The Snazziest Little PA Amp I Have Ever Seen......or Heard (after Conversion)
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- Опубликовано: 9 сен 2024
- This video features a very compact, beautifully designed PA amp (maker unknown) sent to me by a customer to be converted to harmonica use. As usual, we explore every inch of the chassis and circuit.....and then undertake quite a bit of work to not only make it suitable for reliable stage work, but also to determine the best tube (in V2 position) for the circuit. Every step should be helpful to those who seek to perform similar conversions. In addition, I thought the final audio demo was one of the better ones I have heard. See what you think.
As extra features, we will open and view a beautiful gift from a generous viewer and also thoroughly evaluate a very special neighborhood-garage-sale find.
If you enjoy advertising-free videos like this one, please subscribe to our channel.....and consider becoming a Patreon patron at: / uncledougsvintageamps or making a PayPal contribution to dldcam@aol.com. Thanks so much for your time and interest.
Hi Uncle Doug, we love your educational videos and love going on the repair journey with you. Bless you for always sharing your wisdom with us. So much fun hearing you play.
Thanks so much, F1. Likewise on the blessing.
They must have gone out of business just making the top of that thing! Wow!
It would look good on the hood of one of the hot rods :)
+The Guitologist; Brad, I enjoyed this amp so much, that I just had to do a 'little' digging. You may just find this to be of interest: www.americanradiohistory.com/Archive-Catalogs/Lafayette-Catalogs/Lafayette-Catalog-87-1942.pdf (it's "almost" there, see pages 104 and 105)
@@AMStationEngineer Actually Allied catalogs in the fifties carried these but don't remember who made them. They had the exact number of louvers however.
@he's the Master; My gut instinct tells me Arvin, I've seen some pretty strange stuff with their tags on the back. Arvin did a decent percentage of government contracts for A/V equipment, which stayed in regular use until around 1972, when the Title VIII funding purchased Kodak Carousels, and they dumped the old Bell and Howell slide projectors.
BTW, how much £££ to rent the TARDIS for a week??; I want to visit Apalapucia, Amy Pond is trapped there for thirty-six years, ALONE, because of that "Chen-7 Virus" thingy. Coca~Cola of Apalapucia's version of Dr.Pepper, "Professor Pibb", cures ALL coronavirus variants, and cleans mag wheels - too...
Uncle Doug This is another example of a well seasoned veteran and your playing sounds better and better every video. I have to say, I love you man.
The new microphone is a HUGE improvement, too!
The bromance is mutual, Mr. B. Thanks so much :)
@@demagmusic Yes it is. The SM-57 is the standard for almost all instruments. I have at least 20 of them for the drums and guitars. A lot of people will share a single mic for the 2 toms, not me, one on each of everything except the bass and kick drum and that has a direct out and the kick has a beta 52a for each kick.
@@MrBrymstond I agree 100%. I have a few '57s myself
the punches are the way to go, totally professional. great find UC I have been looking for them.
Great find on the chassis punch set. Hint: After drilling a hole with a step bit, I flip the chassis over and run the drill through from the bottom side as well. The next larger step will chamfer and clean up the burrs left - no file work needed.
Chris Kilgore I do the same but now I also use hole saws and the step bit to remove the rough material
To be honest, I normally do that too, Chris......but I kept things simple for the video.
A lot of people are getting away from Greenlee punches and just paying a few bucks to have someone with a CNC water jet hole it out. I was talking to a guy who said he got a RFQ from someone who wanted a run of Collins KWM2 chassis done.
I am sooo wishing I could have found a catch like those punches! Greenlee was THE supplier of chassis punches. I have had a couple over the years but always wished I could amass a set. You are SO lucky!
Thanks, Ray. Every once in a while, something good happens :)
I was going to add a similar comment. Agreed, these are the primo punches. Fine score on those beauties.
@@UncleDoug Those Greenlee punches are mandatory equipment in any shop building industrial control panels. Round ones for conduit penetrations but also special shapes (D-shaped holes, round with keyway, square, etc.) for mounting devices in panel doors that must not be able to rotate - pushbuttons, pilot lights, switches. They cut through 10ga mild steel panels just fine but require a good arm (or power tools!) to turn them.
