I have an old Pioneer PL-7 turntable for my daughter.
I need to find a decent preamp to connect to her laptop or to an amp to listen to them.
Is there anything decent out there for around $100?
The under $50 ones don't have very good ratings.
1/8 inch audio out would be best or USB. Although there are 3.5 to RCA to USB adapters out there.

From what I can find the PL-7 is a MM cartridge.

Update: See last post.

Music Hall used to make good budget stuff.

Just did a search, stuff from Music Hall still available, Music Hall Mini on Amazon for $73, might take a look at that one.

Pro-Ject Phono Box.  $99.00

Google it. Super easy to find it.

+1 another good budget brand.

Art djpre II And a rca to 1/8 cable

We picked up a Phono Box at a stereo store yesterday. (All kinds of 70s and 80s goodies there!)
Hooked it up (see diagram) and it works but the 60Hz hum was awful.
Checked the socket (not grounded - old house) and found one that was - no difference.
Note: the wall wart for the Box is not grounded to the supply. (Only hot and neutral)
Checked the line for noise with a scope - pretty clean, 124VDC.
Checked the DC from the Box power - very little noise.
*Cobbled a line filter together and added it to the Phone Box power - much better but still noticeable.
Pulled the audio line between the Box and volume and hum goes away so it's definitely in the Box. Metal covers.
Tried earth grounding the phono and it got a LOT worse.
Tried separating the power wires and signal lines - no change.

So:
1. Would filtering all three power lines help?
2.Which line needs shielded?
3. Phono Box need shielded?
4. Would separating the three power lines help?
5. How far does the turn-table need to be from everything else?
(Right now everything is sitting on a table.)
6. I read somewhere the TT ground needs to be connected to one of the RCA shields - is that correct?
-4 RCA grounds and TT ground all have continuity.

Attached File

If you have isolated the hum to the phono preamp, maybe return it for another?
I used a uturn audio pluto with good results. Are the speakers on the same table as the turntable? Try moving them.

The volume control is the likely source of your hum problem.
As you noted, OP, a pre-amp should solve your problem.

You could try disconnecting the ground wire that runs from the amp to the plug bar.  Might be a ground loop.

Yep, volume control is junk. I tried another one that I had cobbled together years ago and it had shielded wires.
Much less noise. Unfortunately, the pot is old and raspy so I'm going to see if I have a decent one in the parts bucket.
I thought about installing one inside the phono amp but I would have to cut some traces to do that.
So, next step is a good control and very short (shielded) wires.
I thought about installing one in the RCA cable but I don't think those are shielded.

Another possibility is using an amp with a built in volume control.
There are many che-chinee brands out there, any suggestions on a decent one that isn't too pricey?

@Hellbent_4

Right now I'm using a Marantz PM5004.  Only 35 watts @ 8 ohms, but with the efficient speakers I have (and the 10" powered sub) it gets plenty loud in my bedroom, which is about 4,800 cu. ft.
It's a simple integrated stereo amp that focuses on audio quality - 6 RCA inputs (including a MM phono input.)  No fancy processing, just tone controls.

Very, very quiet.  $449 MSRP (I wouldn't be afraid of a used one if the seller offered a 30-day return policy.)

My guess is the grounding of one of the components is bad, probably the turntable.  Solder joints corrode over time and you lose the low resistance path necessary for quiet operation.  Re-solder the ground wires at the turntable side.

Continuity is not enough, it has to be very low resistance.

If it is quiet with nothing plugged into the phono jack but hums when the turntable is plugged in it is almost certainly a bad ground in the turntable.  You can try a different set of cables but I bet is the ground.

Ground loops suck.  I would try plugging the turntable and amp into different outlets (ideally on completely different circuits).  This has worked wonders in the past for me.

Use audio cables with directional grounding with the shield grounded on the audio source end, and "floated" on the receiver end. Some audio cable do this with 2 conductors in a shielded jacket.

ETA; Also could be that it is humming because it does not know the lyrics

What I wound up doing was to just attach the amp to a radio with aux in.
Works fine sounds good, however: one side is dead.
By swapping sides on the various cables it looks like one side of the TT output is dead.
I checked the connections on the cartridge and they are snug and appear to be correct. (as far as I can determine)
I guess the next step is to hook up the scope to the cartridge leads and see if there is out put.