how I can tell if there is ground on any of these 4.4mm or 2.5mm balanced cables.

It isn’t possible to have a ground on a 2.5mm since the design doesn’t include one having only four terminals which are the positive and negative of each channel.

Not all 4.4mm to 4.4mm cables use the ground connections. I know that the iFi and ddhifi ones do and the GUCraftsman do not.

If the Gremlin needs a ground connection between itself and the source device, and it hums if it doesn’t have a ground, your only reasonable option is a device with a 4.4mm output and a 4.4mm to 4.4mm cable that uses the ground.

Additionally, there is possibly a chance that some source devices may not use the ground of the 4.4mm output, especially if it is a dongle type device usually intended to power headphones and not strictly designed to be used as a DAC and thus does not need a ground connection.

 

[mekap]

This little baby is the perfect bedside companion!

what is this device on the right of Gremlin, is it a DAP or a dongle?