@@UncleDoug You really scored with those punches. Greenlee knockout punches are the bee's knees. I keep debating whether or not to get a set. Already have so many tools that don't get regular use. You can use a ratchet and the appropriately sized 4, 8, or 12 point sockets to make it quicker/easier. 12 point sockets are cheap and readily available.
Again, a real pleasure to view, listen and learn whilst being pleasantly entertained. And in these days of so much sharing of just about all things and activities in life, it is refreshing to know that occasionally you will come across someone who holds the quality of knowledge and the expression of it in a non boring fashion. So thank you for being that guy Uncle Dough.
Thanks so much for your very kind comments, RRG. We really appreciate them.
Another great job! I was amazed that the amp was so quiet..no hum..
And it sounds great to boot! Those chassis punches are worth their weight in gold! Fabulous find! Thanks for another interesting and educational video, Cheers!😀👏👍
Thanks so much, FBH :)
I can see Uncle Doug walking to Kindergarten with a lunch box just like this. Other kids had super hero's, UD had 6v6 tubes in push-pull.
Plug it in and warm up your lunch from the heat of the tubes?
@@goodun2974 I have it on good authority he makes a mean souffle. (his last video had a quip on souffle's)
Yes, indeed, fellows......and I could use the louvers to grate cheese for my rat meat tacos :)
@@UncleDoug , my dad useta' make Cole slaw by slicing a whole cabbage on an antique cabbage slicer with louver-like blades, that he had restored himself and sharpened the blades. Sort of like an old-fashioned washboard or rub-board but with a series of giant Gillette Razor style blades cascading across the frame at an angle. A Cajun washboard players' nightmare, but it worked great.
@@UncleDoug Haha. Very cool little amp you got there UD. One of my favorites.
She's a beaut whether homemade or not( imo )Uncle Doug. Always interesting content here ,thanks !
My feelings exactly, Todd. You are quite welcome.
That output transformer is a replacement ("universal") type. That, and the use of screws instead of rivets for everything, makes me wonder if this was a home-brew item. That style of case was available for experimenters/ham folks way back then. The big cap was also a regular parts shop item. Probably built from plans in an electronics magazine.
That's an interesting theory, Ray, and may explain why there is no mfg. ID anywhere on the unit.
@@UncleDoug That also might explain why some odd 'techniques' were used in the circuit wiring Doug. Omission of grid stoppers, nice long curly signal receivers, and the unusual filament wiring, also connecting a 1/4 jack direct to a power tube.
@Kenny H Oh to own one.
@Kenny H I never said screws were not used elsewhere but noted that this mixed screws, nuts, and bolts - and not in a consistent manner. Transformers especially were often bolted in since there was a common failure rate for them. Tube sockets were also very fragile and anything portable or high-power could go through those parts quickly.
Well, the guy did have some punches on hand.
Wow Uncle D, I am officially jealous of that garage sale haul, good for you!!
What a cool little amp! I love watching your videos. It's like taking an electronics course for free every time.
Tiny but mighty - great job as usual Uncle Doug
Great tutorial / walk through / sleuthing with the tube handbook. I learned a ton tonight, thank you Uncle Doug.
Nice find on the Greenlee punches. I have a whole set myself that were my father's. He was an electrical contractor back in the 50s and 60s. They are all in leather cases. Very cool. A little valuable.
Wow, in leather cases......extra nice, KG.
Being born in 1983, and also not being too into tube stuff until very recently. I had never heard of chassis punches, I would have guessed they used a drill press like you did. Those punches are awesome. I'm big on nice looking work like that. I love what you did with the amp too. It sounds fantastic now. I very cool how you quantitatively showed us the differences between the three tubes. Let's just say I liked everything in the video. Your playing is awesome, you don't hear people play like that anymore. Grateful to you Uncle Doug.
Wow....thanks for all the very nice comments, T1. We're glad you enjoyed the video.
