Sub Sonic Posted March 25, 2020 Share Posted March 25, 2020 Thought it would be interesting to see if other people had plans for DIY builds during restricted movements/lockdowns during the Coronavirus time period. I’ve been working on MarkAudio Alpair 10P cabinets (now sounding very nice after 200 hours running in), and in the works are bass cabinets to suit the same, using Dayton 8” RS225-8 woofers, actively driven. I am also playing with Peerless 8” HDS 830869 woofers in sealed enclosures. I couldn’t decide which of the two bass drivers to match up to the Alpair 10Ps, so I ended up with a pair of each There is also a partly built class a amp build to do, and a couple of sets of small coaxial and wide range drivers to find or build enclosures for. I have purchased a small stock of 17mm formply which I rather like for building the cabinets, and also made up a rough but accurate cross cut saw “bench” to use with the Festool track saw - this cross cut bench is working beautifully, and is much faster and more accurate than measuring, marking and then using the track saw. It is brilliant for mitred boxes, and in fact makes mitred boxes easier to build than butt joined boxes. It can also be used for routing slots when The router is used with a guide rail attachment. What does everyone else have in mind for this time period? Cheers, SS Link to comment Share on other sites More sharing options...
Batty Posted March 25, 2020 Share Posted March 25, 2020 I have a pair of LK1 to build and an LP12 with a blank armboard destined to receive a Hadcock GH228. But no sign of working from home as it is impossible for me to do. I require 3 phase 400Hz power for the equipment I work on. 1 Link to comment Share on other sites More sharing options...
tubularbells Posted March 25, 2020 Share Posted March 25, 2020 Currently performing a full resto on my Ashly MFA8000 amp including panel beating and respray of the chassis (reckon Ace Ventura delivered it!), re-dipping the transformers (as both were noisy), full stripdown & deep clean and complete recap. Some op-amps and transistors also replaced to bring it up to latest V3. spec. 5 Link to comment Share on other sites More sharing options...
BioBrian Posted March 25, 2020 Share Posted March 25, 2020 11 hours ago, Sub Sonic said: also made up a rough but accurate cross cut saw “bench” to use with the Festool track saw - this cross cut bench is working beautifully, and is much faster and more accurate than measuring, marking and then using the track saw. It is brilliant for mitred boxes Wish I'd known about this for my sub build - if it's not too OT, I'd be interested in a pic, or explanation of how it works. I've found quite a few cases where the Festool track saw can't be used without major jig-building, so always looking for ideas. 1 Link to comment Share on other sites More sharing options...
Sub Sonic Posted March 26, 2020 Author Share Posted March 26, 2020 Hi @BioBrian, Here are a few basic pics, I can post more detailed ones later: Basically, the saw track is located on two pins, a fixed pin at the top and an adjustable pin on the lower section. This lower pin is adjustable on the T track so that the squareness of the track to the fence can be perfectly adjusted. The saw track can be lifted off the base. There is a scale next to the top track, the black adjustable track stop can be swung over the scale to set the distance, and then swung back over to set the work piece. This is version one, there are already mods that need to be made to allow mitres in different thicknesses of timber. The little Makita Trimmer router (with track attachment) can be placed on the top of the track to allow easy and consistent slots, such as for grille cloth splines. This version has a track cut down to around 800mm which allows a cross cut of around 650mm, but with a longer track, the base can be scaled up. I’m still thinking how to do angled cuts, such as in the top sections of your speakers. I have a few spare T slot tracks, and am thinking of recessing them into a base so that I can clamp a work piece at odd angles. It’s a work in progress Cheers, Matt. 2 Link to comment Share on other sites More sharing options...
