Confused about adapter for RCA to BNC

What is the source of your BNC?  Do you have a streamer with only BNC out?  

BNC and RCA are not interchageable--they are generally used for differnt signals so even if you had the cable, it wouldn't work.

What is your streamer?

Jerry

Source will be CD transport. 

@stuartk    What are the makes/models of the CD Transport and DAC?

@jeffbij

Jay’s CDT2MK III to Mojo Mystique XSE DAC

https://www.mojo-audio.com/b-stock-mystique-x-se-dac/

https://www.jays-audio.com/cdt2-mk3

Looks like I found one:

https://www.thecableco.com/bnc-to-rcaadapter.html?srsltid=AfmBOop9Z_-DsOBcENbzXsYLJAlzVcrZjtWu4wWYZQjmh0FyDYCN-XIY

Actually, I think this what you are looking for.  

https://a.co/d/96fC28n

Monoprice BNC Female to RCA Male Adaptor - Gold Plated

I have had trouble with at least one RCA/BNC adapter in the past, so you may want to try several different brands to see which works best. They are cheap - at least the Monoprice is gold plated.

kn

That CD transport has an RCA digital output for SPDIF. is it non-functional?

If you are just trying to use the BNC cable I think you would be much better off with a properly designed SPDIF cable.

That said, I found a company that sells a $2000 cable which is a BNC cable with BNC to RCA adapters.

https://www.thecableco.com/tyr-2-s-pdif-digital-cable.html?gad_source=1&gclid=CjwKCAiA2cu9BhBhEiwAft6IxA3nq_ZVJe4rKkRnPxoGwUHCnpD1UUWtFUOVqhNu1gXTwjQwXqi34xoC3_EQAvD_BwE

For digital signals I always recommend silver or silver plated conductors.

Wireworld Wires will make you a cable with BNC on one end and RCA on the other.  I bought one for a clock to DAC and it is much better than an adapter.   

Some adapters are 50 Ohm and Some are 75 Ohm so be aware if you use an adapter,  you need a 75 Ohm 

I would go with a factory made cable

https://wireworldcable.com/products/starlight-10-coaxial-digital-audio-cable?variant=47931732623656&country=US&&utm_medium=product_sync&utm_source=google&utm_content=sag_organic&utm_campaign=sag_organic&srsltid=AfmBOooTBKmwaWEZNWx1JI9tvdkcsAFhzzEJ4_cDKSOSLG__ZoD2CX6mpno

They make higher grades , this is an example. 

If you order one they are available as BNC to RCA or RCA to BNC.   If the source is RCA and the DAC is BNC you want a RCA to BNC.   It has to do with the grounding I believe. 

@stuartk confirm the specs on your bnc cable to make sure it is 75ohm before you buy adapters 

I’d rather use AES from transport to DAC or a proper 75ohm coax cable and not introduce any adapters unless you have a fancy and expensive bnc cable that you can’t part with. I wouldn’t add variables such as adapters to compromise the results.

As @audphile1 has suggested, and my favorite, is AES if your DAC has an AES input.  This comes after trying everything else.

I have used any number of 75ohm, off-the-shelf, BNC-RCA and RC-BNC adapters (often marketed for video use) for S/PDIF connections without any problems.  Never paid more than $2 for any of them.  What have got to lose?

@stuartk - I have the same DAC as you and used a BNC cable (Oyaide 510 ) with adaptors without any problems.  Later, I needed a longer cable and purchased another of the same cable except the longer cable had rca connectors.  I compared the cable with adaptors vs. the longer cable without adaptors and I heard no difference between the two.  Even compared to AES/EBU, I did not hear any reliably consistent differences.  USB may be just a tiny bit better sounding, IMO, but the perceived difference may also be personal preference.  
You found and linked a fancy-schmancy Cardas adaptor.  Just make sure you get the female bnc to male rca version.  In contrast, I used the type of adaptor kr4 was referring to and exactly what was linked by @knownothing for the comparison I described above, and it worked and sounded just fine for under $2, which is what  it should cost to resolve your issue. 

If you wish to lighten your bank account a little more, here's another solution.

@stuartk   It usually is always better to follow the KISS principal.  (Keep it simple...)

Adapters, while they work, sooner or later can cause problems. The extra connections on the signal path, potentially cheap construction, and potential impedance mismatches with adapters...

So, +1 to carlsbad2 and audphile1, get either a good coax/spidif cable (RCA's) or and AES/EBU.

my 2 cents...

