Problem with Paganini DAC locking on input

OK guys, this one has me stumped.

I’m using a Paganini DAC and it will not “lock” onto my Lumin T-1 streamer. Or to be truly accurate, it locked onto to it ONCE but that’s it (have tried it about 10 times, only worked once, so I know it has “worked”).

I have only two inputs: a Lumin streamer and Esoteric CD player. Both of these sources I connect via the two rca digital inputs to the Paganini. The rca digital inputs are the only inputs I can use with the Lumin & Esoteric going into the Paganini on my system. I have tested both of the Paganini digital inputs and they both work perfectly. I have tested two different digital cables and they work perfectly. Every time I select the Esoteric input, it locks on exactly as it should. Every time (accept once) that I choose the rca connected to the Lumin it gives me the “no input” message. Once again, I’ve switched inputs from rca1 to rca2 and the Esoteric always works. Ive tried the same rca1 & rca2 on the Lumin and neither work.

The one time that the Lumin worked was by “luck” …… I sat with no music and as I walked away in disgust, all of a sudden it played the song on the Lumin and it showed as “locked” . But after the song ended, it went back to “no input”. And I tried at least 5 more times after it “worked” that one time and no luck.

I even took the Lumin to a local tech who confirmed that the digital output works perfectly. Also, I can connect the Lumin directly to my preamp via the analogue rca’s (bypassing the DAC) and it plays perfectly. So the Lumin works great.

So here’s what I know:

  • Lumin streamer works
  • Lumin digital output works
  • my two digital cables work
  • Paganini DAC digital rca1 & rca2 work
  • Paganini will not “lock” and play the Lumin no matter what cable or rca is used

So why won’t the Paganini “lock” on the Lumin?
Any thoughts on something I haven’t tried?

Based on the dCS Paganini’s specifications, it has 2 x SPDIF RCA inputs, whereas the Lumin T1’s specification suggests it only has one SPDIF BNC output.

Which suggest you’ve got an interface type mismatch. You’ll need a RCA to BNC adapter for one end of your RCA interconnect.

Anup, may I humbly suggest that @naperaudio already knows that as he says that he has repeatedly connected cables to the Paganini RCA inputs. You can’t physically connect a BNC plug to an RCA socket or vice versa so he must be aware of the issue. BTW, adaptors always screw up the sound in some way not the least because they add more points of connection. so I would recommend having a custom RCA/BNC cable made or, given the possibility of cable directionality, BNC/RCA :grin:.

It is now many years since I had a Paganini DAC and I can’t remember if, like the current products, inputs are only viewable for selection if there is a physical connection. If so " no input" for a selectable input would mean that Paganini has found a connection but that the electrical signal being sent to it is not acceptable or recognisable.

This being so, then this issue may be where the acceptance tolerance ( PLL window) of the dCS input is tighter than the output tolerance provided by the Lumin. We have seen many similar issues recently arising from folk trying to connect LG or Samsung TV’s to their dCS DACs’ Tosiink inputs.

If I am correct ( and I may not be as I am trying to solve the problem remotely) the two products are either fundamentally incompatible or one or the other is out of spec and requires a service. As the Esoteric CD player appears to connect correctly to the Paganini then this points to the Lumin’s output as the problem.

Pete & Anup,
Thank you for your kind responses.

First, I was using a cable with bnc connectors and then utilizing a bnc to rca converter. This was also what the tech used to test the digital output.

Pete, thanks for the insight on possible “PLL” incompatibility. This is beyond my very limited technical knowledge.

A couple of thoughts, which I welcome replies.

I could drive to a local Lumin dealer and borrow another comparable unit (my T-1 is now out of production) and see if another model is compatible. Which “may” help to determine if it is a general problem with Lumin streamers.

Also, I could contact Lumin re: it being out if spec. The only thing is I don’t know exactly what to tell Lumin what needs repair/adjustment , as it does work. Is there something specific that I would share with Lumin (or a local tech) other than sharing my full story as listed in my prior post?

Other thoughts ….

Thank you,

Ahh, right. I wasn’t sure as you only mention RCA in your original post :grin:

I’ve had some experience with Lumin platforms in the past, they were always quite robust and ran to specs. I’d be surprised if the T1’s SPDIF/BNC was out of spec.

Could it be a bad BNC to RCA converter?

Hi Anup,
Thanks for the feedback on Lumin platforms, they do seem to be quality components with good technology.

We think alike on the connectors …. I actually tried all 3 that I had but no luck.

I take it that there is a semantic issue here and you mean adaptor.

If the adaptor is faulty then @haperaudio would likely be unable to view the input as there would be no connection. I cannot say that has to be the case but it is most likely.

So we can assume that the connection is recognised by Paganini but that no acceptable signal is being passed.He has now also removed the question of faulty adaptors from a solution as he has tried several with the same result.

So this leaves his unanswered question :

As meaningful communication from tech to tech usually requires a degree of quantification which we are not in a position to provide I would suggest that his best route is to try another Lumin model and see if the problem persists. If not with the new one he has no need to get involved with any technical reasoning. All he needs to say is this works but my one doesn’t.

BTW the Lumin may be fine insofar as Lumin’s specs, or more accurately, tolerances are concerned but that does not mean that they are compatible with dCS’ tolerances.

Yup, as they’re both 75 Ohms, its just an “adaptor”. I used the term “converter” as it’s what David used in his post above.

Lumin’s not as flaky as an LG or Samsung TVs :laughing:. Based on my past experiences with Lumin, I certainly don’t expect any such significant “compatibility” problems with it’s SPDIF out to a dCS DAC.

@naperaudio David, have you checked the Paganini’s SYNC mode? It should be at “Audio” for both the Esoteric and the Lumin to ensure the Paganini is slaved to the incoming bitstream.

I did check it …. It’s on “audio” mode

Well I guess it is the Lumin ….

I stopped by a neighbors house (who has a Bluesound Node 2i) and asked him if I could borrow it for an hour. I hooked it up to the Paganini with the same cables and adaptors (that I used with the Lumin) and the Paganini locked onto it immediately and it is streaming music perfectly.

So, now the decision is whether to just sell the Lumin and get another streamer or have it repaired/re-spec. Since the cost of two way shipping and repair estimate for something that I don’t know they can adjust seems to present a strong case for selling the Lumin (since I want my streamer to go through the Paganini).

Can’t thank you both for all your help.
It’s always an interesting journey ….