Very good video on the little amp, really enjoyed listening to your knowledge filled info on the repairs. The bit on the chassis punches, my dad had the whole set of these, a really cool tube tester in a wood suitcase type of housing and one of the best Simpson multi meters i had ever used. When he passed away my mom sold all of his stuff in a yard sale before I had the chance to get any of it. I did get his old Weller soldering gun and craftsman tool box. You remind me of my dad when you are talking about the circuitry. Thanks for the video.
You're welcome, Rob. I am honored by the comparison. Out best to you all.
Greenlee punches were designed to punch out holes in industrial electrical cabinets which are far thicker than your home circuit breaker box.
Great video with Lots of great tips!
As an electrician, I can say you got the deal of the century!! Now, if you have and I'm sure you do a socket the fits that square nut and a cordless drill or impact you are golden!!!!!!
Thanks, Duane. I do :)
That old "Mike 1" coupling capacitor was very likely there so that carbon microphones could be used as they were still common back then. no high voltages used, but the DC voltages need to be blocked first
Uncle Doug.
Thanks for yet another entertaining and informative video. Nothing makes my day quite like opening the computer and finding a notification that you've uploaded a new video. I just wanted to say that in a former life I was an electrician and so I have a set of Greenlee punches for 1/2" - 1-1/4" conduit. They're designed to punch main breaker panels which are made of some fairly stout metal. I'm not sure of the actual gauge of metal those are made from but I'd say that 16g is probably a safe bet. I don't recall the actual sizes of hole they make, but I think the 1/2" one makes a 7/8" hole. It's to accept a 1/2' thin-wall conduit fitting so that's why 1/2" is actually 7/8". The sizes are that way all the way through the set. You'll find that it's a lot faster and easier to get an 8-point socket to fit the screw and use a ratchet wrench when making holes like the one you demonstrated for us here.
I see another viewer (Ray Rooney) already mentioned that he thinks the amp in this video is a home-brewed model from back in the day and I agree 100% for the very same reasons he cites in his comment.
Thanks again for another great video. Please keep up the good work. {8^)
Dale
Thanks for all your helpful comments, Dale. We wll :)
The best, single knob amp I've ever heard, and possibly one of the beat 20 knob amps I've ever heard. A harp player should be in heaven with this amp!
Thanks, Tim. Glad you liked it :)
Wow. That is a goldmine of punches. I've used those a lot in electrical work, but I've never seen a vintage set like that.
The 1meg resistors from the unit grids to ground are 'grid leak' resistors. They bleed off the accumulating of electrons that tend to be impressed on the grid from the flow of electrons through the grid.
Really cool case.
Thank you so much of showing us how the sausage is made...
It was our culinary pleasure, John.
tube strengths...the clean sound in your capable hands really bring it on home~ :)
Thanks, Jay :)
I used Grenlee punches a lot. They are hard to beat. They also last a long time. You will lose them before they wear out. Great video!
Or, in the case of my tools, they'll get stolen by your customers before you wear them out.
Sweet haul on the punches!! Greenlee is a top tier brand of contractors.. High dollar & (mostly) high quality.
Step drill tip - Always go a tiny bit deeper so the next step bevels the top side. Then flip the work piece and run it down the same way. Perfectly beveled and clean holes are the result.
Thanks for the tip, J.
Great job, i thoroughly enjoyed this video. Cheers. Andy.
Ford 289 V8..a flashback to my first car, a ‘66 Fairlane wagon. What a dream to work on.
Liked the choice of music at the end. Lonely is the night is a great opening riff.
Thanks, Neil.
Every time you say Jack your cat must get confused. Now I know why he's always coming around you when working on old amps with multiple "jacks". What a cool cat. I had a cat named Jack when I was a kid in the 90's. He was also black with a little bit of white underneath.
Jack understands the subtle inflections in my voice......especially when I say "cat treats" :)
Education and humor at its best as usual, captivating!
Thanks so much, Scott :)
Thank you. I am still learning what tubes do and how they do it. This was a great learning experience. I have a AIMS Eclipsor in the garage that may have a blown power transformer. Time for me to learn how to fix it. Thanks again. Jim
You're welcome, JG. That amp name sounds like a weapon in an old SciFi movie. Good luck with it.
