Chord Mojo(1) DAC-amp ☆★►FAQ in 3rd post!◄★☆

[Kentajalli]

I believe it switches off at around 6.9V.
Batteries, when fully charged, can peak to 8.2V

 

[590839]

what is the minimum voltage for work for chord mojo?
will it work from 7v or 6v?

The auto-shutdown trigger is set @ 6.5V. Once it hits 6.5V, it's bye-bye sleepy time.

While it will work from > 6.6V, the optimal SQ is around 8V so you have to take that into consideration.

If you just want it to work, I guess you can have it hover around 7V so it won't trigger a auto-shutdown. But for max output / SQ, something closer to 8V would be optimal.

Low volume IEM listening I guess can hover around 7V, but for headphones you will need closer to 8V.

Also, you have to take into account a Battery may spec @ 3.6V or 3.7V or in series @ 7.2V or 7.4V but once you measure it is closer to 4V+. I have not try measuring a series yet as the Mojo was an decade ago, but I'm assuming it will hit around 8V on a full charge on a 7.2V or 7.4V spec.

 

[590839]

For example, I run parallel 3.6V on a Hugo2. Four 18650 Batteries in parallel and it hits 4V+ each. The Hugo2 needs two power inputs so I'm actually running 4V+ + 4V+ so around 8V+ total. Total of eight 18650 Batteries.

I don't use the standard 5V charger at all as that can cause major short circuit issues. I moved on from the official Chord charging system and just use my own separate 18650 charger.

What I discovered is with each parallel additon of battery, from one battery to two to four, etc. the total impendance gets cut in half along with overall noise getting cut in half. Lowering the impendance closer to zero is super important for SQ. That is what was accomplished with the Hugo TT, but with supercapcitors. What I discovered is modern Chord DACs don't need to be powered by supercapacitors because it has an updated, modern PSU. Lowering the impendance leads to super tight, visceral bass that you can only find on the Summit-Fi Chord DACs. But I'm unsure if it is the parallel battery pack or because I'm running a much better Galvanic Isolation than the Hugo TT or maybe a combo of both? I also run expensive wiring on my battery packs as another variable. But in the end, the results are bass you can only find similar on the Hugo TT. IMHO, I'm running the #2 Chord DAC in the current lineup because I run my Chord Chain @ 99%+ Chord purity but that's another non-battery topic. But I starting to figure out the battery pack may have a bigger role in my #2 Chord DAC chain than anticipated.

I also got my Hugo2 running off Supercapacitors, but I think I will stick with 18650 batteries. If I had a Hugo1, I would run it off Supercapacitors. But with a modern Chord PSU on the Hugo2, I think sticking with batteries is all that is needed. I would run a Mojo off Supercapacitors but it doesn't run @ ~8V. The Chord era of Mojo, Hugo and Hugo TT have a more legacy PSU than the sequels.

So if I was working on an EOL Mojo, I would consider one of these battery packs instead of replacing a single internal if it was for desktop use. I definately would not use anything Mains. YMMV:

It mentions 7.4V in series on the labeling, but it actually hits 8.4V?

7.4V (working) 8.4V ( peak) 5.5V ( cut-off)

I would only run the official Panasonic Batteries that Chord recommends.

Anyways, I'm a bit offtrack because I'm not quite caught up what Mojo users are trying to accomplish.

Again, if you run a battery pack like this, don't ever plug in a 5V USB cable into the Chord Mojo power side. Use a separate charging system.

From da Man:

No a Hugo 2 and Mojo need at least 6.5v, otherwise it will shut down. And you need 8v to get the best measured performance in terms of OP power too...

I strongly suggest that you do not change the battery, unless you have too; and use the same as the original. The charging circuit is tuned to match those batteries, and you could have a fire or something else serious if you mess around with it!

The good news is that for every battery-powered Chord product in existence, you can worry-less about being a book holder. There's an unofficial way of bypassing the Chord charging if it is ever needed. With every new Chord DAC released, the major concern is what to do when the battery gives out.

I use Anderson connectors so I can easily snap-on and snap-off for offline charging away from the Chord internal charging circuit. I'll try to take photos.

 

[robsonj]

I have a Mojo2 arriving tomorrow. My IEMs are all cabled with 4.4mm balanced jacks. I’d rather not swap all the cables out, so wondering what people are using to adapt from 3.5mm to 4.4mm.

I understand that it won’t be balanced, nor need to be on the mojo.

I see a miriad of adapter cables on Amazon, recommendations would be welcomed.

