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I just bought one on Craigslist

WOW ya can get to work fast with that.

Thank you Phil I’m so excited to get them home and listen to them. So thankful to get them to you Phil. I know they will be outstanding with the rest of my system.

Great video. Thanks for the 'specific' tools discussion. These tools are often glossed over, or emitted entirely from most videos discussing vintage audio restoration and repair. Keep it up.

Hi I have been looking for a tool just like the GC electronics 9446; it doesn’t seem to exist anymore are there alternatives you know of? Thanks for the tour!

Great set-up Phil! I know you said you don't do much SMD, but do you like Chipquik NC191? Been looking at it. I've used: MG Chemicals 8431 No Clean (beautiful stuff), it's rosin (ROL0) based with a bit of resin. Can use with hot air. Chipquik SMD291, resin based (REL0), very sticky, nice for hand-soldering but not hot air (forms a hard puddle). And just bought some French CIF F42202 (ROL0) upon recommendation of SDG Electronics. Looking forward to trying it out. We can easily get Kester solder here in Australia (like you I'm 44 all the way, even for new boards), but none of the fluxes alone.

That is one of the most beautiful prime example of Tin whiskers I ever seen. That thing belongs into Smithsonian 😂

What do you use an impedance analyzer like this for? (An electrician here with electronics hobby on the side) I'd think you might want impedance readings on a frequency sweep, so do you get that data on a serial output or something? Or do you just choose a frequency and get, say, a cap ESR reading from that? edit: Oh, should have watched the full video before commenting, you're showing both use cases I mentioned, haha. Thank you for that, very nice! I have an opportunity to buy one that's damaged for cheap. If it's very cheap, I might take a bite, maybe the fault is within my reach (otherwise that would be a very fancy paper weight).

At 33:01, it's called a "scratch brush"; available with steel or brass bristles as well, but the fiberglas bristles are the most useful. Referencing to 32:34, I often use pencil erasers to clean contacts; *ink* erasers, really, that include some light sand, silica, or pumice for grit. Modern "plastic" (elastomer or vinyl) erasers are, in my experience, too soft to be of much use. Anyway, I love the Eurotool and Bergeon fiberglas-bristle "scratch brushes"; cheap Asian-made sets of similar are available from Amazon etc, but they're not made as well and typically aren't refillable. I have a video about these, and pencil erasers as well, on my channel.

A strong laser pointer, aimed at thr component side of a PC board,, can also shine right through and illuminate the solder joints of the component you want to remove, with a bit more accuracy than a flashlight beam. Ordinary cat's toy laser pointers might not be sufficiently powerful, but I have a plastic-cased NEBO LED flashlight that includes a very strong laser. BTW, when visually scanning boards on old equipment for cold or broken solder joints, it helps to use both warm white LED lighting or flashlight *and* then do it again with a bluish-tinged LED flashlight; the bluish LED has less glare and reflects differently and often shows up bad joints that aren't readily identifiable under the white light. It's also helpful to view the solder connections at an angle instead of head-on; the glare from straight-on visual examination can hide soldering flaws.....

Pozidrive screws are also common in European made devices such as Bang & Olufsen speakers and I am told that Ikea furniture often uses them as well. The heads of Pozidrive drive screws are easily chewed up by use of an ordinary Phillips screwdriver, or vice versa.

I was inspired by your video on electronics reference books, and so I posted 2 videos of my own showing just a small sampling of my own electronics book collection. I also have a video about glues and gluing techniques, and another about useful specialty hand tools for electronics.

Wow nice find Phil, I’ve never seen anything like that before! How long did it take you to notice?

At 21:48, did DeOxit finally abandon their leaky, wasteful, messy, hinged aerosol nozzle and go back to the old-school design, or are you using old-stock cans from years ago? As for magnification, which I frequently need at this stage of my life, I use Optivisor headset magnifiers. They're excellent.

Well, that's a new one on me. But thanks for sharing it, now I know to watch out for it. I work on LOTS of amps that age and older.

I meant to say continuity between the wiper and the case of the pot... of course there's continuity between the case of the pot and the chassis.. sorry!

Thanks for the tour. I use 60/40 Kester and have been using Kester for decades and really like the product. When I did my review of a Hakko solder station, Kester is what I used for the demo section.

