Chord Mojo 2 Thread ___ [product released January 31, 2022 -- starting on page 95 of thread]

[JaquesGelee]

sorry ask question here. Do PW mojo 4.4 and DDHIFI mojo are the same? Is that worth another 100 dollars(US) ? anyone have both?

I got both adapters, same functionality, only other design and price. So the ddhifi one is more than enough and better designed imo. Here is another Link.

@rlw6534: Is this the ddhifi one?

Be careful when removing from the Mojo...

I can't say I was impressed by the very thin wires.

 

[rlw6534]

I got both adapters, same functionality, only other design and price. So the ddhifi one is more than enough and better designed imo. Here is another Link.

@rlw6534: Is this the ddhifi one?

Yes, ddhifi. It works fine after I glued it back together, but still...

 

[OsterhagenMath]

Mojo 2 dropped Jan 31, 2022. Was a long wait after the OG Mojo, but worth it imo.

 

[Hypops]

I'm getting a surprising issue with the Mojo 2 that I'm hoping someone might be able to explain.

I just set up the Mojo 2 to feed two separate amps: a solid state Singxer SA-1 and an OTL Feliks Echo MkII. I am using two separate 3.5mm-to-RCA cables, one for each amp. If I have both amps powered and connected I have no issues.

But here's where things get weird. If I am listening to just the Feliks amp, but power down the Singxer, again no issues. All is great. However, if I am listening to the Singxer and power down the Feliks, I get massive distortion through the Singxer. The same thing happens when I set the Feliks to mute while listening to the Singxer. It's the same distortion I get if I connect the Mojo 2 to a phone without powering up the phone first. What am I missing here?

I'm stumped. I've got workarounds (always power up both amps when I'm listening to just one; or unplug the Feliks from the Mojo 2 when I'm listening to the Singxer), but it'd be nice not to have to do that. Even more, I'm just curious. I can't figure this one out. I've tried powering on different devices in different orders, but the result is always the same.

 

[BS5711]

I'm getting a surprising issue with the Mojo 2 that I'm hoping someone might be able to explain.

I just set up the Mojo 2 to feed two separate amps: a solid state Singxer SA-1 and an OTL Feliks Echo MkII. I am using two separate 3.5mm-to-RCA cables, one for each amp. If I have both amps powered and connected I have no issues.

But here's where things get weird. If I am listening to just the Feliks amp, but power down the Singxer, again no issues. All is great. However, if I am listening to the Singxer and power down the Feliks, I get massive distortion through the Singxer. The same thing happens when I set the Feliks to mute while listening to the Singxer. What am I missing here? The Feliks shouldn't be drawing any power from the Mojo 2 when the Feliks is off, right? Is there something peculiar about OTL amps that makes this kind of a setup a problem? Is it more likely something to do with the Feliks or with the Mojo 2?

I'm stumped. I've got workarounds (always power up both amps when I'm listening to just one; or unplug the Feliks from the Mojo 2 when I'm listening to the Singxer), but it'd be nice not to have to do that. Even more, I'm just curious. I can't figure this one out.

I can't recall the specifics but I read about this when I was wanting to understand the possible problems of splitting the output of a DAC to two amplifiers essentially like you are doing only with a splitter on the RCA output. I believe the Mojo in essence does that internally with its dual outputs being fed off the same circuit.

I recall reading that there can be a problem depending on how power entering the powered down amplifier through the line input is managed and adversely interfering with the DAC somehow.

Sorry I can't recall the specifics of the situation but I believe it is certainly a potential problem depending on the amplifier, one which unfortunately you have stumbled on it seems.

I suspect the only fix is to disconnect each time or put a switchbox in the circuit to switch the DAC output between each amplifier input.

 

[Hypops]

I can't recall the specifics but I read about this when I was wanting to understand the possible problems of splitting the output of a DAC to two amplifiers essentially like you are doing only with a splitter on the RCA output. I believe the Mojo in essence does that internally with its dual outputs being fed off the same circuit.

I recall reading that there can be a problem depending on how power entering the powered down amplifier through the line input is managed and adversely interfering with the DAC somehow.

Sorry I can't recall the specifics of the situation but I believe it is certainly a potential problem depending on the amplifier, one which unfortunately you have stumbled on it seems.

I suspect the only fix is to disconnect each time or put a switchbox in the circuit to switch the DAC output between each amplifier input.

Thanks. Yeah, it seems like it's just "one of those things" that can happen with certain combinations of gear. The only drawback to unplugging the Feliks all the time is that I'm worried that it'll ultimately wear the plug. And because I am who I am, I'm trying to figure out the why of it.

 

[BS5711]

Thanks. Yeah, it seems like it's just "one of those things" that can happen with certain combinations of gear. The only drawback to unplugging the Feliks all the time is that I'm worried that it'll ultimately wear the plug. And because I am who I am, I'm trying to figure out the why of it.

