I have the following set of conditions. My source is a 2 channel DAC board. The output from both channels should be an identical mono signal. I need to feed the inputs to an ICEPOWER 50 ASX2 (BTL Mode from the company). It has two inputs and one output. As I don't have a scope, I don't know whether the signal is inverted on the output of either DAC. It appears that the output is floated above ground as the ground side of the output measure 33.5 ohms to ground on each channel and 67 ohms across both black leads, one from each channel.
I purchased the GhentAudio chassis which is not different than the pictures shown on their web site and I could only find one orientation that would provide 4 screw holes properly aligned with the board. It is more centered than the arrangement shown on the web site and leaves no place to add an RX board if one is needed. There is no schematic or drawing showing how to wire the inputs using the XLR, RCA and switch to select XLR or RCA, so I am not certain how it should be wired up. I am including the information I have on the DAC board output and a photo of the schematic & block diagram shown.
As I understand it, the AMP needs to have one input inverted. Can I just switch one of the ouput leads from the DAC? Will I need to use an RX card and if so, where and how do I mount it? See the actual board mounted in the chassis.
Thank you all in advance for any help you can provide.
I purchased the GhentAudio chassis which is not different than the pictures shown on their web site and I could only find one orientation that would provide 4 screw holes properly aligned with the board. It is more centered than the arrangement shown on the web site and leaves no place to add an RX board if one is needed. There is no schematic or drawing showing how to wire the inputs using the XLR, RCA and switch to select XLR or RCA, so I am not certain how it should be wired up. I am including the information I have on the DAC board output and a photo of the schematic & block diagram shown.
As I understand it, the AMP needs to have one input inverted. Can I just switch one of the ouput leads from the DAC? Will I need to use an RX card and if so, where and how do I mount it? See the actual board mounted in the chassis.
Thank you all in advance for any help you can provide.
Attachments
GND lead can't be used as an input. Already grounded elsewhere.
The first picture shows single ended outputs on J7 & J8.
DAC's DRV602 driver has balanced inputs, but single ended outputs.
You need an unity gain inverter in one channel between the DAC & AMP (page 27 Fig 17 AMP datasheet). A single op-amp and a couple of resistors will suffice, or use a That 1646 or a DRV134 in the middle for both channels.
I understand the need for a single op amp. GhentAudio sells one in the RX board. However, the problem is where to mount it? I can get power from the AUX power on the ASX50 board; however that would mean that the supplied cable they provide to go to the power switch (I presume to light it up when pressed on) would need to be spliced in as it currently is using one leg of the aux power socket.
My other questions are what position should the power jumper be placed for 120V AC operation and how was the XLR, Switch and RCA jack supposed to be wired (with and without an RX module)? They did not mention a need for the RX module on their web site where I ordered the chassis and wiring.
My other questions are what position should the power jumper be placed for 120V AC operation and how was the XLR, Switch and RCA jack supposed to be wired (with and without an RX module)? They did not mention a need for the RX module on their web site where I ordered the chassis and wiring.
barjohn, let's work through the basics: your PCM5101-based DAC has unbalanced outputs. To feed this DAC to a BTL amplifier with differential inputs, then yes, you will definitely need a Ghent RTX module, or some alternative SE-to-DIFF converter.
I'm intrigued by your setup. Are you using two of these ICEpower mono amps for stereo, or just one? What's the application?
And what are the details of your DAC. Is it a commercial product, or DIY?
I think you should mount it beside the P102 input header, in between the amp module and side of the case. The RTX module is just 35mm wide, but if it still doesn't fit, just re-drill some new holes for the amp module and shift it. There's plenty of unused space around your amp module.
I'm intrigued by your setup. Are you using two of these ICEpower mono amps for stereo, or just one? What's the application?
And what are the details of your DAC. Is it a commercial product, or DIY?
Thank you for the feedback and suggestions. My application is for a set of products that I am trying to develop. I was a EE & CS at the technical level many years ago (60's & 70's) but have long been in management & R&D since and I am currently retired.
My project is to develop 3 modules that would be used to turn passive or active speakers into wireless with low latency, solid connectivity and a variety of configurations ranging from 2.0 to 7.1 or 5.1.2 (maximum of 8 channels). To this extent I am looking at using the WISA standard. The three configured application modules would be: 1. a low power (30W) amplifier/receiver, 2. A high power (~200W) amplifier receiver and 3. Just a receiver with RCA output.
I have put together a prototype of #1 connected to my Martin Logan Motion 40s and it works very well. I have just completed a prototype of #3 and it appears to work well. I am now working on #2. I don't think the ICEPower will be my final choice and I may look instead for a digital input amplifier thus eliminating the DAC board in my current prototype.
Currently you can purchase speakers that have WISA capability with an amplifier built in but there are very limited choices available and some have made their systems proprietary and thus are not truly WISA compatible.
I see the market for such a product for people that live in apartments or where they just don't want the hassle and expense of permanently wiring their home or their spouse doesn't like having a bunch of wires all over the place. I am attaching a few photos of my prototype setup. I welcome thoughts and feedback. After I have finalized my prototypes I plan to do a kickstarter type launch and see if the market will support production versions.
My project is to develop 3 modules that would be used to turn passive or active speakers into wireless with low latency, solid connectivity and a variety of configurations ranging from 2.0 to 7.1 or 5.1.2 (maximum of 8 channels). To this extent I am looking at using the WISA standard. The three configured application modules would be: 1. a low power (30W) amplifier/receiver, 2. A high power (~200W) amplifier receiver and 3. Just a receiver with RCA output.
I have put together a prototype of #1 connected to my Martin Logan Motion 40s and it works very well. I have just completed a prototype of #3 and it appears to work well. I am now working on #2. I don't think the ICEPower will be my final choice and I may look instead for a digital input amplifier thus eliminating the DAC board in my current prototype.
Currently you can purchase speakers that have WISA capability with an amplifier built in but there are very limited choices available and some have made their systems proprietary and thus are not truly WISA compatible.
I see the market for such a product for people that live in apartments or where they just don't want the hassle and expense of permanently wiring their home or their spouse doesn't like having a bunch of wires all over the place. I am attaching a few photos of my prototype setup. I welcome thoughts and feedback. After I have finalized my prototypes I plan to do a kickstarter type launch and see if the market will support production versions.
