Need Help Setting Up a Multi-Amp/DAC Switching System for Headphone Testing

[chrisyak]

Hey audiophiles! I'm building a system to quickly compare 5-6 headphone amp/DAC combos. My goal is easy switching between setups to find the best pairings or gear.

The Challenge: How do I feed a high-quality audio source (PC or possibly a streamer) into a system that lets me easily switch between multiple DACs?

Current Idea:

Analog Switcher: Handle output to Amp/DACs for easy switching.

Optical Switcher: Manage digital input to DACs.

Questions:

Optical Switching: Is this the best approach to preserve audio quality?

Streamer vs. PC: Would a streamer offer better sound quality as my source?

Community Experience: Has anyone done something similar? Tips/tricks?

The Goal: Simplified setup for critical listening, comparing gear, and eventually doing reviews.

Thanks in advance for any help!

 

[chrisyak]

I hope someone can help not sure if it's way I explained it or maybe I should draw a layout of what I need to do?

 

[HWB3]

If you look at my avatar, you'll see that I have a three-way switch that I use to control which amp I'm using. It's one in and three out. I run my DAC and EQ in and then select which amp I'm using. Hope that helps.

 

[chrisyak]

If you look at my avatar, you'll see that I have a three-way switch that I use to control which amp I'm using. It's one in and three out. I run my DAC and EQ in and then select which amp I'm using. Hope that helps.

I know the one. You using the XLR version? They have versions with up to 8 XLR I puts.

Where I have been stuck is at two spots:

Let's say I have 3 sources: PC, Streamer and Smartphone. I would need to select the source and it would need to be a digital out source.

From their it would need to be plugged into a another switcher in the input so I could select which DAC it would to to and I could maybe get away with using a XLR switcher as long as it does not try and convert it analog and keeps the digital source.Then it could be plugged into the dacs and the dacs plugged into the amps. That was the audio quality and bit rate is not messed with before it gets to the DAC.

That where the chain gets messy.

I always thought I could just plug in a pair of headphones into the amp and because the DAC is plugged into the amp I'm going to hear the amp and the DAC. Then I could just put a analog switch to the amp and it would be easy.

 

[HWB3]

That's more complicated than my set up. Mine's pretty straight forward. Good luck.

 

[chrisyak]

That's more complicated than my set up. Mine's pretty straight forward. Good luck.

I need it. One of the problems is it's not well documented how to do this stuff. Once I get it set up I am going to do a forum post. I am going to try and outline my stuff. Very simple. Give people a few different options of equipment. Also. I will be open to easier suggestions. I had to Google pretty deep to find some of the solutions. Switching between amps is probably the easiest thing. Switching between sources and switching between Dacs is different because of the digital audio and trying to maintain the source quality when switching.


I've been researching for past few weeks and actually tonight I made some headway. It seems a lot of this equipment is not really consumer level and you have to go to the Pro Audio in order to find it. I may dabble around a little bit more in the Pro audio area to see if they have some suggestions and other products to suggest.


When you get into the Pro Audio stuff, the equipment gets real expensive. Fast. Those switchers are pricey. However, they take a lot of factors into account that some of the normal consumer grade stuff doesn't have, such as an impedance levels, volume levels, noise, interference, conditioning, feedback, this that and the kitchen sink. However, you pay for it.

 

[Thomasr]

I'm not 100% clear on whether you're looking for a digital signal switcher (pre-DAC), analog switcher (post-DAC) or both.

Amazon sells USB-C switchers, so that may solve that problem. For analog switching, multi-pole rotary barrel switches are the way I'd personally go. A 4P4T switch for example would give you the ability to choose among 4 different balanced sources, then a second 4P4T would let you send it to one of 4 amps, etc. Many of these are quite robust, high-current units so you could even use one (suitably wired of course) to send amplified output to one of several headphones.

If you don't give a crap how this all looks, you could even repurpose a few old computer I/O switches, which at this point are basically free if you can locate some. For example, below is an old one I happen to have in a random box of crap. Fabricate some serial-to-XLR adapters and you'd be all set. Stuff like this manufactured in the 80s is typically pretty sturdy and "overbuilt" so if you keep your cable lengths short you should be good from a signal degradation and noise perspective.



... Or, just accept your fate and spend the $$$ on a pro audio unit, which will be guaranteed to work (at an appropriate SNR) and if it doesn't you have things like warranty and customer service.

 

[Thomasr]

FYI, in the watercooler thread, @goldwerger talks about a custom 8-way amp switcher he uses.

 

[goldwerger]

FYI, in the watercooler thread, @goldwerger talks about a custom 8-way amp switcher he uses.

Happy to share more. My original post is on the Watercooler Headphone Edition thread (new parallel WC thread we startd last month for all headphones, amps, dacs, and related desktop/stationary gear and chatter; while the OG Watercooler thread focuses on portable audio):

https://www.head-fi.org/threads/the-watercooler-headphone-edition-–-headphones-amps-dacs-and-desktop-home-audio-related-–-a-freewheeling-discussion-of-gear-impressions-music-and-musings.972819/page-95#post-18176170

 

[chrisyak]

Happy to share more. My original post is on the Watercooler Headphone Edition thread (new parallel WC thread we startd last month for all headphones, amps, dacs, and related desktop/stationary gear and chatter; while the OG Watercooler thread focuses on portable audio):

https://www.head-fi.org/threads/the-watercooler-headphone-edition-–-headphones-amps-dacs-and-desktop-home-audio-related-–-a-freewheeling-discussion-of-gear-impressions-music-and-musings.972819/page-95#post-18176170

Definitely Interested to learn how you set yours up? Did you just use XLR connections and relay switch for power on and off?

