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Post by zappytheviking on Oct 25, 2017 11:38:43 GMT
Great story. Is this going to trigger off a wholesale rewiring of your system then? Most certainly this will be my "gold" standard for ICs going forward, Will be making a similar cable whenever needed. Maximum bang for the buck. Still hesitant about doing speaker wire in silver, would do a litz twisted configuration with thicker silver wire, the price goes up quite a bit when you need 2x5m, might happen one day. Maybe braid a power cable and make it pretty to see it there are any significant gains, not going crazy with it quite yet. @zippy , Good point, will probably be a good long while before it is time to venture further than this solution, it was more than adequate. MartinT ,Thanks, just couldn't resist posting, was so blown away, perhaps it will inspire some cable cynics, as I was, to bump it up just that one little notch and reap the benefits.
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Post by zappytheviking on Oct 25, 2017 0:12:00 GMT
Changed out my old Interconnect in a system I thought was hopeless, I was wrong. In preparation for a new poweramp (Nord hypex NC500) , had ordered some teflon tubing and 0.5mm silver etc to make a stepped volume attenuator. What the heck I thought, ordered some extra bits, I will make an interconnect while waiting. Auditioned it for my mother, played her Celine Dion - Tell Him, duet with Barbra Streisand. With the olden monster cable, comment was, yes I saw her live last year. Pop in the new interconnect............not a sound out of her, after the song, takes off glasses and wipes a tear. Play me Fleetwood- Albatros......louder please . I have been using the Monster cable and random no name "it was in the box" connectors, recently bought a Haim brand cable, looks pretty with braided shielding etc, about 25gbp. They all sound somewhat similar, veiled , unengaging , lifeless, flat. But this is another level. I might be cable naive to the extreme but this, did not expect it at all. Why is this happening? Reduced capacitance, no shielding to drag down HF?? Smeared mids come into focus, bass is snappy, highs are so clear and everything is distinctly placed in a gigantic soundscape. That little bell in the background, the high hat in the distance and so forth. Roger Waters amused to death, Q-sound leaps into action, suddenly there are sounds way back in the left corner of the room, never happened before. Sound stage and clarity are immensly improved. Just spent a good chunk of change on a new amp, now this, 40gbp DIY cables utterly changed the sound from unappealing to full of emotion, decent slam, holographic and straight up enjoyable. I was thinking my 25yo Pioneer amp was rubbish or at the least in need of new electrolytics, boy was I wrong. For the interested, Battery powered Arcam R-Dac, Pioneer A 550-R feeding Troels Gravesen 3Way Mk2. Also tried with a newer Pioneer A509R and JPW-510s, same there, magic. Perhaps the take home message is, dont use rubbish cables, they will make you buy expensive gear . Zippy edit, yes magic can happen with just a slight bump up, doesnt have to cost a mint, certainly worth considering if it is something you've neglected. stores.ebay.co.uk/achtung-audio?_trksid=p2047675.l2563 , he does somewhat similar cables at reasonable prices for the less DIY minded. Recipe: 3mm teflon tube, 0.5mm Elec audio 99.99 silver wire, cotton sleeve for each PTFE tube, twist conductors a few times so they stay together nicely, another larger cottons sleeve, TechFlex carbon for the pretty, W & M Audio CS-306G RCA plugs, 10% mundorf silver solder, shrink wrap to taste. Old vs. New
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Post by zappytheviking on Oct 21, 2017 7:53:03 GMT
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Post by zappytheviking on Oct 21, 2017 7:03:48 GMT
I had a fast click around. Seems its a passive pre with autoformer volume attenuation, using transformers instead of resistors. If I am not totally mistaken it is similar to a Slagle autoformer in a pretty package, they sell versions ready made for +400$ and up. www.intactaudio.com/atten.htmlNot heard one but supposedly its very good.
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Post by zappytheviking on Sept 15, 2017 0:46:14 GMT
I poked my softdomes quite a few times, tried cellotape, nope, what worked for me, toiletpaper tube and give it a suck, popped right out. Not perfect but I am not going to start heating it to get the creases out, good enuff.
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Post by zappytheviking on Sept 14, 2017 23:01:24 GMT
Never heard of that before, will keep it in mind thanks. Thick and gloopy, get that flat base to work with.
