advertisement


DAC tour

No offense taken but all designs have compromises - I found that using circuitry to prevent battery levels dropping when left turned on is detrimental to sound.
My target has always been best sound & I have to balance this against any MINOR inconveniences that is experienced in turning off a device when finished listening!!
If potential users felt this too much of an inconvenience then these are not the products for them.
 
Last edited:
topa said:
No offence, but maybe you should design them to prevent battery levels dropping this low, no matter what end users do...
Click to expand...
I think the only way that can be achieved would be to use a larger case with an inbuilt main PS and have the DAC only work when the mains is on. The DAC would cost more, be larger and be strange in that it would need to be mains powered to work. It's not very difficult to get used to operating the DAC but I suppose for a short demo period and the albeit simple process is new/different.
 
My post about the operation of these battery powered ISO devices was prompted by the finding that the internal batteries on the returned ISO-DAC was < 3V
Now one can operate it like this (as seems to be the case here) but you are not hearing what this particular battery power brings to the sound - you are running the circuits using battery charger board driven by 5V DC input (from USB or PS?). This is far from optimal

In my development of these devices I tested & evaluated many power options. Most designers using these isolation approaches consider the power on the 'dirty side' of the isolation chip as being of no consequence, as the clean power applied on the 'clean side' of the chip is the important power. In my testing I found that this is not the case & instead of using USB power to power this 'dirty side' I use battery power which delivers a small improvement.

The design is not just sticking a couple of batteries into a case to power the circuitry - it has many considerations behind the design - all my design choices are directed towards what sounds best even if it slightly inconvenient to usage. Most everyone who purchases one of my devices is already committed to computer audio & realise that, for best sound, certain things have to be optimised - it's not just plug & play. Once they hear the sound of the ISO device they are very happy with whatever small inconvenience they, at first, encounter in its operation.

I guess that's the difference between sending a device on tour & someone owning a device as the above involvement in computer audio has not always happened so I guess there could be a resistance to it not being plug & play?

Using the USB 5V as the charging PS for the device is meant just as a stop gap for initial testing & is not the final recommended powering option - an external >2A 5V PS is the recommended powering option - this is left permanently connected & powered on. If one goes on holidays or puts the devices into storage then just unplugging the DC plug means the batteries will not drain & will retain their charge for years (there's very little self-discharge in these batteries)

Anyway, I will contact busb about the device he has & see what the best way forward is - either send over two batteries & charger PS or maybe replace his device with one which is more geared towards operation without batteries - where batteries are an option - a BYOB version (bring your own batteries)? Batteries will still deliver the better sound & be immune to the quality of the external DC power used but users can evaluated this for themselves.
 
Last edited:
Ciunas Audio said:
I received a ISO-DAC from the UK today - I presume it is the returned one from busb?

But it has batteries in it & Paul, you were meant to contact me when you received the ISO-DAC from Divedeedog as it has no installed batteries & we would have installed these batteries into it. You are now running the ISO-DAC without internal batteries!!

I opened the returned ISO-DAC & the batteries are below working voltage (<3V) so anybody listening to this would be listening to the 5V charger power supply powering it - not a good test of its audio qualities!!

I'm wondering how these devices are being charged - they are meant to be continuously powered by a 5V supply & not left turned on all the time??

There are only a couple of situations that will run the batteries down:
- if you leave the device turned on all the time
- If you leave the charger plugged into the DC port but the charger unpowered (that includes powering from USB ports which are powered down when computer goes to sleep or is turned off)

These battery powered devices are meant to be continuously charged, as I said already
Click to expand...
Not returned the DAC yet - intend to this Saturday so presumably the one I have has a battery (just pulled the DC jack & it continued to play music). Had an attempted parcel delivery earlier so hope to collect it from the PO before closing time. I'm not expecting any other deliveries so must be the one with internal 5V on the USB outputs. What should I do with the 2 part USB lead the 1st one came with? Wait to see what cables come with the 2nd one? I'm presuming I'll be sending on the 2nd DAC to the next on the list instead of to you, John?
Added:
I'm running the DAC from a 5V, 1A charger so won't need the original cables for the 2nd one.
 
Oh, OK that returned ISO-DAC confused me a bit
So the second ISO-DAC that divedeepdog has sent you, presumably is the one in the PO
When you get it change over the batteries from the current ISO-DAC into it - check their voltage & be very careful of the polarity when inserting them into their holders
This DAC has 5V on USB output ports & should be the one that continues on tour
The 1st DAC should be returned to me, please
 
Batteries swapped & the newer DAC installed. Working as expected without the USB 5V being injected through port 4. I will conduct comparisons with & without the ISO-DAC into my M-DAC+. I will then try out the DAC part straight into my Primare Pre-32.
Added:
I'll leave the DC in connected to charge those rather beefy batteries.
 
OK, minimido won't be available for a week or so - next in line is Martian Sunrise - can you confirm you are ready to audition it next week?
 
Last edited:
Right, thanks!

This isn't directed at you Martian Sunrise - it's just reflecting my experience of this DAC tour so far which I didn't find to be a problem on my last DAC tour (also battery powered)

Can I just reiterate some user requirements that apply to these battery powered devices.
Like most battery powered devices, these can't be left turned on permanently as it will deplete the batteries. This is not a big problem if you own the device - just buy a battery & replace depleted battery but on a device tour it is not really warranted to buy batteries.

There are just two simple operational guidelines to follow:
- leave device on charge at all times (I will supply a 5V PS with the tour device) to ensure this
- don't leave the device turned on permanently!!

If any tour participants feel these requirements are too difficult to follow then they should remove themselves from the tour list - I can't supply replacement batteries during this tour
 
Last edited:
It's been a while but ISO-DAC tour is still running - if people want to be added or droped from the tour list, please post here

Current tour list:
minimodo
martiansunrise
timola - should receive it tomorrow
MagnusH

Hoping to see beameup's posted impressions of the ISO-DAC which he has just sent onto timolo
 
Thanks Martin - you are next as minimodo is too busy to audition - so list is:

timola - should receive it tomorrow
martiansunrise
MagnusH
 
BTW, when trying the USB hub function of the ISO-DAC, the USB cable connecting hub & USB device can have a significance - I've heard USB cables kill the sound, changing it from dynamic & interesting with inner detail to flat & uninteresting (the notes in the right place but ........)

I can't recommend any particular USB cable only give some guidance:
- use as short a USB cable as possible
- avoid USB cables with ferrite rings
- try a couple of different ones if you have access to them - there's no magic formula that I know of - price doesn't guarantee anything

I've tried Supra USB cable which is good
 
Last edited:
Just to clarify - the ISO devices are pretty immune to the quality of the USB input cable -beammeup used a 3 meter USB as input & the sound of the ISO-DAC was unaffected but when he used this 3 meter on the hub output to connect to one of his DACs, I'm pretty sure it affected the sound - the pristine isolated & cleaned USB signal at the hub output was probably less so by the time it reached the end of the 3 meter cable - as I said, shorter USB cables are usually better
 
Just a shame that 'Green Grass and High Tides' by The Outlaws is 15 secs short. Maybe there is a slightly longer live version?
 
You must log in or register to reply here.


advertisement


Back
Top