The company you used looks like they do some really nice work! although it was custom for you, I wonder what they would charge the average customer like me if I wanted the same type of setup?

I tend to like the industrial vintage look of the Violectric / Lake People equipment and it just happens that they make some pretty awesome equipment at the same time. I also like SPL and a few of the old school analog industrial looking amp boxes. Luckily for me Vue meters are starting to make a trendy comeback. This is the company I was looking at getting one built through https://vintagemaker.net/
but I wasn't sure on exactly how I was going to set it up.

Just thought it was going to go with XLR connections and some some basic relay switches and be able to control and switch between any one of my amp/ DAC combos.

I probably will have anywhere from 4 to 6 Amps connected being tested, being reviewed or compared via a ADC / DAC and software.

Thanks in advance for any advice or suggestions you may have.

 

[goldwerger]

Definitely Interested to learn how you set yours up? Did you just use XLR connections and relay switch for power on and off?

The company you used looks like they do some really nice work! although it was custom for you, I wonder what they would charge the average customer like me if I wanted the same type of setup?

I tend to like the industrial vintage look of the Violectric / Lake People equipment and it just happens that they make some pretty awesome equipment at the same time. I also like SPL and a few of the old school analog industrial looking amp boxes. Luckily for me Vue meters are starting to make a trendy comeback. This is the company I was looking at getting one built through https://vintagemaker.net/
but I wasn't sure on exactly how I was going to set it up.

Just thought it was going to go with XLR connections and some some basic relay switches and be able to control and switch between any one of my amp/ DAC combos.

I probably will have anywhere from 4 to 6 Amps connected being tested, being reviewed or compared via a ADC / DAC and software.

Thanks in advance for any advice or suggestions you may have.

the one in the top 2 pictures here is my cutom build which I spec-ed:

https://www.zynsonix.com/Switchboxes_ep_43.html

cost depends on materiasl used (e.g. pure silver vs. copper etc).

This one has one XLR in that can be routed to any of 4 XLR outs, and one RCA int that can independently be routed to 4 RCA out (I have one DAC with both XLR and RCA outputs connected to it, and 8 amps connected ont he other end). The 2 red switches are to limit one of the XLR and RCA outputs, respectively, from working unless the switch is engaged (use case was a power amp connected, where I wanted to have a hurdle to remind myself to attentuate volume in advance)

 

[chrisyak]

the one in the top 2 pictures here is my cutom build which I spec-ed:

https://www.zynsonix.com/Switchboxes_ep_43.html

cost depends on materiasl used (e.g. pure silver vs. copper etc).

This one has one XLR in that can be routed to any of 4 XLR outs, and one RCA int that can independently be routed to 4 RCA out (I have one DAC with both XLR and RCA outputs connected to it, and 8 amps connected ont he other end). The 2 red switches are to limit one of the XLR and RCA outputs, respectively, from working unless the switch is engaged (use case was a power amp connected, where I wanted to have a hurdle to remind myself to attentuate volume in advance)

That sounds like a robust setup. Very handy at the same time, especially with those nuclear football switches.

So you're taking one XLR cable and connecting it to 8 amps correct? Or you're connecting from your switch box to the DAC and from the DAC you're running to 8 amps via an XLR matrix cable? Sorry I was not understanding how making all those connections off of One in and out.....

Sorry just confused on how you're making it happen.

 

[goldwerger]

That sounds like a robust setup. Very handy at the same time, especially with those nuclear football switches.

So you're taking one XLR cable and connecting it to 8 amps correct? Or you're connecting from your switch box to the DAC and from the DAC you're running to 8 amps via an XLR matrix cable? Sorry I was not understanding how making all those connections off of One in and out.....

Sorry just confused on how you're making it happen.

I have one XLR input to which my DAC's XLR output is connected. That can be switched to any of four XLR outputs that go into 4 amplifiers.

In parallel, I have one RCA input to which my DAC's RCA output is connected. That can be switched to any of four RCA outputs that go into 4 additional amplifiers.

At any time, 2 amplifiers may receive a signal, one via XLR and the other via RCA. Both the XLR and RCA selector knobs also have an off position so I can turn one or both of the XLR and/or RCA output signals off entirely.

 

[chrisyak]

I have one XLR input to which my DAC's XLR output is connected. That can be switched to any of four XLR outputs that go into 4 amplifiers.

In parallel, I have one RCA input to which my DAC's RCA output is connected. That can be switched to any of four RCA outputs that go into 4 additional amplifiers.

At any time, 2 amplifiers may receive a signal, one via XLR and the other via RCA. Both the XLR and RCA selector knobs also have an off position so I can turn one or both of the XLR and/or RCA output signals off entirely.

Are all 4 XLR amps plugged in all at once or do you have to do it manually? Same for RCA?

So you have a way of picking which amp gets chosen? How do you select which one of the 8 amps to use?

Can I get a picture of how you have everything plugged in the back of you switcher?

Here is a rough sketch on what I plan to do for giving power to a DAC selector but is hard to find a USB powered switcher.

 

[goldwerger]

see the link I sent in my first post above, it has all the pictures and selectors shown