My Amp Blew Up! 

A costly mistake and live and learn (they say, but who actually does that...?), however it was limited to just one amp board. Still, I had to tear it all apart and check everything to make sure there wasn't any collateral damage. That's the BIG downside of putting so much in one case - it literally took a full day to do that. With the blown board swapped for one of the "spare" channels, I got it up and running again. I'll eventually repair the amp board that blew and reinstall it, but like I said I don't really need it right now for anything important. The two new crossover boards are for the infinite baffle subwoofers that are in the front wall of my listening room. They are powered by a separate 4 channel amp that I built nearly two years ago and featured that build on this channel. While it isn't quite finished, it's finished enough to use every day until I find time to complete it. The crossover points for the sub boards are 15Hz high pass and 80Hz low pass. Both slopes are 4th order. I need to make another for the bass shaker I have in my chair, and that will use the 9th amp board in the case. I need to put the brakes on this new multichannel amp (name change, in case I blow any more boards...) for now, so I can get back to my real occupation - making woodworking videos on RU-vid. I'll get the rest of it done when I get the time. My main channel: ru-vid.com Building my 4 channel subwoofer amp: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-UKhRA_GcmPI.html My infinite baffle subs: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-1hDV54c3tzA.html

Daaang this is the side of reality no one posts. HES HUMAN we see. Thanks for sharing the update of the good and the bad. I enjoy watching your journey with its ups and downs ✌️. Your DIY work is inspiring, keep it up man!

Yeah thanks, i do like this channel 😊 and yes I’m also losing my balance as I get older. So much fun.

I feel ya on the clumsy thing. Last year, I put shrink wrap on all my screwdrivers for that very reason. Glad you salvaged that!

It's amazing amplifier sir 🎉🎉

Thanks for all the shared audio knowledge. Bit late know but being able to access those crossover pots from the outside front/back/side/top, whatever would be convenient. You'll likely keep tweaking them as the drivers' breakin and your ear adjust to the sound. As well, your hearing is likely to continue to degrades just as mine have. Would love more transmission line speaker enclosure education from you.

John builds amps like the emperor builds a death star...

It amazes me how many people don't have a clue what a patent or copy right does.

That's a real bummer when something like that happens! Live and learn, lol! (Funny but not really funny) I've ALWAYS been clumsy myself since I have Asperger's/A.S.D., because one of the "traits" of that condition is bad coordination and relatively poor muscle control, so I deal with that everyday of my life! It makes everyday life difficult, both at work AND in my personal life!

Damn that was bad luck. So sorry. But hey these things happen to all of us. Hopefully you are able to motivate yourself to rebuild the blown channel, even though you don't see to really need it.

Heat shrink over the shaft. Easy to remove if necessary. Not ideal but has helped reduced fat finger fuax pas.

Sorry to hear about the burned amplifier, but you will have it repaired quickly. We often call the Bass shaker the ButtKicher. You can use a regular base unit as a passive radiator by connecting a resistor across the terminals. And you can change the characteristics with crossover components.

Oh man I feel you. Glad it was only 1/10 amps. Great work!! Also about the passive radiators' prices, I DIYed a few myself for my boombox projects. If you dont need a lot of xmax, a 9mm-mdf circle and a speaker surround will do well.

It happens. For some it can happen big time. I built my very first audio amp in 1973 while working as a grad student. Surplus parts (no money) including paralleled small power transformers to get more power (current actually). Unknowingly, connected them anti-phase and, with great expectations, hit the power switch. Kerr-Blam. Took out the 400 amp service in the university lab where I worked. Valuable lessons on reversibility of assembly, partial testing and variacs.

Oh no! You let the smoke out! 😉 sorry to hear about your misfortune but I can sympathize because I’ve “been there done that”. But great looking results with your digital vs analogue plots. 👍🏻👍🏻

Once the magic smoke comes out, it no workie no more.

I'd give my right arm to be ambidextrous!

Genelec have a new "point source" speaker, the 8381A which has a waveguide coaxial and four equidistant midranges surrounding it. It looks more like the one you are trying to do than a Tekton does.

