Guitar Amp Conversion - 1940s Ampro 16mm Premier-10 Projector
Vložit
- čas přidán 6. 09. 2015
- This is a vintage 1940s Ampro Premier 10 16MM Projector. In this video, we will service its 6V6 push-pull tube amp and see how it sounds with a guitar plugged into it. We will also discuss some of the obsolete technologies used in old 16MM projector equipment like phototubes.
Tubes are 5Z4 rectifier, three 6V6, one 6J5, and one 6J7. There is also an RCA 927 phototube in the projector portion for optical sound reproduction.
Schematic: www.paulivester.com/films/proj...
Phototube Info: www.tubebooks.org/Books/Atwood... - Věda a technologie
I went to an indoor garage sale that the city put together and my hopes weren't high until I arrived and picked up a zenith tube radio for a decent deal, then an ampro projector similar to this one and a big box of tubes and an af/rf signal generator from 1950. I really don't have to do anything to the projector to run a guitar through it, I will go through the capacitors and stuff and it has an 8" rola alnico speaker with it. I got the idea from you from this video and the one where you pick up a bunch of projectors and speakers. Thanks for the inspiration.
Thanks for yet another 40 minutes and 9 seconds of inspiration!
Just picked one up at auction for $16.00 . Looks exactly the same, but is labeled century 10. Can't wait to tear into it.
For some reason I'm way more impressed by all this old technology than I am by modern computers. How the heck did they first figure out how to even make speakers work...let alone photo sensitive electron tubes that transmit sound information?!
You can thank Albert Einstein for that (as well as others of course). His Nobel Prize was not for his famous General Relativity paper but for his paper describing and explaining the photoelectric effect.
i dont think Einstein had a thing to do with movie projectors or this old tech. he was a physicist in mathematics, not building electronics. lol
+james corvett - You can't build sophisticated equipment like that without understanding the principles behind it. Einstein and other theorists figured out those principles.
The ripples go quite far. For example, without transistors we wouldn't have (practical) computers. Without quantum physics, we wouldn't have transistors. The understanding of photoelectric effect was one of the cornerstones of quantum physics.
No, Einstein haven't built a single iPhone in his life, but the knowledge he provided allowed other people to eventually get that far.
Like they say - There's nothing more practical than a good theory.
@@xeroinfinity a physicist in mathematics???
@The Guitologist
Thanks for the rundown on the Phototubes!!
I have a few of these and wondered what they were for, now I know!!
THANKS!!
What an interesting combo of instrument and amp!
Not something you see everyday.
Un-killable 16mm projectors, I used them for years in the 1970s in a home theater. Almost silent running, would smoothly run the most damaged film and not lose the loop. Love them.
Yeah! I played my guitar through one of these Ampros for about 5 minutes about 12 years ago... it sounded super cool. Unfortunately, a capacitor or something blew up on me and the amp's internals was packed too tight for me to easily work on at the time. I look forward to the rest of the video and the end result!
Sounds amazing!
I picked up a Bell and Howell 385 16 mm projector made in 1957 about at a junk store this weekend havnt has a chance to see if it will work as an amp yet but all is good on it but did pick up a Rheem Califone A V series 1835 A phonograph unit made in the later 1960's mostly ii think for schools working all the way after i came across this video looking it up i tried one of my guitars on it and could not believe how clean and sharp the sound was so now i have new toys to start looking for so not just projectors
This stuff is really cool. I have a bell and howell filmosound 385 amplifier out of a projector. Projector amps are pure mojo
awesome video. old gear just sounds so damn beautiful
JongThrill I wonder who owns the gigantic prop amp from the Back to the future movie?!I'd like to run across that in a yard sale!
Just picked up a premier 20 today at Goodwill pretty cheap. Although a beautiful art piece for the wall, it does work great and look forward to plugging the guitar into it. Will have to play as is because I would be to terrified of messing something up with what was done in this video. Thanks for the in depth, I learned a lot about my new find. Cheers
You have inspired me to find one of these......which I did. Hope I am successful too, because I was super impressed with the way yours sounded! Thanks Guitologist Brad!
Awesome man. Let me know how it turns out for you.
How’d it go?
any joy with it ?
This is such a great video, thank you! I have happened upon one of these, and am going to use it for an amp. Am wondering if you happen to know what the ohm output on this? I've been unable to find out online so far. Thanks a million!
