RCA 9_JY or 45-J-1 record changer info:
In March, 1949, RCA Victor introduced the 45 rpm record system. Along with the new records, they introduced a new record changer to play them. These were offered in everything from attachments to connect to an existing radio, to TV-Radio-Phono combination units. The attachment sold for $12.95, and RCA was selling them at cost to promote the system...making their profit on the records. The new system quickly gained popularity with jukebox operators, and in 1950, Seeburg was the first to introduce a 100 selection jukebox that played 45's exclusively, the model M100B. By the mid-50s, 45 sales were beginning to overtake sales of 78s, and by the end of 1958, the 78 was virtually dead. A few smaller labels, such as Chess, continued to press both 45s and 78s as late as 1960. The 45-only record players were made from 1949 until about 1958, when the Crescent factory where the changers were made was destroyed by fire. Brands included RCA, Zenith, Emerson, Crosley, Silvertone, Symphonic, Decca, Capitol, and many others. See the charts below for a list of known models.
Getting at the idler wheel:
To get the turntable off you will
have to take the bottom cover off first. Look up inside and you'll see a 4
sided star gear. This gear will rotate with the turntable as it is actually
attached to the bottom of it. Thats
what engages the record drop. With a sharpie pen, mark the position of the star
on the shaft that the star fits on. It has to go back the same way for the
record drop to be timed correctly with the rest of the cycle. If you mess up on
this part, its a pain to get it back in time. Once you
have your mark done, you can remove the star gear. Underneath the gear is also
a c-clip you have to remove. Once that is removed you can grab ahold of the spindle and pull the turntable up and away
from the deck. Needless to say it will need to be re-greased but if the
turntable sticks during the cycle, your idler wheel might be hard and will need
to be resurfaced or rebuilt. Replacements are available too. Like any idler
drive turntable, be careful not to get oil around or on the idler. You can
access the idler once the turntable comes off. The rubber motor mounts may be
shot also but there are sources to get those. I've heard of people mounting
magnetic cartridges in these and were successful at
it. The only trouble is these dont have a 1/2 inch
mount as they are wider so you'll have to be creative. These also required a
bit of tracking force to trip the mechanism so keep that in mind. The needle
originally was located at the very tip of the tonearm
so whatever cartridge you choose will have to have its needle in the same place
to track correctly across the record. These had very little damping made into
them so you'll have to be selective about where you place it to avoid flutter.
The felt on the turntable is not original. It originally had either a tan or
red marblized piece of vinyl where the felt is now.
The vinyl would eventually warp and curl and had to be removed for obvious
reasons. If you need more help just ask as i got a
bunch of these and had to work on all of them. Good luck!
What Tony V said... I have rebuilt
the newer models such as RP-190 using a
Nice early version, here is a
link to some parts lists
http://oldtech.net/TT.html
Well I ripped into it last night and I think I figured it out. After a lot of disassembly I was able to get to the idler wheel and the top of the mechanical chassis. I had to take the tone arm off to do it, at least with the route that I took, I was able to work on it. The idler is in great shape. This thing is built like a tank! It has a very heavy steel chassis and thick steel linkages. No wonder it has lasted as long as it has. After cleaning and lubricating everything that moves and with a little trial and error I was able to get it put back together. After making adjustments it seems to work perfectly now. The needle is missing the tip but it drops exactly on target and the return fires right in the middle of the lead-out groove. The next record drops right on time too. I think I was just lucky on that one.
You can get the rubber motor
mounts here
http://www.tubesandmore.com/
Just look on the left side menu and go to the rubber/antenna items/phono then click on motor mounting grommets. Their $4.50
for a package of 9
Congratulations--you have the first 45 rpm player. I believe 9JY's were made in 1949.
You can find that on
phonoland.com electronic phonograph section.
As far as tracking and record wear are
concerned, I believe the trip mech in the RP168 is
lighter and a better design, allowing for somewhat lighter tracking. You can
get the trip pretty light on a RP-190, but it's a little tricky sometimes, it
has to nudge the cycling cam and it's mass.
