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Aussieamps

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About Aussieamps

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  • Birthday 28/10/1961

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    Tasmania
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    Australia

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  1. A lot of the design process for the DIY boards involves trimming the cost of BOM for SMD components(Multiturn SMD Trimmers can cost as much as $8.00 each), personally I do not have any issues with the adjustment as I am very use to the very small trimmers. But having said that I understand the frustration with adjusting small SMD trimmers. They can be fiddly. 🙂 On some of my commercial designs, I do use opamp based DC servo's for DC offset control and they work very well indeed, keeping the DC offset to within 1mv or less all the time. 🙂 The DC offset trimmer on the NXL800 board will have a transition delay between adjustment because of the 100uf feedback capacitor being part of this circuit. The SMD footprint for both of these trimmers could be easily replaced with multiturn SMD trimmers if so desired. 🙂
  2. If mains clipping is happening then can you tell me what the measured primary AC mains input is please, loaded and unloaded ? As this would explain why the needed voltage are not there. All specifications for the power transfomer were at the time (11/07/2017 from ) are rated for at least 240vac been feed into the primary winding, to achieve the specified output voltages. See copy of email dated 11/07/2017 Hi Ozzie Here are the transformer details as requested so you can use the Volt One regulator. 2.5KVA core 1 x 240vac primary winding 1 x electrostatic shield between primary and secondary windings 4 x 60vac secondary windings each winding @ 10 Amps 4 x 70vac secondary windings each winding @ 350ma Primary winding exit point 12 o'clock 2 x 70vac winding exit point at 9 o'clock 2 x 70vac winding exit point at 3 o'clock 2 x 60vac winding exit point at 9 o'clock 2 x 60vac winding exit point at 3 o'clock All primary and secondary external windings wires to be 300mm flexible leads END Game: What I am willing to do is to order you another power transformer with updated primary and secondary voltages that will hopefuly over come the apparent issues with your local AC mains , I will require that you send the transformer you have to me in exchange. Given the current situation in Australia (COVID-19) I have no desire or time to continue this conversation in a public forum, please contact me via email so we can arrange the exchange. I hope this helps you?
  3. The mod does not work because the raw input voltage into the Volt one is not enough to allow the Volt One to adjust correctly to the needed output voltage. 70 volts AC will and should result in having a raw DC voltage of approximately 98vdc been feed into the Volt One regulator. The math is as follows, 70 volts AC X 1.414 is 98.98, however in real life it is more like 98 volts. If you are not getting the 98 volts as a raw supply then you need to look as to why this is not happening. My first suggestion is to see why the Volt One RAW supply is only 92 volts, possible cause it is been overloaded, the protection poly switches on the Volt One are rated at around 200ma trigger, so anything above this the poly switch will trigger and become a large value resistor in which case it will drop excessive voltage across it. The input stage/driver stage should not need anything like this amount of current. The reason the Volt One will increase the output voltage swing and therefore the power output is the extra voltage present on the input driver stage helps to over come the several volt losses in the input/driver stage, this will then allow 3 to 4 more volts to be applied to the load, even 83 volts dc on the output stage stills allows this to happen. its one of the reasons in the installation manual I supplied to you that I suggest the input stage supply rails are adjusted to at least 5 volts above the main unload output stage supply. The reason from memory and it was I think a couple of years ago, I speced the transformer to 60 volts is with the volt one approximately 800 watts into 4 ohms could be achieved, also given your amplifier was going to be driving 2 ohm loads or lower I reasoned for better reliabliity reasons that a 60 volts AC supply would help with lower output stage dissippation. I hope you can see I have not tried to disceive you but to try and give you the best amp that could be supplied with this DIY module. Look into why only 92 volts raw supply is there, if needed unload the Volt One so it is not connected to the amplifier modules, and test the module again. If you have excessive loading after reconnection to the modules, you will need to find out why this is happening, remember I did not build your amplifier and I am not present actual to see and do some test actual, so the more information you can feed me the better. That way I can help you the most. 🙂
  4. Hi Guys If the on board LEDs on the Volt One regulator board turn off it only means one thing, that the main raw supply voltage has been reached. (With a +-85v regulated output) As the Volt One has an approximate 6 volt input output differential this would mean the raw supply voltage is approximately 91 volts, which is much lower than it should be given the raw AC voltage should be approxiamtely 70vac - 0 - 70vac, the input DC supply would be approximately 98vdc per supply rail. The onboard MOSFETs are rated at 200VDC and the input rectifiers are rated at 600Vdc, while the 100v rating for the caps is close it is still ok as all good quality caps are conservatively rated with a +20-30% long term surge rating. Given the info here I would be looking at what is happening with the RAW supply voltage. This can be checked by measuring across power ground and RAW supply input. The contact points for each raw supply is the grid array of gold plated through holes around each power mosfet or the metal tabs on the surface mounted mosfet. I hope this helps?
  5. You would be surprised how many users would attempt this plugged in. I have seen some crazy things in my 30 odds years in this industry. At the very least the terminals should be shrouded with a perspex or plastic cover. Just saying... 🙂
  6. I am not sure I would expose any user to those live terminals😲
  7. Hi Musicbee Currently I am deciding whether a dual mono version is the best offering or going down the pure mono block version will be what is offered. Expected pricing will be in the $3500AUD to $4000AUD range for a dual mono. I hope this helps?
  8. IMHO Purifi just shot their OEM's in the Face and them self's in the foot! 😡
  9. I can tell you it was a great night, there were more people turned up than chairs. Caught up with some old friends and listened to a great sound system. What was other peoples impressions?
  10. Thanks it was really nice meeting you as well, very happy you enjoyed the evening, it was excellent for us as well. really great night😀
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