Why does my Chord dac only want to be powered by its walwart ps?

Big Red Machine · « **on:** 16 Jul 2015, 01:29 am »

That silly dac is silly good but 3 different linear and/or bench power supplies that I have tried cause the dac to unsynch and then even after repowering it will not fire up even though the "on" light inside is visible through the window.

The stock walwart is 12 vdc, .62 amps.

I have tried other center pole positive power supplies capable of 1 or more amps and all do the same thing. I was thinking a better supply, especially linear supplies, might give me an improvement. But I can't even give it a ride around the block so far.

Any ideas why 12 vdc isn't 12 vdc? If the draw is .62 amps or less from the walwart, why would another supply not be working if it can go higher than .62 amps?

ted_b · « **Reply #1 on:** 16 Jul 2015, 01:38 am »

All my 12V external power supplies work for the Chord 2qute (and all the Qute series, as documented in my reviews..Like the Hynes, JS-2, etc). Which DAC, Pete? Did you reboot the server?

mr_bill · « **Reply #2 on:** 16 Jul 2015, 02:57 am »

Ted,
Which Chord Dac is the one to buy? Hugo or new 2Qute or other brand??
I need a Dac for my two channel system - not headphones.
Bill

Big Red Machine · « **Reply #3 on:** 16 Jul 2015, 11:36 am »

Quote from: ted_b on 16 Jul 2015, 01:38 am

All my 12V external power supplies work for the Chord 2qute (and all the Qute series, as documented in my reviews..Like the Hynes, JS-2, etc). Which DAC, Pete? Did you reboot the server?

Qute EX I think it is. Great dac, but even after rebooting everything I cannot get any external supply to work. You can see the dim light inside telling you it is powered, but no more action when music is played. It may be the dac refusing the power supply but geez, 12vdc is agnostic.

bacobits1 · « **Reply #4 on:** 16 Jul 2015, 11:46 am »

Great DAC!!
I have the QuteHD and no problem ever with the LPS (12v/ 1 amp/30watt) I'm using.

http://www.ebay.com/itm/TeraDak-DC-30W-TOUCH-DC12V-1A-Linear-Power-Supply/130912875418?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D32297%26meid%3D8858c50123294bb8a7a1de9c898a8ba7%26pid%3D100005%26rk%3D2%26rkt%3D6%26sd%3D121639821450

This is what I'm using. Taradac's site states it was specifically for the Chord Qute HD

Nick77 · « **Reply #5 on:** 16 Jul 2015, 12:17 pm »

Just built this Sigma11 LPS 12v 3 amp with a Switchcraft 2.1mm plug and works fine on new 2Qute.

Tomy2Tone · « **Reply #6 on:** 16 Jul 2015, 12:26 pm »

Hey Nick77, I remember reading this earlier in the year from Head-Fi from Rob Watts. Not sure if things have changed and he now recommends after market ps's but this always stuck in my head about the 2qute.

The initial 2 Qute listening tests revealed the mains powered 2 Qute sounded very similar to a battery powered Hugo.

Battery power has enormous advantages over mains operation, principally very low noise, both in band and more importantly RF noise - much lower than SMPS or linear PSU. RF noise is a hobby horse of mine, as it creates noise floor modulation when random RF noise inter-modulates with the audio signal in the analog electronics. The brain is extremely sensitive to noise floor modulation, as it interferes with it's ability to separate sounds out into individual entities with placement data.

I knew that Qute was sensitive to the power, as too many audiophiles had reported improvements when using better PSU's. This was in spite of Qute's extensive RF filtering and regulation. Part of Hugo's musicality was down to the battery, so I was determined that 2 Qute would have no SQ losses due to mains powering. This was not a simple design challenge, and involved a radical restructuring of the internal PSU arrangements.

So I was very pleased that the SQ tests had given me Hugo performance but with a mains powered 2 Qute. This was not the easy challenge that at first sight may appear.

But was it completely insensitive to the mains? Simply hooking up a linear PSU would not be a good enough test, as it needs RF isolation too. So I decided the ultimate PSU from an impedance, in-band noise, and RF noise isolation POV was a 300A car battery (I used a jump starter type - they are low cost and can be re-charged) and yesterday did the listening tests with 2 Qute using the car battery against the standard Chord mains unit.

I spent much of the afternoon doing my standard listening tests, and could not consistently find a preference - I was struggling to reliably hear a difference. When you are struggling to hear a difference, its usually because that there is no difference! There was no consistent difference in sound-stage, instrument separation and tonal balance. So as a sanity check, I thought I would test it against the original Qute - and immediately I could easily hear the difference - sound-stage was much deeper, instrument separation was better, and it was much smoother with the battery. All SQ hallmarks of reduced RF noise.

So don't bother connecting up "better" PSU's with 2 Qute, as at best it will sound the same, at worst you will damage 2 Qute - some of these units have too high an OP voltage, destroying the protection circuits of the DAC.

Rob

Nick77 · « **Reply #7 on:** 16 Jul 2015, 12:34 pm »

I think maybe he is really trying to prevent using aftermarket supplies that dont have any OV protection and damaging units. I suspect they had a lot of repair issues from people using poor supplies. Although all systems are different and maybe he heard nothing.