I pretty much agree on the above posts,
i have put Pickering NP/AC
or Stanton 500's in all my 25+ RCA 45 units and they work
and sound great. The Ortofon OM Pro also works quite
well and will give a brighter sound. The 168 can track at 3 grams and a 190
between 3.5 and 4 provided arm shaft and trip slides are spotless clean and
smooth.
I find the 168 to be quite smooth and gentle (but fast) if
it has the dash pot. I also find the 168 to sound slightly better when modified
with the magnetic cartridge due to the aluminum tonearm
being more rigid than the plastic arm on the 190 which has a little spurious
resonance, but the
difference is slight.
i agree that the 168 without the dashpot is too kamakazi for todays
use.
I modified a couple of mine with a 4 pole shaded stereo
motor and wired them for stereo playback.
One thing I never see mentioned is that the original
factory stylus in the
190 was much more compliant and could track 60's records
at the original five grams, but I have never seen this stylus offered
separately, even back in 1964 when I tried to get one. I remember
the only available stiff stylus and all of a sudden by
player back then wouldn't track any new records circa 1964.
Another mod that improves both the 168 and 190 is to mount
them in
a very heavy sand filled base (only the console type
version of the 168 will lend itself to this), I have two modded
like this hooked to my
modern high end system and the sound is quite incredible
and closer
to my $5,000 Sota Cosmos
turntable than you would think!
Dan, I found the piston and sleeve
assembly you need. PM on its way. Here are a coule of pics to let you see how
it's assembled. I think it's best to pull the c-clip and put the whole assembly
on and attach the sleeve bracket to the table. You will notice they used rivets
to attach the piston mechanism. You should be able to remove your old tone arm
lift lever and put the one on that I have. It will be the entire lift lever
with the extension already riveted on.
The “dashpot”.
An NP/AC is a sturdy, high output
magnetic cartridge that can track at 3-7 grams. Here, one is installed in a
45-EY-4 with a battery operated phono preamp mounted
to the muting switch terminals. A 45-EY-4 never sounded so good.
David,
I shaved each of the mounting posts with a razor blade and
wedged the cartridge between the posts and attached it to the roof of the tone
arm with dots of contact cement.
My biggest problem getting a magnetic cartridge to work on
an AC/DC chassis was hum. I had one of those little solid state phono preamps with an outboard power supply. I noticed that
when I unplugged the power supply with the record still playing that the hum
totally quit and the record played until the power supply filters discharged. I
connected a 9-volt battery in place of the power supply and eliminated all hum.
RCA uses separate grounds for the phono
cartridge and motorboard, just like the newer
automatic turntables of the ’60 and later that used magnetic cartridges. It’s
important to keep those grounds separate to avoid any hum problems.
There is no hum induced by the phono
motor, even with a plastic turntable.
The debate over the 168 vs 190 IMO always gets tossed around.
I've seen it happen a lot. It's
apples & oranges to me.
Indeed, the 168 had more parts, costed
more to produce, but performed very well normally.
I tend to agree with orthophonic's
comment about the 168 having a better tonearm with
less resonance.
RCA chose the 190 to reduce parts count and costs for the
most part.
But that cycling cam wears out faster than the 168's
positive and quick design.
But the 168 when properly set up played like a gem.
And yes, the dashpot makes a huge improvement too.
I own a 45J attachment player with the 168 changer AND
a 45ey2 with the 190 plus amp.
They both play nicely, are in
mint condition, and of course restored by yours truely.
My 168 has been fitted with the Pickering NP/AT too,
tracking at 4 grams, but played over a good system exhibits a tad bit of hum...
that's the 2 pole motor issue.
I may build a motor shield underneath to block the hum,
unless I can come across a suitable 4 pole shielded one.
Tech,
If
you are using a single audio cable without a separate ground lead, this may be
the reason you are experiencing hum. The audio lead should only run to the
cartridge leads. Add a separate ground lead to the metal sub chassis and ground
it to the amp chassis. In this configuration, the ground strap on the NP/AC
will have to be removed so it doesn’t bridge the signal ground to the chassis
ground through the metal tone arm. The strap shouldn’t be removed on a 190
because of the plastic tone arm.
