ARC DAC8 improved performance

[rom661]

Hi everyone. This will probably be limited in interest to those who own an Audio Research DAC8.

 

There is a mod you can do to your unit that takes a matter of minutes and, should you choose, be completely reversed in the same amount of time. It's truly a no risk venture.

 

If you take the top plate off of the unit, the most time consuming part, 3-4 minutes maybe, and look, from the front, at the right rear corner you will see two square boxes encasing two cables. These are ferrite filters. They are located just above the USB input board. Ignore the round one just below these; it can't be removed. The boxes just pop open by inserting a small screwdriver into their latches. Simply open them up and remove them.

 

One of my guys in the store and I were dumbfounded at the result. The sounded opened up by a considerable amount, not that it was noticeably closed in before. More resolution but in a very relaxed way, much like real music. The bass was changed slightly, although I need to spend more time comparing there. It became more articulate, perhaps slighly less weighty but I had the impression that what I was hearing was more accurate and controlled.

 

I've done this in the store and at home. Perhaps in some systems it would not be as beneficial. In both that I tried it in, it was a distinct and worthwhile improvement in sound. If you're so inclined I suggest leaving the top off; you can add the filters again in a minute or so for A/Bing. I didn't have to go back and forth, although I will at some point. For me, in my systems, the improvement was obvious and verging on the dramatic.

 

If you have any questions, feel free to ask. Again this is easy both to do and undo.

 

Have fun

 

Rick

 

[AudioExplorations]

A. ARC screwed up in their design and this 'tweak' improves sound in most/all systems.

B. This 'tweak' has somehow masked a shortcoming in Rick and his dealer's system making it sound better as a whole.

 

[Julf]

"If you have any questions, feel free to ask."

 

Do you know what the ferrite filters are actually supposed to do? Are they between the power supply and the circuitry, or in the mains feed to the power supply?

 

[rom661]

Sometimes I hate posting things here... Joost, I'm curious as to where your absolute knowledge of these things come from. Please don't make extreme statements about things when you don't have anything to base it on. The rings are mandated for radiated noise considerations. Look inside your computer. This was not a design issue. Do you own a DAC8? If not why do you care enough to make accusations?

 

Your comment about masking a problem in my system is a crock. You don't know anything about my system. And I don't have a dealer; I am the dealer.

 

This was intended to be useful information for DAC8 owners, not for people to take uninformed shots at a product or my system. Obviously I have a vested interest in the product. I'm not trying to sell it; I'm trying to offer hopefully useful advice to people who have seen fit to invest in it.

 

Julf - I really didn't look. The cables seem to feed the USB board as best I can tell. I have trouble seeing things like this but I will try to find out. I don't think it's from the main power supply. I believe they are there to block radiated interference. In the systems we tried it in there was no noticeable effect on anything around it. I believe it to be a required precaution.

 

Rick

 

[Priaptor]

respect your opinion. I will give it a shot. I appreciate the post.

 

 

Curious what your preliminary perspective is on their new Ref DAC?

 

[The Computer Audiophile]

Thanks for the info Rick.

 

Any idea what ARC thinks of this mod?

 

 

 

[rom661]

Let's see... I do know that they think it sounds good in their listening room. As far as their official position, I don't think they have one. It is not the sort of thing that could void a warranty or anything like that.

 

They will, of course, abide by all the rules in terms of company recommendations and production units.

 

Make sense?

 

Rick

 

[rom661]

Thanks for the kind words. I'm afraid I don't have a great deal of information yet about the piece. I've had a couple of brief conversations about it and saw it at CES, but it was a passive prototype.

 

As to the little I do know, the tube complement is the same as the REF5/REF Phono 2, all the digital inputs of the DAC8 plus ethernet, a front panel display with menus, and a chassis that appears to be the same size as the REF5. I don't know what capabilities the screen will provide. Oh, and it isn't going to be cheap. I guess that's signifant as well. It seems that they kind of jumped past what I thought would be the next step, sort of a CD8 level piece, and gone to a higher level Reference product more in keeping with the Anniversary preamp, although the price is certainly less than that.

 

Sorry, that's all I've got.

 

Take care

 

Rick

 

[AudioExplorations]

Rick, sorry, it was not my intention to offend. Please re-read my post with that in mind. I am simply stating the two possible explanations why modding the DAC may improve the sound.

