Heroic Restoration of a 1948-52 Kalamazoo KEA Amp with an Unusual Circuit
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- Опубліковано 12 вер 2019
- In this lengthy and rather complex video, we will completely refurbish a truly wretched old barn-find 1948-52 Kalamazoo KEA amp, with a very unusual method of Phase Inversion. Virtually every single part has to be repaired or replaced.....with the goal of turning a lost cause into a real gem. Watch to see if I manage to accomplish this unrealistic goal.....and you will be rewarded by a long-overdue and pleasant surprise during the audio testing.
In addition, we will open some fabulous gifts from generous viewers with help from Jack & KC, and put an end to percolating carburetors on the 1932 Ford Pickup. Hopefully, there is something here to please everyone.....God knows we tried :)
If you'd like to support our advertising-free channel, PLEASE SUBSCRIBE and consider becoming a Patreon patron at: / uncledougsvintageamps or making a PayPal contribution to: dldcam@aol.com. Thanks !!!
Here is a link to Craig's video in which he designs and constructs the Volt and Amp Monitoring Unit: • 190729 Valve Studio - ...
In Sweden we are after work, so sushi, beer and Uncle Doug's new video. The longer the better!
That's what she says...
That sounds like a good combination, Echo. She said the same thing to me :)
@@UncleDoug you guys :) None of your saucy stories in front of Jack & Kasey thanks
Yes, Yes, Yes!!! on the SM57!!! I think it is definitely worth the trouble. I humbly suggest moving the mic a bit off center to get a more balanced sound; centered is generally too bright. Also, it looked a bit too close to the speaker (for my taste). I hope you will continue using the SM57 for future videos. Perhaps you can come up with a mic placement you can use consistently for all recordings.
BTW: The worst thing about the camera mic is the automatic gain control and the way it tends to overload.
I think you should consider recording some new demos of your fabulous amplifier collection. I would be willing to send a supply of catnip and assorted kitty treats to help entice Jack and Ollie into some additional recording sessions.
Thanks for another terrific and inspiring video!
You're quite welcome, John. I will experiment with microphone placement and will consider using it to re-record some amps from previous videos. Thanks for your input :)
Yes, The Big Test will be perfect. Camera mic make all these amps thin but you always say they have balls.
Nice, sunday test will be perfect
definitely. best amp sound on an UD video yet
My comments exactly, thank you John.
@@UncleDoug My only question Doug is, why didn't you mount a modern fuse holder on the back panel, so the fuse can be easily serviced?
The SM 57 makes a huge difference. I feel like I can actually tell what the amp sounds like now. Good Move...or Jack and Ollie have gotten much better.
Thanks twice, CF :)
The microphone is worth the effort. Nice tight sound. Thumbs up.
Thanks, Roscoe :)
Definitely the microphone. Was never impressed with the sound of some of your old amps. Now I am.
SM57 all the way!, just move it off center a bit :)
Thanks, Russell. I will. Thanks !!
I agree about the new mic.
Totally prefer the SM57. It adds clarity and dynamic range. Agree that it should be slightly off centre. Thanks for doing that.
Uncle Doug, The center is usually too harsh. Consider angling it so that the mic's diaphragm is parallel to the cone's surface. I find it's more natural sounding when the sound waves come from a parallel surface.
@@UncleDoug SM57 is the way go, definitally. I notice though some high frequency jitter in the recording. Don´t know if it´s from the metal grill or not. I suppect it being from the sample rate from the audio recording of the Tascam. When you collate the video from the camera with the audio from the Tascam. whatever export format you use should have a matching audio sample rate to the original so you won't get any digital artifacts.
SM57 is a keeper. The sound is better.
Great just turned Saturday video.
Thanks for your input, Erik :)
Don't you just love Uncle Doug's funny sarcasm. But always make it work good again.
