Project "Mitchell Model 1265 Portable Suitcase Record Player, Selenium Rectifier Replacement"

It has been a long time since I made any new posts because I am no longer that free anymore as I am now working full time.

But today I finally got around to replacing the 'dangerous' selenium rectifier that is present in the Mitchell Model 1265 turntable that I restored some time ago. The rectifier can apparently fail catastrophically and emit poisonous smoke during use! I thank the person who left the comment here on this blog highlighting that fact to me.

I am not good with hardware and circuits, so I had no clue on what to replace the rectifier with. A good consultation with my more technically inclined brother revealed that I only required a modern day IN4007 diode to replace it: a very simple and quick fix!

This is the modern day diode versus the selenium rectifier (the component with the multiple gray square plates).

It only took me about 5 minutes but took my brother a good half an hour of circuit tracing and Googling!

After everything was done, I plugged in the player and it was still working like before...and now it is slightly more future proof and will hopefully last for a very very long time!

Link to previous post on the restoration of this player: http://projectrepair.blogspot.sg/2012/05/project-mitchell-model-1265-portable.html

Project "Mitchell Model 1265 Portable Suitcase Record Player"

i actually bought this player sometime last year from a seller on ebay without having any prior knowledge on both the brand (Mitchell) and the player. it wasn't in working condition and he was selling it at quite a cheap price (all in all plus shipping about $60 SGD). it could play 33, 45 and 78rpm records and it was electric so i decided to get it mainly to play 78's because although the gramophone i have could play 78's, its heavy tonearm would eventually ruin the records after many plays. this player had an inbuilt loudspeaker and would be ideal for listening to 78's (especially the more modern non-acoustically recorded ones).

i tried for many days to search online for this brand of player as well as the specific model, Mitchell Model 1265, but to no avail. there were no examples of it anywhere and those that i emailed had never heard of this model before. it comes in a plain suitcase form as shown below:

when it arrived, i realized that i had made quite a big mistake. the player was made to be played in the USA and accepted only 120V mains supply at 60Hz whereas where i am (Singapore), it is 240V at 50Hz. while i could easily get a transformer to convert 240V to 120V, the difference in mains frequency meant that the motor of the player would not spin at the correct speed. the player also emitted a loud hum when i turned it on, and when i attempted to touch the tonearm i got a good shock from it.

i put the player into the corner of my room and never touched it for a few months while i occasionally went online to search for any other examples of the player and the brand (none at all, if you were wondering).

a few months ago i did take the player apart and took a good look at its innards...and it was a mess...and unfortunately at that time my compact camera that i had always used to take the pictures used in this blog decided to give up the ghost and i was left with just my phone's camera to take pictures and i didn't do a good job documenting it.

it wasn't pretty...

to summarize quickly, i had to clean out the decades worth of dust and mold inside the suitcase and then replace the parts that were the most likely to have failed over the years. After taking a good look around, it was clear that the only components were the capacitors and the vacuum tube. in the picture above, i already replaced the biggest capacitor in the amplifier (the silver cylinder thing). it is actually 3 capacitors in one big cylinder with a common ground.

on the cylinder it is written:
GUDEMAN (the brand)
MEL - 42110 (the part number i guess?)
RED 40MFD 150VDC
RED 40MFD 150VDC
BLU 20MFD 25VDC
BLACK COM - NEG

so this means that the respective wire colors are connected to capacitors of that value and voltage rating inside the cylinder. i bought two 47uF capacitors rated for 160VDC and one 22uF capacitor rated at 50VDC as replacements and soldered the connections together. you can see the difference in sizes a few decades of technology has given us:

there was another capacitor in the amplifier and it was a paper-oil capacitor with a wax coating. after researching online, it was clear that this capacitor definitely had to be replaced because paper capacitors are well known to fail from old age.

i bought a modern aluminium capacitor with the same ratings, .1MFD (100uF) and rated for 200VDC and soldered it into place.

the amplifier has one 25L6GT vacuum tube and it glows orange when the player is powered up. i know next to nothing about vacuum tubes and i didn't fiddle with it. i know enough to identify that if the tube is glowing in colors other than red-orange then it should be discarded, and also that if the top has turned a milky white instead of transparent then it should also be replaced. this one had none of the above and so i kept it in place.