The 9-EY-31 below was built by Crescent Industries for
RCA. The changer, amp and speaker are all stamped RMA-150. It has been fitted
with an NP/AC and doesn’t have any hum at all. It uses a separate ground lead.
Even though it only has a single ended 50L6 amplifier
and a 5¼-inch speaker it has very good bass response so hum would be a problem.
When I did the 168 upgrade, I changed
out the original stiff tonearm wiring to new, 5 wire
twisted pairs.
These lead to a shielded mono magnetic preamp underneath,
than fed to an audio cable out of the unit.
The hum I'm experiencing is motor-induced hum, which
varies in intensity as the arm is moved towards the center of the record.
That is why I stated my idea about somehow either
shielding the motor to nullify the hum OR trying to get a suitable replacement
4-pole motor that would eliminate this problem.
I believe the 168's that came with magnetic cartridges
also had a motor just for this purpose.
In addition, during my overhaul, I devised a nifty way to
pull back the idler wheel when "off" to keep from getting "flat
spots" and that annoying thump-thump...
It's basically a cable attached to the idler arm and
routed to the on-off switch assembly on the chassis.. works like a charm too!
Those 168's had a stronger idler spring then the 190's....
the reason being more drive force to keep the changer going though the cycle.
Tech,
That was
my point. The attachment models used the single ground on the single RCA jack
to ground the cartridge as well as the sub-base assembly and tone arm. Models
with built in amplifiers used an electrically sepprate
ground lead for the sub-base assembly.
Likewise, just about any component record changer /
turntable using a magnetic cartridge uses a separate ground lead for the
changer base plate because it reduces hum better than a single ground from the
RCA cables. With the audio jack disconnected from the pre-amp, a DC resistance
check between the cartridge signal ground and the changer base plate and tone
arm will show no continuity.
When the grounds are separate, only the little shell
around the cartridge shields the coils within the cartridge and any noise on
the sub base and tone arm are drained off through that separate ground lead.
That leaves a cleaner ground path on the signal ground to the preamp, reducing
hum and noise.
We are both using Pickering NP/AC cartridges on RP-168
record changers with 2-pole motors. Yours suffers from induced motor hum, mine
does not. That leads me to believe that your signal ground and sub-base ground
may be one and the same.
One additional note, I left the the
motor pole ground lug disconnected from the sub-base so it's not grounded.
Ceramic Cartridge EQ:
Magnetic cartridges are constant-velocity devices: the
signal is proportional to the velocity of the stylus. Since high frequencies
cause the stylus to "wiggle" faster, you naturally get an increasing
velocity (and hence signal level) as frequency rises. The cutting head used to
make the master is also a constant-velocity device, so a magnetic cartridge
"matches" the characteristics of the cutting head. The RIAA EQ is
applied during cutting in order to restrict excessive groove excursion (bass
cut) and to overcome surface noise (treble boost). When you play a record that
was cut with a constant-velocity cutter using a constant-velocity cartridge,
you therefore need to apply inverse EQ to correct the frequency response.
In contrast, ceramic cartridges are constant-amplitude devices. In other words,
the signal level is proportional to the amplitude of the side-to-side motion of
the stylus. There is no natural tendency for the signal level to increase at
higher frequencies (because the amplitude doesn't get bigger), and hence RIAA
EQ should not be applied. Of course, the frequency response characteristic you
get out of an unequalised ceramic is only
approximately OK-ish. But since its intrinsic sound
quality is so low that's an academic point.
We also both agree that amplitude response gives you an accurate signal for about 80 percent of the frequencies from 20-20 KHz. Problem is, the RIAA curve is not a simple slope, but it has this shelf between 500 and 2150 Hz. nCeramic cartridges doin't have that shelf in their response curves. Unfortunately, this is right in the midrange where the ear has great sensitivity to such errors. So ceramic cartriges congenitally sound a little off in the midrange unless somehow some electrical circuit puts the shelf back in.
From the ceramic phono input, the signal went through a small network: a
(680kOhms//270pF) in series with a 3.9k resistor to ground. One pole of the
input selector switch was inserted before the phono
preamp, selecting the signal at the 3.9k resistor (phono
2 cer), or at the other phono
input (phono 1 mag).