Glad you enjoy it, Dwight :)
Uncle Doug, I felt like I was really hearing one of your amps for the first time! I love your videos anyway, but that was a real treat. Others have given good input on mic placement, but I would love it if you kept that up. Thank you!
You're welcome, B55. We will.
some mighty fine git-tar playin there Uncle Doug!
Thanks, Mr. P. All credit goes to Jack & Ollie.....my furry musicians.
Yes! The SM57 makes HUGE difference for the better.
Yep, I have a 52 Gibbsonette with the original Jensen FC 10. That amp was the first amp I ever repaired. I have been hooked on this hobby for over 20 years now. As an USAF Avionics tech and an IBEW JW, I had the background to learn tube theory. Thank you for the advice over the years. The Zoo sounds great!
Vintage amp resto AND hot rod repair!? With a cold beverage in hand surely heaven doesn't get any better. Uncle Doug your workmanship is always awesome! Nicely done again. what a sweet old amp that can be enjoyed for another 50 years.
Cheers from New Hampshire.
Thanks so much, Ken. Likewise from the Sunny Southwest.
Oh yes, definitely the SM57. Great episode again, thank you.
Enough about the sm57 we already knew that. The sound of that Kalamazoo amp is the story here, brought to you by that awesome sm57
Only a Master could accomplish this feat of craftmanship to bring this gem back to life.
You are too kind, M......but thanks ;)
SM57 for the win! And you played Thin Lizzy! You were on top, now you´re on the stars of my consideration!
Wow, high praise indeed. Thanks !!!
I must be living right. Walked into the house after a "lovely" session with my oral surgeon to find a 1+ hour of Uncle Doug goodness!
I hope our video dulls the pain, Michael :)
Welcome back. Bless you for sharing your wisdom with us!!!
Thanks, F1. It's a pleasure.
Yes on the mic! Now you can crank the amps for us overdrive aficionados! Agree on the off-center mic placement, or centered and pointing just off center. Drive those power tubes!!!
WoW! Uncle Doug, that sounds fan effing tastic. Good job to you and the gentleperson that provided the project amp from Kalamazoo.
Thanks so much, RB. Amen on Jim's generosity.
SM57 - big improvement. The audio is a joy to listen to.
Thanks, Dave :)
100% improvement works for me uncle doug keep up the brilliant work yours in from the UK,
Got to love radiomuseum.
Any random thrift store "find" I come across, I use that website to quickly get an idea of what I might be getting myself into. Invaluable for many things.
Indeed, Smithii. They are an excellent resource.
Wow! The sm57 sounds great!
I'm not sure how much of the improvement is from the SM57 or if te amp is just that good, but sounds absolutely amazing. The tone is full and round, much like my ex, except this is very pleasing to my ears.
One again you knocked it out of the park.
That was a brilliant solution to the fuel issue. I was about half way expecting you to prank us with the old hot rodder trick of dumping a bag of ice on the intake and calling it good. ;-)
Thanks, Randy. No pranks :)
Apparently way back in the 40's & 50's, because the controls were at the base of the amps they were probably mostly used presented on a table top rather than being a floor amp.
Amp sounds amazing.
Glad to see both your packages from Colorado passed the "cat" scan.
Another great resurrection of a classic old amp.
Thank you for all you do.
Much better sound with the sm57, UD. Now the amps will sound more unique. Great effort too!
I’m getting a SM 57 and see if my guitar playing improves also😆
This project turned out very nice
100% improvement with the SM57, so worth the effort, thanks Unc.
Nice playing at the end there, Doug! Thank you for moving up the amp, big improvement over the camera mic. Aiming the Mic slightly away from the voice cool should improve sound quality even more. Tim
IKEA amp?
Thanks for the video! SM57 a bit off center for the win! That's the most shrill point where it is now.
personally I found the tone of that Kalamazoo exquisite...and with a very nice compliment of tasty riffs!!!
Every video of yours that I watch I learn so much, this video it's speakers, speaker gaskets and speaker dust caps. Thank you so much, again.
