I should point out that 'Uncle Doug' DOES replace power cords with polarized-grounded 3 prong, 3 conductor power cords. In his 'famous' example, it is not possible to flip the plug! However, it is possible an idiot may have wired the outlet wrong, with a H ~ N reverse, which will then present danger.

You are dah man!!! Great video thank you so much for explaining things directly and not abusing metaphors. It's so much more intuitive and effective explaining things directly. Do you have a patrion? I've never subscribed to one before but I would definitely make you my first, I'm actually learning something here.

Fix the pin 1 problem and proper grounding scheme will work. If there are ground loop issues, fix them.

I don't get it. In the diagram, you have a 2-prong plug, one lead goes to chassis ground. The two leads go on to power supply and a capacitor in parallel. I would think if the capacitor was shorted or leaky, it would either burn or the circuit breaker would trip. How does that give a shock to someone touching the chassis any more than if the capacitor were working perfectly? Likewise if the capacitor were open?

Number seven, potentially the worst. Thinking all caps sound the same if the values are the same and just stuffing in whatever you have on hand to save a buck.

In 2020, I totally recapped an Marantz CD-73 cd player that I purchased as broken on an auction. The first obvious problem it had was a broken switch that prevented it from recognising the door was closed where the standby lamp should glow which it didn't. After that was fixed, it had a hard time spinning up the disc I put in it, and took several tries to make it finally spin up and start to read, after that it did worked. But every time after that, it needed to sit for at least 5 minutes after a boot-up before it would read the disc. Now when I decided to replace all of it's electrolytic capacitors since I knew it was mostly working, I did every one in one shot. After that, I measured and tweaked the output voltages first before connecting the PSU board to the main circuit board to make sure it was putting out the proper voltages accordingly to the manual, as many of the new PSU capacitors had more than the double capacitance that was printed in the service manual, the rest was the same as the old ones. After that when I tested a cd again to check it was working before putting everything back together, the laser started to make a loud squeeking noise and failed to read the disc. It made me very worried that I might have messed something up during the progres of recapping, so i disassembled it all again and checked every circuit board three times without finding any error apart from leaving some flux behind from all of the soldering. So I gave all of the circuit boards a through-out cleansing to make sure there where no possible contact between the traces due to the flux that I used, and put everything back together again. Then it didn't squeek that harsh when reading the disc, and it finally started to play again, and I was very reliefed. It had now worked flawlessly for over 4 years since then, and is still playing cd's like new with great sound quality despite being an early model from 1983. So I'm very happy that it worked out so well, and managed to increase its value by 6 times I originally paid for it, as it is now sellable as working and serviced if I ever wanted to get rid of it, which I wont.😁 So lesson learned, always clean the circuit boards after soldering to be sure it will function at the first try (if the repair is successful and all what it needed)

And this seems to be mainly an American problem. These hyper-dangerous configurations are rare in Europe, possibly because you learn lessons faster at 240v.

Hi Alan from New Zealand here. Great Video! A fairly experienced 70 Yr oldTech, I have never struck a fixed bias Triode OP before! I am repairing one of these Amplifiers and wondering how you set the bias on your repair? I have added some 1 Ohm precision resistors in the 50CA10 cathodes and before trying to adjust I am getting 6 - 8 mA per tube. Would that indicate that the tubes have lost emission? I am being extremely cautious so that I do not destroy the very rare tubes. I suppose I am looking for reassurance before I crank the bias current up. The amp sounds nice, I have not had a Scope on it yet to look for crossover distortion. This Amp is a rare 240V model and they derived the 100V for filaments from a tap in the Primary Winding which I think is a bit Naughty!

Great video. At a time I serviced Asrock motherboards, and those very often had the polarity marks of the CPU VRM caps reversed. One had the be careful when recapping one of these motherboards.