Just found one of these units in the basement of a Frank Lloyd Wright building in Wisconsin. Pretty cool, mine appears to be a slightly older unit, with a US Navy inventory tag on it. Thanks for all the great info, and look at the innerds. I've got lots of work to do, but it's fun just playing with this great old, made well in America, stuff! Thanks
That sounds great!
Just found this! man that thing sings!
thanks for the info.....
Thanks! Yeah, this is a cool piece of gear. Beautiful and functional.
Tim Pierce, session guitarist, has a converted film projector that he did a short demo on, but I can't find it now. That sounded awesome too.
Old school are amazing
Sounds great
Some thoughts about the film sound system. On the film there is a sound track to the side of the images. It is a visual representation of the sound wave. The wave is printed on the film twice, once in mirror image, on the left and right sides of the sound track, and the track is blackened from the wave to the edge on each side, while the center remains clear.
The exciter lamp shines through a narrow slit, through the film and onto the phototube. The amount of light hitting the phototube will vary depending on the width of the clear space on the film.
The phototube is a DC device that varies the current it passes depending on the amount of light that hits it. If the light is varying, the current varies with it. Think of it as light controlling the grid of a triode. The brightness of the exciter lamp is like the bias on the grid. Couple the varying DC through a capacitor and the rest is a normal audio amp.
Best guess is that the little oscillator was the most efficient way to adjust the brightness of the exciter tube.
Yeah, I'd say you're probably right. Gotta be something like that.
There were actually a couple of types of sound tracks. Variable density was used by some labs where the sound would lighten and darken the sound level. Variable slit types would produce an almost oscilloscope-looking track. and later on 2 tracks were squeezed into the space giving stereo capability. (As far as I know this last technology was only used in Europe.) I won't go into magnetic tracks...
Cool vid Brad!
+Raymond Nijenhuis Thanks, Raymond! Thanks for taking the time to comment!
Great find!
+Ryan Conroy Yeah, I thought so too. Thanks for watching! :D
Thinking about building a cigarbox guitar!nice vid love em
I have an early 60's amp from a Bell&Howell projector. With an eq pedal to push it a little. Turn it up full and use the guitar volume to go from very clean to awesome overdrive at ideal band volume. I think it's rated at 30watts. It's just a little too noisy to use live. I think it needs a few caps changed somewhere, but just a beautiful tone.
Enjoyed the video. I have a Premier-20 but the power transformer is bad. Any ideas on where to pick a good one up for a reasonable price? I would like to replace the caps as you did and mount the components in a custom cabinet. The only number on the transformer is 18385. I also have the Ampro speaker and cabinet. It may just make more sense to build a guitar amp from scratch.
Larry urbanski of Urbanski Film sells the belts for this projector. Ampro also made the Premier 20 and Premier 30 projectors, each with progressively higher output wattage of the amplifier.
Hey Brad! I finally got to play through a 1940s Ampro projector last night! You are not kidding about how great it sounds. After running it to a proper guitar speaker and a tube screamer, it embarrasses some other "guitar" amps in my collection. He also gave me the pick of a shoe box full of vacuum tubes seem to be pre- and power amp tubes. Going to experiment with those in my champ next. Most of the tubes seem to be 1940s-ish. Any I should keep an eye out for?
Hey Brad, just picked one of these up for free and really appreciating this video. Thank you.
I'm new to re-purposing vintage electronics, and don't know what that dynamite-looking thing coupled to the power transformer is. I would imagine its a wax/paper capacitor, but it doesn't show up in the layout diagram for this thing, and there's no value printed on it. It looks like you wound up keeping yours in, but stated that you replaced all the caps... isn't that a cap?
I expect you could just remove the photocell tube (or the light bulb that excites it) to eliminate some of the contributed noise. I also noticed that touching the guitar strings cut down on some of the noise so a genuine grounded power cable might help a lot too.
You can find a belt for this on Ebay! Other wise check with Ubanski in Chicago, Illinois.
Hi Brad, I have recently been reading an article in a 1950's mag about exciter lamps which may shed some light(!) on the oscillator circuit. Simply put, the low voltage filtering of the day wasn't up to the task. Apparently it was common to feed the bulb from the heater wiring, via a rectifier & cap filter. Large caps were uncommon & very expensive at this time & it was simpler to feed the bulb from a frequency well away from that of the audio spectrum - hence the oscillator. This same article covered adjusting the photocell. Without seeing the schematic in detail I'm guessing this varied the HT on the photocell anode.There was a strict reminder to not use a standard multimeter in doing this as the metering circuit would load the HT thus giving false reading. It was then possible to put too much voltage on the photocell & if memory serves, anything over 90 volts causes the gas to ionise & the cell is ruined. Thank you for a most unusual project.