the loudspeaker on the player had a small tear on the cloth (more like paper) diaphragm and i did a quick fix by sticking a small piece of paper with some light glue over the hole. i've done this before and it works well...it's enough to stop air from leaking out and the sound will still be as good as a normal diaphragm.

the main problem after all this was that the motor still doesn't spin at the correct speeds. a record player is worthless if the songs it plays are all in slo-mo, unless you intend to use it in a horror house or something...

there is a knob on the side of the turntable to select the speed of the player. when it is in the off position, the motor still runs.

as you move the knob from one setting to the other, it adjusts the position of the grey wheel shown in the picture above. the wheel touches the shaft of the motor which has three different thicknesses. this enables the speed of the grey wheel to change while the speed of the motor stays constant. (think of it as a gearing system). to make the wheel turn at a faster speed, i put different thicknesses of heat shrink tubing over the shaft to make it thicker and allow the grey wheel to turn faster.

after a few hours of trial and error, i found one type of heat shrink tubing that added enough thickness to the shaft to make it spin at 78rpm when the knob is at 78. unfortunately, i could not get the correct shaft thickness for the 33 and 45rpm speeds but 78 is good enough for me!

again, if you're wondering how to verify your record player's rpm, just use a strobe disc that can be found on the internet and print it out. i've been using the same disc to calibrate my gramophone and it has been accurate enough so far.

as my country's mains supply is 50hz, any light will flicker at that frequency and when the bars of the 50hz strobe disc at the rpm you are calibrating for seem to be stationary, then you know that you have the correct rpm.

the last thing that needed to be replaced was the cartridge. the original one that came with the player was an Astatic cartridge that had the numbers "16L3" on it.

again, there wasn't much information available about this cartridge online. i sent out emails to a few different turntable needle stores and only one had the exact same cartridge available but was selling it at $100++SGD which was insane.

i finally stumbled upon this site: http://www.needles4turntables.com/ceramic.htm and sent an email asking if it will work with my player. he replied and recommended that i get the Pfanstiehl P-51 cartridge with the 3mil needle that will work well with 78rpm records.

he shipped it out the day i made the order and it arrived in 7 days (USA to Singapore) and i proceeded to connect it to the tonearm.

the reason for the shoddy wiring you see in the picture above was because the new cartridge is a lot smaller than the old one, thus the wires could not reach the connections. i extended the wiring by splicing new wires to the old one but i didn't have wires of the same thickness, thus resulting in the frankenstein-ish work...

i turned the player on and used a toothpick to lightly brush the needle on the cartridge and there was sound coming out of the player's speaker!

i put the player back together and put on a 78 record and it came aliveeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee!

Project "Emerson/Baird Wondergram"

i bought this thing online and waited a long time for it to ship from halfway around the world. it was a gamble because i know from the seller that the motor on the player spins but the sound doesn't work at all and it would be worthless as a record player if it didn't make any noise whatsoever!

so anyway, this is an Emerson Wondergram made in the 1960's. as you can see it is a battery powered portable record player that plays both 33rpm and 45rpm discs...a 'Wonder' for its time and weighs a 'gram' (ok not really, but see what i did there? hurhurhurhur) it comes with a holder on the top cover for a 45rpm adapter too which is pretty neat.

*EDIT* i totally forgot to mention that this player originates from the UK made by a company called Baird, but sold in the USA under the Emerson brand. the player has the Baird brand on the bottom plate that say "Baird, Made in England, A Camp Bird Product" (what is Camp Bird anyway?)

*EDIT* in case you're wondering the size of this, here's a tissue box for comparison:

when it first arrived, the motor spins but sounded like a jackhammer. when i tried to put the needle on a record, the entire player just ground to a halt. obviously the motor just didn't have the juice and was in need of some restoring.

opening it up isn't hard, just remove all the screws you see on the outer shell and you can lift the innards all out. as you can see from the pictures above, this thing was hideously dirty and dusty inside. the dampening sponges under the speaker and the motor were hardened and flaking debris each time i moved it, in short it was a real mess.

the way the motor runs the records at 33 and 45rpm is a real curious thing as it doesn't 'directly' spin the record like in a normal player. you can see the motor in the picture above and the shaft is touching one of the two rubber wheels. when the motor spins, it turns both wheels as well. the clever bit is that both wheels are set at different distances and this enables it to play records at either 33 or 45rpm.

