I was in the same position as you are now, about a year ago. The digital world in model railroading can be a little overwhelming when you first start. So take it slowly one step at a time and very quickly certain things that seemed confusing become normal.

I cannot answer all of your questions, but I can get you going with a couple of them.

First of all, your listed transformers are the old blue style analog transformers that should not be used to power your digital controllers. The reversing spike on these transformers can damage the digital decoders.

In the digital system you generally have one controller that will control the trains on your layout, unlike the analog world where each loco and isolated track needed its own transformer. Therefore, you do need to convert your analog locomotives with the high efficiency motors and digital decoders in order to assign a unique address and set features for each loco. if you try to run an analog loco on a digital system it will only run at full speed.

For the conversions of your locomotives I suggest you do a Google search for each such as "Marklin 3147 digital conversion" and see what comes up. You'll be surprised what comes up, including tables and associated conversion parts required.

You don't need a 60215 to run digital. You could go with the older 6021 and associated memory and keyboard units quite readily available on eBay. You could also go with either an MS1 or MS2 depending on how much you want to be able to do. One caution though is you state you want to be able to power track and catenary separately. That you cannot do easily with the new digital controllers and it is actually no longer even recommended (this has been subject to previous debates in this forum). I, like you, wanted powered catenary and have for the time connected my old analog transformer to my overhead and run those locos in analog and all the track powered ones in digital. However, you have to be very careful not to fry the digital system in a derailment or other possible short between the 2 systems (at least take the pick up shoes off). Now that I finally have a CS2 I am second guessing myself regarding powered catenary. It may not be worth the risk.

I'm sure others will chime in with answers to your other questions.

Cheers
Peter

No problem, there are people here only too happy to help. We all had to start as newbies once.



I think you will find the 34691 already has a Delta decoder, so this is already 'digitised' as far as you are concerned. You should find relevant information in the instruction book for the loco about this. If it has the little DIP switch "mouse piano" then there will be instructions on how to change the loco address using this. Otherwise it may have a 'factory set' address, which you shouldn't need to change, but there is a choice of 15 possibilities if needed.

To convert some of the other locos you will need to follow specific instructions about the motor parts required, but for most of these locos you should be able to do what you want with 60760 decoder kits. Another avenue might be to see if people are selling Delta decoders on eBay, as this may be a minimal cost route to digitising locos.



This transformer (as already stated) is not recommended for powering a digital system. The design of these transformers allows spike noise from the mains to come through to the secondary side, which has the ability to upset the digital system. The recommendation is to get one of the 'white' transformers. Any of the 'blue' transformers are considered not suitable.



Yes, and Yes.


Not necessarily - see what I said above. You may be able to pick up some Delta or 6080 decoders second hand, which will allow you to convert locos to digital without changing the motor. These decoders have miniature DIP switches (often called 'mouse pianos') for setting the loco address. If you need to buy the later decoders these have to have the address set by the controller, which is a potentially fiddly process with a 6021 controller, but much easier with a mobile station 2 (ms2).



Ask here - there are a number of people here who have been commercially involved in upgrading locos as well as many more amateurs who have done it. I will be surprised if there isn't a loco on your list that hasn't been done by someone here.



No you do not need a cs2, for the number of trains you want to run that would be overkill. However my recommendation would be to get an ms2. These are available with matching transformer at reasonable cost, and have the delightful feature that you can add a second ms2 to the system, thereby having two throttles available. You will find it will be very hard to run multiple trains on a single track if you have only one throttle. The ms2 is nicer than the ms1, although I believe you may be able to have an ms1 as a second throttle to an ms2, but I have no experience with doing this.

You could get a 6021 controller, but again I would advise you to get additional throttles. However because of their 'retro' value these seem to command unrealistic prices for their age.

Search eBay for two books that will help you get started. One has catalogue number 0303 and is the original booklet by Marklin on getting started with digital. The other has catalogue number 0308, and is a later hard cover book that covers much more. They both appear occasionally on eBay, but be selective, as sometimes the price asked for them can be excessive. Both are available in English, but you may find German versions offered. Also check your local second hand book shops or 2nd hand goods stall at your local train shows for these. You will find them in the strangest places as many people don't appreciate just what they are about, and they get disposed of in various ways from estates and the like.

There was one print run of 0308 in English, so it is fairly hard to find that.

I had forgotten about the digital special MM. That will also help you, again available in both German and English.