Everybody loves a shop tour! One note re: drills: Clutch settings can vary. I have a dewalt whose "1" setting is light enough to drive screws into plastic, but I have a cheapo power screwdriver that I got on amazon whose lightest setting is still too strong. In addition, you'll notice yours has a brake. On my cheap one, the bit continues after letting go of the trigger, coasting to a stop. I don't even use it to tighten anything.

Great tour and so much of the information that I have been looking for. Much appreciated.

I want one

This has been great, so few tours skip into the hardware immediately, not covering more detailed methods of work. Thanks for this.

Great Video. Where did you learn you Electronics Repair skills . ?

I have the FR-301 that I keep for back up, but upgraded to the Hakko FR-410, it wasn’t a small upgrade. There are obviously diminishing returns, but once invested it’s definitely a purchase you’ll come to love. Much faster heat recovery, no problem with large ground planes that the 301 seemed to struggle on a bit, even when turned up. Also the vacuum is in the station body and obviously they can put a better vacuum in, it clears holes much better. It’s also much quieter, it’s nice not having the hand piece vibrating because a pumps going. There is a vacuum indicator to let you know how effectively you’re doing. Mostly though it’s the heat retention and the much better vacuum. I never pull the 301 out and if for whatever this 410 was to die I’d in a heartbeat buy another, wouldn’t want to go back to the 301 full time. Also should note, I use it everyday sometimes multiple hours a day. Also, I ended up getting rid of the Quick air station, couldn’t get over the flashing lights. Bugged the crap out of me. Another UA-camr (SDG Electronics) did a deep dive on it and found it was a nature of the design, it isn’t not something that can be corrected. I got a Best BST-863. Most importantly no flashing and a small upgrade from 1000W to 1200W.

Something usually overlooked with the Dynaco amp restorations is the resistance of the power switch, which i've found in some cases to be very high (into the Ohms range vs milliohms) and also with significantly changing values with each operation. What I usually do is install a current day equivalent except a two pole unit, and parallel the poles. Thought it doesn't look like much of a switch I've found, using a milliohm tester that the resistance is often significantly lower than those beefy looking toggle switches that are often used as replacements.

I pretty much followed your part 1 and 2 on some Mark III’s. I had bought a pair recently and still have them on my workbench. one had an 80/40/30/20 - and it too was wired wrong (80uf off of pin 8). I have used these before, but after watching your video I decided to double check it. I also used the CL-80 thermistors. Great advise on the power cords too.

Damn. NAT makes probably the best tube amps in the world. Hope you kept them....

I hope you get your R&S analyzer up and working working! Cool to see such specialized equipment.

Great minds think alike ! My collection is almost identical.

its a dream lab man !!!! - i really wish i had room for all....!!!!

Phil they look great on video. I hope they test well once you do your magic to the two. After all they are 1959 amps. The distortion numbers will be a bit higher. No need for the third to be worked on I brought it for spare transformer if needed. I’m excited to see them. Thank you so much Phil

Yep 1990s HP the time when they reached thier zenith of mechanical engineering, it was quickly becomming too expensive to manufacture even off shore to make any money, 😢

Yep 1990s the time when HP was starting to drop all thier documentation for new instrumentes, If I remember correctly there was a big battle between the hardware side of HP and the software😂 side

I was lucky to spend a hr at Phils Lab today meet and greet and dropped off my two Stromberg Carlson AP-437 6550 p/p mono block 1959 original boxes NOS amps plus a third AP-437 in case a part is needed, I can say Phil comes very recommended by many tech men. Thank you Phil. I can’t wait to view my amps go through your magic . Better when I get it all back to my home for some critical listening time.

Good info. Have you built your own amp yet, or are you intending to?

Excellent video Phil. A comprehensive guide to the guides we need to guide us through repairs!

The GE Transistor Manual. Thank me whenever you want.

Great work. I'll echo what Herb said, these multisection caps have an inverse reaction to their stationary ESR rating. Essentially, if it sits for a year or two without use, the ESR value will show rather high. However, once power is applied the caps will reform after a few days of regular use the capacitance value will settle and the ESR value will go down considerably. What that means is they'll warm up due to the resistance, but as they reform you'll notice that they go cold - this is when they've been reformed. In the same way, anytime you have an amp running and the multisection cap is hot, it has developed permanent series resistance, time to replace.