I love my chassis punches but a step bit can replace about 10 different sized punches for ⅓rd the cost of a single punch, new. I only have 1 punch for 9-pin sockets and 1 for octal. Without the step bit I would be limited in what brand of socket i could use in my builds.
With your experience ………… my hat is off to you sir for taking on unique jobs. Great work man!!!
Thanks for watching, David :)
great garage sale find. The punches probably belonged to an electrician as they are for punching holes in j-boxed for conduit connectors. Greenlee is a electrician tool supplier located in Rockford Ill.
Thanks, Joe :)
Not only did you get a good deal; you got the best there are!
Yay.....a win....win :)
Hi! For replacement can type replacement electrolytic capacitors try Hayseed Hamfest. If they don't have exactly what you need, give them info re: physical dimensions, mfd and voltage etc. and they will build to order. Great for when originality is important.
Thanks, Daniel. I have used them in the past for custom-built can caps.
Thank you Uncle for another very interesting documentary.
wow that thing compresses beautifully... Thanks Doug!
Thanks, CD :)
Very sweet little amp. That looks like a "Bud" box from the late 50's, I see them in my catalogs. They were made in various sizes and styles for project building.
I wonder if someone makes videos on harp tones and how to achieve those, since we spend countless hours detailing guitar hardware .
Put a little oil on those cutting tools :)
Thanks, Richard. There is a possibility that the unit was hand built. I agree. It would be interesting to know what component values are best for harmonica use.
Oh my, this is a sweet one Doug.
That Ampro cab is an eye catcher indeed!
Warm sounding amplifier and great for blues ala ZZ Top. Gorgious little amp!
Glad you liked it, Amo :)
Love the video Uncle Doug - beside the overall (as usual) fantastic and informative content, gotta say that the pink wire comment: "dipped in Pepto Bismol" really struck my funny bone, another classic Uncle Doug bit of subtle sarcastic humor - - so, thanks for a great video and an the LOL !
It was our pleasure, Skip :)
Hello, James here. Once again, thoughtful, creative and well-explained. The shielded cable tip is gold. I have miles of these laying around
Thanks, James. This type of shielded cable is threatening to bury us if we don't start recycling it :)
What a great voice you have Uncle Doug.
Thanks so much, Jeff. I feel the same about your very special guitar playing ;)
GREAT FIND on the sheet metal punches. Looks like a real nice set. A very good filings-free alternative to step bits, especially useful if you’re doing mods to old work like the other day when I had to cut out a square hole to retrofit a 3-wire+fuse power socket. Filings everywhere and fitting a jeweler’s saw into a small space full of components was no fun either.
Thanks, Aero. They've been really helpful :)
Some Ford Falcons had 289v8s to.
Thanks for the Amp
Insights. Nicely done.
You're welcome, Dwight. That engine in a Falcon would be a great combination !!
Really missing your posts UD., whether it be amp related or automotive. Maybe it’s just me, but your videos are quite enjoyable and addictive.
Thanks, Glenn. We are currently working on a couple new videos.
Congratulations on the great find on the hole punches, uncle Doug. Definitely safer than the step bit and cleaner cut. Only reason I use step bit is the cost after pricing both types new.
Yeah they work really well, even 16 gauge stainless steel! You need to use some kind of oil on the inside of the cup side, & on the outside of the punch side, every time. Probly a good idea to wipe them over with a film of oil after you've finished with them as well.
Large transformers do indeed perform differently to small ones, and the reason for this is that ferromagnetic transformer cores will conduct a magnetic field reliably only up to a certain strenght, past which it becomes saturated and it starts conducting the field just about as good as air or other materials.
Having a core with a larger cross section means that the magnetic flux density through it is much smaller compared to a small transformer (In other words, the magnetic field is distributed on a larger area with less intensity), the core stays well below saturation,, and thus the transformer has a larger linear region of operation (and so, less distortion).
Smaller transformers run into saturation much more easily and in theory you can get a sort of overdrive effect just from the transformer core if you run enough power through it.
Thanks for your very knowledgeable input on this subject, Mr. TM.
