Garbage to Gold - Making a Record Player Preamp from Junk Parts
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- čas přidán 1. 05. 2017
- This is a 1967 RCA Victor VJP16 Solid State portable record player with some problems. The crystal piezo cartridge has completely bitten the dust and the amp isn't powerful enough for a magnetic or ceramic piezo cartridge. So it's either buy an expensive NOS crystal cart, or recycle some random spare parts to scratch build a solid state preamp around an MC1458P integrated circuit, allowing us to use a good but inexpensive Pfanstiehl P188 cartridge. Spoiler alert: we end up going with the scratch built preamp.
- Věda a technologie
UPDATE: I drilled a hole in the back of the tone arm and attached a large counter-weight with a screw. Tracking pressure now down close to 5g.
oh now I read the update after posting about tracking pressure... :-\
You are very talented great job!I subbed.Cheers
wow. just amazing job. love to watch every new video you upload, because its like heart surgery and you bring alive so many lovely machines. keep on. cheers
Man, my 15yo daughter got a vintage record player for her birthday from a friend and it has no sound from speakers. Can find any info on the DSP. It has no audio out jacks. Only hear from the record itself. Watching this has me questioning if I can fix it. There's's a lot I don't know about record players.
Gotta give it to you.... very few repair technicians would go to all this trouble to salvage a substandard phonograph such as this, but you not giving up on it is quite commendable!
Just got one with a good cartridge, only needed lubrication to run well! Thanks for taking the time to share this.
That crumbly stuff is a substance called "Rochelle salt" a piezoelectric material that you can actually make from simple ingredients. The problem with it is that it is hydrophillic. and draws humidity from the air which causes it to swell and crumble.
This was used in microphones and phono cartridges from the '30s on. Construction was ultra simple: a piece of the material was mounted in a shell and a rubber arm was fitted over it and that in turn connected the stylus to it. Movement from the stylus flexed the crystal generating an electrical current. Later versions (like today's cartridges) used a modified formula to make the crystal more durable and less humidity friendly. some were even painted to form a barrier. This new formula was not as energetic as the original though but coming in the age of cheap transistors and foreign labor it was no problem with new gear.
Fun video with a bonus. Best example of the effects of a filter cap doing its job.
My goodness, that was eye-opening!
I always enjoy great videos of vintage repair you have a great channel I really enjoy it and look forward to what you are going to fix next all the best always
my dad worked on all kinds of radios and such as a hobby and had tons of old tv and radio parts and tubes.He built me my first guitar amp out of junk and it sounded a lot like my 1974 fender deluxe I had bought later on.
@The guitologist I am pretty sure you will never read this comment but I have to put it here anyway. Totally unrelated to your video except the ending where you play one of my most beloved records from my childhood. The second I saw the cover I heard the "Funny Frankie Fireman" song which was my favorite story from this album, yes the one you now hold/own. I love all the stories but Frankie was my favorite. Sadly that album was lost many years ago, but the memory of it is still with me 50 years later. I was 5 when I got this from my mother and I played it endlessly in my room. I am sure she was sick of those stories (especially Frankie) but she never said a word she just let me be alone with my silly stories. For me Frankie really was "Brave and Ready, staunch and steady, tried and true as the Red White and Blue." I will never forget those words or the hours I spent listening to this and many other stories on different albums. So thank you for this great rescue of an old record player and for re-ignighting a long lost memory of an old man with a love of stories.
Hi Brad, good on you for seeing this through to the bitter end! I grew up with crystal cartridges _ they are now scarce as the proverbial hens teeth. I don't think they are made any more which is why the ones for sale are so bloody expensive,. Thanks for another very clear & instructional video.
If im in a plane and the pilot announces lady's and gentleman fasten your seat belts we have electrical problem, were going down. Im going to hope to God your on board! great job, well done Brad.
