Up the top of your screen (to the right of the 'Search' window), you should see an envelope sign.
Click on this and it should take you to a screen where you can search for 'andyr'. Once you get this ... you should be able to send me a msg.
Yassou.
Hi fellows.
Last weekend I started looking for the parts of AN 4R. The FQA36P15 is out of stock at all the big suppliers(Mouser,RS,Farnel UK etc.)Mouser have 117 weeks for backorder. Do you have any idea where can I look for it? Or if any of you who has got some in stock and would like to sell a couple of them, i would appreciated it. Thanks anyway
Last weekend I started looking for the parts of AN 4R. The FQA36P15 is out of stock at all the big suppliers(Mouser,RS,Farnel UK etc.)Mouser have 117 weeks for backorder. Do you have any idea where can I look for it? Or if any of you who has got some in stock and would like to sell a couple of them, i would appreciated it. Thanks anyway
Hi Meta,
Good choice to build the AN 4R. Very nice amplifier, I have heard AndyR's here in Melbourne and it is stunning......
Any 280W pmos hexfet with a rating of 35A or better and 150V rating is fine, although it's nice to have a lower Ciss (gate capacitance) of less than 4nF is helpful. There are plenty, and most of the ones are in IXYS versions.
But be warned, some of the IXYS mosfets are quite expensive, and this reflects the supply line issues since Covid.
Cheers,
Hugh
Good choice to build the AN 4R. Very nice amplifier, I have heard AndyR's here in Melbourne and it is stunning......
Any 280W pmos hexfet with a rating of 35A or better and 150V rating is fine, although it's nice to have a lower Ciss (gate capacitance) of less than 4nF is helpful. There are plenty, and most of the ones are in IXYS versions.
But be warned, some of the IXYS mosfets are quite expensive, and this reflects the supply line issues since Covid.
Cheers,
Hugh
Hugh,
Thanks for your immediate reply.
Price is no problem to me. Give me the best and particular type of that IXYS for N and P mosfets please.
Thanks
Spiros
There is another critical question.
According to Andy's 4R BOM there are parts from AN 8R that have been left blank at the cells of AN 4R XLS and are not going to be soldered to XRK's fine 8R pcbs. i think I have to jumper those empy pad holes. haven't I ??? Please advise.
Thanks a lot.
Spiros
Hi XRK,
Thank you very much for your increadible work of AN.
I have just ordered the pcbs from etsy for 4R build.
Before ordering the parts I want you to make clear to all 4R buiders what to do for a correct parts installation.
I have checked both 8R and 4R schematics and the AN pcb as well.
I have noticed that in place of unused parts, as R136 for example, there must be a jumper. There are no resistors for the green and red led in the BOM. In 4R schematic, the green led is indicated as 1N4148, C6 is indicated 100uF and 220Uf( in the BOM - in 8R it is 470uF)).There must be a snubber board BOM too. If somebody of you, don't make some things absolutely clear, the amp will not work properly. It is very critical to be defined what someone has to do with the pads of unsued parts in 4R pcb.To be jumpered or left as they are? Please advise.
Thanks a lot
Spiros - Athens, Greece
Nice cpu cooler Jim! Probably use an aluminum bar with two tapped holes to allow clamping screws to hold MOSFETs in place. Use the snubber boards with flying leads. Be sure to use some Kapton tape to insulate exposed wires. Ceramic insulator pads should go in between the mosfet back and the heatsink. I did something like this on the LuFo prototype with 3 MOSFETs.
I also used this style of cooler on the Mother of All MOFOs. I later switched to Noctua fans which are silent.
I also used this style of cooler on the Mother of All MOFOs. I later switched to Noctua fans which are silent.
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Thanks for your order. I’ll leave it up to folks who have built the 4R variant to comment. I have not built it myself and it’s been a few years now so I can’t recall anything special about unpopulated pads - other than if you use the through hole compensation silver mica caps, no need to use the SMT option in the same spot. You will see that the two pads are connected. Use one or the other but not both. I seem to recall that the one pot on the input pair can be replaced with a resistor. It’s not needed. This amp has zero tweak pots for adjustment once that is fixed value.
God knows would be my initial answer but yes a bit like X explained I'll probably drill and tap into the surrounding ally. Or see if I can use this spring loaded fixtures. Got all the ceramic pads ready. Got the other sinks mentioned in this thread too, just thought I'd take a look at these. I've got a 600VA 29vac trafo salvaged from an old Arcam AVR so shall see if it sage enough down to 28 or so.
Thanks for your input X.
