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A little help with an LP player problem...
Posted: Tue Mar 25, 2008 1:36 pm
by dtemp
I bought a record player recently off of this forum, along with a bunch of LPs. I haven't used a record player in a LONG time (since futzing with my dad's back in the day).
For some reason, the audio is very quiet coming through my amp. I'm using a basic Sony stereo amp, and the radio and other sources come in a fine levels.
Does anyone know why this would happen? My wires aren't crossed (no jokes please), but I did not have time to try different cables since I had to leave for work.
Any suggestions?
Re: A little help with an LP player problem...
Posted: Tue Mar 25, 2008 2:07 pm
by The Big Ben
dtemp wrote:I bought a record player recently off of this forum, along with a bunch of LPs. I haven't used a record player in a LONG time (since futzing with my dad's back in the day).
For some reason, the audio is very quiet coming through my amp. I'm using a basic Sony stereo amp, and the radio and other sources come in a fine levels.
Does anyone know why this would happen? My wires aren't crossed (no jokes please), but I did not have time to try different cables since I had to leave for work.
Any suggestions?
I certainly hope some stereo junkies from the past chime in. I think there is an impedence match problem here. I think there is a transformer that is used to match the turntable to the amp.
Rick Denney has to know something about this....
Jeff "And write a three page post about it, too" Benedict
Posted: Tue Mar 25, 2008 2:25 pm
by SplatterTone
If the amplifier does not have an input labled for phono input; i.e. you are trying to use an "AUX" or "VCR" or "LASER DISK" (OK ... if it has "LASER DISK", then it's going to have "PHONO"), then you will need a pre-amplifier to go between the turntable and AUX input of the amplifier. The signal output from a phono cartridge is much lower than a normal AUX device. Radio Shack (back in the day) used to sell these little pre-amplifier for about 20 bucks.
Posted: Tue Mar 25, 2008 2:30 pm
by SplatterTone
I should add that if you see this extra wire along with the two audio plugs from the turntable, there should be some kind of screw type terminal near the phono inputs on the amplifier (or pre-amplifier) where you must attach that wire. If you don't attach it, you will probably get a significant amount of hum.
Posted: Tue Mar 25, 2008 2:38 pm
by dtemp
SplatterTone wrote:If the amplifier does not have an input labled for phono input...then you will need a pre-amplifier to go between the turntable and AUX input of the amplifier. The signal output from a phono cartridge is much lower than a normal AUX device. Radio Shack (back in the day) used to sell these little pre-amplifier for about 20 bucks.
I think we have a winner. Thanks for the help, I already have one on order ($20, just like you said).
Thanks again!
Posted: Tue Mar 25, 2008 3:01 pm
by Mojo workin'
I should add that if you see this extra wire along with the two audio plugs from the turntable, there should be some kind of screw type terminal near the phono inputs on the amplifier (or pre-amplifier) where you must attach that wire. If you don't attach it, you will probably get a significant amount of hum.
Yes, if the turntable is not grounded, it may cause this.
Re: A little help with an LP player problem...
Posted: Tue Mar 25, 2008 11:05 pm
by Rick Denney
dtemp wrote:I bought a record player recently off of this forum, along with a bunch of LPs. I haven't used a record player in a LONG time (since futzing with my dad's back in the day).
For some reason, the audio is very quiet coming through my amp.
As you have heard already, outputs from higher-quality cartridges used for vinyl records are not as high as line-level audio output for other devices or even for old, cheap record players. There is also a linearity question. Records are cut within physical limitations, and the frequency response curve is purposely non-linear to keep the full dynamic range within the physical constraints of the medium. That curve was standardized by the RIAA, and you must provide RIAA equalization or the music will have poor fidelity in addition to being too low. The phono preamp (whether external or built into your amplifier) should do both of these things.
I have on my agenda a project to transfer the best bits of my LP collection to CDs. Because of this issue, I could not just move my lovely old belt-driven Technics to my office next to my computer. There is no phono input on computer sound cards. I have since bought an external USB sound interface that I can plug into my regular stereo. The little Radio Shack phono preamps are fine for listening, but my old stereo preamp is several orders of magnitude better in sound quality, and I finally decided it was easier to put a laptop next to the stereo than to put a turntable next to the computer. At my present rate, I should get to this project in about 26 years.
Rick "afraid to listen to the new Dukes of Dixieland collection more than once before recording it onto CDs" Denney