On Thu, 18 May 2017 10:56:05 -0400, Michael Black wrote:
On Thu, 18 May 2017, wrote:
I went to a rummage sale and the guy had a box of cables for 10 cents
each. Some computer power cords, and some RCA cables, and a couple phone
cords. 16 cords total. I offered $1 for the whole box, and he agreed.
He asked me why I needed all of them. I told him I work on electronics.
Thats when he said he has something I might want. He went in the house
and came out with a Kenwood Basic C2, Stereo Control Amplifier. Made in
(1984-90). The guy said it's dead, and he was going to throw it away, so
I can have it. He said he connected speakers to it and it dont do
anything.
I got home and was getting out a RCA plug to connect to the output
terminals, to hook up a speaker, when I began to look closer at it, and
thought "this is a preamp, not a power amp". To make sure what I had, I
looked on the web, and found this:
https://www.hifiengine.com/manual_li...basic-c2.shtml
I have to admit, this is called an "amplifier" so I did sort of think it
needed speakers, even though RCA plugs are not usually used for speakers
except some of the real old cheap stuff.
It turned out this was my lucky day. This preamp sounds great. (And I
didn't even connect it to my main power amp yet, I just connected it to
a small mono guitar amp that I use for testing stuff in the shop. It
needed a little contact cleaner on the selector switches, but works
great.
I am a little confused though about the phone switch.
It has the following selections:
MM (Moving Magnet)
47K
100K
MC (Moving Coil)
10 ohm
30 ohm
100 ohm
Ok, I understand what they are saying, but how do I know if my cartridge
is MM or MC, and what the resistance rating is?
This appears to be a real useful thing, but I never even knew there were
different kinds of cartridges. In the past, I just installed a cartridge
and plugged it into "Phono".
Most cartridges (unless it's a really cheap turntable in which case it's a
crystal or ceramic cartridge) are moving magnet. At least that used to be
the case, the moving magnet coil ones were the exception for the ones who
wanted to spend more, and you'd need an extra preamp for it.
Maybe that's changed, with fewer people owning turntables, maybe the ones
using them tend to use moving coil cartridges.
But the default is moving magnet.
Michael
Good article on that website listed. I have two turntables. The cheap
one has a non-removable (as far as I know) cartridge. I dont have a
cartridge number, but its an AIWA turntable, and takes an AN-11 stylus.
The good turntable has an Audio Technica AT5011E. I also have a spare
cartridge from way back, (new in the box), Electro Voice V100.
I'm pretty sure the Audio Technica and the Electro Voice are both MM.
Probably the AIWA one too, unless thats a crystal or ceramic.
I imagine there is a place to look them up, but I have not yet tried to
find a website that lists them.
As far as using an ohm meter. I do understand the old analog ones are
probably not a good idea. I do have a modern digital one (not one of
those cheap HF ones). But what about using a VTVM. I may be wrong, but
it's my understanding that VTVMs are safe to use on darn near anything.
I have two of them, a Heathkit and an Eico.
(Presently the Heathkit one tends to act a bit flakey, probably needs
new caps, but the Eico works fine).
But it's probably easier to just look them up by model.
Not to mention..... Both the AT and the EV have FOUR wires coming from
them, but when they exit the turntable, they only have TWO (as in RCA
plugs). What are the other two wires for?????