Thanks

 

[vandung2510]

I have a Mojo2 arriving tomorrow. My IEMs are all cabled with 4.4mm balanced jacks. I’d rather not swap all the cables out, so wondering what people are using to adapt from 3.5mm to 4.4mm.

I understand that it won’t be balanced, nor need to be on the mojo.

I see a miriad of adapter cables on Amazon, recommendations would be welcomed.

Thanks

Just buy the ddhifi adapter.
Or order some diy adapter. I ask my local diyer to make that, you can buy it from Xinhs on Aliexpress

 

[mathi8vadhanan]

I have a Mojo2 arriving tomorrow. My IEMs are all cabled with 4.4mm balanced jacks. I’d rather not swap all the cables out, so wondering what people are using to adapt from 3.5mm to 4.4mm.

I understand that it won’t be balanced, nor need to be on the mojo.

I see a miriad of adapter cables on Amazon, recommendations would be welcomed.

Thanks

https://www.amazon.com/DD-DJ44CPro-Advanced-Pentaconn-Connecting/dp/B0CLLTCSLL
if you don't want to wait a week,
https://www.amazon.com/dp/B08V97K1LX

 

[590839]

The Hugo2 and Mojo are similar for the power requirements along with the same JST 2-pin connector. Both optimal is around 8V-8.4V. Hugo2 splits the power so you need two power inputs while Mojo just one. But once it adds up, it's similar.

Here is my Modern Day Hugo TT (Technically a Hugo2):

My modern day 10-element, 49,142 Taps Hugo TT has double the batteries of the Hugo TT for even lower impedance along with double the time. It's unhindered too as there is no constant 12V Mains charging component compromising the chain. I use Mundorf Silver Solid Core wiring from Batteries to the PCB. I don't know if this had a contribution to the tight, visceral Bass but all I know is that the sound is pretty much perfect with this 4 X 18650 config on each side. Enough that I gave up going with Super Caps (Plan A).

The Max gauge for JST 2-pin is 22 AWG. The Mundorf Silver is 24 AWG from Anderson Connector to PCB. 15.5AWG from Battery to Anderson Connector. There is a Neotech 22 AWG Solid Core wiring available but it is too stiff for JST. Mundorf is much more pliable so I'm sticking with Mundorf going forward for my Chord projects.

I completely avoid the Chord charging system and use my own external 18650 charging. Similar if I was charging 18650 for Radio-Control Vehicles. Charging is all external away from the Hugo2. I just snap-off and snap-on the Anderson connectors when I need to charge.



To convert a Hugo2 into a Hugo TT, you need perfect Galvanic Isolation. I do use the below Super Caps @5V for my perfect Galvanic Isolation which also powers the Chord USB Receiver giving it a significant increase in SQ. This is via a USB optical cable, not those regular noisy RFI USB Cables.

I also powered my Hugo2 with a pair of the below Super Caps, but it hovered low 7V. Since I perfectly replicate the Sound Characteristics of a Hugo TT with a pair of 4 X 18650 with Solid Core wiring at the standard 8-8.4V, I'm staying put as I get a perfect Sound Presentation, perfect timbre, Soundstage Depth, etc. that you would expect in the Summit-Fi Chord DACs with my Modern Day Hugo TT. I would only Super Cap if I needed more performance or for 24/7 Convenience (No regular External Charging of Batteries). The Super Caps are designed for 24/7 Industrial Use for a 20-year life.

By using four batteries instead of one, it halves the impedance twice. Having a low impedance helps to have that tight, visceral Bass. The Hugo TT did it with Super Capacitors, but now that technology has caught up (updated Chord PSUs) you can just scale 18650s to have a similar effect with more modern Chord DACs.

So I guess both my 18650 with Solid Core Wiring and my Super Caps are both 1S4P configs. Next year, likely 1S8P on both as I do enjoy halving the impedance. By following the Chord Hugo TT Implementation Model of low impedance power source and Galvanic Isolation, you can create a Modern Day Hugo TT with a Hugo2. The Chord Hugo TT Implementation Model was applied to the Hugo1 to create a TT. I just apply that model to a Hugo2 to create a Modern Day TT.

So while low 7V is doable, ~8V optimal.

 

[robsonj]

Just received my Chord2, loving it so far, but having issues with usb cables, I purchased the following... https://www.amazon.com/dp/B09MLFPLZS?psc=1&ref=ppx_yo2ov_dt_b_product_details, but it craps out and I just get white noise when playing hires audio from Apple Music via the connected iPhone 15. Seems to work fine with the HiBy R3 Pro connected, and sending music via airplay, but that caps at 44.1kHz ish.