That's great to hear, Brian. We're glad the videos are helpful.
Indeed on the SM 57 mic. Has a depth and fullness the camera mic doesn't.
Up to and beyond your usual fine work, my friend ! The amp sounds really fine and hardly no work required...he he ! Just as a thought, the standard for rating speaker efficiency, the mic is placed at 1 meter at one watt of power. The new mic sounds great and if I understand you placed it directly in the YT feed ? That would while sounding much better which it does, my thought is to record the file separately and place it in a digital file that we could download separately from a dropbox or similar, in order to get a full clean playback to play through our own DAC without YT compression.
As regard to our other project "SB swap", UPS seems not to be able to find it though all say it is coming. As usual no good deed goes unpunished. I will advise.
Cool licks and Hot days in El Paso, keep your head down and keep 'em coming !
Robert aka jagjet
PS the rush of fuel might even be the cause of float bowl woes as well, a vented cap might even stop the problem.
I was thinking the same thing with the pressure build up in the tank. As the fuel evaporated from the bowl, it was refilled and the cycle repeated. Now that the super engineered heat shield is in place, and a vented gas cap, neither should pose a problem again. Even with the added motor booze to the fuel. ;-) The new Shure Mic is great! Way better dynamics than the camera mics.
Thanks, Robert. The method of digital recording was described in the video, and the percolation problem was completely resolved by the insulator plates and the vented gas cap.
Wow! Two spare carbs for when each working carb needs a rebuild! I'll never forget the time I sheared off a bolt when trying to rebuild the carb on my 356 C.... It was the first one, so I took it and the rebuild kit to my mechanic.
I had no idea Brown Recluse spiders even smoked cigarettes. Probably menthol. Your videos are so much more than just amp-education, Uncle Doug. Thank-you for that.
Love your videos! Cheers to you and your rascals.
Thanks, John. We try to work in all sorts of informative tidbits, to keep our viewers well informed :)
Miked Amps please! better to appreciate the jewels' sound. Thanks UD!
As long as it doesn’t interfere with Ollie and Jacks playing use the microphone
Love the look and sound of the Kalamazoo.The kitties certainly stole the show, hope they handle their addictions properly. Hot rod fixes ta boot, UD you are a wealth of knowledge and I am a grateful student, thank you sir.👍
You're welcome, Philip. It was our pleasure :)
UD 👉 Your diligent dedication to Restoring wretched wrecks like this Cantankerous Kalamazoo know no apparent parallel 👏
We are not worthy
"Canary on Crack"!
Jack and Ollie's band name?
Keep the mic,,, much better sound.
It looks like I will, RR. Thanks !!
@@UncleDoug Definitely a good mic choice, UD. Sounds great.
Wow! The SM57 is the ticket! Thanks for the great video. Now my withdrawal pains are gone and I'm floating through schematic heaven.
Thanks, Thomas :)
One thousand percent improv. Great Job as usual.
Thanks, Steve.
Uncle Doug, I'm sorry I missed the original airing of this video, you we're on fire comedicly! And the amp as well as your work were as usual, very cool.
Thanks, Tim. Glad you enjoyed it :)
“A canary on crack” Only you sir, my goodness I enjoy your videos!
Ha-ha-ha.. That was a breeze Doug.. Well worth it though.. Much clearer and accurate sound with the industry standard SM-57.. I like the sound and look of the amp. Not bad for a 1940's design.. As they say : "There's nothing new in rock'n'roll". You make it look oh so easy, but us older viewers know what's involved...Great restoration again..Many thanks..
It was our pleasure, Pete. So glad you enjoyed the video.
what started out like scenes from indiana jones in the temple of doom,
after some fendering off brown recluse arachnids, then transforming
this lost arc into a veritable holy grail of an artefact,, utter genius
uncle doug,
You should be writing movie scripts in Hollywood, William. I'd pay to see the plot you described ;) Thanks !!