andyr Posted March 26, 2020 Share Posted March 26, 2020 12 hours ago, Sub Sonic said: Thought it would be interesting to see if other people had plans for DIY builds during restricted movements/lockdowns during the Coronavirus time period. What does everyone else have in mind for this time period? Cheers, SS I am building a pair of Class A Push Pull ss amps from Hugh Dean - see here: https://www.diyaudio.com/forums/solid-state/344540-alpha-nirvana-39w-8ohm-class-amp.html I'm building these to drive my Maggie 3.2 ohm mid panels plus 2 ohm ribbons - so I'm building the 4ohm version. (This has +/-20v DC rails instead of 27v - so there are some component value changes from the 8 ohm version.) The build involves a matching PS capable of supplying 5a continuous to each board - see here: https://www.diyaudio.com/forums/group-buys/336479-slb-smooth-butter-active-rect-crc-cap-mx-class-power-supply-gb.html It's 4 of each PCB, for my setup - so a long build process. Being Class A, there's a lot of heat to be got rid of - 130w per channel. Rather than using a 350mm deep, 5RU case with finned heatsinks (which would be needed for passive cooling), I have taken the approach of using a CPU cooler stack (with fan) for each pair of MOSFETs - see here: So I can use a normal 3RU case with no finned heatsinks. When I've finished these ... I'll set up my us cleaning tank & dryer - and get stuck into all the unwashed LPs that have accumulated in the last year! 4 hours ago, Batty said: But no sign of working from home as it is impossible for me to do. I require 3 phase 400Hz power for the equipment I work on. I think you mean 3 phase 415v, B? Andy 2 Link to comment Share on other sites More sharing options...
Sub Sonic Posted March 26, 2020 Author Share Posted March 26, 2020 @andyr I had a play with those heat pipe heat sinks recently and they are incredible at moving heat Link to comment Share on other sites More sharing options...
andyr Posted March 26, 2020 Share Posted March 26, 2020 (edited) 2 minutes ago, Sub Sonic said: @andyr I had a play with those heat pipe heat sinks recently and they are incredible at moving heat Great to hear, SS! Did you use a fan with the CPU cooler - or just by itself? Andy Edited March 26, 2020 by andyr Link to comment Share on other sites More sharing options...
Sub Sonic Posted March 26, 2020 Author Share Posted March 26, 2020 16 minutes ago, andyr said: Great to hear, SS! Did you use a fan with the CPU cooler - or just by itself? Andy I used a fan. I am part way through a just-for-fun class a amp project and was working out whether to go water cooled or heat pipe. I am going water cooled purely for fun, but if I was after a practical solution, the heat pipes are the way to go. I did a fair bit of searching on fans in order to keep noise down, and also with water cooling it is easy to add radiators (ie surface area) to allow low speed fans. Heat pipes are going to be less risky and more reliable though. Noctua make some nice fans, I am actually starting to use them in machines at work now too. SS Link to comment Share on other sites More sharing options...
Sub Sonic Posted March 26, 2020 Author Share Posted March 26, 2020 Hi @andyr, just curious how you are going to mount the output devices? I assume perhaps some sort of clamping arrangement? SS Link to comment Share on other sites More sharing options...
Sub Sonic Posted March 26, 2020 Author Share Posted March 26, 2020 400Hz sounds like aircraft or industrial work to me 1 Link to comment Share on other sites More sharing options...
andyr Posted March 26, 2020 Share Posted March 26, 2020 36 minutes ago, Sub Sonic said: Hi @andyr, just curious how you are going to mount the output devices? I assume perhaps some sort of clamping arrangement? SS Yes, SS. The MOSFETs are actually soldered onto a 50 x 20mm-sized PCB, together with 4 SMD components (and lie flat on the PCB) ... this assembly - together with its 2mm ceramic insulator - will be sandwiched between the copper pad on the CPU cooler and a 6mm right-angle bracket. The CPU cooler is bolted to the aluminium bracket - which is bolted to the floor of the case. This arrangement holds the CPU cooler horizontal, so the fins themselves are vertical. Andy 1 Link to comment Share on other sites More sharing options...
Sub Sonic Posted March 26, 2020 Author Share Posted March 26, 2020 @andyr A 2mm ceramic insulator sounds pretty thick? SS Link to comment Share on other sites More sharing options...
andyr Posted March 26, 2020 Share Posted March 26, 2020 34 minutes ago, Sub Sonic said: @andyr A 2mm ceramic insulator sounds pretty thick? SS True, SS - compared to say mica washers. But you can actually get them up to 4mm! So 2mm must be OK. Andy 1 Link to comment Share on other sites More sharing options...