I used to work with equipment that had a saturable reactor , which I assumed was a transformer. Upon powering off said equipment to fix, I had touched both output leads and woke up faster than drinking an espresso. After, Turd boss explained when shorted the magnetic field collapses releasing energy .. oopsy
@@circuitsandcigars1278 saturable reactor ... Not a couple of words that I hear used often together. Reminds me of my first wife, and why I left her. Well that and the black eye.
The hole cutting, the punches are nice - you get a nice ring of metal for future use
Yes, indeed :)
It's very clean and expressive, which is what I would expect from an amp with a triode input. Since it's going to be used with a microphone it would be nice to hear what a 6SU7 sounds like in there, that is if they weren't so expensive; I have several of them I got for a steal, including a matched pair, in a big tube lot which came from the estate of a silent key.
Thanks, D20. I'm not familiar with the 6SU7 tube.....but will read up on them.
At 41 minutes. What an awesome tone! The guitar lessons you have given your pets are paying off.
Thanks, JG. They are quick learners :)
That punch set looks complete. Amazing steal! (pun intended)
Another little tip on using the Greenlee punches - keep that drive screw's threads lubricated with light oil when using it. Makes it a lot easier to turn the screw and makes the screw last forever. Also, a light coating of oil on all parts of the punch will prevent rust. I have a complete set of punches from 1/2" all the way to 2-1/2". They are 40+ years old and look and work like new. Great tools as you have already mentioned.
Thanks, QL. I will oil them carefully and often.
nice job uncle doug nice job...........you rock....
Great video. Lots of information on tube functions and reading the circuit of the tube. The tube book was cool too. Greenlee the is best hole punch ever made. You got a great deal. They make hydraulic punch sets for thicker metal now.
Thanks for all your nice comments, Walt.
PUNCH SET IS FANTASTIC
O.M.G. $40??? A couple of weeks ago I was looking at buying 1 or 2 for amp chassis work and decided they were a little rich for my blood.I'd call your find an absolute steal!
Thanks, Michael......but when you add in the $400 in gasoline wasted on attending the preceding fruitless garage sales, I guess it all balances out :)
Great score with the Greenlee punch set.
The information that you share is above and beyond for me as well as the player 🙏🏼 thank you
You're welcome, Charles. We try to please ;)
Nice catch on the Greenlee punches. Have a set myself, including 9, 15, and 25-pin D-subminiatures and several square and rectangular punches. They are still available, but not inexpensive.
Again, thank you for the excellent lesson.
A way to test which tube you have is to throw it on your tester and compare conduction to a known example of one of the tubes. Probably I'd start with putting the tester in SL7 mode. If it isn't the SL, it would probably read really weak.
Good idea, Brad, and I generally do use the tube tester, but I thought the fans might enjoy a side-by-side comparison. I was a bit surprised by the magnitude of difference between the final volume with the two different tubes.
@@UncleDoug Yeah, way more fun your way.
@@UncleDoug , 6SL7 is roughly equivalent gain to 12AX7 gainwise, (actually more like a 5751, which like the 6SL7 has a voltage gain of 70) 6SN7 roughly equivalent to 12AU7 ( gain is 20).....12AX7 gain is 100.
Bonjour de France , je vous suis au moin deux fois par semaine . Respect. Bonne continuation Thierry
Thanks so much, Thierry. We're glad you enjoy our videos :)
Yup, PUNCHES r the best : ) Wonderful set u have there. GREAT FIND use those for ELECTRICAL PANELS all the time.
You can use the step drill bit to clean up the burr either by hand or very carefully with a drill motor by turning the metal piece over and using the step dill size for the next step just enough to clean up the burr. I talking about using the angle portion only maybe about .020 of it.
Yes, indeed, and I generally do that, William......but I was in a "stone age" mood during this video :)
Super cool ! Snazzy P.A. and snazzy shop speaker.
You're the bee's knees, Jason :)
From Leo: The chassis punches are gold. I just paid $50 for a single 1-7/32 for installing 1" conduit in a hoffman box.
I cannot tell you how many hours I spent with drill bits and a file in the 1960's as an electronic hobbyist. To mount a 3 inch taunt band meter in a panel, I would drill dozens of 1/8" holes in a circle and after chiseling to connect the holes I would use a rat tail file to clean it up. My labor time was pretty cheap back then.
