My provider GGS.ch has the TV channels only from 370 MHz , so I cannot answer the question directly. But unfortunately I found that this tuner is much less sensitive on high frequencies. With the old single tuner I got all the stations with a relatively constant reception strength of 39.5 to 41 dB. With the Twin Tuner, however, the reception strength is only 30-37 dB. The stations with 30 dB are just fine. But if I use a double antenna plug to be able to use both receivers in parallel (otherwise the double tuner makes little sense...), they no longer work. The original single tuner gets more than 38 dB on all channels even with the double plug and works without problems. The problem with the twin tuner is on both channels and the weakest stations are those with the highest frequency of 594 MHz. With the original tuner there is no noticeable drop at high frequencies and the same stations can be received at around 40 dB, so it can't be the cable system. I have now bought an antenna amplifier (one input and 2 outputs), and now it works. But I would probably go for a clone today and not buy original DMM. If DMM is so expensive, they should at least deliver quality!

I have the problem that on tuner B1 the frequency 466Mhz does not work (3Sat HD, BBC One HD & BBC Two HD), on tuner B2 it works. Is this also a problem with a faulty tuner? I only received the tuner from digitec 2 weeks ago. New delivery, so I guess the teething troubles should be off the table!

DMM Expensive? They used to be, now they are cheaper than the nachamer boxes and clone boxes. I have the DM900 UHD. The hammer. Something seems to have gone wrong with the first batch of dual tuners, they are replacing them now, sent them to DMM, unfortunately not registered and now both my tuners have gone missing on the way to DMM :( So now I have to buy a new dual tuner.
I have a DM900, DM820 and a DM520 and I am very happy with all of them and they are cheap in comparison.
Just wanted to know if these tuners are still from the first batch or are new.

If someone also has problems with this tuner, he can also look in the "Dreambox Board" under DM900 and then under DVB-C "Cable tuner Si2169C on lower frequencies problem?" and read up (have not made a link, because I do not know if that is desired here).
They are being replaced and seem to have no more problems.