Well, in all likelihood I wouldn't, but when mentally considering a Purifi build I would go with the Neurochrome buffers. So, it's mostly understanding whether I sacrifice any potential flexibility going with the prefab route.
Connectivity wise the Neurochrome boards can use the same connections, but guessing the pcb layout would need more work.
You might want to drop an email to Tom at Neurochrome to see if there has been enough interest to produce a kit or pre-assembled version via his TCA brand.
You will need a different ribbon cable. Tom can tell you the parts to order. It's a simple build. There will be no matching holes for the standoffs but the connections are tight. Some putty would suffice. The standoffs do not carry any current. Tom's board does not have a voltage regulator unless you ask for one. You will have to set the SMPS to do the regulation. Those NC500 boards do have regulators so the SMPS is set to send unregulated when you get it. The input wire from the xlr's will have to be replaced. A plug is used on the stock input board. Bare wire on Tom's board.
@barrows,
What was your final solution to resolve the power supply pumping with the Connex power supply (more capacitance, inverting I/O on one channel, different PS, something else) ?
TIA
well....
I tried adding the extra capacitance as suggested by Connex, but that did not solve the problem. I ended up using a Hypex SMPS 1200 instead which has no issues. I still end up using my linear +/- 17VDC supply for the input stage and modulator, the amp sounds fantastic. Next experiment is to try some Sonic Imagery discrete opamps in place of the eval board's OPA 1612...
Inverting one channel was not a good option for me, as I run a sub from the speaker outputs.
I tried adding the extra capacitance as suggested by Connex, but that did not solve the problem. I ended up using a Hypex SMPS 1200 instead which has no issues. I still end up using my linear +/- 17VDC supply for the input stage and modulator, the amp sounds fantastic. Next experiment is to try some Sonic Imagery discrete opamps in place of the eval board's OPA 1612...
Inverting one channel was not a good option for me, as I run a sub from the speaker outputs.
I am going to build a 7 channel amplifier for AV purpose
Any updates on your 7 channel build ?
How is the SMPS3K working out ?
TIA
input LPF question anyone?
Hi folks, I am considering adding a simple LPF to the input of my Purifi build (using the Eval board). This would be just to roll of the very low bass in order to save the amp from needing to deliver really high currents, and to keep my speaker mid-woofers from hitting their stops with occasional very low frequency pulses (mostly can happen at high volumes with some electronic music, big timpani thwacks, etc, I use a sub for low bass).
So the plan would be to put 4 film caps in series with the inputs. I am just not sure what R value to use for the calculation. The Eval module has a differential input impedance of 10.2 Kohm, would i use then 5.1 Kohm to make my calculation for the -3 dB point? Or, should I measure the resistance to ground of each input (pins 2 and 3) and use that number for the calculation?
I am only looking for a -3 dB point of around 40 Hz.
Hi folks, I am considering adding a simple LPF to the input of my Purifi build (using the Eval board). This would be just to roll of the very low bass in order to save the amp from needing to deliver really high currents, and to keep my speaker mid-woofers from hitting their stops with occasional very low frequency pulses (mostly can happen at high volumes with some electronic music, big timpani thwacks, etc, I use a sub for low bass).
So the plan would be to put 4 film caps in series with the inputs. I am just not sure what R value to use for the calculation. The Eval module has a differential input impedance of 10.2 Kohm, would i use then 5.1 Kohm to make my calculation for the -3 dB point? Or, should I measure the resistance to ground of each input (pins 2 and 3) and use that number for the calculation?
I am only looking for a -3 dB point of around 40 Hz.
External Negative Feedback using reversed Bi-wire cables
Would there be any benefit to use a bi-wire cable backwards (2 pairs of speaker posts on the amp side, 1 for power, one for feedback) to implement external negative feedback closer to the speaker's terminals ?
image from AudioXPress Purifi Article
TIA
Would there be any benefit to use a bi-wire cable backwards (2 pairs of speaker posts on the amp side, 1 for power, one for feedback) to implement external negative feedback closer to the speaker's terminals ?
image from AudioXPress Purifi Article
TIA
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