@stuartk Like some others here, for years I’ve used a much cheaper adaptor to the Cardas adaptor you already found with no problems or sonic compromise. Let your brain be your guide, not necessarily what you read. BTW, love your Craftman style home and listening area.

@stuartk - I agree with @marco1 on both the adaptor and "your Craftman style home and listening area."

Back in September in my 6 DAC thread, you commented on our styles being similar.  I do have a few pieces, some old some not so old, but your place is the real deal and the vibe is very cool.  Congrats on maintaining it as the builder intended!  BTW, is that a red husky laying by the doorway?  I have had 6 of them!

The potential problem is characteristic impedance.  Digital signals at at a frequency where impedance mismatches will cause reflections so you may need to try different.

@mitch2 LAYING, really, in public.  I hope he was just lying.

@retiredaudioguy - Damn huskies, ya never know what they are up to 

I thought it was a rug before….see the water bowl now 🙃

Check out Black Cat bnc -> rca adapters. A bit pricey but excellent quality.

Wow-- sorry for my inattention. I had no idea so many had responded.

I hope you’ll forgive me not responding to every response, individually. I received pneumonia and shingles shots yesterday and am not "feeling up to par" (my hair’s no longer long, so cutting it is a moot point)...

@carlsbad2

Yes -- I inadvertently damaged it. The transport is really heavy and I’d prefer to not ship it from N. CA to Texas for repair. The fact that the DAC doesn’t have a bnc input is more the issue, in this case.

@mitch2

Good to know! I actually just bought the DAC (largely on the basis of your "6 DACs" thread, BTW). Hawthorne said they’d ship me an adapter for no charge. Don’t know what brand. I didn’t ask. I haven’t received the dac, yet.

@audphile1 , @steakster , @jeffbij

Well, for my budget, my $1700 Synergistic research bnc cable does qualify as "fancy". It might not for others, here. Thanks for the warning about the 75 ohm rating, @audphile1 . I could get it reterminated I guess. I’ll contact Synergistic. I bet it won’t be cheap! I’d rather not sell it and take a loss. It’s the most expensive cable I’ve bought, so far.

@marco1 , @rja

Had fully intended to buy Black Cat but The Cable Co. no longer carries them and the Black Cat website lists a price of $165!

@marco1 , @mitch2

Thanks for the compliments. It’s not actually "the real deal" - we couldn’t afford to slather the walls with vertical grain Doug fir or have any fancy wood joinery. But it’s close enough for us. Dog was a Malamute/Husky/Wolf hybrid -- one of two sisters we adopted. Yes; those dogs are very appealing, as long as they are contained. They love to go under/over fences and roam! Our last two have been Pyr crosses. Also lovely dogs.

Thanks to all for your comments!

Both the DAC and the Cardas adapter arrived today.

I was excited to hook up everything, only to quickly realize the Cardas adapter is way too big for the RCA input on back of the DAC.  

Given the cost of audio gear and what a pain it can be to assemble good-sounding systems, you'd think the least manufacturers could do would be to standardize these connections.  Apparently that's asking too much.  

@stuartk hope you recovered from those shots! That Synergistic cable should be very nice. I would evaluate with it. Sorry to hear the adapter doesn’t fit. But I’m not sure how it can possibly be too big. Does it not make the connection? Can you order an adapter from amazon just to evaluate the DAC?
https://a.co/d/3hjs0JR
Another option is to order a basic AES cable just to get a feel for the sound.

https://a.co/d/2MaBs5Z

Ah I missed that you damaged the AES output in your Jays. Guess adapter is the only option now

@audphile1

... or getting the cable reterminated. I reached out to Synergistic but they haven’t responded yet.

Regarding the poor fit, the interior dimension of the barrel of the male rca end of the adapter is too big compared to the exterior of the barrel of the female rca socket in the dac. In other words, it’s too loose of a fit. By a lot. It simply fails to make the connection. The last time I demo’d ICs from The Cable Co. I ran into the opposite problem with one cable pair.

I found an adapter listed on the Transparent site for $10. Given their reputation for expensive wire, I was very surprised!

Today I also discovered that due to the stiffness of the Synergistic cable (twisted geometry) , the only way the Mojo will fit into its bay is parallel to the back wall. I could live with this, but it looks a bit weird.

I’m feeling better, today, thanks.

Interesting. Strange choice by the dac manufacturer 

@stuartk - The analog rca jacks in the X SE are "Furutech rhodium plated low-mass RCAs directly soldered to the PC board." The digital S/PDIF rca jack looks different so I am not sure whether that is a Furutech or not. However, I have never had an adaptor or digital rca cable fit loosely so that is very odd about the Cardas adaptor.

