Ah, my bad: The pcb dimensions can be found in the build guide, as well as images for the 4U and 5U heatsinks. But the 3U is somehow missing, right?
What is the BOM cost for a pair of amps (i. e. one stereo unit)? Would be nice to see this in the opening post either here or in the GB thread.
I can't tell you exactly, but I have spent around 350 Euro / USD (almost the same at the moment) at Mouser. This includes CMF55 Resistors and some bits for the PSU but no PSU Caps yet. It also doesn't include all kinds of semis, because I have sourced them elsewhere.
On my side it adds up to:
- 50 Euro boards
- 350 Euro Parts Mouser
- 65 Euro small Heatsinks / shipping by @fireanimal
- 180 Euro Kit of semis, some are matched, incl. shipping
- 120 Euro 2x Antek AS-4445 plus
- 80 Euro shipping (still same total price as with comparable transformers from toroidy.pl, but more copper weight)
- 150 Euro for 8x PSU Capacitor
- 60 Euro 2x soft start board China
- 50 Euro hardware, fuses and wire
- 20 Euro PSU boards prasi
So total costs will be about 1200 Euros with my existing 4U 300 Chassis for a dual mono build.
Hope it will be worth it..
@AddiDub, thanks a lot for the detailed breakdown! I'm sure it will be worth it, you will get a state of the art amp with no corners cut.
Just ordered everything for a 3U stereo SMPS version with Yageo resistors (incl. shipping, VAT, fees):
In total I guess it will be ~1.100€
- 55€ boards
- 260€ 3U/400 chassis + customized heatsinks by modushop
- 60€ small heatsinks by fireanimal
- 170€ SMPS800RE
- 470€ Mouser+Farnell
- 40€ additional parts (e.g. eBay)
In total I guess it will be ~1.100€
Hi everyone,
I was wondering if anybody could help me with choosing capacitors 115 and 117? It looks like it should be done based on speakers and rail voltage but I'm not sure how that works.
My speakers are 4ohm, 59v rails.
Thanks
Jeremy
I was wondering if anybody could help me with choosing capacitors 115 and 117? It looks like it should be done based on speakers and rail voltage but I'm not sure how that works.
My speakers are 4ohm, 59v rails.
Thanks
Jeremy
As far as I know, if you just want to listen to music, the first part showed in the sheet 3 of the BOM should be ok. Only if you want to make tests with sine waves at full power at 4ohms, you might want to consider the other listed parts.
Gaetano.
Thanks for your answers. I thought there might have been more to it considering the range in values. You've made the decision much easier.
Cheers
Jeremy
Cheers
Jeremy
Noob question: There is no problem with using KSA1381 / KSC3503 for Q11 / Q13 with rail voltages <65V, right?
Up till now I spend 1000,- euro. I expect another 500,- euro worth of parts will be needed, adding it up, approximately 1500,- euro.
Wolverine EF3/3 PCB's – 70 euro
Toroidal 1 kVA – 155 euro
Power supply capacitors KEMET 4 X 36.000 uF – 165 euro
Output and driver transistors Onsemi 2SA1943 2SC5200, MJE15032, MJE15033, KOA emiter resistors, Onsemi bridge rectifiers – 130 euro
Resistors, capacitors, pre drivers, various parts – 250 euro
Case Disipante 4U – 30 cm – 180 euro
Metal parts for case interior and cooling – 50 euro
Hi guys, a practical question: do you think 6mm height standoffs between the board and the heatsinks are good or for some reasons should I go much higher? I noticed that 10mm is a bit too much because with this height drivers leads barely reach the soldering vias... What's your thoughts?
Gaetano.
Gaetano.
I always used 8mm standoffs for my builds. 6mm can be a tight fit with power transistors.
Regards
All this information is in the build guide. Point 12 IV.
8mm is the minimum and 10mm is the Maximum.
For EF3-4 boards with the drivers mounted on the main heatsink use 10mm if you can even if the driver legs are just poking out the holes.
This will provide the maximum clearance between the body of the driver and the underside of the pcb.
Please read the build guide carefully.
I have had a few people ask me the difference between RAW and Finished heatsinks, so I just want to clarify.
RAW - As Cut. Needs cleaned up, holes deburred, holes tapped, pin holes drilled and pins installed.
Finished - Plug and Play 😀
Also I have shipped enough of these now, shipping is usually $10 USD anywhere in the world I have shipped to.
RAW - As Cut. Needs cleaned up, holes deburred, holes tapped, pin holes drilled and pins installed.
Finished - Plug and Play 😀
Also I have shipped enough of these now, shipping is usually $10 USD anywhere in the world I have shipped to.
Hi Stuart, unfortunately the drivers leads poke out of the board very little, if they don't at all. So I believe I won't go with 10mm standoffs. But, of course, I'm plenty of six and ten mm standoffs... :-(
I used 10mm with the EF3-4 boards and had no issues. Sticks out just enough I didn't have to trim the excess.
These are great standoffs, excellent quality and are the correct length for the UMS heatsinks. They are a bit pricey though.
M2103-3005-SS
M2103-3005-SS