There is one offer on AliExpress that claims to have 1100 TDA1317 in stock for 18.05 USD and from another seller TDA1316T for just 4.20 USD, even more stock and less in bulk. It is sad to know how many working electronic devices get destroyed for chips in China, but I doubt the flow is still going. Did anyone try to order such an IC?
Other ICs seem available on other platforms via direct contact.
I am considering ordering some for my 2nd gen mods to create a replacement read-/write-board rather than modding working ones.
I’ve gone on Octopart before to find out if anyone had any DCC chips and I also found out that there were some sellers in China that claim to have them.
Whether it’s true is doubtful. They could be fake chips (unlikely because what would you fake them with) or they could just be bait (you make contact and they make you pay for a large shipment and they only send you a few that they have and then they try to sell you their other stuff and never leave you alone and never give you a refund).
Use caution. If you decide to try and buy a reel of shady DCC chips, create a new email account for communication so you can close the account if they bother you too much, and use a credit card that will give you your money back if you end up not getting what you ordered.
I don’t want to fear-monger here but a large amount of new-old-stock of a chip that literally no-one has needed for 25 years seems very shady to me.
I’ve been thinking for a while that it would be an awesome idea to design new boards and make them available. We could either make imitation boards with the same layout as the original boards, or we could make different boards e.g. with through-hole capacitors that will last longer, maybe even with through-hole resistors so they’re easier to build.
We could even do this for other boards, not just the DCC900 read-write board though that one is the most common problem in our world.
All the parts except the DCC IC’s are standard and are still available, including the connectors.
We might even consider making our own boards that are the same size but have an FPGA replacement for the DCC chips, but that will be for later. And FPGA’s pose other problems such as complex power supply requirements with sequential startup, parts that are difficult to solder by hand, etc. But that can be solved in other ways, e.g. putting an FPGA board like the UPDuino or ICEStick on top of our board. Then the (non-)availability of most DCC chips becomes a software problem. Eventually the only problem that remains to keep DCC alive is the head and the availability of tapes.
@drdcc Would DCC900 replacement read-/write-boards for maybe 50 USD in total including everything be worth it? Should be pretty easy given that those ICs do work and they don’t increase the price after they see demand. But I don’t see the need.
A replacement in standard parts may be possible even without FPGA with some clever Microcontroller code for the multiplexer and the alternating recording which are by far the trickiest parts.
For now, my goals are simple:
Bit identical DCC dumps and restores
Enough understanding of the DCC format to master own dumps
A working ITTS implementation
These parts may reduce the need to mod something already working.
Off topic (possible insanely complicated solutions):
Tape: Slicing VHS and/or Barium ferrite tape
Heads: libresilicon.com made some breakthroughs in simplifying manufacturing of silicon
But as I already stated in other posts I want to push DCC to its limits compatible with unmodified devices but not further. Technically your PASC encoder would be in violation of the specified encoder but as long as it plays flawlessly on all devices, it does not matter,
Would you prefer through hole or SMD? I’ll reach out to some half-decent brokers to find out what they charge on top and if the stock count is even real.
Update:
The TDA1317 seems to be available NOS at perfectly reasonable prices with roughly 100 in stock.
The TDA1616T is as already mentioned available at a half decent price desoldered on AliExpress, I hoped to find something else but until now nothing more trustworthy than that offer.
The rest are standard parts where I would choose quality parts reputable suppliers.
@all Can you measure the dimensions precisely including cutouts, screw-holes, thickness and so on?
@drdcc Would you prefer empty PCBs, PCBs with the standard components preassembled or the organisational clusterfuck of letting the sellers of the DCC ICs send to the PCB manufacturer for assembly? The write current resistor could be through hole for easy use.
@Jac I am sure you will proof read my design, right?
Assembly got relatively cheap these days, but logically has to be SMD for machine assembly. But you can assemble the TDA1316T, TDA1317, the resistor for write current and depending on the manufacturer maybe a little bit more yourself? But having the whole load of passive components preassembled will definitely be a huge help.
I propose to go with 5-10 prototype boards which will cost far less than expected.
