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FAB2306 – Balanced Line Receiver

FAB2000 Input Modules
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FAB2306 is our Line-Level Balanced Receiver. The FAB2306 uses a THAT 1206-series InGenius balance line receiver chip.  The THAT 1206 uses bootstrapping to raise it’s common-mode input impedance into the meg-ohm range without the noise penalty of using high value resistors. They behave like transformers, able to maintain high CMRR over a wide range of source impedance imbalances, even when fed with an unbalanced signal. But unlike traditional transformers, they offer DC-coupling, low distortion and transparent sound.

The FAB2306 Line Input Module allows you to create gear that works with line-level balanced signals.  There is no need for 48V phantom power, or -20dB padding for this module unlike the FAB2010 Mic Input Module.



3D Rendering of FAB2306 Line Input Module.




FAB2120 – Carnhill Input Transformer Module

This is similar to our FAB2110 Input Transformer Module… but instead of using a CAN type transformer, we’re using a Carnhill/UK Input Transformer, (model VTB-9045) typically used in Neve preamps.

The VTB-9045 Carnhill Transformer is a Low Level Audio Signal Transformer, with a turns ratio of 1+1:2+2.  DC Coil resistance is 24+24:130+130 ohms.

To mount the Carnhill transformer horizontally on this FAB board, a separate Carnhill PCB Adapter is also required.  Both boards will be provided when you purchase this FAB board.


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Passing your Audio Signal through an Input Transformer

Here’s one of the simplest way to use our FABModules….  Hook up the following FABs together:

FAB2010 – XLR Input Module
FAB2110 – Input Transformer Module
FAB3010 – XLR Output Module

All that’s missing is Power, if you want to enable the -20dB Pad, Phantom Power and Polarity Reverse functions. Otherwise, it will still work without power applied. After all, it’s just an input transformer inserted in your signal chain.

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FAB2110 Input Transformer Module – Prototype with parts

Populated our FAB2110 Input Transformer Module with parts.  Here are some photos showing a Jensen JT-11K8-APC Input Transformer mounted on it.

The board looks good, but I’d probably add another mounting hole on the lower right corner, just because the board is a little unstable with a heavy transformer mounted on it.

I’ll build another prototype using a different Input Transformer, like an Altran or EA brand.

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FAB2010 Prototype – populated with parts

Populated the FAB2010 boards tonight. I put too much solder paste on my resistors so I need to be careful doing that. It’s a little hard because I’m just using a plunger to dispense the paste. I need to get one of those solder paste pump dispenser. I’ve seen them on eBay for around $150 or so.

Anyway, here are some pictures.

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