I've watched both parts 1 & 2 of this series. I do not recall seeing mentioned that, while an isolation transformer is a mandatory item, online reviews of them have revealed that some of these units are not "Tech grade" types, that is to say that the "earth" [green] lead from its power cord is connected thru the unit to the ground pin terminal[s] of the recepticle[s] on the front of the isolation transformer. Many TrippLite units, among other brands, were made this way. Some are designed for hospital use or for reducing noise - not for equipment isolation - and their product descriptions do not always specify this difference. Before buying or using a so called "isolation transformer" from any manufacturer, verify there is, in fact, no connection between the ground pin of its power cord and the ground pin terminal of its outlet[s]. Easily done with an Ohm meter. Or take the cover off of the unit and visually verify that there is no "earth to earth" connection inside the unit.

Anything worth doing... is worth doing right; or to put it another way: "there are many ways to do a 'thing', but there's only ONE right way.

Now, any advce on a the X cap versus the Y cap approach to minimizing noise? What about using both? Would an X1Y2 set up provide better noise suppression, especiall in a noisy enviornment?

Your electrolytic can cap tabs are the common (neg) for all 3 electrolytics? I have an electrolytic that has a black cardboard housing. It has 4 separate tabs for 4 electrolytic caps. ( 2-30's and 2-20's) So the tabs on the carboard cap are the negative for each electrolytic?

Why is the warning blurred on the qd

Most of the time when a band brings vintage gear to an event with a professional sound system, and the musician gets electrocuted on the microphone, it's because the professional sound system is entirely grounded, from the microphones, to the mixer, to the amp, etc. That vintage guitar amp was fine on a dry wooden floor. Enter a grounded metal object, and now there is a current path from your guitar strings to the grounded microphone. Doing house sound, all stage outlets are on GFCI. No exceptions. Yes musicians will complain their vintage gear trips GFCI breakers, so they can't use them. I've had to explain to musicians how their favorite surge protected and filtered power strip will trip the GFCI. Use our outlets without your filter to power your equipment here. We are not electrocuting anyone here today. You can buy a non contact voltage tester. Plug in your gear and check if the chassis is hot before touching anything grounded on stage. If your non contact voltage probe finds your amp is hot, don't use it until it is fixed.

Great video. Thank you.

Great advice. I have personally fallen for the 'leakage of glue' 😅😅

If you’re installing a fuse, it should be the first stop of the black wire in any build. Just saying.

At 13:28 is that a dead cockroach? LOL 😂

Greatest series. Watching you doing actual troubleshooting and hearing your thought process is invaluable information. Thanks.

Hi, do you recap the Century L-100 crossover in a video? I am wondering about the Solen vs other manufacturers. Thanks\s,BK

seems like a bad idea to me

Love, love, love your content. Helped me once again!

I upgraded from my already great Parasound Zonemaster 2 and Parasound 2125v2 to NAD C298 and PS Audio S300 (dual mono amp). ------ source=Apple Music lossless quality

Nice to have an update on what’s going on in the new Blueglow barn. It looks awesome and so neat and tidy. You must be a magician or wizard to keep up with your day job and have a space that is so organized. Maybe it will give me the kick I need to clean up my own basement. Happy new year.

Lock the gates!

I'm So enjoy your video😊

My IT was telling me about some guy that died when he decided to take apart a PC power supply unit (i think) that had been unplugged for YEARS and still carried enough stored power to kill him.

Hi that amplifier inside build is something like an horror house , never see something so bad.

Fairchild . Ex Military ? .

Happy New Year Mark . You helped Me out 8 Years ago or so with My Reel to Reel . Bought in Germany I 1979 and it's still going g Stro g . Enjoy Your New Years with the Family

Great hearing from you! You obviously do NOT suffer from Adult ADD syndrome! You’re accomplishing enough stuff for two people. Really like the videos thanks!

Good for you! A listening room is a wonderful thing to have. Glad life is treating you well, it sure is nice to spend more time smiling than frowning isn't it? Nice to see the old turntables, back in the '70's at a college radio station we had two RCA monster turntables with Shure tonearms and Stanton 681EEE cartridges. Slip and back queuing with one hand, running the mix board with the other. Juggle two of those and a few Spotmaster cart machines and things could get downright busy. Great fun. Those old Stanton cartridges weren't the best audiophile grade ones, but they had the mechanical strength to handle the tight back and slip queuing done in broadcasting. My nice Ortophon stuff would have been destroyed in a few hours or less!