Indeed, Barb. I see these gems as a real windfall :)
I got my start in electronics when my father in law gave me a brand new RCA 25 inch solid state console television. He had taken it to several shops to try to get it fixed and no one could fix it. When I got it I took off the back and plugged it in and turned it on and immediately I found a smoking resistor (the old smoke test). Since I didn't have a schematic I just suck a 100 k ohm resister in its place and presto the TV came to life. Then when you would walk around on the floor of the house we rented the video would come on and then go off--an intermittent problem. So I pulled out the IF can and took it apart and found a solder ball that was rolling around inside and shorting out the video output transistor. Dumped it out and we watched that TV for around 20 years. It had great convergence and finally developed a high voltage leak which I fixed with some silicone sealant. Finally after a few more years it developed another high voltage leak that I could not fix and that's when we got rid of it. The original tube sounds like a 6SN7. Hardly any distortion and pretty loud for a small amp.
Thanks for the interesting repair story, Rusty.
Thanks for another very informative and entertaining video. You are an excellent teacher!
It was our pleasure, Phillip. Thanks !!!
Uncle Douglas
Besides your expertise at resurrection of these wonderful vintage amps , I so look forward to your demos. Your playing is beautiful. So darned clean. Love it.
Thanks so much, Ray. Praise for the demos goes to Ollie & Jack :)
Yes the 6SL7 has a great sound. What a nice little amp, as always good job. Thanks for the video.
Thank you UD for sharing another jewel of knowledge and know how with us mortals!👍👍👍
love the acca dacca at the end mate. well done !
Good amp video.
And good deal on the punches. At our workplace they have those Greenlee punches and they have gone through 12 ga steel even to mount Allen Bradley 800T series industrial indicator lamps and controls. They have a hydraulic hand pump tool that operates the very same kind of punches with an adapter. So there's that if you go into production.
Thanks, Daniel. I would love to have one of the hydraulic pumps for the punches......maybe some day :)
Hi Doug,those punches were used by a lot of Electricians.Back in the day before pre-punched junction boxes,Sparkys had to punch holes for your various connections And yes they are very expensive but worth their weight in gold . Nice score man,you lucky dog.Hahaha 👍🎸😎
Salutations Uncle Doug,
Well I missed commenting on the Kay amp so here goes, Great Save! I must agree, unbelievable sound out of the eighth-inch speaker. I was surprised to see a filter choke on an electro-dynamic speaker, perhaps it was built before the bean counters figured out that a field coil would make a passable filter choke. Beautiful end result I would be willing to bet the Harmonica player will be very pleased with it. Now the snazzy little amp, what a fantastic little gem that turned out to be. (post circuit corrections and tube substitutions that is). I get the feeling that it might have been worked on previously by a Solid-State technician just judging by the DC blocking cap on input two and the flat three-wire power cord. On the filament wiring, another RUclipsr that I subscribe to Paul Carlson, Mr. Carlson’s Lab, worked on a couple of high-end tube type Hi-Fi’s. They also had filament wiring right against the chassis, although it was tightly twisted. I questioned him about that and he responded that it was a often debated subject between guitar amp designers and Hi-Fi designers as to which method was superior for hum reduction. The guitar guys say flying twisted leads and Hi-Fi guys saying twisted wires flat against the chassis right up to the socket terminals. He said in his experience both methods are effective. Surprising that the untwisted wiring was so quiet. Final result was as usual superb. On that output transformer, I have an output transformer, a Hammond 125E that is variable impedance depending on the load impedance. It comes with a chart giving the impedance of the transformer with a 1.5 through 16 ohm load. It varies the impedance from 8000 16000 ohms on the center tapped primary. It would make any difference with DC only on plate current but what about a 8000 cycle tone? Perhaps that was why that amp had such low plate current values with the 5Y3 rectifier. Perhaps the designers were compensating for an unknown load impedance to protect the 6V6’s from too much plate current. Hmmm, might be something to test if I ever get the time. I was elected President of the Amateur Radio Club that I am a member of. Not realizing that I was going to be the president of a nonprofit corporation as well. Talk about getting a crash course in corporate paperwork filings, Wow! It has been a very busy month. And still not finished. Another wonderful video and look into a screw bearing for your Greenlee punches, if one of the big ones doesn't already have one. It makes a huge difference in how easy it is punch through thicker metal. The newer punches have a splitter blade machined into the punch that cuts the slug into two pieces. I have used a hydraulic punch set to punch 1 1/2 inch holes through 1/8th inch steel many years on bag chutes at a feed mill to install infrared counters. Great find, you will come to love them. I love mine. Until next time, looking forward to it as always.
