sbelyo Posted August 25, 2019 Report Share Posted August 25, 2019 (edited) 14 minutes ago, vivolo said: Does anyone have any extra Blue Hawaii PSU boards that they would be willing to sell me? I prefer to build a BH PSU as it is cheaper than a GRHV, and I am trying to make this more of a "bugdet" amplifier build. Did you want the Blue Hawaii Ultra mini? I believe I have one set of Electorstatic CFA boards and a BH Ultra Mini PS board. Edited August 25, 2019 by sbelyo Quote Link to comment Share on other sites More sharing options...
mwl168 Posted August 25, 2019 Report Share Posted August 25, 2019 Finally cased my ES CFA amp. Returned the bias resistors to 1M with the larger heatsinks. Running 20mA bias for the output sections. 10 Quote Link to comment Share on other sites More sharing options...
sbelyo Posted August 26, 2019 Report Share Posted August 26, 2019 That's mad cool! Quote Link to comment Share on other sites More sharing options...
joehpj Posted August 30, 2019 Report Share Posted August 30, 2019 On 8/26/2019 at 12:16 AM, mwl168 said: Finally cased my ES CFA amp. Returned the bias resistors to 1M with the larger heatsinks. Running 20mA bias for the output section. It was quite hot in this size with that current of my build. Is your amp running hot too? Quote Link to comment Share on other sites More sharing options...
mwl168 Posted August 31, 2019 Report Share Posted August 31, 2019 8 hours ago, joehpj said: It was quite hot in this size with that current of my build. Is your amp running hot too? Where I live, the ambient temperature at this time (end of August) is around 70 F, about 22 Celsius. The heatsink temperature of the amp gets to about 45C fully warmed-up. When I first cased the amp, the ambient temperature was around 27 Celsius and the heatsink was ~ 48C not quite 50. I can see the heatsink hit high 50's C in Taiwan where the ambient temperature can easily hit low to mid 30's C this time of the year. Quote Link to comment Share on other sites More sharing options...
soundwave Posted September 13, 2019 Report Share Posted September 13, 2019 Stax DIY newbie here. Great looking amp @mwl168 A couple of questions if I may: 1. This is probably a stupid question, but how do you adjust the volume on this amp? ? 2. What are the width and depth of this chassis? Is the front plate available also in black? 3. Roughly how much did this cost? Quote Link to comment Share on other sites More sharing options...
mwl168 Posted September 13, 2019 Report Share Posted September 13, 2019 (edited) 1. I use the digital volume on my DAC but you can easily add a volume control to the amp. 2. This chassis I use is quite small - dimension is 160mm x 70mm x 311mm. It's only for the amp circuits and you cannot fit the entire amp in it. There is a PSU in a separate chassis. As an example, you should be able to fit the entire amp including the PSU in a chassis like this. 3. My rough estimate for parts alone would be about $700 US that also covers chassis, transformer, connectors, wires and a reasonable 4-gang volume pot. Like most things these days, labor is the biggest investment. Cost can escalate quickly if you start getting into fancy chassis, volume pot and boutique parts (resistors, capacitors, wires, etc.). Edited September 13, 2019 by mwl168 1 Quote Link to comment Share on other sites More sharing options...
soundwave Posted September 14, 2019 Report Share Posted September 14, 2019 Thanks! I would use this together with ADI-2 DAC which has quite configurable line out volume options, so I guess I could easily live without a volume knob as well. Now I will look if there is a thread about voluntary builders, for a fee of course. I also sent out a question to my facebook network if there are any electronics builders out there. I decided that optimally I would like to build one myself with somebody who knows what he is doing. Starting with this, completely solo, is probably not a good idea. ? Quote Link to comment Share on other sites More sharing options...
vivolo Posted October 9, 2019 Report Share Posted October 9, 2019 I have created a BOM for the Blue Hawaii ultramini Power supply. I still need to select the big caps and screw terminals. If anyone sees any errors or if there are better parts that can be used, please let me know. https://www.digikey.com/short/pww5c5 Quote Link to comment Share on other sites More sharing options...
starcat Posted February 22 Report Share Posted February 22 On 10/9/2019 at 3:55 AM, vivolo said: I have created a BOM for the Blue Hawaii ultramini Power supply. I still need to select the big caps and screw terminals. Which PSU is this exactly? Can link to any schematics with details? Thanks Quote Link to comment Share on other sites More sharing options...
JoaMat Posted February 23 Report Share Posted February 23 This? kgbhultraminipsv4.zip 1 Quote Link to comment Share on other sites More sharing options...
jose Posted February 23 Report Share Posted February 23 BH Mini PSU Resistor Mouser P/N 100R 2 660-MF1/2CCT52R1000F / 273-100-RC 1.2K 2 660-MF1/2CC1211F / 273-1.2K-RC 330K 2 594-5093NW330K0J 3W L=20.5mm 430K 2 594-5093NW430K0J 3W L=20.5mm 4.7M 1 594-VR37000004704JR5 HV 1M 1 72-T93YB-1M Trimpot Semiconductor IXCP10M90S 2 747-IXCP10M90S * FQPF8N80C 2 512-FQPF8N80C * LM7815 1 512-LM7815CT / 863-MC7815ACTG * LM7915 1 512-LM7915CT / 863-MC7915ACTG * Zener 24V 2 78-BZX85B24 100V 2 625-Z4KE100A-E3/73 / 78-BZX85B100-TAP 100V*2+150V*1=350V 150V 4 625-Z4KE150A-E3 100V*1+150V*2=400V 1N4007 2 625-1N4007GP-E3/73 Capacitor 0.1uF/1KV 2 505-MKS4.1/1000/10 P=15mm 80-PHE426PB6100JR06 220uF/500V 4 598-80LX221M500K452 D=30mm * KX 80-ALC10A331CF450 470uF/35V 4 P=5mm/D=10mm FC KW Other GBU610 2 621-GBU610 / 625-GBU8M-E3/51 * 3N254 1 625-3N254-E4 / 625-2KBP10M-E4 * Heatsink Large 2 532-530002B02500G H=63.5mm * Heatsink Small 2 532-581202B25G H=50.8mm * 1 Quote Link to comment Share on other sites More sharing options...