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Post by zappytheviking on Sept 14, 2017 22:40:40 GMT
Summer and power tools makes time fly. Building your own without auditioning is a gamble, yet the promise is value for money and satisfaction in making something. Why these specifically, high sensitivity +91db, 8ohm and a reasonable price, will be able to use class-A or tubes without needing monster amps. Here are more details for the interested. www.troelsgravesen.dk/SEAS-3-Way-Classic-mkII.htmIt all started with a pile of wood, 21mm birch ply, solid as a rock and heavy as sin. Glue and screws for the poor in clamps. Mid range shelves with accompanying blowholes. Some more stabilization for the lower section, only slightly wobbly circles. Starting to glue in the assorted pieces one by one. A speaker stand might be good to have, random leftover wood found and shaped. Some time later, a lick of paint and 12kg of oven dried sand from the yard. An early look at the semi finished speaker with measurements drawn on the wood. Gluing in 4mm bitumen pads with some rather black and sticky building goop, Mass loading and vibration dampening, speaker is starting to get heavy, my poor back. The back will be fastened with a large handful of screws, this air-cond foam strip does a lovely job at making an air tight seal. Further damping with cloth stuff included in speaker kit. Hot melt glue worked really well. Another day of sanding, rounding and shaping. Leveling the panels with a router, so handy and fast, just make sure you have some spare bearings for the bit, they tend to fly off. First layers of primer, I really should have kept sanding, you can never have too perfect a foundation before paint. In hindsight, I should have used some form of sealer on the wood first. Next time I will try car body repair putty and sealing that with epoxy, used some regular wood filler, gave me plenty of trouble later by poking thru the finish. Wind gusts making my expensive 2K spray paint fly away and into my eyes, unexpected rain, flies landing on ooh so shiny a surface, must be water right. I finally built a ventilated indoor spray booth After 4 layers of black and 5 layers of laquer with occasional sanding between layers, a bit better. Some wet sanding, 800-1200-2000. A bit of cutting compound and finishing off with car wax. Before the grand finale, the crossovers, made them all separate, better for bi/tri wire some day in the future. Well, here we are, a functioning speaker, the finish is still not where I would like it but after 2 months of hard work it will have to wait, perhaps next summer. A lesson learned for a high gloss finish, use a cheaper acrylic lacquer for the base coats, finish off with the 5-10x more expensive 2K for a hard surface. Oh and avoid corners when machine polishing, it will rip the finish right off. What do they sound like? Well, firstly consider I am using an ancient entry level amp, it does muffle things up a bit. They are heavy beasts, will weight them later, as a guess 35kg a piece. Having a hard time saying exactly what this speaker sounds like. What strikes me most is the clean mid range and bass. I do not lack for a subwoofer, it fills the room quite well. A thought that came to me when I first heard them, somehow I expected a good speaker to be bombastic and dynamic. Boy was I wrong, quality in this case is a large and effortless sound, well balanced. I was expecting a monster truck, preconceived bias haha, I got a Steinway grand piano, not complaining. Is it a good speaker? well yes, I will attempt a write up later on when I have proper amplification. To anyone building these, they open up remarkably after 2 weeks, was not happy at first, burn in time is real . Next upgrade is a fitting amplifier and later on a DAC-pre, perhaps the AUDIO-GD NFB-28.28. If there are questions do ask and I will try to respond
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Post by zappytheviking on Jul 8, 2016 11:17:57 GMT
Those are some amazing holiday snaps you put up, talk a about a view. That tower would make a great SECA, even has its own lightning rod on top.
Again , thank you.
It's like high school, getting told the answer and smacking yourself, stray copper hair, geez.
I am looking at tutorials on amplifiers and trying to understand how things are working. In that vein, could you tell me what failed on the board, any other bits that failed when FET got shorted?
Also have you put out a higher resolution circuit diagram? Having a hard time reading part numbers while meditating on how the amplifier works.
Hopefully I will eventually be able to repair this circuit, want to keep it working the rest of the ride.
Next step, put together the PSU boards, a week or two.
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Post by zappytheviking on Jun 23, 2016 10:46:53 GMT
Looking good there Colin.