I Think it sounds great.
Hey Guitol :)
About halfway through the video you were perplexed by the lamp with the tube driver - my guess is that an oscillator is used to feed the tube and hence the exciter lamp at a frequency that wouldn't produce beat frequencies in the system audio somehow. Perhaps there's some light-flickering bleed-through from the film frames themselves and they used this oscillator circuit to combat that. I could be way off, but that's my initial guess :)
if you send an audio signal to a light bulb (flashlight) you can send the audio signal across the roomm and pick it up with he audio tube and reproduce the actual sound across the room
Yes. Radio waves, light waves, all electromagnetic spectrum.
The oscillator driving the lamp helps to minimize hum & noise in a way similar to "Bias" on magnetic tape.
Thanks for your comment. I appreciate you shedding some light on that.
The patent that can be read at www.google.com/patents/US1974900 looks mighty similar to your circuit.
I'm from Louisville and my father had one of these. I wonder if it's the same one?
Because the photocell will convert ANY light that strikes it the exciter lamp must not have ANY modulation of its own. 60 hertz will be detected as the filament will actually lighten and darken (flicker) and produce a loud buzz. Large value/low voltage capacitors were not available when this was built so instead of running on low voltage DC they used a high frequency oscillator to supply the exciter voltage. That pushed the frequency above the lamp's ability to transmit audible fluctuations.
Your extra 6V6 is this oscillator.
This design was used by nearly all projectors of the tube era (yes, there were exceptions that used neither oscillator OR lamp) but the design was not carried over into the transistor units. They mainly used transistor regulated DC with large value capacitors to smooth the exciter supply.
Amazing that that old teq sounds so good for a guitar... Shame Lester paul never got on it first :)
Just like the ones we had in grade school in the 50's. I was in the AV Club.
I have an odd question, there are many tubes not specifically designed for audio purpose, would it be possible that these can be used for a guitar amp? I'm interested in trying the random ones (mostly from TVs and some other random applications) that come up for sale on my country's equivalent of ebay.
is there a tension missing for the belt?
I believe that the center tab will balance both of the 6l6.
I have an old tv test pattern generator, do you think it would be a good candidate for conversion? If I send you the schematic could you give me any tips?
Hi G, Nice amp, nice CBG. I build the classic 3 string, but have parts to make a 6 string. I have to keep a lookout for old equipment like that. Take care, C.
This CBG is one of my favorite guitars. Just feels right. Has a nice hollowbody tone. I constructed it using a neck pocket
The Guitologist Hi G, Thanks for the reply. will probably do similar. At least the CBG's have light weight going for them, not to mention killer sound, IMO. Be good, C.
I recently acquired one of these I already owned an Ampro Stylist (the smaller version) I attempted to recap it and to my surprise the entire amplifier is smashed inside a tiny little square box it was nearly impossible to get at the capacitors without cutting at least 15 wires. Because of this I failed so it is now a 16 mm projector for silent films. My question to you is on a scale from 1 to 10 how difficult is it to recap the amplifier in this unit.
The projector lamp is connected post rectifier and needs AC so the DC is oscillated by the tube and associated circuitry. there is also the adjust for lamp intensity and another that could be for hum cancellation? dunno, The phototube is used to read the soundtrack from the edge of film.
I seem to remember it was a hummy supply. Quite prehistoric :) I put an external DC supply and LED on the end of the weird little glass-optic thingie, easy retrofit.
Do you have the schematic of this one? I have one of those and I want to mod it
There has been at least 1 band using projectors on stage, even showing the movies backwards; even 2 at once while playing their songs to a rowdy audience. Pretty random and funny to some people. The technology is fascinating. I wouldnt have just explored it on my own.
Nice work on the rebuild of this unit! Wondering if you could answer a couple questions for me since I just picked one up: I don't have the power cord but when I unplug the pig tail coming out of the unit into the DC converter outlet into an extension it powers the motor, pulleys. The light bulb does not turn on. Are you able to get the light bulb (main projector bulb) to turn on or do you actually need flim going through it? I would like to test the bulb, any experience you can share would be greatly appreciated. Thanks for taking the time to document what you did.
