What TIU is Rev 13-A

That is the hardware revision meaning the design, layout, and circuit board of a specific revision.

That particular one is a fairly common unit before the revision L that then came with USB.

Firmware- can be updated on ANY version to the latest.

Hardware- is what it is.

https://www.youtube.com/watch?v=g6Cr9YhkfiE

You need a USB to serial cable or a computer with a serial port and cable.

You need an audio cable that is 1/8th in stereo jack on both ends- this is how the TIU knows to be in firmware update mode.

You need a phone handset coil cord- for updating any remotes to the latest matching firmware.

Edit- also you need to power the TIU either with power in on fixed 1 channel, or the aux power input jack.

As far as versions- just FYI from a previous thread

@Dave Hikel posted:

Hi Rodger,

Here's a quick run through TIU history...

Rev. G - This was the original, released in April, 2002.  Unlike all later TIU's, the Rev G's had the black terminals on all four channels tied together.  They are also the only TIU revision without internal blade fuses and were vulnerable to shorting out with older transformers with slow acting breakers.  The G's can be identified on the outside by the lack of a revision sticker on the underside.  The G's also have a "ProtoSound 2" logo painted on the top of the case.

Rev. H1/H1A/H1B/H2/H2A - The "H" revisions added the blade fuses for auxiliary circuit protection and isolated the black terminals on each channel.  The G and H revisions all used 5 volts chip sets.  The various alpha numeric iterations within the "H" revisions represented minor hardware changes on the circuit board.  All "H" revisions came with an identifying sticker centered on the underside of the case.  The H1's were painted with the "ProtoSound 2" logo, but from the H1A on MTH switches to the DCS oval logo on the top of the case.

Rev. I/I1/I1A/I3/I3A/I3B - The "I" revisions moved from a 5 volt to a 3 volt chip set.  The various alpha numeric iterations within the "I" revisions represented minor hardware changes on the circuit board.  All "I" revisions came with an identifying sticker centered on the underside of the case.  MTH used a sans serif font on the revision stickers, which has often lead to confusion.  Many people mistake the "I" for a "1."

Rev. L - So far there has only been a single variation of the Rev. L.  The L uses a 3volt FPGA chip set with improved signal recognition, which effectively improves track signal quality.  The "L" also added a USB-B port, which can be used in lieu of the RS-232 port to connect the TIU to a PC for updating firmware and transferring files.  You can identify the Rev. L by the sticker and the USB-B port.

@spudder posted:

Is this TIU desirable?

Again, that was one of the last revisions just before Revision L. While revision L might have slightly better signal strength on the outputs and the USB connection, a revision I3 has fuses, is a later revision, so yes, I would consider "desirable".

I had personally owned an used an I3 for some time before selling them off to needy customers in this high demand period of time.