1967, the year i was born...you should be a teacher ..shop class all over again. thanks
The cartridge used was a ceramic cartridge which will put out about 300/400 mV. It is in no way a magnetic cartridge, which. would only put out about 2/5 mV. A magnetic cartridge would also need a tracking force of probably 2/4 grams and need RIAA EQ, way over the top for such a low lost arm and amplifier. All that was really needed was a simple preamp with 300MV input to about 2 volts output, but saying that your preamp did work. I'm amazed it did because a mic preamp would typically have a 1/4 mV input which should have been somewhat overloaded with the cartridge 300/400 mV output. Maybe the lower input impedance of the preamp shunted part of the cartridge output, who knows. But it did work so well done!!
Michael, thanks for the comment! The website called for a tracking pressure of about 4g on this cart. Not sure why I called it "magnetic", but you're right, the site clearly says "ceramic". I think I did mention that also. But anyway, I think the preamp worked because it was also a compressor. Actually, it seemed to work rather well.
I had the one speaker version of this RCA phonograph when I was a kid in the 60's. But 8 grams for the tonearm? Now I know why all my childhood records got trashed.
White powder and a small scale in the same video. So much for keeping the DEA off your back. lol
Love watching your videos! and thanks for showing the links to the web pages where you find your resources!
I love the way you put the crap on top of the speaker
$40 fret saw to mod a record player cartridge. This channel is awesome. Tinkerers unite!
hahaha...yeah, if you don't have the saw already that would mean something sensible like a box cutter would have to be used.
Lovely nostalgic vibe all round.
love your videos lefty... Used to repair amps before going back into gigging full time. Great explanations. Will subscribe.
Thanks, Clarence. Welcome to the channel!
super great repair, restore!
the ending was surreal .
That is a ceramic cartridge you used, not a magnetic. All the craptastic suitcase players use it because it has more output
really enjoyed this one. Especially the record!!
The P-188d is a ceramic cartridge. It is significantly lower output (approx 0.35 vs. 3.0 volt of the original crystal cartridge), but it is not a very low voltage moving magnetic cartridge...but it looks like your compressor circuit is working to limit the gain. Also, to get the most out of your ceramic cartridge you would theoretically want your preamp input to be very high impedance (1 meg ohm). At lower impedance you should lose bass...but maybe not noticeable with those small speakers.
A counter weight on the end of the arm would be a simple solution for the tracking pressure.
A tongue depressor or popsicle stick attached to the end of the arm with a few nickels or whatever positioned in the right spot for desired needle pressure was my first idea.
You might come up with something more clever and ascetically pleasing.
Great job on that preamp!
I did think of that. I also went back in and removed a little bit of glue and nylon from the mount, but that didn't reduce pressure by much. Took off about 1/10g. Any counter weight would need to be small profile because there isn't much room between the back of the arm and the case when closed.
I love how they call it 'twin speaker', implying that it's stereo when it's clearly not.
Electronics companies were cutthroat back then. They also used to put extra transistors in radios just so they could claim there were more transistors as a sales tactic, when the transistors weren't actually hooked up to anything!
+The Guitarologist I'd heard of that, a long time ago, and had forgotten about it! I remember thinking at the time that if the 'functional' transistors ever died, you had spares built in, lol.
Great. I think I heard that in high school. In the early 1980s. Gads, I'm old.
xaenon, They didn’t imply anything. They didn’t say stereo...
Well, they COULDN'T say, legally, that it was stereo. But making a big deal about 'twin speaker' (which actually has NO technical advantage in a player like this) makes the IMPLICATION of two channels, or as we like to call it, 'stereo'. They toss another $1 speaker into it, jack up the price another $5-10, and it'll still appear to be the better deal than an actual stereo with the higher price tag. And technically, they don't even have to hook the speaker up! It's essentially a 'passive lie'. They're not actually telling you it's stereo, but they try real hard to make you THINK it is. Classic snooker and misdirection. The advertising industry was BUILT on this tactic.
My daughter is an artist who uses charcoal in a lot of her work and she gets a great deal of variety of tints and shades by varying how much charcoal she uses. So I believe that unit is CHARCOAL and not blue
It's better than a Crosley. Nice job!