Oh my. lol. You're killing me.

More clumsy with age. You are not alone friend.

Do you use any delay for phase alignment between the drivers?

As far as being Clumsy goes... I started out that way. I was severely under-weight, clumsy, not coordinated at all. The kid that they would pick last in Gym, for good reasons. Turned out that I had a mild Gluten Intolerance (I didnt know until much later in life)... which caused me to be under-developed, weak, low energy, even mentally foggy / slow.. etc. When I turned 20, I started taking up a Chinese Martial Art... and doing it on a very Hardcore level ( 4 to +8hrs every day ), as well as a daily 1hr hardcore "Core" workout routine. In about a years time, I was in the best shape of my life. After 3yrs, I was defeating blackbelt level fighters, that were 2x my own mass and strength. I became lightning fast, graceful as a Cat, surgically accurate, and incredibly powerful. I realized that most issues with being Clumsy, have to do with not having enough strength / muscle. And obviously... as we get older, a lot of us lose a lot of strength, because we are not anywhere near as Active, nor as Physically Stressed. There are other things too.... such as developing excellent tendon strength... which is one of the keys benefits in long session Tai Chi practice. Anyway... An Actual Surgeon needs the ultimate steady hand control.. otherwise they will accidentally cut something that shouldnt be cut. Their constant practice of very slow and controlled movements, builds up their muscles in such a way... that they gain that level of super-precision. Its very different from Gross motor control.. like throwing a baseball. In KungFu, one of the methods of developing surgical control of ones kicks... was to slowing extend the kick outwards, and slowly retract it... over and over again, for like 1hr sessions. Its easy to throw a fast kick... because most of movement is based on mere momentum. But when you slow it down... it forces you to have to gain strength and control over the entire line of the kick. People whom dont do the slow motion training... tend to have very sloppy kicks.. and they fatigue MUCH faster (leading to even worse kicks). Similarly, we did slow motion pushups for precision arm control... as well as the same back and forth slow-motion extensions and retractions. Basically, I just wanted to state that if anyone is having issues with being clumsy... that they can change it, if they put in enough efforts. Its not a permanent biological, nor age related issue. The other component, is Focus / Attention. That can be solved with daily silent 1hr meditation sessions. Takes about 100 consecutive days to develop the permanent "Quiet Mind" state. Simply count each Inhale and exhale, in Seconds. Scientists recent discovered that such meditation caused the brain to actually grow in Density and Connections. They did before and after MRI Brainscans... which is how they realized and proved this. And the good thing about it... is once its developed, you never lose it. You can stop meditation altogether... and that gift of Quiet Mind, will always remain with you. When your mind is Silent.. its much easier to pay attention to the Present (The GIFT). You can learn much faster, and you can do things with much greater levels of focus... as a result. (While ADHD people will likely always have issues... I have heard that this practice still does greatly help them control their issues.. much better than before)

I have blown amps, but it was plain stupidity on my part. I am also more clumsy as I age but the brain does not seem to be doing any better either.

Name that amp "Demon Core."

There are a few companies using that or similar arrangements. No patent or copyright laws broken here

I blew up an amplifier. It was being weird one day, sound was odd, I turned it up (should have turned it off), kawblewy. It had developed an input stage problem and was trying to make DC. Audio was working against that of course going in the opposite direction and saturating harder the other way. Luckily fuses took most of the abuse.

What a journey! Thanks for sharing. Question, any consideration to off-loading the bass shaker duty out of the multi-channel onto a dedicated amp? An argument can be made that it'd be a good idea. Your loudspeakers aren't too power hungry. Subs, ... IB alignment requires minimal power to hit full excursion. But I'd suspect your shaker rig might need a lot of power and control. Perhaps it'd be nice as another control point, as its own entity. Offload curent draw and heat. Ease of adjustment (tactile rigs are tweak intensive). Really digging the content Much appreciated

John, but what really matters "HOW ARE YOUR EARS NOW!" cause without them your amplifiers and listening room is mute/moot, unless you're only concerned with bass levels.

i made a huge spark on my F5 amp when the screwdriver i was adjusting the bias with slipped... thankfully nothing was permanently damaged.