@audphile1 , @mitch2 

Because I've run into a situation where the barrels on an rca IC pair didn't fit the Jacks on my Hegel H390 (several other cables fit just fine), I'm inclined to give the dac builder the benefit of the doubt but I can't definitively prove whether it's the dac or the adapter that's to blame in this case. 

I'll just have to see how the adapter that I'm expecting to arrive later in the week fits. Hopefully, it won't continue to be be an issue, going forward.

And the cardas adapter fits just fine on the rca outs of this dac? Interesting to try it just to check.
If the new adapter isn’t a tight fit I would reach out to the manufacturer and confirm i looked at a few pictures and I see different connectors are used for coax in and it’s not consistent from dac to dac…this is typical with boutique manufacturers as they would use whatever is available  I’m not excluding the possibility for that being the case even with the parts used inside the chassis as well. 

@audphile1

To be honest, it never occurred to me to try it on the analog outputs, as that wasn’t what I would be using.

Note that when @mitch2 looked at his Mojo Mystique XSE, he said "The digital S/PDIF rca jack looks different". I can’t see a discernible difference on mine but it’s entirely possible he’s detecting a difference I’m overlooking. After all, it happens all the time that I can’t find something and my wife points out that it’s right in front of me! ;o)

@stuartk no big deal. I know you wouldn’t be using it on rca outs but thought to have an additional data point to determine the culprit…is it the Mojo rca jack or the cardas adapter that is the culprit. 
 

You don’t want to give up on your Mojo DAC and end up like Austin Powers….

@audphile1 

Agreed --  it would be foolish to give up right away on the DAC due to this issue. 

BTW, Synergistic quoted me $150 for retermination. Still waiting to hear about turnaround time. 

I emailed Black Cat and they said they're no longer making the adapters The Cable Co. used to sell for about $30. Now they only make a different version in pairs for $150 - 160.  

@audphile1 

My guy at The Cable Co.suggested I try gently bending the "leaves" inside the male rca barrel inward and doing so, I was able to get the connection seated without slipping off. Ideally, I'd like it to be tighter and I may experiment further but for now, I'm going to concentrate on evaluating the DAC. It's certainly brought more resolution (without sibilance, so far) and improved the bass reach and presence in the mix. I don't know how long it's been powered off, so I'll continue to listen, give it more time

I once had the opposite issue of yours, @stuartk . My transport had an RCA digital out, but the DAC I bought had a BNC in. The Dac did come with a male BNC to female RCA adapter and I am sure I must have used it initially (this was almost 30 years ago) but I did contact Canare Cable and they made up a digital cable that was RCA on one end and BNC on the other. Fast forward to a few years ago, I was having trouble with that cable (the DAC was intermittently unlocking from the transport) so I broke out he adapter that I mentioned but I noticed that the SQ was noticeably worse. I contacted Kimber and they made me up another RCA to BNC cable (I think it was D60) and that did restore the SQ. I was using that until a few years ago when I bought a new CDP.

Anyway, I did read that you resolved your issue for the time being, but just wanted to add my own experience with RCA/BNC adapters.

@stuartk great news! Hopefully the DAC meets your expectations!

@stuartk - I am glad you got it to work.  Enjoy the DAC.

I am surprised more equipment manufacturers do not use BNC connectors for digital cables.  To me, they seem to make a better connection than RCA.

@immatthewj 

I've been told both: that an adapter is bad and that it makes no difference. I'm getting a different one in a few days. It will be interesting to hear if they sound different. I'm not fundamentally opposed to getting my cable reterminated, BTW, if I decide to keep the dac. 

@audphile1 

Thanks. We'll see. 

@mitch2 

You could be right. I've never done a comparison.

I've been told both: that an adapter is bad and that it makes no difference.

@stuartk , I am certainly no expert on the subject.  There may be variables involved that have an effect on how one feels about it..  I remember when my old Canare  RCA to BNC cable started acting up I was feeling pretty proud of myself for knowing where I had put the adapter that the manufacturer of my DAC had provided.  I really wanted it to sound good, but it didn't, so that is why I wound up biting the bullet and buying another cable.  I suppose this may be one of those YMMV things. 

@immatthewj 

It seems to me there are are very few things in audio that are NOT susceptible to YMMV.

It seems to me there are are very few things in audio that are NOT susceptible to YMMV.

I agree.

@immatthewj 

Speaking only for myself, It can be both freeing and crazy-making...  

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