Excellent channel. :)
As soon as you said it got power but no sound I thought to myself, I bet the cartridge is shot. If you grew-up with record players, you don't have to be an electronics repairman to know that it's usually the cartridge. They're very delicate things. I don't care if I ever see another. Viva la CD!
I once changed a Crystal cart (6-8g tracking)on an old Bush record player to a Sonotone 9TA HC (4-6g tracking) and hoped for the best. Of course BSR turntables had a spring under the arm which you could detach and put more or less tension on it to vary the weight. I have no idea what I ended up with but the change reduced the volume of the unit by quite a lot (amplification by single EL84 as I recall) so the volume control was constantly at maximum, no complaints from parents!The things teenagers do to "improve" things..........
Might have been commented already but the bottom "code" is the date of manufacturer....08/07/1967....i feel really clever now!!
The top code is this weeks winning lottery numbers, ill spilt it with you if a win
They make much better replacement styli for this cartridge and even the best ones are dirt cheap. If you get one with a metal cantilever, that is going to really improve the sound quality and the tracking quality.
That's a sweet record player nothing like the old school one
The 1458 produces muddied sound in audio projects, if you wanted to brighten up the sound considerably, you should switch to a NE5532. For this project it won't get better than that.
To reduce the power line hiss place a .1UF non polarized capacitor across the power line, close to the large filtering cap and also across the 1458, #4 + #8 pins.
Thanks for the tip. I'll consider that for the future. To be fair though, this didn't turn out muddy. It's fairly balanced. There are some mid frequencies that resonate as you turn up the volume, but that could be down to small speakers in a plastic cab.
Good job 👍🏻
It is the same routine for any player. Turntable first.
The usual procedure is to lubricate the turntable bearings and clean the trip-and-return mech or any dried up grease.
A cartridge which contains a Rochelle Salt crystal of such output this would also drive a 6BQ5 tube direct. Try getting a good one of those with a turn-under stylus.
The old turnover types were record-killers, not stereo compliant. That tracking weight is ballpark for the high-output crystal cartridges.
That ending was awesome. Hahaha!
I did that with a motor from a Magnavox changer . the difference is amazing
Indianapolis! I live 25 miles south of there.
Ok! I think we might be getting there
Nice little project! I wouldn't play any valuable vinyl with a tracking force of an 8 gram weight. I was thinking you could counterbalance the arm at the other end. Oops I should have read your pinned comment!
dig that craaaazy Thorenz turntable, yeee haaaa
Awesome!
Magnavox made a STEREO record player in the late 60's that ld quite similar that i thought about getting to have as a unit to take with me
that looked similar that is
8 grams that needle really digs in. you could hotglue a popcycle stick to the other end of the tone arm as a counterbalance so you could at least get the needle tracking at closer to 3 grams. at 1.5 grams it tracks so lightly if you breath on it it will skip. anyway, great video on repairs. its always a miraculous thing to me. :-)
The best part of this record player is the two "alnico" speakers.
I scrap alot of tv's and physically cut out the amplifier section and use that for my amplifiers...just follow the speaker wires down to the board and you will be close to the amp section...some of the large projection tv's have amps that are rated at 25 watts a channel..nice video..
Only problem would be knowing where to cut. A schematic or layout diagram would be helpful for that. You'd need to figure out where to hook in power and input from there.
I just go from the IC amp chip to the first capacitor for the power...and find the input terminals of the IC for input and speaker out..its not too hard...
Why didn’t you order the flip over stylus for both l.p. & 78 r.p.m. records; and why didn’t you convert the 2 speakers to stereo?
Totally off topic but have you ever opened up any modern Traynor amps and if so what do you think of their build quality?
I would add a LM7812 voltage regulator and tie the power input right to the 21 volt main supply rail for the main board. Since your preamp does not draw a lot of current you should not need a heat sink for the regulator. Using a dropping resistor is not a great idea for solid state. The voltage will fluctuate as your current draw changes.
