Bottlehead Forum

General Category => General Discussion => Topic started by: oguinn on September 23, 2019, 05:24:02 AM

Title: A/B testing DACs
Post by: oguinn on September 23, 2019, 05:24:02 AM

I've gotten some FLAC (shitty pun, sorry) over using a low-end DAC with my equipment and started researching spendier gear. DACs get expensive pretty fast!

I picked up a used Schiit Modi 3 over the weekend and am keen to see whether there is truly a noticeable difference between that and the JDS Labs ODAC I've been using for the past year or so. My gut feeling is that there won't be, but if there is I might be persuaded to save up for an even better DAC in the future. If not I'll settle where I am. I'd like to run the test in a way where I can relatively seamlessly swap between the two.

I typically run the ODAC through the optical in, but there aren't two optical ports on my ancient Mac Pro so I'll need to run both DACs on USB, I suppose, to get a true A/B. There are a series of issues with this approach, including:

• It won't be a blind test since 1) I'll know which outputs on my unpowered switch line up with which DAC, and 2) I assume I'll need to manually switch between the DACs on the computer as well.
• In real-time it's comparing USB to USB, which isn't likely how'd typically listen.

Does anyone have experience with A/B testing DACs? Any tips or tricks you'd recommend?

Title: Re: A/B testing DACs
Post by: EricS on September 23, 2019, 02:47:09 PM

No specific experience with comparing DACs, but for any reasonable A/B attempt, you need to try as carefully as possible to match the output levels of the two devices under comparison.  Small differences in volume will make a larger perceptible difference than other details or flavors.

Title: Re: A/B testing DACs
Post by: Doc B. on September 24, 2019, 06:17:15 AM

I came across one of several proof of concept prototypes we built for the Bottlehead DAC while moving stuff last week. Can't recall offhand the types of inputs it has or the maximum sample rate. It was used it for quite a while before we did the production prototype. If anyone is interested I will have a look at it and determine how it is set up.

Title: Re: A/B testing DACs
Post by: oguinn on September 24, 2019, 06:21:26 AM

Definitely interested. Let me know.

Title: Re: A/B testing DACs
Post by: pboser on September 24, 2019, 07:06:51 AM

Dan, I'd like to hear about the prototype too.  Thanks.

Title: Re: A/B testing DACs
Post by: EricS on September 24, 2019, 08:05:55 AM

That sounds interesting!  I'd like to know more...

Title: Re: A/B testing DACs
Post by: Doc B. on September 25, 2019, 04:59:38 AM

I picked it up yesterday afternoon, but forgot to find a suitable power supply. I'll find one and report back about what I find.