So looking for a short usb to usb cable recommendation please?

I did find a cable laying around that works fine, but its about 6foot long

 

[vandung2510]

Hi y'all.
So i have a Mojo 1 and i want to convert it to full time desk setup.

I found some really nice 7.5V and 8.4 linear power supply adapter for cheap.
I wanna ask if there's any risk involve when doing the mod? (Other than voiding the warranty). Is there any safety measure i can do?

Also, when would i need to use something like this? I think it has a lot of capacitors but i have no idea what it does.
Hope you guys can help me :>

 

[robsonj]

https://www.amazon.com/DD-DJ44CPro-Advanced-Pentaconn-Connecting/dp/B0CLLTCSLL
if you don't want to wait a week,
https://www.amazon.com/dp/B08V97K1LX

Along these lines, this just became available on drop.com for anyone interested...

https://drop.com/buy/cayin-ph-35x-3...ontent=1721366277656.742283327056680372524936

 

[mathi8vadhanan]

Hi y'all.
So i have a Mojo 1 and i want to convert it to full time desk setup.


I found some really nice 7.5V and 8.4 linear power supply adapter for cheap.
I wanna ask if there's any risk involve when doing the mod? (Other than voiding the warranty). Is there any safety measure i can do?

Also, when would i need to use something like this? I think it has a lot of capacitors but i have no idea what it does.
Hope you guys can help me :>

You can check with @NeedtoBurn , he has done practical conversions for OG Mojo.
He's just installing a female DC port on the 3.5mm port side and using an external 18650 battery pack like this Eachine 7.4V 18650 Li-ion Cell Battery Case
or Omnicharge Omni 20+.

 

[vandung2510]

You can check with @NeedtoBurn , he has done practical conversions for OG Mojo.
He's just installing a female DC port on the 3.5mm port side and using an external 18650 battery pack like this Eachine 7.4V 18650 Li-ion Cell Battery Case
or Omnicharge Omni 20+.

Holy moly a 250$ battery?? I bought the Mojo 1 for less than 150 lol.
But thanks for the answer. I'll check his posts

 

[vlach]

I don't use the standard 5V charger at all as that can cause major short circuit issues. I moved on from the official Chord charging system and just use my own separate 18650 charger.

Again, if you run a battery pack like this, don't ever plug in a 5V USB cable into the Chord Mojo power side. Use a separate charging system.

Very interesting and useful info, thank you.

Out of curiosity; why do recommend against charging an external battery pack using the 5V USB from the Chord Mojo power side? This would not be any different than charging the stock/internal battery. Whether the battery is located inside or outside the device shouldn't matter since it is connected to the same terminal.

Also not sure why a 5V charger would cause major short circuit issues. If short circuits are a concern, wouldn't this problem also apply to the 'separate' 18650 charger?
Just about every device nowadays; cameras, phones, tablets, DAPs, remote controls, etc. all use rechargeable batteries and 5V chargers. I've never had any problems, in decades.

 

[590839]

Very interesting and useful info, thank you.

Out of curiosity; why do recommend against charging an external battery pack using the 5V USB from the Chord Mojo power side? This would not be any different than charging the stock/internal battery. Whether the battery is located inside or outside the device shouldn't matter since it is connected to the same terminal.

Also not sure why a 5V charger would cause major short circuit issues. If short circuits are a concern, wouldn't this problem also apply to the 'separate' 18650 charger?
Just about every device nowadays; cameras, phones, tablets, DAPs, remote controls, etc. all use rechargeable batteries and 5V chargers. I've never had any problems, in decades.

The 2S, 3S, 4S, etc. external battery pack's use a different BMS than the circular BMS on top of a single 18650 for the Hugo2. For OG Mojo, the built-in BMS on the OG Battery was designed to be in sync with the Chord Charging System. By using a totally different BMS, it's likely it is not in sync with the Chord Charging System. The Hugo2 uses an "Intelligent Desktop Mode" too, so it's just better for me to eliminate Chord Charging out of the equation.

Since there are no BMS specs available from Chord and I'm purely in a Desktop situation, there's no need to take any risks. Also, I consider external charging more robust as I can power 4S @ 5A for much faster charging. Relying on the Chord Charging System for 4S must take days to charge and generate heat internally.

