What is the difference of a "Type A to Type C cable" and "Type A to Type A cable plus Type A to Type C connector"?

Question

I have

• (A) a Harddisk box equip with TypeA connector come with a TypeA to TypeA cable(USB3)
• (B) a Macbook Pro of late 2017 with all ports in TypeC connector

So, for using the harddisk box, I have to add a TypeA to TypeC connector for connecting them.
TypeA<============>TypeA + [TypeA to TYPEC] Connector

Because there are 2 connection points plus the flaw design of Macbook Pro TypeC ports, it always lose connection.

So, I try to connect it with a TypeA to TypeC cable which is also supporting USB3. (The cable is coming form another Harddisk box which is TypeC in native but coming with a TypeC to TypeA cable for compatibility with existing Windows machine)

Then I try to connect the (A) Harddisk box with this TypeC to TypeA cable.
TypeA<============>TypeC

The Macbook Pro does not recognize nor response.

So I would like to know what is the difference between

1. TypeA to TypeA cable plus a TypeA to TypeC connector
2. TypeC to TypeAcable (Not usable when reversing when TypeA to TypeC?)

in nature to make such difference? And what should I do or what type of cable should I get so that the TypeA Harddisk Box can work with a native TypeC to typeA cable?

Many thanks.

Answer 1

I wonder what is the difference by a TypeA-TypeA cable + TypeA female-TypeC male connector and the TypeC-TypeA cable

The difference is this: "the TypeC-TypeA cable" is intended to be pluged into regular TypeA USB host, which is always a host. The Type-A end has no means to communicate this to Type-C end, so the Type-C end is HARDWIRED to represent itself as "USB host". For this purpose the Type-C end has 56k pullup between VBUS and CC pin (some cables have 22k or 10k, which causes troubles sometimes). So when you plug the standard "TypeC-TypeA cable" into your MacPRO, the Mac thinks that the cable is the host, and host-host connection doesn't engage, and your HDD doesn't work. And since the HDD is not a host, the MacPRO can't work as device, so nothing happens.

The "TypeA female-TypeC male connector" is a different one. Its TypeC end has 5.1k PULL DOWN, which indicates to MacPRO that there is a device attached, and the MacPRO will enable VBUS, and your TypeA HDD will start communicating. The connection, however, will be less reliable because of reduced signal integrity - extra connector causes imperfection and degrade signals. More, many "TypeA female-TypeC male connectors" are made by people who have no foggiest clue what they are doing, and internal wiring is frequently very terrible in terms of super-speed transmission line quality. This is likely why you have an unreliable connection to HDD.

To make your illegal TypeA HDD to work with a single cable with a TypeC port, you either need to find another odd TypeA to TypeC male cable with 5.1k pull-down on one of CC pins, or to make your own using available breakout TypeC assemblies and very-very careful soldering. It might work.

Answer 2

I bought this box from Taobao: https://gd3.alicdn.com/imgextra/i3/38611242/TB2VLrBclUSMeJjy1zjXXc0dXXa_!!38611242.jpg

That Model 396U3 HDD enclosure is also sold on Amazon.com by Wanlonxing.

Since that enclosure has its own built-in power supply (so that it can support a 3.5" HDD), it does not require any power from the USB interface. Hence its Type-A port in all likelihood has the power-pin unconnected.
So although it has a host-style USB port, that port cannot behave like a USB host.
Therefore there should be no host-to-host conflict with a USB Type-A-to-Type-A cable

And what should I do or what type of cable should I get so that the TypeA Harddisk Box can work with a native TypeC to typeA cable?

According a Q&A answer by the seller (Wanlongxin Seller on November 28, 2018) on Amazon, this enclosure does not work with a host Type-C connection.

Question: Is this case backward compatible with USB 2.0?

Answer: Yes, this case backward compatible with USB 2.0. But not compatible with Type-C.