A switchbox would alleviate that concern but of course adds more cost, probably isn't easy to set up in a nice elegant system and may require new cables.

Might be simpler to get a second DAC and have standalone systems, maybe even another Mojo 2 if you are recouping some funds from other sales as mentioned elsewhere ?

 

[Hypops]

A switchbox would alleviate that concern but of course adds more cost, probably isn't easy to set up in a nice elegant system and may require new cables.

Might be simpler to get a second DAC and have standalone systems, maybe even another Mojo 2 if you are recouping some funds from other sales as mentioned elsewhere ?

Ha. Nope. My desktop chain is already more complex than I'd like. No harder to swap out cables than to use a switch box (and requires fewer boxes and cables). I was just hoping for a simple plug and play solution. I'd sooner sell the OTL amp than add yet another piece of kit to my shrinking desktop real estate!

 

[Serhiy]

I'm getting a surprising issue with the Mojo 2 that I'm hoping someone might be able to explain.

I just set up the Mojo 2 to feed two separate amps: a solid state Singxer SA-1 and an OTL Feliks Echo MkII. I am using two separate 3.5mm-to-RCA cables, one for each amp. If I have both amps powered and connected I have no issues.

But here's where things get weird. If I am listening to just the Feliks amp, but power down the Singxer, again no issues. All is great. However, if I am listening to the Singxer and power down the Feliks, I get massive distortion through the Singxer. The same thing happens when I set the Feliks to mute while listening to the Singxer. It's the same distortion I get if I connect the Mojo 2 to a phone without powering up the phone first. What am I missing here?

I'm stumped. I've got workarounds (always power up both amps when I'm listening to just one; or unplug the Feliks from the Mojo 2 when I'm listening to the Singxer), but it'd be nice not to have to do that. Even more, I'm just curious. I can't figure this one out. I've tried powering on different devices in different orders, but the result is always the same.

Most likely your Feliks is shorting the input connectors after power off, which is causing an overcurrent in the Mojo.
Try use impedance adapter min. 30 Ohm.When you turn off your Feliks, Mojo it will be loaded with 30 Ohm and not 0 Ohm. https://www.aliexpress.com/item/32819682262.html.

 

[Meridian7]

Most likely your Feliks is shorting the input connectors after power off, which is causing an overcurrent in the Mojo.

Also thinking in that direction. Shorting or something else, anyways affecting when off. I found this remark fitting the effect obseved.

 

[Daniel Johnston]

Thanks. Yeah, it seems like it's just "one of those things" that can happen with certain combinations of gear. The only drawback to unplugging the Feliks all the time is that I'm worried that it'll ultimately wear the plug. And because I am who I am, I'm trying to figure out the why of it.

As others said, the Felix is shorting out the RCA inputs. It’s a well known issue using one source component to two amps. It’s not the Mojo2 at fault.

A Schiit SYS is $50. It’s a handy and cheap fix.

 

[Hypops]

Most likely your Feliks is shorting the input connectors after power off, which is causing an overcurrent in the Mojo.
Try use impedance adapter min. 30 Ohm.When you turn off your Feliks, Mojo it will be loaded with 30 Ohm and not 0 Ohm. https://www.aliexpress.com/item/32819682262.html.

Also thinking in that direction. Shorting or something else, anyways affecting when off. I found this remark fitting the effect obseved.

As others said, the Felix is shorting out the RCA inputs. It’s a well known issue using one source component to two amps. It’s not the Mojo2 at fault.

A Schiit SYS is $50. It’s a handy and cheap fix.

Excellent. Thanks, all.

I'll start with an impedance adapter since it'd mean not having to futz with anything. If 30 Ω is the minimum I should try, would it make sense to go even higher just to be sure? Amazon (my only option since I'm in the US) has as high as 600 Ω.

 

[Serhiy]

Excellent. Thanks, all.

I'll start with an impedance adapter since it'd mean not having to futz with anything. If 30 Ω is the minimum I should try, would it make sense to go even higher just to be sure? Amazon (my only option since I'm in the US) has as high as 600 Ω.

Depends on the input impedance Feliks. There may be significant attenuation of the input signal.

 

[Hypops]

Depends on the input impedance Feliks. There may be significant attenuation of the input signal.

Specs have the Feliks amp at 100k, but obviously that's when it's powered on. No idea how (or if) that changes when it's powered down (impedance is largely the result of passive components, yes?). Would it be wiser to overestimate and just pick up the highest impedance value adapter I can, or to underestimate and go for the lowest value I can get away with?

But if the concern would be an attenuation of the signal when I'm using the Feliks amp, I don't think 600 Ohms would matter much against the existing 100k. I've used it with my Denafrips Ares II DAC without issue, and that's got a rated output impedance of 1200 Ohms.