You nailed the ZZ Top Brown Sugar tone with that Kalamazoo! Even with the camera mic, that sounded like the spitting image to me. I had always thought the Rev. Willy G. was playing a 6G3, but wow, that Kalamazoo sounded right! Do like the new SM57 too, off center would sound great. Thanks for all the videos!
The black paint inside the air intake is a nice touch 👌🏻
Hey Uncle Doug! Just wanted to tell you how much I’m enjoying your videos. I took radio and tv repair in trade school back in early 70es. I ran little repair shop until got on regular with postal service. I also play guitar in bands as a side line for many years. So now that I’m retired I’m enjoying playing guitar and doing hobby electronic work. I really love the teaching videos. They remind me of school and has been a great refresher coarse for me. I also Love the pets and hot rod video as I’m a pet and car lover. So keep on picking and saving those old amps.
Will do, Lanny. Thanks.
Love the subtle humor, these are great well defined videos!
Thanks, Shawn. Glad you enjoyed it.
Wow great video! This answered all the questions I had about that old Bell & Howell amp, it's been driving me crazy not knowing how it works
Thanks, Mark. I'm glad the video was informative.
I have several 57s and they are my go to mics. Sounding great I think and from the resurrected Kalamzoo. Good stuff Doug,, thanks pal.
It was our pleasure, Carl.
The 57 was nice. I also liked the camera mic- because being further away, you also got a bit of natural room reverb- like you would with a room mic mixed in. Give Jack and Ollie a high five for us!
Thanks, Pyro. Will do :)
SM 57 does your work more justice Uncle Doug.
Chalk ‘n ‘ Cheese..
What a great ole Amp.
You brought it back from the Brown Bread....
Heroic indeed !
Thanks, RR :)
That thing sounds amazing! I think I have all the major components out of an old tube television to do a similar build from scratch. This will be my reference video. Thanks Uncle Doug.
the new microphone makes all the difference in the world. Thanks for another great video filled with comedy and useful information.
You're welcome, Charles. Thanks for your input.
I was immediately struck by the improved sound quality of the SM75. More fiddling for you, but quite noticeable at this end. And wow! What a repair! When you subtract the bits that you replaced, there’s not a lot left. Congratulations on your persistence, and ultimate success in this restoration/rebuild.
Awesome restoration (or resurrection!), that 6SJ7 really has a unique chime. Ace work and special thanks on explaining the phase inversion on this one!
You're welcome, Juan. Glad you enjoyed the video.
Thumbs up for using the SM57 for amp demos, sounded better :-) Minni sends greetings to sister KC and cousins Jack and Ollie.
I wouldn’t hesitate in the least to take that amp on the road. Sounds wonderful Doug.
Wow, thanks, Mark :)
The SM57 is an improvement. Mic placement experimentation might help de-emphasize the increased high frequency response. The auto gain of the built in camera mic is eliminated as well with the new set up. The carb nut count reminds me of the sponge count we do in the OR, although dropping a nut into the manifold would be far more calamitous IMO;) Thanks for the amazing service you provide. The few dollars spent on Patreon is the best ROI out there!
It's our pleasure, Frank. Thanks so much for your nice comments and patronage :)
Hello Uncle Doug. You have inspired me to make my first comment ever! I have been a huge fan of you for a long time. What you do is on a higher level than anyone else on UA-cam. I flipped when you showed your little dp008. I love that unit as I bet you will too
I have the 24 track but still use the little guy a lot also. Thanks again for all you do.
Thanks so much for your comments, Stratman. It's great to hear from you. Yes, we really love our little DP0008, and used it quite often back when I was recording tunes and tracks.
Thanks for including the SM57, really appreciated!