Once again, a whole slew of great comments, Mark. I too was surprised by the absence of hum with the un-twisted filament leads.....but will continue to use my standard "twist and swoop up, over, and straight downward to socket" technique. Congratulations on your ascendancy to the Radio Club throne.....if anyone can run it right, it would be you. I will check the boxes for a screw bearing, and will order one if needed. Thanks again for your time, interest, and great input.
I've had pretty extensive experience with Greenlee punches and I thought I'd offer a little tip or two for working with them.
If you get yourself a (1/2" IIRC) 8-point socket for use with your 3/8" drive ratchet handle it will fit that square-headed screw and make punching that smaller hole go a lot quicker and easier. Then when you have to go with one of the bigger punches that uses the much larger screw, you still drill for the smaller punch and then punch with the appropriate smaller punch, just large enough to allow the bigger bolt, or screw, to pass through. It's a lot easier to punch that big hole than it is to drill it. Plus you only need to keep the drill bit for the smaller screw with your set which is also convenient. So one bit for drilling with the square-headed screw then punch the hole for the larger screw.
Excellent advice, DE. Thanks !!!
Hi Doug, another blockbuster mate! You did a great job fine tuning that little big amp, it sounded so sweet for it's size. The extra gain of the 6SL7 was so evident on the screen trace, that's a great way to show people the performance differences between different valves. And going through the databooks to compare specs & pinouts. Well done! You're a good teacher too! Do you sing or whistle too? You're a man of many talents, & it's pleasing to see someone using them all so well, & sharing them too.
Wow....thanks for all the very nice and positive comments, Neville. I've had many varied hobbies over the years, including vintage jukeboxes, hot rods, antique clocks and phonographs, vintage British motorcycles, photography drones, and wristwatch/pocket watch repair. I always enjoy a new challenge.
I've never seen a Hole Punch kit before, Very impressive!
Thanks, Tim. It is indeed :)
Very cool looking amp. Thanks for the education. Great work Uncle Doug!
That dial numbering is typical for a PA, with 0 db (unity gain) in the center, with + and - gain on either side.
Hi Jim, I have 3 Bogen PA's, a Davis, a Bell and a Harmon Kardon also.. 4 are 1950's and 2 are mid 60's, and none of them have the volume or tone labeled in such a fashion. The Harmon Kardon does have one knob in that style, but in reality is for mixing Aux 1 & Aux 2 volumes together. I think that style is used with active tone circuits. Tom
I mostly play with and collect older TVs and stereos. I sure didn't know that about input wire. It makes a ton of sense. I was on a lead to think bigger is always better when it comes to wire gauge. I do know that with current draw, it is and perhaps it is better for sound from speakers.
Yes, indeed, Jeffery. If a wire is going to be carrying a fair amount of current, i.e. over 1A, it should be of a stouter gauge, i.e. 16 or 18 ga., whereas low-current wire can be of a smaller gauge. Signal wire in the early stages of amplification carries virtually no voltage or current......hence the small gauge shielded wire is perfect.
A good way to tell if it's 6SN7 or 6SL7 is to measure voltage drop on cathode resistor and calculate current through it. The 6SN7 should have almost 10 times as much current as the 6SL7. Thanks for another great video Uncle Doug. By the way my nephew and all his friends call me Uncle Dale.
Thanks, Dale. Since both tube and socket were unmarked, an additional problem is whether the tube present in the amp was the proper tube in the first place. I thought it best to do a comparison and go with the (obviously) superior tube.
Thanks again, Uncle! Great find on the punch set too! Cheers!
The wire color is said to have a major effect on the tone. Pink wire will make the tone bright, bubbly and bouncy. Really good for Polka and accordions.