Hi Mark. Would this design accept the KT-150 tube or the KT-170? If yes, what would be the power output? Tx!

I may have missed it, but i didn't hear you mention what size fuse you installed.

Hi Mark, thanks for the video! I have been enjoying the series, watching and rewatching every single step and I am eager to one day in the future build something like this. Thank you again!

I didn’t have Deoxit on hand but I did have wd40 contact cleaner and it worked fine as well. Cleaned the problem areas on my newly bought Technics SL220 and now the speeds are spot on. Also remove old grease with isopropyl alcohol and add white lithium grease with a qtip. Old grease can also be part of the problem too.

Wow. How nice it is that all those old caps and resistors are still more-or-less in spec. I recently dug up my 240 which I had in storage for about 20 years and unfortunately nearly every resistor I checked was WAY off value (the 2.2Megohm resistors for example measured between 2,6M and 3M) and the caps were trash, too. I kept all the old parts in a glass jar for sentimental value, though.

Recorded and mixed many albums on 604Es, many with Mastering Lab custom crossovers (you will like them), some with an additional woofer. One of the best was a single speaker ported set in Studio 1 at Sunset Sound Hollywood sized very similar to yours. Those tracks played everywhere brilliantly and were used to set up many systems. Lovely, detailed sound. Miss making music on em. (We also cut out the divider cells in the tweeters on most of the systems which I don't think anyone would have the guts to do at this point)

All these tube amps 🤩 Wow!!!

Keep 'em coming.

Great video Mark love the gear I got JE labs 2a3 tube that I love and I love the turntable s got a vintage thorens td 124 that I had restored to play my mono Jazz records from the 50s and I love the vintage speakers keep bringing more to us, And I enjoy your pass video with Dennis Had I have his line and phono preamp he designed years ago which are with me today and playing great music, Happy New Year Ed in Brooklyn New York Happy listening and many blessings 🙏🎶🎵🎊🎉🎄

Another great video. I cleaned and lubricated all the strips on a Jupiter 8 a while back and can now see that it's something I'll have to eventually consider a least partially doing again someday. And here I thought I was done with that fix forever (wishful thinking). Glad to know i used the right fluids for the right things. I guess the guys at the shop gave me correct info.

Thank-you for pointing these out. Very good lessons here. There's an audio cap in the Amiga 4000 that's installed backwards from the factory. I also liked the lesson in differentiating between glue and leaking fluid.

Was the 807 amp you showed in this video before or after your Kegger/Blueglow KT88 project? I built the KT88 amp but converted it to 1625 tubes (12v heater version of 807). I would be interested in the circuit of your 807 amp and the difference between it and the KB KT88 circuit.

2.3ma leakage would be enough to trip a GFIC. Also when dealing with old vacuum tube gear, the filament/B+ transformer has failing insulation inside which causes AC leakage of the primary to the chassis which creates another shock hazard scenario. A replacement power cord with a earth ground is thought to be a fix but it isn’t. It’s a poor bandage at best. This creates a low ever increasing dead short, which will become a fire hazard. Most AC circuit breakers are 15 or 20 amp. A fire can start long before it trips. You might want to share how to check for a leaky power transformer in vintage vacuum tube gear. To be absolutely safe a GFIC circuit can save you and your home.

08:30 Those Fairchild turntables look like what we used to use in the military for AFRTS.

How do I get ahold of the replica h1000 guy?

Great update Mark! Lots of interesting projects that I’m looking forward to seeing. You’ve inspired me to dig out an old 1958 Realistic Mark 7 broadcast turntable and tonearm that I’ve had stored away for years. Happy New Year!

Bourbon, Altec, Tubes? That sound familiar and incredible.