starcat Posted February 23 Report Share Posted February 23 (edited) Any non-obsolete replacement for the 3N254? Thanks! Adding to the above BOM: Here the Mouser basket as well (which is missing the obsolete 3N254 bridge rectifier): https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=9472151902 I would also exchange the 220uF/500V cap with a Nichicon LGN2H221MELB45 as it is rated up to 105°C and even cheaper. Edited February 24 by starcat Quote Link to comment Share on other sites More sharing options...
starcat Posted February 27 Report Share Posted February 27 (edited) Question regarding the bridge rectifier 3N254 - both alternative parts 3N254-E4 and 2KBP10M-E4 seem to be unavailable as well. Anyone used successfully any other replacement? Thanks. Edited February 27 by starcat Quote Link to comment Share on other sites More sharing options...
Pars Posted February 27 Report Share Posted February 27 How about 621-KBP201G (Mouser PN). Haven't tried it but same specs. These bridge rectifiers are common parts and shouldn't be a problem to replace. Also a Rectron MDA201G would be another one to look at. 2A 100V bridge rectifier in an appropriate case/footprint and pinout. 2 Quote Link to comment Share on other sites More sharing options...
jose Posted February 28 Report Share Posted February 28 There you can use anything that has a minimum value of 100V @ 2A 1 Quote Link to comment Share on other sites More sharing options...
starcat Posted February 28 Report Share Posted February 28 (edited) Thanks guys. I'll try the Rectron MDA201G. It looks pretty much identical to the 3N254, same pinout, size and specs. Only diff is the 3N254 is max rated at 60amp vs 50amp for the MDA210G. The 621-KBP201G doesn't seem to be available soon from Mouser. Just found, the VS-2KBP01 looks like a new direct replacement from Vishay. Edited February 28 by starcat Quote Link to comment Share on other sites More sharing options...
iemphile Posted March 1 Report Share Posted March 1 I used a KBP210G successfully for a different amp. 1 Quote Link to comment Share on other sites More sharing options...
Pars Posted March 1 Report Share Posted March 1 When I look at the KBP201G on mouser.at, it shows 429 available (same as Mouser US)? 1 Quote Link to comment Share on other sites More sharing options...
starcat Posted March 3 Report Share Posted March 3 (edited) This looks like a very nice case for a dual chassis design for the static CFA3. PSU chassis: mount the kgsshvpssicfetsinglenewrightsws and kgsshvpssicfetsinglenewleftsws GRHV boards on the sinks together with goldenreference6d GRLV in the middle/front and a transformer in the middle/back. Might be even room for two GRLV and two transformers for total symmetry. Amp chassis: two balanced CFA3 boards mounted on the sinks. Will be pretty empty in the middle. The internal hight of 73mm might get tight but probably enough to fit the 63.5mm wide balanced boards; or mount them horizontally with some L-brackets. What do you think? I think I might go for it. Chassis dimensions in mm are: outside W360xD270xH86, inside W280xD255xH73 Or just use single chassis with both CFA3 boards mounted on the sinks and a kgbhultraminipsv4 board in the midfront and a transformer in the midback. Edited March 3 by starcat Quote Link to comment Share on other sites More sharing options...
starcat Posted March 3 Report Share Posted March 3 On 3/1/2021 at 4:23 PM, Pars said: When I look at the KBP201G on mouser.at, it shows 429 available (same as Mouser US)? Indeed the 621-KBP201G is available, just ordered a bunch, thanks. Quote Link to comment Share on other sites More sharing options...
jose Posted March 3 Report Share Posted March 3 CFAe runs hot, VERY hot. I would prefer a "normal" heatsink... 1 Quote Link to comment Share on other sites More sharing options...
starcat Posted March 3 Report Share Posted March 3 Hmm, you might be right Jose, but the fins of the small enclosure Michael used above doesn't look like being much more of actual real estate... Btw, which one is it exactly? This might fit in the two balanced boards, the BH mini PSU and a transformer in the back. Bit too high probably but for the sake of bigger sinks. Chassis dimensions in mm are: outside W320xD315xH120, inside W220xD300xH112 1 Quote Link to comment Share on other sites More sharing options...
starcat Posted March 14 Report Share Posted March 14 Ordered 2oz differential boards (for the BH Mini v4 PSU as well), all the parts from Mouser and the black chassis above... so the CFA3e is on the build list as well. Quote Link to comment Share on other sites More sharing options...
starcat Posted March 27 Report Share Posted March 27 (edited) Some progress here and waiting on the KSc2752 transistors... Will be ordering the transformer, thinking about 2x [email protected] secondaries for the BH Mini PSU in order to get out 400V for the CFAe boards. This is what @jose has chosen. @congo5 however used [email protected] and ended up with 399VDC using the same BH Mini PSU. Any thoughts after running those for a while? Edited March 27 by starcat 1 Quote Link to comment Share on other sites More sharing options...
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