Wow , now that's the way i love an amp to sound! Powerful, clean and clear as a bell. Another winner from our uncle Doug. I suspect similar mechanical adventures to yours to be the genesis of the phrase ... driving me nuts. Also a likely band name
Thanks, Ken :)
Indeed Uncle Doug the Shure mic IS worth the trouble because the sounds are rich and vibrant and does not sound "tinny" unlike the sound which comes from the camera mic. Thanks for investing in it and taking time to set it up. Love it. :)
Incredible those ancient caps didn’t leak everywhere!
I really enjoyed the "Gretschy" tone and then the More than a Feeling lick made it awesome! Great sounding little beast amp!
Thanks, Sam :)
Another perfect restorstion to bring this old beauty back to life. I also noticed how you installed the four screws holding the speaker in place, with slots seating at the same angle. Beautiful work Uncle. Thank you for sharing your work.
I like when you used the "old terminology, cycles-per-second (CPS) "......nice job on the amp, Doug !
Thanks, Tom. I guess we old timers still stick with primitive terminology :)
Love your sarcasm
Uncle Doug your absolutely right.
Thanks, Dwight. My wife would probably disagree ;)
Dear Uncle Doug,
Yes, the sm57 is a clear improvement, sounds terrific! One big reason for the improvement is the proximity to the amp, i.e. the removal of the room sound. YOU DA MAN!!!
Very nice show. New mic: Super-duper. Heinous improvement. At last I (we) can hear the authentic results. The thing you do is all about fidelity. It really deserves the respect of a high fidelity reproduction. Thanks for a great show.
Thanks, Rowdy. You're right and you're welcome :)
What a beautiful amp - I have a weakness for round speaker cutouts, and that speaker grill is classic! "Kalamazoo" reminds me of the "Kalamazoo Bass 50" I used to have, with two original C10N Jensen speakers), two EL-34's, and big transformers. That was one I shouldn't have let get away - the guy who sold it to me said his band mates begged him not to sell it...
Spectacular repair/restore of this 66 year old Kalamazoo KEA. Your patience with testing, disassembling, replacing, reassembling, then re-performing those actions over, and over is admirable. Before adding the SM57, the tonality was reminiscent of early Buddy Holley. The Shure added a mid-rich fullness in the chord voicing. This was very well done! I can't believe I missed this episode.
Thanks so much for all your very perceptive comments, Alex. We're glad you enjoyed the video and the new microphone.
Howdy.
Old carburetor Toyotas used to have the same problem. Very difficult to start with warm engines on hot summer days for people who didn't know the physics behind. People just kept pumping the pedal resulting in flooding the intakes and combustion chambers. And all wet spark plugs, of course.
There was this Lady living in my parents neighbourhood. She could not get her Camry to start. I saw my chance to excel and asked if I may try. Sure enough that was ok.
So I pushed the pedal to the floor and turned the key hoping that the throttle open the excess fuel would vent out and the engine eventually ignite.
Bull's Eye. After, say, 5-10 sek.s the engine fired up with a terrible blast from the exhaust !
The Lady got startled but she was so happy when the engine had settled and ran smoothly.
Man ! Did I feel like a million dollars ? Yes Sir !
Regards.
Thanks for sharing this tale with us, Eugene. The old "hold it to the floor and dry out the cylinders" approach was always a good move back in the old pre-fuel-injection days.
Way to go, Doug. Yet another amp that is right out of my collection. I have one in mint condition that I only had to change the electrolytics on. It even has a cover. A minor point, the handle should be white. Keep them coming. About 40 more and I will have reference videos for all my amps.
Yes, I saw in photos that the handle was white, but what are the odds of finding one? I took the path of least resistance and used the brown one I had :)
The SM57 is an awesome upgrade! Maybe pointing it a bit away from the center of the speaker will remove a bit of top end that close micing usually produces
Agree, I'd move it a couple inches left of center, or aligned with the dust cover seam on most speakers. Sounds better than the camera mic dead-on though!
Great amp! Came out wonderful and now with SM57, nothing but gold. Love that six pack you got on that motor. Always a wonderful look.