I noticed an immediate density to the sound when I installed LPS. Still real early though as not fully broke in yet.

ted_b · « **Reply #8 on:** 16 Jul 2015, 12:38 pm »

First off, it is misinformation to say that Chord will void the warranty if using an external ps other than theirs. That is not true.

Second, I wouldn't use a 3rd party until a new Qute is broken in and you can evaluate the chnages/improvements...because just the first 48 hours (clock) and the next 200-300 (break in of caps, etc) are huge variants. Rob and I chat a lot about power supplies, and he is convinced that the 2Qute doesn't respond to a good linear. I have found each generation (HD to EX to 2Qute) responds less and less, but if you have one I'd definitely try it when applicable. Using it on the HD is a no-brainer, for example.

Pete, I have no good answer for your ps dilemma. Mine (all 3) worked fine with any and all external 12V/1A+ power supplies, assuming pin and barrel compatibility.

Big Red Machine · « **Reply #9 on:** 16 Jul 2015, 02:56 pm »

The only partial victory I had was a benchtop labpower suppliy where I dialed in .6 amps and 12 volts but then it starting dropping out more and more and finally just didn't stay consistent for me so I bailed on it.

Maybe I just need to get a small 1 amp ps but I am seeing comments here it may not make much of a difference with this unit because it is the version just before the 2Qute version.

I gotta say the system sounds fantastic. Someday I'll try a Bricasti dac, but my money plans are elsewhere right now.

sfox7076 · « **Reply #10 on:** 16 Jul 2015, 03:13 pm »

Had the same issue on a 24v, Nova II phono preamp (battery charger) that I wanted to plug in to my LPS because I had the extra 24v lead out. Well, that failed... Wouldn't work at all. It was 1A out, but the original wall wart was only .5A. No luck and I will never know why... I could get 24v and a current draw over .7 amps out of the cord, but the Nova just wouldn't draw the current when it was plugged in. Sigh.

Big Red Machine · « **Reply #11 on:** 16 Jul 2015, 03:35 pm »

Quote from: sfox7076 on 16 Jul 2015, 03:13 pm

Had the same issue on a 24v, Nova II phono preamp (battery charger) that I wanted to plug in to my LPS because I had the extra 24v lead out. Well, that failed... Wouldn't work at all. It was 1A out, but the original wall wart was only .5A. No luck and I will never know why... I could get 24v and a current draw over .7 amps out of the cord, but the Nova just wouldn't draw the current when it was plugged in. Sigh.

I need to measure the draw of that walwart. My guess is that the better supplies are not being triggered to do anything because the draw is so low and the walwart is just balls out all the time.

Philistine · « **Reply #12 on:** 16 Jul 2015, 07:02 pm »

Quote from: ted_b on 16 Jul 2015, 12:38 pm

First off, it is misinformation to say that Chord will void the warranty if using an external ps other than theirs. That is not true.

Ted, one of the Chord guy's that participates in the Head-Fi forum advised that the warranty would be voided if damaged occurred using other psu's, this is where it probably came from. I received my 2Qute yesterday and was surprised by the psu looking like it belongs to a call phone.

Big Red Machine · « **Reply #13 on:** 16 Jul 2015, 07:16 pm »

Quote from: Philistine on 16 Jul 2015, 07:02 pm

I received my 2Qute yesterday and was surprised by the psu looking like it belongs to a call phone.

Yep, that's the one. The only one that functions for me so far reliably.

bacobits1 · « **Reply #14 on:** 16 Jul 2015, 08:13 pm »

Of course that's where I read it. Ya have warranty issues don't mention external PS. DUH!
Ted IS Mr. Chord and deals with them all the time I presume, he has 3 LPS's.
That puny thing is junk really for the cost of the DAC's doesn't sound bad but does not manifest confidence
in our little Audiophile minds.

Philistine · « **Reply #15 on:** 17 Jul 2015, 04:14 pm »

Off topic but 2Qute related.

I'm still in the stone age using a Squeezebox Touch as the source, currently streaming Tidal to burn in through Coax SPDIF. Is their a preferred input option for the 2Qute in terms of optimum sonics?

ted_b · « **Reply #16 on:** 17 Jul 2015, 04:21 pm »

USB is galvanically isolated, so USB. Rob agrees.

mr_bill · « **Reply #17 on:** 17 Jul 2015, 04:37 pm »

Ted - do you like the new 2Qute better than Hugo? I need to buy a Dac.

ted_b · « **Reply #18 on:** 17 Jul 2015, 04:45 pm »

They are virtually the same, with 2Qute being cheaper, better connectors and galvanic isolation on USB. So yes.

Big Red Machine · « **Reply #19 on:** 17 Jul 2015, 06:26 pm »

The 2Qute has some of the Hugo capability in it if I recall over the EX unit I have (older model) but I hafta say the EX is an amazing unit. I'm not sure upgrading to the 2Q would be worth it at this point. A very musical, toe-tapping unit.