Did a Facebook market place search like you suggested, found me a 576 for $500 20 minutes away from my house. Barely any wear on it, user and service manual included.

I'm not an audio guy per se, just an analog-ish EE. Bob Pease's book was originally a series of articles in EDN magazine, and it was great! I saved most of them and used them to help teach my friends the principles of troubleshooting analog stuff. The Art of Electronics is a great book on the big world of electronics too. The semiconductor companies used to publish a lot of books. National Semiconductor had an Audio Radio Handbook that had a lot of good design guidance. Not sure if it appeals to this audience, but I enjoyed it.

Fantastic video, Phil. As hobbyists, information found in books such as these is indispensable. I’m definitely going to follow your recommendation and purchase some of these. I’m still very green, even clueless, when it comes to much of what’s covered in many of these books, so it’ll be a good place to start. Thanks!

At 31:22 , definitely a UK-centric book; although Ive worked in audio sales and repair all my life, I've never heard of Lin, Tobey and Dinsdale, Bailey, or Hardcastle and Lane amplifiers! (Linn, yes, having once worked for a Linn/Naim dealer, but not not Lin). Interesting to see several sections listed on "dead amplifier technology". I've never heard of ultrasonic biasing....

Good list. I can personally attest that the Theory and servicing of AM, FM, and FM stereo receivers is an excellent book. I’ve been enjoying Douglas Self’s small signal audio design for the last two months and it is excellent as well. I would add in two books to your list - The benchtop electronics handbook by Victor F.C. Veley, it’s a great reference book to keep on your bench when you need to look something up quickly (i.e. resonance in a series LCR circuit, page 202, Millman’s theorem for AC circuits, page 243, etc.). The second book that I would add to your list is Practical Electronics for Inventors by Paul Scherz & Simon Monk. I really appreciate the straight forward to the point writing style of Practical Electronics. I’ll be checking out some of your recommendations for tube amplifier reading material. Good video, thanks!

Thanks for this video . Well done I will check some out mate.

This is a great reading list. I wasn't aware of any of the FM servicing/theory books except the first one which is great indeed. I can recommend Terman as a general electronics book for valve circuits. It is worth getting a nice edition. It goes into more depth and theory than the RDH, it's a proper textbook -- not a handbook. There is a huge audio engineering handbook -- I forget whose it is -- which goes into all the aspects of audio engineering and recording to an adequate depth for a handbook. Other books I could recommend are for very esoteric subjects and perhaps slightly controversial so not much point mentioning them in the context of building a general list.

Great channel - great work!

Phil, by and large , the F&T caps get better with use. I check leakage and ESR with my Sencore LC71 prior to install. After some time , they measure better with some hours of use. I have several newish CE caps in my junk box that got leaky in a high voltage use situation. BTW Vishay offers a HVR series metal film resistor specifically for high voltage circuits. In a three wire power cord , consider using a bridge rectifier as a ground lifter ( 1.2 volts ) rather than a direct ground connection to the chassis. This eliminates most ground loops but keeps the user safe.

7:33 I would leave it as it is. It will only take one slip and you will be regretting you ever did it. Nothing easier than blowing up an analogue meter--I know because I have done it. They don't make them anymore so if you blow them, it will be quite an ordeal to fix it and it most likely never be the same as before. Why mess with a perfect instrument? Besides, this set up you could easily replicate with cheap modern components if you wanted--a lot of people build their own for a portion of what this is worth.

5:56 You can find plugs for these sockets still. They sell them new if you know how to search for them but if in doubt you can always find them on ebay. I thought they were rare but they are not. They go for a range of prices so you may need to be a little judicious in your selection but on the other hand most of those on ebay look like they were made at the same factory.

This is awesome. I never knew these existed.

Have you got any explanation why Dynaco decided to have this huge square hole on the chassis exposing the circuit board? I cannot think of any reason for it other than it being a marketing gimmick. If I owned a pair of these, I would ensure this hole would be covered by a sheet of metal and the circuit board lowered in the case as it is a safety hazard.