Thanks for the suggestions. I'm just starting to venture a bit more into SS.
After reviewing the power supply maximum voltage rating of the LM1458 is can work with a plus and minus 18 volt power rails if using a bipolar power supply. In the single power supply circuit you are using using the 21 volt power directly from the main board would look like a plus and minus 11.5 volt bipolar supply. You would not need a regulated power supply at all.
I knew there might be a pitfall of unregulated supply going in and thought that using a second diode to rectify my preamp board's own separate supply might help curb the need. It does seem to operate ok, so maybe this circuit is just really tolerant, or the regulated supply isn't needed.
Hey Brad. I know a lot of people collect Vinyl. Are people still playing albums rather than using all the other options available? Also, what about reel to reel... Is that still a viable technology.
this is a ceramic cartridge that you are eplacing the original cartridge with it is a crappy crosley cartridge but at least you are not bothering with a junky crosley product nice unit
Any particular reason you went with a compressor for the preamp? That looks like what the diodes are for - part of the compression circuit.
It was one of the few preamps I found for that IC that looked like it would be easy to build and might work well. I thought some compression might even improve the performance of the unit. I think I was right to choose a compressor because, as Michael pointed out in another comment, that circuit was designed for a magnetic microphone and the higher output ceramic piezo cartridge might have overloaded the circuit had I not done that.
Great stuff!
I didn't understand why you made the cartridge mono, but there's a lot in this world that I don't understand.
He wired it in mono because he's driving a mono amp, and since most records are stereo, you'll want to sum left and right paralleled into a single channel. While the set has two speakers, it is nonetheless monophonic. As I pointed out to someone else, it would be fairly easy to convert this thing to true stereo, and all changes would be completely hidden.
too cool
Did you keep the compressor? Also I seem to remember on crystal cartridge preamps they didn't bother with RIAA equalisation as the response curve of a crystal cartridge is sort of close to it anyway. The MM cartridge will need some bass boost and treble cut to sound neutral.
He was mistaken about installing a magnetic. That cartridge is a ceramic; it's the same one found in most 'suitcase' record players sold today.
Please forgive my ignorance and forgive me if I'm asking before you mention it (we're 10 mins in) but does a ceramic cartridge not need RIAA equalisation?
Ceramics generally do NOT require equalization. When RIAA was devised, they more-or-less had crystal cartridges in mind, because it was the most prevalent type at the time, and their modern ceramic descendants work much the same way. Magnetic cartridges DO require RIAA eq, though. Something about the way magnetics work; I cannot recall the details.
Pre-RIAA records did use different EQ curves, though, and each record company had their own scheme, and it was often tuned to sound best on their own equipment (RCA records would sound best on RCA equipment, etc). RIAA just standardized a single curve, that's all.
Another part of the equation, not often recognized or discussed, is the impedance of the amplifier's input stage. Most modern stereo equipment does not provide a proper impedance for a ceramic/crystal cartridge, and as a result the sound often lacks bass.
I have the same problem,,,,,,do you have a schematic for this preamp?
That thing was built 2 months before I was born
You can glue a counter weight on the other side of the arm to make it track for less :D (just a suggestion).
I glued a cartridge bracket in my Magnavox changer with contact cement
Totally enjoyable video. So, not counting your labor of love, how much did you invest beyond the cartridge, if I may ask? Did/do you turn it around on ebay for a profit?
Uh, I had like $16 or something in it. Monetarily, it's a bust for sure. But it was fun and I got a video out of it.
You know what they say......genius is a small distance from insanity! Just kidding! Really! Only you would have the patience and determination to make a throw away record player come back to life! I hear you could sell it in Japan for big yen! You do some great restorations. Even 60's SS! Thankz
Cool, but why...LOL...LOL Great video.
Why don't my junk shops have cool stuff like this?
Where you live?
Madison Wi
Because most of it get sold online now, and either never reaches the thrift shop, or gets sold online by the thrift shop without ever reaching the sales floor. Goodwill and Salvation Army used to have equipment like this all the time.... even as late as 5-10 years ago. Not anymore.