 

[AudioExplorations]

I mean if this mod improves the DAC in all system it could be considered a design flaw right? If it just in your system and the DAC works better in other systems without the mod then I can think of no other explanation...

 

[rom661]

Thanks, Joost

 

I'll take it in the way in which you intended it. Actually there is an option c, which I believe is the case. I kind of allude to it in the comments above.

 

Again, I appreciate your follow up and happy listening.

 

Rick

 

[andrewd01]

Thanks for the tip. I own DAC8, but am using Offramp 4 to convert USB from Mac Mini USB to BNC input on DAC8.

 

Can you confirm if the mod suggested only improves USB input or does it also improve RCA/BNC SPDIF inputs too?

 

Many thanks,

Andrew

 

[rom661]

Andrew

 

Great question. I never even thought to check. I don't have a SPDIF source at home so I'll try to check it at the store. Shows how thoroughly computer audio indoctrinated I am, I guess.

 

Thanks for the idea.

 

Rick

 

[AB835]

rom661

 

Thanks for the tip. I made the mods you suggested to the Dac8 last night and I must admit there is a noticeable improvment as you indicated. Funny thing is this mod reminded me of some time ago when I purchased 2 identical Kimber USB cables and removed the ferrite beads from one so I could see it made a difference, which it did. Thanks again.

 

[Arcguy]

I don't think ARC can publicly endorse removing the ferrite cores since this would violate the CE and maybe FCC approvals. Ferrite cores tends to roll of edges of fast rising signals to reduce radiated emi emission. This has been my experience from years of EMI testing.

 

[rom661]

I don't have any knowledge of ARC publicly endorsing what's under discussion. I'm relating my own experience. If what you say is correct, I doubt that they will send out a newsletter advocating it or make a production change. I have found the same issue to be true with a line of power cables we carried. As someone else pointed out, an early Kimber USB cable also sounded better with the ferrite rings off. I doubt that it was a concern in that case, just not a good design.

 

I'm usually pretty cautious about such things. I have five year old pillows that I'm still afraid to remove the "Do Not Remove Under Penalty of Law" from.

 

I see you just joined in the last five minutes. Welcome to the forum.

 

[rom661]

Yeah, I did the same thing with the Kimbers. It's good to hear the improvement validated.

 

Thanks

 

Rick

 

[andrewd01]

AB835, it would be good to know what inputs you are using and if the mod effects SPDIF inputs as well as the USB input (see my post above). OP is not using SPDIF source.

 

Many thanks,

Andrew

 

 

 

[deho]

Same question as Andrew since I use a Weiss INT202 to convert from Firewire to XLR digital input on the DAC8 ...

 

As I previously said on this forum, the use of Firewire -> AES/EBU via the INT202 was a noticeable improvement over the USB input. Rick's smart mod seems to confirm that the USB implementation on the DAC8 has still some room for improvement ...

 

But Rick, I'm curious, how did you came to try that tweak ? Was it the Kimber cable experience that suggested you to try a similar approach ?

 

[AB835]

Andrew

 

All listening since making the mods rom661 suggested have been made using the USB input with a AQ Diamond cable. I also have the capability of using a Wavelink feeding the DAC8 thru BNC. I will try to compare the BNC output with and without the Ferrites tomorrow. I am also very interested to see if improves the BNC input also.

 

[rom661]

I haven't had a chance to try it yet. I will be very interested in what you find. I don't really know what the cables are handling, so don't know if it will be helpful.

 

Rick

 

[Priaptor]

biggest pains is removing the screws, which I have been too lazy to do as yet, but will do this evening.

 

Just one question. Are those ferrite cores just a snap close latch that can be put back on at some time in the future? I am just asking for purposes of resale, should at some point in the future, I choose to sell the unit.

 

 

 

[rom661]

Yes, Priaptor. Just a latch kind of thing. Easy off, easy on.

 

Rick

 

[dummy]

Have you got the new ARC DSPre yet?

 

If so, would the mod apply to It also?

 

Thanks!

 

 

 

[Priaptor]

Thanks

 

Rick, just curious if you have tried Chris's CAPS 2.0 and JRiver with the DAC 8. I have finally settled on this as my source and love it more than any other source I have tried and I have tried them all.

 

Next up, is upgrading my REF 5. Looking forward to that.