The main bulb should come on with one of the switches.
I have one of these projectors but the power transformer is shorted out. These projectors will also run off 120 Volts DC (Apparently available in some locations back in the 40's/50's). The audio amp portion only runs off 120 AC. That pigtail is connected directly through the 1.5 amp fuse and the on/off switch of the projector volume knob, to the primary side of the audio power transformer. The DC converter outlet is connected directly to the AC plug that you don't have. The instructions to unplug the pigtail when running the projector from a DC supply just disconnects the audio power transformer which only works on AC supply current.
All I know about the projector lamp is that turning it on without the motor running will burn it out in a hurry due to excessive heat. The motor is connected to a fan that cools the lamp. It's probable that your lamp is burned out. You shouldn't have to have film in the projector for the lamp to come on. Also check out Uncle Doug and ElPaso TubeAmps channels. Hope you got yours running.
towards the end he plays those those chuck berry riffs and it sounds pretty close to that type of gain and tone
I notice you did not address the large brown tubular component strapped to the underside of the amp. I'm guessing that it's some kind of capacitor. What values?
Certainly no lack of creativity with this. How does the cigar box hold up to the tension of the strings? I want to make something like this but do you know how many lbs of pressure the guitar strings create?
It has held up pretty well overall. I do need to brace the top a bit better next time I change strings. I may add a full sized end block to help with that, otherwise, it's held up well.
You're on to something here after reading the comments, having such polarized comments. This is a very novel idea to me, sounds great, going to be looking for new!
I could have probably, in hindsight, gone in there and heavily modded this thing into a roaring little overdrive beast for guitar too. And I'm just in love with the idea of sitting one of these on top of a guitar cabinet onstage and rocking the heck out while a classic 16mm film runs on the wall. What a visual.
Heck ya! Now I have to sweet talk my friend who is into 16mm to part with one. I'm binge watching your videos btw, my TSL 100 is getting new tubes still.
poot111111 , I have a premier 20 with speaker for sale
poot111111 good working condition
Brad, Lovely video. I just reckon it would be awesome rocking up to a pub gig with this unit as your main amp head! I would get some old reels to add for effect!
+Dan79istheman Yeah, that would be flippin' cool. Imagine having some old 16mm movie from the silent era, or some film noir masterpiece projected on the wall while you jam through the amp! It doesn't get much more 'hipster' than that. :D
+The Guitologist Great idea! My Eiki 16mm projector has a mic input which I use with a hi-fi phonograph to add music to silent films the projector is screening.
Is yours SS Hunter?
The RCA sensitivity to near-ultraviolet gave it an edge over other systems.
could you use the photo tube for optical compression
I don't know. Not sure how I'd accomplish that. Hmmm...
I'm doing a guitar amp conversion to one of these now,... and I'm removing the whole projector side of the unit cause it's irreparably fubar. Thanks for your video and information. It's very helpful to me!
+Guitologist I have an old 1940's Ampro PA-3. Would you be interested in converting this beast into a guitar amp for me?
I have this unit and oil is leaking from somewhere in the tube amp section?? Could it be the metal can capacitor?
Thanks for the comment. Not sure what that could be unless it's melting wax from the transformer or maybe some of the insulation on the wires is turning to an oily substance (which can happen) and is oozing with the tube heat. Either way, it sounds like you have something possibly overheating. If you have not recapped this unit, you really should! I would not attempt to use it any more without new caps.
I will do as you say. Agreed, I won't use it anymore until repairs are made. When was playing it smoke came out of it and I quickly unplugged it. Thats when I opened it up and found oil dripping from the can capacitor. The rectifier tube was red hot too. I am going to extricate the amp from the projector and start the component replacement process. All the caps (wax and electrolytic ones) will get replaced. BTW the tube amp sounded great ! also the smoke I saw did not result in the Amp frying, some how it still works but It takes like 3 minutes before any sound will come out of it. Can you please provide a link to the repair manual?
I didn't use a repair manual. That wasn't oil if it was coming from the cap can, it was electrolyte. You probably had a ower cap shorting and it probably also took out your rectifier tube. Change ALL the caps in it and check all components around the power section. Change main power resistors and check all plate resistors in the amp.
What ohm speaker do you use with this amp?
8 ohm
..I had an old Kingston guitar that had that same neck, ..late 60's, ..japan.