Pink is also the official color of Big Clive's channel.
Yes, but the owner favors harmonica......which requires dark, murky colors, preferably dipped in cheap whisky and liquid nicotine :)
I hear Eddie Van Halen favors brown wire, for its tone.
I'll see myself out.
fortj3 Ed’s amps tend to have the pound cake aroma. I would stay away.
We have an 18v greenlee punch at work used for punching conduit holes from 1/2” conduit ,which is a 7/8 hole , up to 2” conduit which uses dies similar to these.
That sure sounds better than my crummy open-end wrench, Tony.
Hey,uncle doug👍a Million and billions of the best rockn rolly's for your channel!🤝😁this old tubeampys looks like steamy,oldycar 🏎🏍motors/machines!great !i love it to see your skills !
Thanks so much, Francis :)
Nice score on the punches. Now you only need a few D shaped ones and you are set for life. I love these Greenlee punches.
What is the benefit of the D-Shaped punches, Alan, other than they would allow me to personalize my neighbor's car hood?
@@UncleDoug D shaped holes for some fuse holders. The D shape makes it so it doesn't spin when you tighten them to the chassis. There are also double D punches, flat on two sides. They get used a lot in military style connectors. I work at a Navy base so I get to see lots of cool electronic stuff.
Interesting little PA amp. Looks like a home brew :)
Many have said that, Frank. If so, it was well done.
That is one sweet sounding amplifier.
Thanks, Brad.
Greenlee knockout punches are the bees knees for sure! I will never forget the first time I discovered them. I was blown away amazed, as prior to that I had only known step bits and (gasp horrors) hole saws.
3mm / 1/8th steel is the largest I ever used a Greenlee on. It got it done but I wouldn't recommend haha! I believe 10 gauge is the limit they report.The only thing that is truly horrible about Greenlees is how expensive they are. Even used, typically you pay $25-50+ per punch, with the less common and/or bigger sizes bringing in a larger price tag. I only purchased the 1/2 conduit punch brand new. It was the slug buster model, which creates two bits of metal instead of one. Not really needed for 1/2 size, but it was what was available and on the much bigger sizes the ones that create a ring can be quite a pickle to get the ring out sometimes. I paid $60 USD for just that one punch!...
You got an amazing deal on your set, and more often the "radio chassis" vintage Greenlees are in better condition/less abused then say used ones of common conduit sizes from electricians. I just got lucky and scored a vintage Japanese radio chassis punch set for $40. However, I just got another shock and amazement! If you have a Harbor Fright (yes, I spelled it that way on purpose! tehehe), they have a 4 punch kit for an unbelievable price of just $25! They also have a 5 punch hydraulic kit for $100, another amazing deal. I am constantly blown away by what HF dabbles in, and this discovery is a much welcomed one.
Actual hole size (stated size on punch)
Hydraulic set $100 (SKU 96718, 56411)
*28.32mm (3/4" Conduit Punch)
*34.6mm (1" Conduit Punch)
*42.86mm (1-1/4" Conduit Punch)
*49.21mm (1-1/2" Conduit Punch)
*60.32mm (2" Conduit Punch)
Manual set $25 (SKU 60575, 91201)
*22.2mm (1/2" Conduit Punch]
*28.32mm (3/4" Conduit Punch]
*34.6mm (1" Conduit Punch]
*42.86mm (1-1/4" Conduit Punch]
I will be trying to get my paws on the manual set, maybe a couple at that price! Some things one shouldn't buy at the Fright shop, but the manual set is one I would certainly class as a should buy. You really can't go wrong when you get 4 brand new punches for less then the price of one used Greenlee!
Thanks for all the helpful input, RO.
what a cool little amp!
Nice work!
I like the idea of wrapping the replacement for the can cap with sprinkler wrap and remove the old can and put them there instead - but of course you would need to do the wiring with long nose pliers
Hello Uncky Doug lovely to have you back again an excellent video this think you got a great tone form it best wishes. Ged Devon
I'e got an '82 Seymour Duncan Convertible 100 that I'd love to see a vid on. .You're great!
That's a little new for us, Sam. Thanks so much :)