when you put a 45rpm record that has a smaller diameter than a 33rpm, it would only touch the inner wheel that spins the record faster since the wheel is nearer the center of the record. when you put a 33rpm disc it will touch the outer wheel. since the 33rpm wheel is further from the center of the record, a 33rpm record would not touch the 45rpm wheel at all because that wheel is smaller...ingenious!

after inspecting the circuit, checking for continuity, dry solders, cracked solders, broken wires, etc etc...i spotted this in the picture below:

well there's your problem! the capacitor across the speaker is obviously blown and its guts have leaked out. it needs to be replaced.

as you can see, i have a big thumb. and also this capacitor is 100 micro farads and rated for 6 volts. my brother was kind enough to explain to me what this capacitor is for (to convert a DC signal into an AC one so that the speaker would work) and even drew a diagram out.

the entire circuit in the player only has 3 capacitors. one going to the speaker (100ufF, one on the motor (100uF) and one on the main circuit board (10uF). i decided to change all 3 to modern day equivalents and although that's not the purist way to restore antiques, it is hard to trust 40 year old electronic components to last very long nowadays (if you can find them!).

the picture below shows the difference in size of the original capacitor and its modern day equivalent. i couldn't get my hands on a 6V rated one and got a 16V one (it doesn't matter).

while i was changing the capacitors, i managed to break some wires just by moving the player around my desk. the wires were all corroded and i replaced all the wires (not a lot, about 7 all in all) with new ones.

so its out with the old and in with the new!

the solders in the picture above shows that this machine was obviously assembled by hand. i used new solder for the new wires, and resoldered all the old solders as well just in case there were dry...i figured this would ensure there were no breaks in the circuit and give the player another few decades of life.

the single speaker has the brand 'ELAC', i googled the brand and apparently it's still around today...they must have partnered with Emerson back in the day when this player was produced.

on the left side in the picture above you can see the auto stop mechanism. when the arm reaches the end of the record the mechanism will push away a metal contact, opening the circuit and stopping the player completely.

after resoldering, rewiring and replacing the capacitors, i worked on the cosmetics of the player because it was heinously dirty! a quick polish with the novus plastic polisher (previously used on the westclox alarm clock) and it gave the shell a nice sheen to it. (before and after on the left and right respectively)

ok...granted it's not much of a difference but it'll take ages to buff the scratches away, i'll leave them there for the 'rugged' look.

*EDIT* you can see the Baird brand between the two upper legs in the picture above

i managed to order a new needle online to replace the worn out one that came with the player, no prizes for guessing which is the new and old needle.

in case you're looking for the needle for this machine, it is an electro-voice 51 (ev51). it is a ceramic cartridge and has 2 sapphire tipped LP points (so more bang for your buck because its two needles in one!).

so anyway all that was left was to slap in new fresh batteries (4 x C-sized, in case you're wondering) and test it out...and it works!

Project "Technics SL-Q3,I Don't Want To Set The World On Fire, by The Ink Spots"

i don't want to set the world on fire, by the ink spots...made famous all over again by a game called fallout 3.

i didn't fix this turntable, nor did i restore it in any way...this actually belongs to my father and i got it on a long term loan from him since he didn't really use it that much (nowadays, but it has surely been used for many many hours by now) and he's been keeping it in a good and working condition for about three decades.

anyway i have recently been extremely intrigued in records ever since i got my hands on the gramophone and brought it back to life and although i'm really lagging behind in terms of music technology, i think many people have been missing out on something.

records are difficult to maintain...they require a good cleaning with a velvet brush before every listening to get the dust out of the grooves otherwise you'd have clicks and pops. i have a cleaning solution specially just for the disc, and another different cleaning solution specially for the needle. troublesome...troublesome...but that's why it makes everything better.

it's just something about the tediousness of setting everything up that makes you appreciate the sounds even more, it's also something about the concept of being able to hold analogue music in a physical form instead of ones and zeros that makes it simply wonderful. on top of all that, i think the sounds coming from a vinyl disk sounds so much warmer and natural than from other mediums...plus they all come in a big folder that is so much easier to read than a standard CD album.