Has there been a issue with these things loosing data??
That's what we're trying to find out. With other digital format converters (DFCs), yes, users have encountered issues - dropped samples, introduction of artifacts, etc.
Its not like a has sample rate convertion
No, but the DFCs are built to convert a S/PDIF coax signal to optical. However, virtually no manufacturer follows the S/PDIF standard. Since the S/PDIF source and the DFC both may not follow the S/PDIF standard, the combination of the two non-standard S/PDIF specs may create a situation where the DFC has trouble converting the signal it's receiving because the signal falls near our outside it's specified tolerance. The problems may appear readily and audibly in a short test. The problems may not occur audibly initially, but perhaps reveal themselves over time. Or the source device + DFC may have not problems at all. We don't know, and I believe that's the point Bean is trying to make.
I haven't seen any mention by Dr. Phob that he's listened to the
complete recorded WAVs (20+ hrs) to identify if they contain audible dropped samples or artifacts, nor have I seen indication he's checked them for bit accuracy against a control file. IME, it's much easier - and more authoritative - to verify bit-accuracy than casually listen to the WAVs played back. If the DFC proves bit-accurate under controlled conditions, I would hold a high degree of confidence using it in the field. If it does
not prove bit-accurate, I would have very little confidence using the DFC in the field. If it is not bit-accurate, but the DFC doesn't present audible dropped-samples or artifacts under a short duration of testing, I still would have very low confidence - if it isn't bit-accurate, then
something is not functioning properly in the source signal > DFC > target recorder chain and IMO this
something will eventually manifest itself in audible artifacts or dropped samples.
Given history of people trying various DFCs and encountering trouble with them, I wouldn't trust this particular DFC (or any other one, for that matter) until I had a chance to verify it's bit-accuracy. This is exactly why I tested the Hosa ODL-312 before using it widely in the field.