Batty Posted March 26, 2020 Share Posted March 26, 2020 (edited) 3 hours ago, andyr said: I think you mean 3 phase 415v, B? Andy 3phase 115v 400Hz Andy. Not a normal supply. Edited March 26, 2020 by Batty Link to comment Share on other sites More sharing options...
surprisetech Posted March 26, 2020 Share Posted March 26, 2020 For starters, my project will be just getting a couple of my systems installed and up & running after next Tuesdays house move. That will include routing some speaker cables (for surrounds), ethernet cables & antenna cables under floors &/or in ceilings. Might be playing a bit more physical media for a little while, although Wifi and Internet radio will be handy until the ethernet and antenna cabling is complete. (Now where did I store that Wifi dongle?!) Link to comment Share on other sites More sharing options...
andyr Posted March 26, 2020 Share Posted March 26, 2020 1 hour ago, Batty said: 3phase 115v 400Hz Andy. Not a normal supply. Thanks for expanding my knowledge, B. I had no idea there was such a thing as 3 phase, 115v 400Hz! My house is supplied with 3 phase, 240v 50Hz - 3 phase is needed to drive the lift and the car stacker. (But I use 1 of the phases for my music system - so when the lift/car stacker ain't working ... it's dedicated to my music. ) Andy Link to comment Share on other sites More sharing options...
Batty Posted March 26, 2020 Share Posted March 26, 2020 These requirements are for work, not home. As guessed by SS it is an industrial site I work on and linked to Aircraft. Can't supply anymore data, sorry. SS probably can guess where I work from this extra info. 1 Link to comment Share on other sites More sharing options...
Sub Sonic Posted March 28, 2020 Author Share Posted March 28, 2020 Hi @BioBrian, Here are some extra photos of where the track fits into the base. Pins are M6 304 shoulder bolts cut to size. First pic shows the lower pin, adjustable on the track to square up the track to the fence: The last 3 pics show the top fixed pin and the stop/measuring tape. The main drawback at the moment is that really only one thickness of sheet can be accurately mitred, will have to work on an upgrade for this.. Cheers, SS 1 Link to comment Share on other sites More sharing options...
Whites Posted March 28, 2020 Share Posted March 28, 2020 (edited) My project is very simple compared to the ones above. Sheet of ply from Bunnings an hour and a bit and all finished. Edited March 28, 2020 by Whites Inserted phot. Link to comment Share on other sites More sharing options...
Luc Posted March 28, 2020 Share Posted March 28, 2020 On 26/03/2020 at 12:08 PM, andyr said: I am building a pair of Class A Push Pull ss amps Too damn clever Andy! I'm always in awe of people who build electronic stuff. Timbers one thing but this stuff...wow. My project requires someone with a good knowledge of Japanese Kanji as I'm building a swinging shingle, you know, like the ones you see in movies outside of 18th century or 19th century pubs with the Prancing Pony inscribed on the board as it creaks in the wind. I've got to come up with an idea for an Acupuncturists clinic. A hangmans post is my first thought with two bits of chain holding the sign but...it's getting the right Kanji on that sign that's the worry. Link to comment Share on other sites More sharing options...
andyr Posted March 28, 2020 Share Posted March 28, 2020 56 minutes ago, Whites said: My project is very simple compared to the ones above. Sheet of ply from Bunnings an hour and a bit and all finished. Cable lifters? If so - great design! Andy Link to comment Share on other sites More sharing options...
andyr Posted March 28, 2020 Share Posted March 28, 2020 17 minutes ago, Luc said: Too damn clever Andy! I'm always in awe of people who build electronic stuff. Timbers one thing but this stuff...wow. My project requires someone with a good knowledge of Japanese Kanji as I'm building a swinging shingle, you know, like the ones you see in movies outside of 18th century or 19th century pubs with the Prancing Pony inscribed on the board as it creaks in the wind. I've got to come up with an idea for an Acupuncturists clinic. A hangmans post is my first thought with two bits of chain holding the sign but...it's getting the right Kanji on that sign that's the worry. Contact @Ittaku, Lee - he does Japanese translations, so he may know kanji. Andy Link to comment Share on other sites More sharing options...
Whites Posted March 28, 2020 Share Posted March 28, 2020 (edited) @andyr Yes, cable lifters, might have based the design on a commercial product Edited March 28, 2020 by Whites Link to comment Share on other sites More sharing options...
Luc Posted March 28, 2020 Share Posted March 28, 2020 5 minutes ago, andyr said: Contact @Ittaku, Lee - he does Japanese translations, so he may know kanji. Andy I met him at Joz's. couldn't remember his name. I contact if I can't get it right. Link to comment Share on other sites More sharing options...
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