1965 Valco Airline 62-9025A (Supro) Complete Teardown, Service & DEMO
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- Опубліковано 23 лют 2016
- In this video, we'll take an epic journey from the unboxing of a vintage 1960s Valco Airline 62-9025A, through it's troubleshooting and service (with a recap and fix of the faulty reverb), take a thorough look at the schematic, and ultimately to a SEARING tone demonstration in which we'll really open her up and blow the walls out of my living room!
The Airline 62-9025A is the same circuit as the Gretsch G6152, the Supro S6422TR, and the National N6422TR. All these models feature tremolo and reverb. All have a 5-watt output. The Supro and Airline versions had 10" speakers while the National had 2x8" and the Gretsch version had a 12".
This circuit is one of the most sought after of the Valco circuits simply because it is a single-ended, class-A, 5-watt, 6V6 based circuit, so it's small and studio-friendly with those killer overtones only a single-ended, class-A amp can provide, but it also includes Valco's outstanding tremolo AND it's cheesy, unmistakably 60s-sounding reverb circuits! So, if you're talking about both a great recording amp and a perfect small amp for micing up at a gig, this is the Valco you want! I've owned several examples of this circuit, and this one might be the best-sounding example yet.
Cosmetically, there are some nicks and dings and a bit of staining on the cream and black covering, but overall it doesn't look abused. I've cleaned it up pretty well.
The reverb has been serviced and all electrolytic caps have been replaced. New 3-prong power cord installed and death cap removed. The original speaker was DOA when I got the amp (burnt voice coil), so I've installed a 1963 Jensen P-10S, which is a smooth-cone 9W AlNiCo, and I'd call a definite upgrade for this circuit anyway over the stock C-10R. It sounds absolutely heavenly in the amp. There is a bit of rust on the speaker, but it's well broken in and in perfect operational condition.
All tubes are the original RCA and still going strong!
Follow the links below to see other examples I've had of this circuit in the past!
National N6422TR - www.youtube.com/watch?v=Wzdak...
Another National N6422TR - www.youtube.com/watch?v=Zy6z4...
Supro S6422TR - www.youtube.com/watch?v=rQBDo...
Another Supro S6422TR - www.youtube.com/watch?v=1vBI1...
Another Airline 62-9025A - www.youtube.com/watch?v=3YHNj...
A very interesting and informative video, Brad. It's great to see an original 6422 circuit. I was surprised that the two 20uf filter caps in parallel were original (although that big red cap looked a little "after the fact" :) and that, in contradiction to the schematic, both triodes of V2 were utilized, also in parallel ala the parallel 12AT7 used by Fender in this location. The reverb tank was every bit as strange and unconventional as I imagined, but it sounded darned good. Overall very entertaining with an excellent audio demo at the end. Rusty and I give this video two thumbs and two dewclaws up.
Ok, I am chiming in. I am a guitar player of 45 years and I don't know much about what you are doing, but am very interested in learning about what makes those boxes produce the beautiful sounds that they do. I really enjoy and appreciate your content. Thank God, for He has blessed us all with one talent or another. Oh, and I am really impressed with your guitar skills as well, Dude you rock! 🎼🎛️🎶📢🔌📣
Brad, great job on all that you do. I'm an older guy who cut his teeth on tube gear. I really appreciate the thorough why you go thru the amps. especially like you sharing your thoughts on your trouble shooting methods. It reinforces my own thought process when reparing. I always agree with your methods. Makes me want to watch more because I know you are sharing truths with all of us who watch. Keep dragging those schematics out and showing us what you are thinking and doing. That way we all learn. Thanks again.
This is the first amp I had! I traded a bag of weed for it in the mid 70's. Great amp!
The journey of the this video is epic! From the unboxing of horribly packed amp to the trouble shooting of all the different unexpected problems made for a great informative video. By the way it was packed it is a blessing you got this amp out of the hands of whoever shipped this thing. Always great to see a video that shows the real time investigation of what is wrong with an old classic amp. Great Job!!
Cool to see the inside of it. Been checking out where Valco used the class 2 ceramics as opposed to film caps. Bout to embark on building a Gretsch 6161 from a Knight that has the same tube compliment. All British Mullards in great shape!
Great video and repair as always. Just as an aside, I love that little squeal you get in some of your runs.
Very nice sounding Amp. I love your playing style. Great demo. Thank you for all you do.
This amp seem to be correctly wired from the factory as per the schematic for the Supro S6622 which shows that the second node of the power supply is 10uF in parallel with 20uF as Brad found on this amp. The first node on the Supro is just 20uF feeding the output xformer. The Supro S6622 schematic also shows the correct wiring for V2 with both triodes in parallel. Brad's observation on the ceramic capacitors and their contribution to the cutting tone is significant to builder /players with good ears.
Ramble on... I love all thing tube amps and seeing how you troubleshoot these old amplifiers is really cool! Thanks!
These vids are so great. Supro's have such a cool history with LZ but i myself didn't know of the connection to Airline until later. Ha, i remember looking for a used Celestion 12'' and found one at a shop in of all places, Sausalito, Ca back in the early '90s. When i got there, the owner was demoing a guitar for a 'customer' (probably a tourist) and was cranking away thru an Airline head plugged into a Marshall Lead 12 flat cab and sounded killer . When i said i'd called about the speaker and said i had a Lead 12 head with no cabs (found used), he took his power screwdriver, took out the alnico Jensen 10 he wanted to keep (can't blame him) and ran screws for the 12 and sold it to me. I was stoked, even if the grille cloth was brown from the sun. Just masked the white piping and hit it with flat black spray paint. I think he said he'd modded the tone stack or caps or something on the Airline. It sonnded awesome.
Great video! Glad to see Doug's comments.
👍 your commentary is entertaining as anything. Keep the camera rolling. It’s interesting to watch you go through the diagnostic process.
There's something about old tube tremolo... sweet! I shared this on my Fakebook. An impressive little amp, much enjoyed. Thankx, Don
Wow that does sound great! Articulate but not harsh
Wow! That's the best sounding amp I've ever heard!!
I really like watching amp techs works... Cheers to you, Mr. Carlson, Uncle Doug, etc.. for letting us watch your shop. I've done a few fixes, but I'm still a rookie. Everyone was a rookie once, so I don't let that deter me from trying. It's already broken, right?
Love the sound on these amps.
This was an awesome vid, Brad...very informative. I like the way you dig for the reasons why a certain amp sounds the way it does, rather than simply regurgitating someone else's 'wisdom'...I'll have to experiment with the ceramic caps in the circuit to hear what is there...please do more of these whenever possible (maybe a Sunn?)...or, should you ever have the chance, a first generation Gibson GA-40...
Sometimes i hear you & other youtubers say, "this vudeo is getting long" & they plan on ending the video when, I am Not ready for it to end so, I woukdn't worry about a video running on or people not liking the content, If they don't like it, they woukd watch something else...I personally lusten while im at work & watch at home when i should be practicing but, your video's remind me to play so, There is that!!! I like your video's! Good content reveals itself!!!