Hey John, quick question. On the outputs I see you used NJL1302/3281 5 pin devices. I’m thinking it would be cool to make most of my speakers powered and using these amp modules if the gerbers are available. The outputs are the only things i need to buy and to get the best price I would buy in bulk from Rochester, but there is a minimum. Would you used NJL0302/0281 devices which are basically identical to what you uses except they are rated at 180w dissipation vs the 200w yours are, I would get 64 of each. Or NJL21193/21194, you get the 200w rating, plus higher voltage and current rating, but step down to 4 MHz transitional frequency vs the 30 MHz of yours. In this case I’d get 194 of each for the exact same price!!! I’m sure either would be more than enough quantity wise, but more is better? This question coming as if I were to use the same rail voltages as you’re using. Since you designed the board I though you would be the best person to ask which would be better, lower dissipation or lower Ft? Thank you! Oh I should let anyone wondering why, the originals are not available.

I dont believe that two woofers, is the same as a Passive. With the Phillips Woox system I used to own... The type of low frequency sounds that the Woox passives made, was FAR deeper than the woofer driver itself. According to what Ive read, you have to Tune a passive using the proper Weight on the rear of it. In fact, the Woox passives would get much more dynamic low bass, the higher I raised the Volume... as that "Excited" them to a much greater Resonance level. However, Phillips recognized that if you wanted to play your music at lower volume levels.. but still wanted big bass thump... that something would need to be done about this... So they added a special EQ setting on the Boom Box, that you could Toggle. I believe that this EQ just basically boosted the Lows, while leaving all the rest the same. The increase in bass levels... caused the Passives to Resonate much greater, even at those lower volume levels. Now... you could always modify a normal woofer / subwoofer into a passive... but you would still need to remove the magnet, and add the proper weight to it. The Woox system was very interesting, in that it had like 3 expansion rings... allowing it to expand much further than a typical passive. Also, the woox unit was actually two of these passives, spaced apart about 1 inch from each other. There didnt seem to be a notable mass on them... but Its been a long time. My memory is fuzzy... and even if they did have a mass hidden behind the Caps.. it might not have been heavy enough for me to recognize. Also, after trying to replace a foam rotted woofer out with another brands... I learned the hard way... that the Woofers themselves were special. The Taiwan mfg. that made the drivers for Phillips, developed the 6.5" woofers to have an Extended Throw / Travel... which allowed for greater bass responses, low distortions, and greater Passive "Excitation" levels.' The crazy thing was... those little Woox speakers put out deeper bass than my EPI's that have 8" woofers, and are like 2x the cabinet volume / size. That said, the EPIs were still far superior overall. Much greater accuracy, details, and a 3d Soundstage that couldnt be beat. Not even close.

A second woofer is an excellent choice. Far better than a port or a passive radiator. Sealed bass plays lower and it's easy to EQ to get the same low frequency extension with a Linkwitz transform filter. In my opiion the Tekton patent is a joke. It simply can't be valid. People have been selling speakers with multiple drivers and even multiple tweeters for many years. So it's not novel. If you read it, they talk a bunch of non-sense about the mass of the domes being very low so they match the mass of the instrument that created the music. What a load of crap.

I blew up an amp. Tested it continuously at its rated power. Germanium transistors went pop. You live and learn.

Use ceramic trimmer tools.

Tecton and about 30 other people that think they are original thinkers, have patents that are similar to what you have done. Patents are of limited utility. A 10% variation negates the applicability of the patent claim. Sorry about the magic smoke. Been there. Mark

So, the right title is "I blew my amp"... Sorry to hear this!

Nooooooooooooooo!!!!!!!!!!!!!!!!!!

Ya know in today's audio Market, and I am estimating "Your" Time to be at least worth 50 or 75 an Hour! Remember this is my opinion but I would be on the Phone to Emotiva because they are a company that will build you exactly what you want and not rip your head off doing it!!! That's all, you can tell me where to put my ideas!!!