Rob Watt's comments on the subject from years ago also allowed my cutting off the Chord Charging System easier before my default Hugo2 Batteries finally gave out:

No a Hugo 2 and Mojo need at least 6.5v, otherwise it will shut down. And you need 8v to get the best measured performance in terms of OP power too...

I strongly suggest that you do not change the battery, unless you have too; and use the same as the original. The charging circuit is tuned to match those batteries, and you could have a fire or something else serious if you mess around with it!

He adamantly stated don't, "The charging circuit is tuned to match those batteries" (1S BMS). It's great advice because of the high risk. But it's nice to be free of the Chord Charging system and it opens more doors, but that means I won't be able to use the Chord Charging system again.

For example, I plan to eventually run a pair of Ultracapacitors to power the Hugo2. Even though the Ultracapacitors are only one-way power, I would not dare plug in 5V on the power input of the Hugo2 and try to use the Chord Charging system to charge Ultracapacitors:



It's just not worth the risk as my Ultracapacitors and external battery packs have a much more robust charging system. The Chord Charging System becomes a dinosaur.

I just treat it like it was a Radio Control Car. Charge a few battery packs externally then plug into Radio Control Car:

I am not dependent on the Chord Charging System at all. It gets me completely Off Mains.

Also, I like to use expensive Solid Core Wiring and Solder on my PSU's:

So, I would never go internal on a "Desktop" unless I had no other option. Going external allows me to upgrade the wiring as my goal is to get as close to zero impedance as possible on PSUs.

My Ultracapacitors are equivalently better than Car Batteries so "effectively zero impedance in the audio bandwidth". The 4S was a stepping stone as with each scaling from 1 to 2 to 4, it halves the impedance. With the 4S, I get tight, punchy visceral bass which is usually normally only available on the HugoTT with a low impedance PSU so I was able to replicate that and hope to do the same with Ultracapacitors.

But tech changes dramatically over time, so the Chord Charging system becomes obsolete. If I was doing an OG Mojo with an internal battery, I would just use Anderson connectors to Snap-On and Snap-Off to my own external charging system if needed.

I try to follow the HugoTT Implementation Model to see if I could build a Hugo2TT and it worked. So here, Rob Watt's scaled to 1 to 2 18650 to half the impedance and mixed in a 5F Super Capacitor to even the swings. It was a great setup for it's time but that was a decade ago. I went to 1 to 2 to 4 18650 with expensive wiring to half the impedance then half the impedance, but no Super Capacitor needed as a Hugo2 has a more modern PSU. I'm just going to run Ultra Capacitors out of convenience (No need to externally charge) and hope they match the performance of a 4S. I have a baseline now for tight, punchy visceral bass so if my Ultra Caps can't match or exceed that baseline, I go back to 4S. I did consider the same brand and type of Super Capacitors on the HugoTT between my 18650s and the Hugo2, but I couldn't justify as UltraCaps are a much better investment.

 

[590839]

What I would probably recommend for Domestic USA OG Mojo users is to try BatterySpace since they have a 20% Restocking Fee (+ UPS fee to send back) if things don't work out. I believe they send Internationally too, but there's no sample size yet that this will work for OG Mojo. I believe their HQ is in Japan, but this is their USA shop.

https://www.batteryspace.com/

Then select something like this with the Panasonic NCR18650BF Batteries (Official Hugo2 Battery):

Bare wires is good so you can make your own Anderson Connectors for easy Snap-On and Snap-Off to externally charge. There's lower priced too if you want to limit risks.

The 5A charger is good, so I don't recommend skimping on the external charger.

https://www.batteryspace.com/smart-...-ion-polymer-rechargeable-battery-pack--.aspx

It can hover around 8V:

But absolutely try to avoid LPS otherwise you will constantly be battling with issues going forward. There was a propaganda bot trying to influence Summit-Fi Chord Users to procure LPS so they can sell Ferrite BNC Cables (More RF Noise, More Revenue from Ferrite Cables. Ferrites are like $5 a piece, Cable hovered around $2500). Don't be influenced. LPS's are for $4 OEM DAC chains, not FPGA DACs:

So if the 18650 external battery packs work with a OG Mojo like it did with my Hugo2, I think it's a much better investment as you can scale over time as needed. LPS is a sunk cost that will degrade SQ. Also, a possible fire hazard. It leaves you with no OUTS.

This expensive one uses 18 Batteries once you outgrow 2S, 4S, etc. for less frequency of external charging. I would probably consider 18 or 36 batteries if my Ultra Capacitors don't work out: