stevoz Posted December 27, 2018 Share Posted December 27, 2018 (edited) Let's see, when this thread and project started......Abbott was PM, Obama was President, Cameron was PM of the UK and Buddy had just played his first season with the Swans.....time flies, it's a different world now................but one thing is certain, this system will be worth waiting for. Edited December 27, 2018 by stevoz 2 Link to comment Share on other sites More sharing options...
acg Posted December 27, 2018 Author Share Posted December 27, 2018 3 hours ago, davewantsmoore said: Someone should come in here and make a "So?... in by Christmas then!?..." kinda joke. It would nearly be as funny as it was 3 years ago. Hah! (all in jest) Merry Speakering A. Four years Dave! It did start out as just building the horns and went manic from there. Suddenly I was building the amps and trying to make it look great and it has just got out of hand...everything but the horns are pretty much made....oh my. 1 Link to comment Share on other sites More sharing options...
acg Posted December 27, 2018 Author Share Posted December 27, 2018 38 minutes ago, stevoz said: ................but one thing is certain, this system will be worth waiting for. I hope so Link to comment Share on other sites More sharing options...
acg Posted December 27, 2018 Author Share Posted December 27, 2018 Got a bit of lathe time in today remaking the Fundamentals horn. The throat was not good enough in the originals...too bloody tight to sand properly and I had a paint run in an unreachable area, so they are being redone in a slightly different way so that they end up spot on. It will take a while to get them done but they must be complete before I reconfigure the lathe to turn the front half of the huge 110hz Upperbass horns. I still have about 6 weeks of work to finish that was supposed to be done by Christmas...oh well...so taking all of January off to finish this project is not possible, but I have talked to my clients and am planning to work on and off for the next couple of months to get them out of trouble while giving me some sanity time so I don't burn out. Perhaps week on and week off, or fortnight on, fortnight off for a while, we will see, but this is happening. Might even work the hot days in the office and go in to the shed when the temperature is tolerable. A little more turning tomorrow. 4 Link to comment Share on other sites More sharing options...
davewantsmoore Posted December 27, 2018 Share Posted December 27, 2018 (edited) 11 hours ago, acg said: Four years Dave! Yeah, I know.... The first year was fair enough.... It's as bad as the dragons in the game of thrones TV series. PS - This is why I do not post any projects.... they're ugly, never finished, inconclusive failures.... and there'd be similar in by xmas jokes. So here I am picking on someone else. Quote trying to make it look great I find this bit a real showstopper (or my projects). 10 hours ago, acg said: this is happening Edited December 27, 2018 by davewantsmoore Link to comment Share on other sites More sharing options...
Nada Posted December 28, 2018 Share Posted December 28, 2018 13 hours ago, acg said: ...so taking all of January off to finish this project is not possible I think you've made remarkable progress at a rapid rate given the scale and breadth of your project. Im in awe of your skills and energy. Thanks for so courageously sharing the process too. A project this big is likely to be a lifelong adventure. So I wonder how big your shed is and if it has renovation potential for a huge man shed? The horns deserve a big space and might need generous listening distance for integrating. You could also design bass horns into the attic or crawl space...... Link to comment Share on other sites More sharing options...
acg Posted December 28, 2018 Author Share Posted December 28, 2018 11 hours ago, davewantsmoore said: PS - This is why I do not post any projects.... they're ugly, never finished, inconclusive failures.... and there'd be similar in by xmas jokes. So here I am picking on someone else. Plenty is learned by failures. Not ugly = a whole lot of work. Roast me all you like, I've earned it, haha. I would still like to know what you have tried and why you moved on. 2 Link to comment Share on other sites More sharing options...
acg Posted January 1, 2019 Author Share Posted January 1, 2019 Fundamentals Horn V2 is underway. First time around I had trouble with the throat so this time I've gone slower and have been more precise. The first 4 rings of 32mm MDF have been done in three stages: 1 ring trimmed and sanded and checked; glue on the second ring then trim and sand; then glue on the 3rd and 4th rings and trim and sand. All a day apart because the glue needs 24hrs to dry. Four rings is twice the length of my fingers so I have primed the throat and will sand it back while I can still reach it...but again it is time because 4 coats of primer brushed on in the course of a day takes several days to properly dry. I'll sand it back tomorrow or the next day and make a call then whether to add more coats of primer. In the meantime I've glued together the remaining rings in two groups based on the length of my cutting tool, so after the throat sanding is complete I'll glue on the next set of rings and trim them to shape and then on with the final group of rings. The outside of the horn is being made balanced and round as I go but is not being cut to the final shape just yet. This horn is about half a meter long so when the final group of rings go on and I get the rollers under the mouth I'll cut the outside profile in one smooth hit which should leave me with less fixing up to do at the end. 2 Link to comment Share on other sites More sharing options...
acg Posted January 1, 2019 Author Share Posted January 1, 2019 DSET Assembly I've also started putting together the first of the 6 Channel SET's. Very excited I am! It's been a bloody grind with a couple of issues which more experience would help me to sort out in a timely manner, but I have perservered and I reckon I can nut it out from here. Four multimeters is not enough and I am tempted to hook off to Jaycar and get myself some more cheapies...six channels is a lot to debug simultaneously. Here she is on the bench with three snake like umbilicals winding down to the power supply on the floor. At the moment I am only testing the First Stages (or driver stages) and the complicated Bias system. I had a problem where the gas regulator tube for negative bias was taking a couple of minutes to ignite plus one of the driver tubes was not conducting and I wasted two days trying to figure out why. On 28/12/2018 at 7:43 PM, acg said: Plenty is learned by failures. Heck yeah ^^^^. These irritating and frustrating couple of days meant I double, triple, quadruple, pentuple (ha!) checked the circuits and while I found nothing really wrong I learned a whole lot about how the circuit works and do not think that it was an entirely hollow effort, because I've gained that little bit of experience that I had lacked at the beginning of the week. So pretty... Tomorrow, I will begin the next round of testing by applying more high voltage to the chassis for the Second Stages, Single Stages and DHT. Wish me luck!! 5 Link to comment Share on other sites More sharing options...
davewantsmoore Posted January 1, 2019 Share Posted January 1, 2019 1 hour ago, acg said: Wish me luck!! Be safe! Link to comment Share on other sites More sharing options...
Silent Screamer Posted January 1, 2019 Share Posted January 1, 2019 Seeing an acg post with pictures, is like finding out there is a new episode of Project Binky available (Hmm both taking about the same amount of time to build ) 2 1 Link to comment Share on other sites More sharing options...
acg Posted January 1, 2019 Author Share Posted January 1, 2019 11 hours ago, davewantsmoore said: Be safe! It's a pain to wait 10 minutes after shutting down the amp for those massive capacitors to bleed down, but I would prefer to keep breathing at this stage of my life. High voltage electronics is not the kind of stuff to be doing if you tend to rush things...and you guys have seen no evidence of me ever rushing anything (4 years later - now I roast myself too) 4 1 Link to comment Share on other sites More sharing options...
Silent Screamer Posted January 2, 2019 Share Posted January 2, 2019 2 hours ago, acg said: It's a pain to wait 10 minutes after shutting down the amp for those massive capacitors to bleed down, but I would prefer to keep breathing at this stage of my life. High voltage electronics is not the kind of stuff to be doing if you tend to rush things...and you guys have seen no evidence of me ever rushing anything (4 years later - now I roast myself too) I've been building my electric trike for 8 years and my sub boxes have been planned for nearly as long, so I am not one to talk (people, glass houses....) Link to comment Share on other sites More sharing options...
Nada Posted January 2, 2019 Share Posted January 2, 2019 20 hours ago, acg said: ..... Wow. 1 Link to comment Share on other sites More sharing options...
acg Posted January 4, 2019 Author Share Posted January 4, 2019 Phwew, the first DSET is operational, finally. It has taken a lot longer than I thought it should have but all six channels in the first monoblock are now operational. It is a thing of beauty to look at and to be honest every time in the last week that I have turned it on for testing I turned off the lights so that the glow could send its good vibes my way. Over on the far left is the DHT driver tube, in this case a 45 globe, but I can put in that socket many 2.5V and 4V heater DHT's from the early part of the last century. Next step is to make it safe, copy the wiring for the second monobloc, and then cart them upstairs for further testing and debugging. Such a relief to finally have one going. As a matter of interest I did a rough noise measurement at the output of each channel to see how my layout choices have been successful: A - 0.2mVAC B - 0.2 mVAC C - 0.3mVAC D - 0.25mVAC E - 6.7mVAC - the DHT Channel - most of this would be AC hum but it was a little dangerous to reach around to use the hum pot to cancel this out, so I did not F - held the 111dB/w/m sensitive RAAL Lazy Ribbon to my ear and could not hear a thing A good start! 9 Link to comment Share on other sites More sharing options...
Rabbitzilla Posted January 4, 2019 Share Posted January 4, 2019 Looks amazing! Link to comment Share on other sites More sharing options...
Buffle Posted January 4, 2019 Share Posted January 4, 2019 That does have allure. You must be feeling hugely satisfied to be getting to this stage. You have far more patience than me! Link to comment Share on other sites More sharing options...
Silent Screamer Posted January 4, 2019 Share Posted January 4, 2019 Are they technically a mono block when you have multiple amps in the same enclosure? One thing they most definitely are, is a thing of beauty. Link to comment Share on other sites More sharing options...
acg Posted January 4, 2019 Author Share Posted January 4, 2019 10 hours ago, Silent Screamer said: Are they technically a mono block when you have multiple amps in the same enclosure? One thing they most definitely are, is a thing of beauty. One amplifier chassis per speaker is what I would call a monobloc. Are they still monobloc when there is on power supply box and one amplifier box per speaker? I dunno. 10 hours ago, Buffle said: That does have allure. You must be feeling hugely satisfied to be getting to this stage. You have far more patience than me! It feels great. 11 hours ago, Rabbitzilla said: Looks amazing! Let me know when you get away from the Land of the Long White Cloud...I have vinyl withdrawals and need a fix...haha. Seriously though, enjoy yourself. Link to comment Share on other sites More sharing options...
acg Posted January 4, 2019 Author Share Posted January 4, 2019 Measured the power draw this morning... It's a 4 minute startup protocol. It briefly draws an amp when plugged into the wall and the services LPS fills its capacitors, then settles down to virtually nothing, less than 20w. Then I hit the power foot pedal and the AC filaments/heaters are all lit up and being direct AC there are no caps or other electronics so not much of a spike. The bias and 1st Stages are powered 45 seconds later (just past 1m on the graph) and there is a 5A spike as the power supply caps are filled. That sits at about 150w until three minutes later the DHT, 2nd Stages and Single Stages power supplies are energized. The DMM logs once a second and managed to capture about 11A, which is as much as the mains supply is rated, maybe a little more...perhaps I should put in a soft start. Anyway, after that the amp sits on a pretty neat 400W power draw at idle. Being Class A that should be where it stays even when playing music. So, 400 watts power draw to light up a combined total of 30w-33w of output power...yep, that's definitely Class A operation...haha. Will have to check to see what fuses I have put in the beast and see if they can be trimmed to suit this power draw. 4 Link to comment Share on other sites More sharing options...
davewantsmoore Posted January 5, 2019 Share Posted January 5, 2019 3 hours ago, acg said: One amplifier chassis per speaker is what I would call a monobloc Yep, every channel in the amplifier is mono (not stereo). 3 hours ago, acg said: . Are they still monobloc when there is on power supply box and one amplifier box per speaker? I dunno. It feels great. Let me know when you get away from the Land of the Long White Cloud...I have vinyl withdrawals and need a fix...haha. Seriously though, enjoy yourself. Link to comment Share on other sites More sharing options...
Nada Posted January 5, 2019 Share Posted January 5, 2019 6 hours ago, acg said: .....So, 400 watts power draw to light up a combined total of 30w-33w of output power...yep, that's definitely Class A operation...haha. Whats will the total power load be for the full system (400W X 2) + ? Link to comment Share on other sites More sharing options...
acg Posted January 5, 2019 Author Share Posted January 5, 2019 2 hours ago, Nada said: Whats will the total power load be for the full system (400W X 2) + ? Yep. I've already put extra solar panels on the roof to offset the expense...seriously. Dac, preamp, turntable and a couple of computers will probably put the total power draw for the system to a bit over a kW. 1 Link to comment Share on other sites More sharing options...
almikel Posted January 10, 2019 Share Posted January 10, 2019 Yep. I've already put extra solar panels on the roof to offset the expense...seriously. Dac, preamp, turntable and a couple of computers will probably put the total power draw for the system to a bit over a kW.Heating in winter sorted[emoji106] 1 Link to comment Share on other sites More sharing options...
acg Posted January 18, 2019 Author Share Posted January 18, 2019 (edited) Fundamental Horns V2 are turned... A pair of the smaller 400Hz Midrange horns can be cut, turned and primed in a weekend. These larger 250Hz Fundamentals Horns take about 3 days all up to build to the same stage but it has to be done in stages because the throat is just so inaccessible for sanding and priming. There is no substitute for experience and this second time around the result is so much better, especially for this larger horn. In the photo below you can see right up to the throat that has been primed and sanded at an earlier stage...not much room up there. I love the profile of this horn... The last stage of turning of this horn is to cut away the centimetre of rim that runs on the roller. It is effectively running without support at this stage and these horns both spun at circa 250-350rpm without the hint of a wobble once they came away from the roller (you can see the rectangular steel plate that the roller sits on in the photos). Nice! Edited January 18, 2019 by acg 11 Link to comment Share on other sites More sharing options...
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