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ghost4man

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About ghost4man

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    Gosford
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  1. Andrew, Just to add to Andy's comment I would look for an amplifier which is 2 ohm stable. From memory another SNAer had an impedance graph for your speakers and if memory serves me correct they do dip down quite low. Another consideration is that Maggie's tend to be highly inefficient. Whatever piece of gear you do choose be mindful that at the bare minimum it needs to handle 4 ohm loads without too much stress. Maggie's are amplifier sensitive unlike other speaker ranges especially if you want to get the best out of them. Ozzie
  2. Hi Andrew, What Andy said. The amp that you have unfortunately won't cut the mustard I'm afraid. Maggie's are extremely current hungry and has the tendency of testing any amplifier it's presented with. Don't forget that placement is also crucial where inches can and do count in terms of of sound presentation - they do like a sweet spot. I would also look into integrating a sub for the bottom end. Cheers Ozzie
  3. That was quick. Interested if sale falls through.
  4. Mate, I would be looking at these and contacting @GroovyGuru: They appear to be expired but you could make enquiries. That is an absolute steal at that price. I have been to Peter's place and his gear is immaculate. In saying that I have no commercial interest with him. Ozzie
  5. Hi guys, Just a quick update. Obviously have had a number of people PMing me asking what is happening with the build. Given the circumstances behind COVID-19 I made a purposeful decision to limit posting given the fact that there are far bigger problems in the world at this minute. We will be building a sturdy box so the amplifier can be sent back to Anthony as we reached the point where we did everything we could but the limitations of the transformer and the ongoing concern with the Volt One regulator could not be successfully addressed. To that end I thank Anthony for his offer. I have also been able to communicate with a former SNA member who many of you - Trevor/Zaphod - who will put the amplifier through its paces and report back. Please note regardless of the current situation I was going to do that anyway as I wanted a clean bill of health. I think any DIY build which includes electricity needs or should have this done. Who wants to start a fire in your own home because of faulty equipment. Ozzie
  6. Hi Marc More than happy to take those technical issues and resolving in private. I would however like to keep the thread open as I have had a number of people PM me along the way. Some in fact went down the route of purchasing their own modules like I did as a result of the thread. Its inevitable that things happen along the way.
  7. I have a big concern related to the above which I will post later and which highlights one of my biggest disappointments thus far. It relates to the advertised claims of the modules which quite simply cannot be met and what is currently being reflected right now. For now - No cigar for the polyswitch. There is virtually no voltage drop across them. The voltage across the caps and there is some ripple as expected. For example the positive rail measures as follows:- Maximum voltage = 96V Minimum voltage = 93.6V Average Voltage = 95.2V Some voltage drop across the diodes as expected.but the assumption of clean sinusoidal mains is questionable and would be viewed by many as being incorrect..Most mains supplies are truncated and the peaks are clipped so instead of the expected peak of 99V we are only getting 96V which is already a drop of 3 Volts.This would apply to the main B+ supply as well so the supply rails are under spec because of mains clipping. With a 6V dropout voltage the maximum regulated output voltage is 93.6 - 6 = 87.6 and is indeed what we are measuring!
  8. Just to clarify the following results came to light - Volt one measurements with recommended mods. AC input 70 Vrms Unregulated DC = +/- 93V Max Regulated output = +/- 86V How is this supposed to help with a main B+ supply from a recommended 60 Vrms transformer yielding a supply rail of only +/-83V no load. In any event irrespective of the voltage range on the FETS and the caps these will not be pushed anywhere nesr their threshold for reasons already stated.. Raw supply voltage measurement is only confirming the existing problems and as such it appears that this build is nowhere near what is to be expected in terms of power output. The VOTLAGE regulator is at this stage yielding highly undesirable results notwithstanding the issue with the main B + from the transformer. What voltages should we see on the main B+ supply rails to the power stage and the regulator output in order to achieve 500/800 wpc and how to balance that against a transformer that was spec'd to 60VRMS. That is the question that needs to be asked.
  9. Okay so the suggested mod was undertaken with the following result - With the mods the power output seems to be down at 48.5Vrms before clipping which is equivalent to 294 watts into 8 ohms. Also max regulated output voltage has reduced to +/-85.5V no signal and +/-81V at full power before clipping the regulators are not even regulating properly. Testing suspended due to such poor results. On this basis it is apparent that the mod does not yield the desired result. In fact the complete opposite seems to be the case. Mod to be reversed.
  10. Correct mate. In this particular instance the caps are +100V so sailing very close to the wind. Bear in mind as well that your FETS have to be rated accordingly as well. Good points mate.
  11. Your first port of call is to ensure that you have a transformer that is properly rated. If that doesn't happen then your output will never achieve what you want. The voltage regulator isn't regulating accordingly. So what you say about plug and play is correct to a certain degree but you still have to set the regulator. In this case +/-92VDC. Its falling way short of this mark which is evident in the leds switching off. Thats for both regulators as well so its not isolated to one only.
  12. According to Anthony after having run some numbers the Volt One regulator with its current configuration should be capable of 97 volts output with the right input voltage and higher voltage rated input caps. Additionally with 98 volts dc input from 70 VAC windings 90 volts output shouldnt be a problem. My problem however is two fold. The transformer windings weren't rated accordingly to achieve this but the big issue at the minute is that the regulator is nowhere near the ball park in terms of desired performance. Above 85 volts and it simply does not regulate properly. A classic case of what you think and hope will occur but no cigar. Will be interesting what the outcome of this mod will yield.
  13. Ongoing concerns continue with the Volt One regulator. Anthony Holton has recommended a mod by way of a parallel addition of a 100k resistor across the existing 22k one to raise the voltage with the vire to ultimately raise the output. The primary concern that I have at present is the need for the mod in the first place. By rights the Volt One according to the numbers should be achieving the necessary voltages to achieve the stated output figures. At the minute this is way off the mark. More to come..
  14. What a beautiful set up. May I ask what amplifiers you used to run them with.
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