So you don't burn the one of the 6l6.
Yes, you have an excess 6V6 used in the exciter circuit. I recently scored a B&H 302 which is a 15W PP 6V6 guitar amp with no modifications necessary. Pretty much the same as yours. My excess exciter tube? Well that just happened to be a vintage B&H 6V6GT made by Mullard! A premium 6V6 tube worth more than I paid for the whole thing. ;^)
+PaulinTaegu Love it when that happens! He who dies with the most vintage tubes wins! :)
+The Guitologist If you happen to live in Seattle there is another one of these exact models for sale on Ebay for $75 bid $99 BIN, but it's local pickup only. ;^)
So glad the Projector was not Modified in make the Guitar amp. Now Someday You will be good to go to use the projector pat if you find a belt for it
+reeltoreelrules That's kind of the beauty of this model, you don't have to do anything to make it a guitar amp really, just service it and get it working. Thanks for watching! be sure to subscribe.
Please keep this as original and functional as you can. If you want a theremin, just build one! Any thoughts as to why the exciter bulb is driven by an oscillator instead of directly off the filament winding of the power transformer? Isn't B1 the bulb that lights the soundtrack on the film?
The fact that it's an oscillator makes me wanna use the light sensitive tube and that 6V6 exciter to build a tremelo on this. My guess is all you need is the right size cap and a pot to get the frequencies where ya want them and bam, you can make a trem in this thing with no extra parts.
Ampro made a similar model with a humongous Carbon-Arc lamp housing & supply. I had one, it actually worked. cough cough ;)
The sound film projector was invented at Bell Labs. Thus the Westrex/Western Electric on the patent plate. As an unrepentant A/V geek for almost my entire time spent in school, I knew what would happen if that exciter lamp ever blew.
Nice cigar boxguitar
It would be awesome if you converted the film reel to a tremolo like uncle Doug built
+Ivan Duke I did have the brief thought that if we have a photosensitive tube there, there might be some way to turn this into a sort of theremin.
Just ripp out the electronics, built a case around it and hook it up to a cabinet. No soldering requiered..
I know it is totally the wrong sound but all the comments about rocking out through the amp while the projector shows images in the background just brings to mind the video for Metallica's One.
Hillsboro illinois
I found a valuable link for a clear version of the schematic. Here it is. www.cinerdistan.com/16/2-uncategorised/557-ampro-2
I just found one while i was moving lol who want it
I'll take it if you don't want it. Email me: bradlinzy at gmail
You said "uh" 2,138 times.. I think you have a problem...
Did you maybe get the way you over-elucidate by saying overly fancy words from letterman? I loved watching this one.
just buy a guitar amp without destroying a rare projector
+Atomicflash500 This was basically just serviced. It's still a fully working projector with a new belt. I agree with you though, I thought it was way too cool to start removing parts not needed in the amp section. I do talk about that a little in the vid.
Thanks for the comment! I appreciate your perspective.
+The Guitologist "Rare projector "? I see these at swap meets often and usually ten dollars or best offer. I think it's a good thing to repurpose a projector into a funky vintage guitar amp. It's a win-win that you turned out to be a great guitarist in the video. Bravo!
you r jealous you wern't the one who found it. nothing is better then finding a low dollar tone machine at the goodwill. great vid :)
I got to comment here.... From a usefulness standpoint the projector is totally obsolete and using it will eventually result in mechanical wear and break down. It is only good for nostalgic or historical purposes until it cannot be repaired. The video is piss poor in comparison to the enduring excellent sound of the tube amplifier. There is no access to manufacturer spare parts because they are no longer in production (extinct) unless you can obtain spares from another scrap unit. Salvaging the audio amplifier makes a lot of sense, because it can be kept alive due to the mass interest and demand for tube amp replacement parts. Transformers, vacuum tubes, resistors, caps and pots will always be available. Good luck trying to find an optical coupler to read the audio on the side of the tape when it breaks on the projector. Nice work Guitarolgist ! Thanks !
Thanks for the comment! I will say, this old stuff is so well made, it would not surprise me if this projector was still usable in 100 years given routine maintenance. Parts may eventually become a real problem, but there are still parts around for these. If you want to view old 16mm films, let's say you found one in your grandmother's attic or something, you'd need one of these to view it. Might be important family history or world history you're preserving. Never know. It's worth keeping this stuff alive if we can.