The white powder in the original cartridge - is that the remains of the 'crystal'? I remember reading that older record players used Rochelle salts as the piezoelectric elements; I guess that's what happens to salt after humidity and time do their thing.
What a mess....
I'm working on restoring a 1948 Emerson radio-phono; the original 78 rpm record player is pretty much a lost cause thanks to someone's previous efforts to 'repair' it (missing parts now) and I'm planning on substituting a cheapie BSR 3-speed changer; do you think that preamplifier circuit you built would be suitable for this project?
Yes, that powder was probably humidified salt. That's the conclusion I eventually came to as well.
If that preamp worked in this build, it should for for what you're doing too. A stock magnetic BSR cart should output about the same as the one I used here.
+The Guitarologist The BSR actually has a stock cartridge, what I assume is ceramic (early 1970s). I've been kicking around the idea of converting to a magnetic, but to do so I have to change out the headshell too because it's the 'narrow' one. Oh, and by the way, I loved your solution to mounting the new cartridge in your record player. Genius!
Speaking of Emerson radios, I found a company that makes repro knobs that are the same type as the one you identified as 'original' in your 'bulletproof' Emerson radio. Just in case you're interested.
www.renovatedradios.com/product.php?product=204
beutifull. always related to that one. wast not want not! love it
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Why did you wire the cartridge up to be monophonic? That's a stereo rig...two channels, two speakers. And the cartridge is also stereo.
No. It has two speakers, that's true, but they're being driven by a single-channel amp. As for it being a stereo cartridge, mono cartridges are getting difficult to find and expensive, so the alternative is to convert an inexpensive, readily-available stereo cart to mono.
You tell for sure it's mono by looking at the wiring in the tone arm. Stereo requires a minimum of three leads - left signal, right signal, and at least one ground (with some equipment actually requiring two grounds, one for each channel). Only two wires in this - one signal, one ground. The schematic also shows a single amplifier channel.
Don't feel bad about thinking it was stereo. Calling it a 'dual speaker' set was a marketing gimmick to deliberately mislead the buyer into thinking it was stereo. The fact that you thought so, too, is proof that such marketing tricks work.
This thing would be insanely easy to convert to true stereo, though, if one were so inclined. It would require only swapping out the stock amp for a stereo item (I would source one from an old set of computer speakers), adding a third lead to the tone arm, and setting up some sort of proper power supply.
Rob Chapman liked one of your videos
I saw that. I think he subbed too. Maybe he wants to learn how to repair a $10 record player. :P
It's charcoal!
Yeah, I can step back and see that now, but with the camera on and talking out my ass spur of the moment...it COULD be blue! :D
@@TheGuitologist it's Royal Blue Kingsford Pale Charcoal...An RCA custom color like Daphne Blue and Shell Pink.
Huh, if i remember right, MC1458 is prone to audible crossover distortion, it's not usually the best idea to use it in audio reproduction gear. Then again, looking at the rest of that amplifier, perhaps it didn't deserve anything better.
Wonder why the own gain of the device was low though? I mean maybe it's fine without preamp when it's all closed up and enclosure resonates, or maybe one of the transistors simply started to go and lose gain?
I wondered the same thing. I know the crystal carts have more output and the amps are lower gain as a result, but this thing was so quiet I initially thought the amp was dead.
that pfanstiehl cartridge is ceramic not magnetic it has a lower output not all ceramic cartridges have high output
You are correct. I realized shortly after making this that I was in error. Ceramics are lower output than the crystal carts you found in many old cheap players. Magnetic is the lowest output, but usually the best fidelity. Thanks for watching!
People want these record players for the old and new records
It might need a new motor and cartridge
You should do a video on speaker date code identification if you have already done this please send me the link
For my own future reference, 12:33 for start of preamp build
Puff & Toot??? sounds like a youtube prank farting video!! LOL
You can get those cartridges for less than 2 dollars from China with free shipping. I recently bought 10 of them for 17 dollars.
