Yes, I am using hypex modules albeit without modifications suggested by Andrej.
I must confess I was not aware that speaker protection is on-board until I bought them. Amp standby is another nice feature, allowed me to use cheap but good looking power switch.
Regards
Marko
Guys, is it great that everybody is having fun but I am still worried because I confess that I don't fully understand the philosophy behind the diagrams proprosed for the bridged VSSA connection particularly the sharing of the feedback caps between the two modules and the bipolar supply with virtual ground: that one will need high voltage main supply caps (which are more expensive) and I suppose that virtual ground, if not connected to central or star ground will make the whole amp floating...please some kind soul explain what are the best decisions, as my first inclination was to connect everything from a +/-25DVC regulated supply (and use my cheap and good Rubycon ZL) in the classic way.
Hi Mauricio,
In XVSSA the negative feedback is split between two amplifiers and is no longer referenced to the GND. As well speaker connections are no longer referenced to the GND. It is very similar to what Patrick (EUVL) did to F5.
You can definitely supply this balanced VSSA in a classical way, with (+) (GND) and (-)
I just tested that it works without the GND connection to power supply and that is an advantage in some cases. It brings flexibility in the first place.
Just finished my Power supply build, with a trafo of 2x 50Vac/6.5A output, two diode bridges and two ELNA 18000 uF/71V and I can measure exactly 71V unloaded at their terminals. All of the components were in my house.
I will reference the virtual GND to the case. Either connect directly to the chassis or (most probably) via a DDRC. The pin 1 from the XLR connectors I will connect directly to the chassis and only there. Pins 2 and 3 only to the inputs of the amplifiers.
Hope this brings more light. Thanks BYRTT for your input!
Cheers!
Many thanks BYRTT and Mettalicus69 for the explanations. Clearer now.
True floating would need double insulation, right?
I got a true floating schematic with "charge-transfer supply", which is rather complex. In fact my plain VSSA will be powered (today, hopefully) with "charge-transfer supply" but non floating this time. This clever circuit, extrait from -ECdesigns-'s work for low power circuits, disconnects main PS caps during charging pulses.
https://picasaweb.google.com/lh/photo/UyHCdD9B2QkYmc8HPORBqtMTjNZETYmyPJy0liipFm0?feat=directlink
Thanks again and keep the good work.
M.
True floating would need double insulation, right?
I got a true floating schematic with "charge-transfer supply", which is rather complex. In fact my plain VSSA will be powered (today, hopefully) with "charge-transfer supply" but non floating this time. This clever circuit, extrait from -ECdesigns-'s work for low power circuits, disconnects main PS caps during charging pulses.
https://picasaweb.google.com/lh/photo/UyHCdD9B2QkYmc8HPORBqtMTjNZETYmyPJy0liipFm0?feat=directlink
Thanks again and keep the good work.
M.
Based on discusions earlyer in thread the value 10K is OK. Regarding decoupling i will rather use xx working-ours to get circuit DC output to zero than using a cap, but this is personal preference and can be discussed forever between people's preference for or aginst caps for decoupling. So suggestion is measure your lightspeed circuit DC output and if clean couple direct is an option. Think Andrej also best like direct coupled, this is based on other threads with VSSA where most seem to use cap, and Andrej's GB VSSA don't.
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You need to install 10uF caps first, before taking any serious listening
Choose between Epcos or Vishay MKT capacitors...
I not always remember quite right, but think Andrej claimed somewhere 50 hours before onboard caps have setlled to point where golden notes get out of circuit. 10uF film caps is big quistion, mine thinking says that this is very widebander amp (MHz) and big elcos (2,2mF alone) has inductor effect and doen't work very well up high, and therefor use of the film helper is needed (wideband circuits need to be trimmed well behavor even we can't listen these high bands). Proposal to accelerate process, let it be turned on 24 hour a day with music playing for some days.
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I found something interesting in the TI LM-4702 AN concerning gate resistor valuse for good square waves for different output devices. I'm not sure how applicable it is to this situation but the more knowledgeable of you can decipher it for the rest of us. In chapter 9 it specifies values for different output devices which could effect the HF qualities of the amp.
http://www.ti.com/lit/an/snaa045a/snaa045a.pdf
http://www.ti.com/lit/an/snaa045a/snaa045a.pdf
It is probably more interesting for people like me, who are building the through-hole versions with the RENESAS 2SK1058/2SJ162. I noticed that the recommended gate resistor was on the high side compared to the values recommended for the ALFETs in this thread. (I already increased my Rgn and Rgp values by about 50%, and they are still lower than in this ap note.)
Guess it is non subject because you have layout and component values with published perfect 50KHz squarewaves in thread, and Andrej's GB have published 100KHz perfect squarewaves here in thread. So AP-note more valid for members using layout and values for new designs, and there it can be good knowledge.
You are right, for those who just use the values I posted in the BOM, a non-issue, but some of it is still interesting reading, along with the application note on the ALFETs.
I know from questions I have received that some people will be experimenting with the component values on the TH boards.
Having the link in the Through-Hole thread will help, and it may save me some time explaining what I did and why.
I have been searching all the usual suspects for the two values of Nichicon FG caps needed for the GB boards. NO body in the UK seems to stock these, and only Mouser seem to list them! Their delivery seems to be stuck at 17 weeks or thereabouts for the past few months!Anyone gt any suggestions for a European seller who actually can supply?
Very many thanks.
Hi Mouser has both for immediately delevery, maybe because of technical angel to their country-sites, see links:
UFG1H102MHM Nichicon | Mouser
UFG0J222MHM Nichicon | Mouser
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Mouser is nothing you'd like to deal with:
- They don't have a secured payment method via a bank web site: mean you let *them* your credit card number.
- They don't accept Paypal.
- And they don't even have a bank account in France to make wire payment !
I'm stuck with my order.
- They don't have a secured payment method via a bank web site: mean you let *them* your credit card number.
- They don't accept Paypal.
- And they don't even have a bank account in France to make wire payment !
I'm stuck with my order.
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Hi Christophe try the links, it is the Swedish coutry-site for Mouser and doesn't matter because both you and brianco order from EU country. When you get to paying and logging into your acount at that country site, your connection exchange to "https" so no security issue. Maybe Mouser France don't do that i can't tell, but Swedish site do. But caps are expensive and discount starts high at 25 pieces, so when i ordered i took Panasonic FR in same order, much cheaper and discount start low.