Good to hear the part arrived, was a little paranoid if I should have sent it registered, the fates have smiled upon thy work once again.
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Post by zappytheviking on Jun 20, 2016 9:54:58 GMT
MikeMusic Hehe, that might be the look, modern tech from the 70s. @colin Excellent, updated. What of the PSU relay removed? Add a wire over what relay would be turning on/off?
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Post by zappytheviking on Jun 19, 2016 21:31:15 GMT
Also I have rearranged the PSU which has with this simple mod will force the PSU board to close down in constant current mode. Less chance of smouldering FET,s Change R10 to 1K and R11 to 10K, Change R13 to 1K and R10 to 10K as in this circuit. I just started checking what parts I will need for PSU and bootstrap and perhaps protection board. A synopsis, checking on the changes. PSURemove relay www.audiochews.com/discussion/1608/building-colins-seca-kit/p12Unsure about details, straight wire and all is well? R10 - 1K R11 - 10K R13 - 1K and R10 - 10K , did you mean a different R?? BootstrapDidn't see parts numbers so I thought I would run it past you, these ok? x2 PANASONIC 100 µF, ± 20%, 35 V, 10 mmx2 DIODES INC. 1N4002-T Standard Recovery Diode, Single, 100 V, 1 A, 1 V, 30 A as per update seca.freeforums.net/thread/2/seca-kits-colin-wonfor
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Post by zappytheviking on Jun 13, 2016 15:40:21 GMT
Thank you. Actual weight? The case/cover is only 2-3kg.
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Post by zappytheviking on Jun 13, 2016 14:09:14 GMT
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Post by zappytheviking on Jun 11, 2016 3:25:29 GMT
I woke up, the SECA had been running over night, I put on a tune. Its......Its........Its......... How can this tiny speaker do this, this, I...I.....Mind Blown. After warming up, burning in, whatever you might call it, 30h of on time, the change is shocking. I thought it sounded really good yesterday. Imagine a 2m wide bowl behind the speaker with a little stuffing in the back, suddenly it's gone, the sound is everywhere. I can go 4 rooms away and still hear it clearly. The bass drum sounds like it is in the room not stuck to the speaker, the guitar is so clear it's like having a 3m tall man in the room gently playing a 2m tall guitar to you. I used to strive for positioning myself juuust right to get a sense of space and stereo image, getting the best FLAC encoded recordings, shielding my speaker wire, what the hell was I thinking, those little baby steps, how did I not know about this, someone should have told me. Everything sounds so real, who cares about being wrapped in music when you can swim in an ocean of it. This is in mono!!!!!!
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Post by zappytheviking on Jun 10, 2016 13:47:47 GMT
Whenever I can I will make the trek, it's about 1000km south of here.
Haha, he has some Tannoy Canteburys, I will never own a pair but would be nice to have a listen.
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Post by zappytheviking on Jun 10, 2016 13:37:15 GMT
I better not tell you about peltier's then, space parts are above my pay grade so to speak ;-)
They are a very useful invention.
This is shaping up to be the amp of a lifetime, there is no way I am ever parting with this one.
It sounds great AND it scratches that tweaking and upgrading itch nicely. This is exactly what I would do to a PC, tweak it to the enth degree , see what it can do.
Just bumped up the bias to 295mV, took proper temp measurements with room at 20C, heatsink 29C, package 51.2C, No worries with heat at all.
As for being able to tell, so far this amp is destroying all the mass market systems I have ever heard. I must say that might not mean much, I have not spent a day with any premium equipment +2K, best I have at hand is a Marantz PM6005 and tannoy mercury speakers. Right now with 1 20y old JPW 510 it sounds amazing. So exciting to hear what happens with the mod and PSU board.
Wouldn't that be something , trek to the HiFi store with my mystical wooden box, show them what's what hahaha.
I might need to ask you for guidance on the mod, I dont feel too sure about peeling off bits of PCB.
James,s Seca is spectacular, I have read that thread so many times, when he gets the tri-amp setup going I will aspire to copy him as best I can.