I can't believe the improvement in the guitar sound with the new mike! Wow
Nothing like an Uncle Doug episode on a slow Friday morning at work.
......and you're getting paid to watch it !!!
haha! at work, it's more like listen to it, and glance over once in a while. I learn a ton just by listening. Something of a lost art
An exemplary result considering the adaptations and modifications
in componentry, great work uncle doug, i must say the new mic is
infinitely more articulate ,every note seems to ring beautifully, to the
point that no bum notes existed hahaha ,i really enjoyed this re-build
thankyou ,
Thanks so much, William. So glad you enjoyed it :)
Love your sense of humour uncle Doug
Thanks, Bob :)
Lovely valve compression & sustain with the Kalamazoo.
Great fix on the carbs too!
Uncle Doug I love the way you work, always keeping a level head while working through issues. Part of troubleshooting is knowing what to look out for, I have learned so much from your channel, thank you. I look forward to each of your videos.
You're quite welcome. I must admit, however, that a "level head" is not always present, and a fair amount of cursing, shouting, and threatening with hammers does occur from time to time.....but they end up on the cutting room floor when the video is edited :) I really appreciate your nice comments :)
Hey Doug, the Kalamazoo amplifier you have is a Gibson Gibsonette, made in a least two different versions, the one you have with no driver stage and one with a 12ax7 pre and driver stage with two 6V6s in parallel. I am rebuilding the parallel version. The wallpaper covering on the Gibsonette is very thin and mostly missing, recovered in tweed, three coats on poly, reconed 10" Jensen speaker, sounds great. Thanks for all of your videos, there are all ways FUN!
You're welcome, Gary. Good luck with your project.
Another vote for the mic. Thanks Uncle Doug.
Sir, having just discovered your channel (I'm a bit slow) I want to say a big thanks for unlocking the mysteries of valve amplification. My late Dad was an engineer on valve circuits, working on radar in WWII and later with Kodak. When I were a lad, I annoyed him by choosing a Vox Conquerer transistor amp over a Vox AC30, because it was lighter and had more built in affects. Very little did I know back then! Apart from the smoother sound, there's something much more organic about a valve amp that has been assembled by a human and that you can actually see working. Even though I've used several valve amps since, I didn't take a lot of interest in the workings, until recently, when I bought a late 50's record player, with a simple circuit, to hopefully get working again (parts on order). There's also a 1940 Epiphone Electar sat in the corner, which will need new caps. Your videos are proving invaluable in giving me the safety conscious confidence to get stuck in. The bonus is that you are a great instructor, with the dry wit to go with it. Cheers!
Thanks so much for your very nice comments, Graham, and best of luck with all your projects. Be careful :)
In the UK we have an invasion of brown recluse spiders, I have my vintage amps set up to begin my nest harvesting enterprise, your videos never fail to inspire me ;) +1 for the SM57 as well :)
The nests make for a good smoke, Dr. P, especially in a pipe. Thanks !!!
I love the SM-57 instead of the camera mic, even if just to do away with that ringing sound on high notes the camera mic usually presents.
Pro tip on the 57. Aim it right at the seam of the dust cap and you can go 5-10Deg off axis. Will give a fuller sound (dead on the cone will result in a LOT of high end). Slightly off axis will help with plosives. Also 1.4X the cone diameter away will allow the full frequency of the speaker to be picked up (no need to angle the mic then).
Great vid!
Thanks for the detailed info, Doug.
Great decision to get the SM57. You can really hear all thee fine details of the amp. As other below suggested, move the mic slightly off centre, like edge of cone.
Another beautiful restoration
Thanks, John.
Wow, another great fix Doug. I'm constantly amazed with how these old amps actually sound..! That SM57, fo me anyway sounds great. You certainly have some fine and talented followers. That guy Craig is another super clever guy.Such talent amongst you guys has me in awe..I'm still learning and the fog is getting clearer and clearer..Ed..U.K...😀
Thanks so much, Ed. Glad you enjoyed the video :)