Have you compared the Japanese to Chinese ones? How do they compare?
I believe they are exactly the same. If you do a search on ebay for "Turntable Phono Cartridge w/ Stylus Replacement", loads of sellers are listed from China and Malaysia. They all look exactly the same. I suspect they are all from one company in China or Malaysia. I got mine a few weeks ago for a price of $1.71 each. It appears they went up a little and are hovering at just over $2 as I write this. The seller I ordered from went up to $2.20. I guess they constantly adjust their price to compete with each other. The far east cartridge price war, lol. You will find two model numbers. The 188 and the 190. The 190's come with a mounting bracket with the standard 1/2 inch mounting holes. The 188's don't come with the mounting bracket. You will also see that some have plastic cantilevers and others have metal cantilevers. I've tried both which sound the same. I've installed them in several early RCA 45 rpm only record changers with very good results. The original ceramic cartridges in the RCA players are almost always extremely weak or completely dead after close to 70 years since they were originally installed. So I was delighted to find such inexpensive replacements.
the china carts compare quite will there good for something like this they put a good strong signal out I build my preamp using a 2N4401 using the amps own power supply that way I only need 12 parts on my board
Thanks for the tip! That is cheap as dirt.
What circuit are you using?
8g... oh dear... RIP records
A lot of things which are called charcoal are gray. I guess they mean used charcoal?
The number on the case also had a 67 in it
I'm wondering, Sir, would you be able to help me in repairing my burnt Crate V100 head?
I'd like to help, but I don't even have time to fix my own stuff. I've been referring people to ampgarage.com/forum/ or el34world.com/Forum/index.php
Thanks man. Hope you find time for your projects!
A briac PZQ stanchion circuit would be easier.
No idea what that is. Got a schematic link?
Well, I dunno about 'gold'!
08-07-67 August 08,1967
I had to look very carefully at that date - the last digit was so badly stamped I thought it was a '2', so I was translating it as 1962. Which puzzled me; the styling is a little too modern for 1962, and 'solid state' was kind of rare that year as well, outside of battery-powered radios.
Magnavox made a STEREO record player that looked alot like that
You could make this thing stereo with very little effort - and the changes to make it that way would be completely hidden.
@@xaenon a speaker for the added channel could go in the lid and the lid be made remove-able
But why such a old part... That op amp is a dual u741!
NE5532 would be a much better somewhat modern and cheap alternative.
Because I have 9 of them on hand. Using what was already in my parts bins or in junk pile.
The Guitologist Certainly makes sense. and its not Hi-fi anyway so it doesnt hurt that much. Nice work on making the old thing work again :-)
I have found some parts over on Elex Atelier's website - prices range from good to nuts, but you know better what things should cost: www.elexatelier.com
that's just me but I wouldn't trouble myself for a $10 goodwill turntable and just throw one of those cheap PAM8406 modules in there and actually make it stereo at the same time:
www.ebay.com/itm/351803301576
just leave the original electronic in there in case some purist wants to restore it as original in the future
This was more about playing around wasting time while I had nothing else on the bench. You're right, I'll never get paid for the time spent except in pleasure of seeing it fixed.
+quaxk That's a damned good idea, actually. It would be compatible with the ceramic cartridge output already, so no preamp required. The conversion to stereo would also be accomplished, but you might have to replace the speakers - look at the schematic; the originals are fairly high impedance (something like 17 ohms each for the twin-speaker setup, and 32 ohms for the single-speaker rig) but that wouldn't be a big deal. Of course, you'd also have to swap out the volume pot for a stereo pot. If you want the tone control to still work, you'd have to build a circuit for it, but with that player it wouldn't do much anyway. And, of course, you'd have to run one or two more leads to the cartridge. Still an interesting idea, though.
capacitors are fried...
looks like charcoal to me
the sound is not good I am quite disappointed
Put oil in the middle of the record player so it will play❤