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Post by zappytheviking on Jun 10, 2016 11:39:42 GMT
Now you tempt me with another 7W, I wants it so bad, how am I going to resist. I barely have 1 working channel as it is. Will it work well with the PSU board later? I dont have insomnia but I get obsessively interested and keep going until I drop, effectively the same. Cooling things is almost a hobby in itself for me, I can ramble on forever, apologies for the wall of text. I would love to toss around ideas on cooling, who knows, I might come up with something useful. What is really great about peltiers is the pinpoint precision you get if you throw enough power at the problem. I remember looking at a peltier controller circuit. The thing is, every time you stop feeding power the heat seeps back, so you need to always have a current going through the peltier. A PID that controls Voltage somehow or PWM with a positive DC offset would probably be best. If you ever want a FET at a precise temperature for some form of testing, peltiers are perfect for that. Heatpipes on the other hand are amazing at moving heat away from a concentrated source, I think that's a big part of the temps I am getting with relatively little heatsink mass. Heatpipes contain water/ethanol/acetone under vacuum that boils at a specific temperature, the vapour spreads the heat along the pipe near instantly, usually they are set for 35-50C depending on what type of heatpipe you select. There are specialized ones too for odd applications like satellites with helium or some other gas in them to operate well in the void of space. Anyhows, there are reasonably priced 10 and 20cm ones on ebay and you can easily buy or drill a plate to fit them directly on the FETs, as long as you have good cooling on the other end they will be magical. www.ebay.co.uk/itm/6mm-Heatpipe-for-DIY-Fanless-PC-Passive-CPU-Cooling-System-220mm-/171806190750?hash=item2800726c9e:g:lJwAAOSwZd1VZvH9Here is a pad to attach the heatpipes. www.ebay.co.uk/itm/DIY-Aluminum-Thermal-Mounting-Radiator-Pad-for-3-x-6mm-Heat-Pipes-/171816661141?hash=item2801123095:g:JnQAAOSw~OdVcchaIf you wanted to cool a FET quickly and spread the heat onto a heatsink then heatpipes are a good solution, there are even flat ones, you just cant drill into them or they wont work. www.ebay.co.uk/itm/HEAT-PIPE-ULTRA-FLAT-1TX100L-MM-Part-AMEC-THERMASOL-MHP-1220A-100A-/271932773766?hash=item3f5074d586:g:NEcAAOxyBjBTPxmiA side note , TEGs, more heat resistant peltiers used to generate electricity instead , I really want to build one for our cabin in the woods, generate electricity with the thermal differential AND heat the cabin. www.ebay.co.uk/itm/TEG-Power-Thermoelectric-Generator-Wood-Stove-/221382596452?var=&hash=item338b6e5764:m:mE-Ah0y1F7FpiEcpHB3r1MA
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Post by zappytheviking on Jun 10, 2016 8:48:40 GMT
Again, thanks for the support, above and beyond. 3 PCBs left to build, I am sure there is a use for them :-)
Best Tommi
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Post by zappytheviking on Jun 10, 2016 6:10:10 GMT
Sadly I ordered 8 of them earlier this morning together with a dozen fuses. Much appreciated Colin, thank you.
Martin, I am getting +20/-20 seems ok.
I have been listening to music in mono today and damn does it sound good. Even with 1 piddly desktop speaker you can hear the difference. Running at 280mV on the bias, heatsink barely hitting 40C at lowest fan speeds, package is about 55C.
Responsive bass that thumps you out of nowhere, almost fell out of my chair listening to a heavy metal ballad with a sudden thunderous whack, majestic. A cello in the background, sweetness is the only word I can think of right now. The sense of depth in the midrange and the tiny details, yummy.
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Post by zappytheviking on Jun 10, 2016 0:50:58 GMT
Update on the repairs, new FETs arrived. Fumbling in the dark with this, please do chime in with any thoughts. Still keeps popping the right side fuse, measured D5-8, the next thing after fuses, AC to DC rectification I would assume, not on chart but what else could it be. The left set does not conduct(Mohms in both directions) and the right side ones do. Unclear on exactly why a half working rectifier would roast fuses, still, these diodes died when the short drew a large current that's for sure. Is half wave rectification enough to bust a fuse? Maybe when I replace the diodes I get both fuses burning out, wouldn't that be something Going to order a few 6A20G swap all 4 out and cross my fingers nothing else is fried, the 4-5 day wait for parts is tremendously frustrating, but this will get fixed dammit.
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