How to connect a line signal to a guitar amp?

Question

My Laney Lv300 Tube Fusion Combo amp, doesn't have a Line-In, as such. It merely has one "Input" on the front, for the guitar and a pair of FX sockets, as an FX Loop (FX Send and FX Return). It also has one "Speaker Out" socket, for connection to an 8ohm-plus extension speaker.

What I need to know is this, is there any way for me to connect an MP3 player for example, to this amp?? I know that it is a Valve Driven Pre-amp Combo and that the two inbuilt 12" Celestions may not be the correct ones to give me an excellent audio out for general music, but my requirement is just to be able to generate an acceptable audio outside, for a forthcoming Open Day. I do also understand that the potential Stereo output from the MP3 player will have to be resolved to mono.

I do have a pair of 8ohm PA speakers that I can use as well. I plan to plug one extension speaker, into the single provided extension socket and I also plan to install a separate second output socket, into the rear of the amp cabinet, using a switched 1/4" Phone socket, that should then isolate the inbuilt speakers, when the extension is plugged into it. That will allow me to run at the minimum 4ohms that the amp requires.

Any thoughts, comments or suggestions on the best way to do all of this, would REALLY be appreciated. The speaker mod, I am sure that I can resolve, but the method of connecting an MP3 type player into the amp, to play music for the masses on that day, is something that I am desperate to sort out.

Thanking you in advance for ANY help with this....John.

I have managed to partially answer my own question. I dug out an old Vestax PCV-150 that I have and ran a 3.5 stereo jack from the player, which terminates in 2 phono jacks that I plugged into one of the Line input banks on the Vestax. The output from the Vestax, has been taken from one of the two "Sub-Master" 1/4" sockets, connected through a standard guitar lead, into the Laney amp Input. I plan to try using a "split lead "Y" connector", which will allow me to use both of the Sub-Master Outputs from the Vestax, as soon as I have one available, whilst still using the guitar lead into the amp.

Latest update.... I purchased a 1/4" "Y" split lead recently and connected the joined "Y" end, into both of the Sub-master output connectors on the Vestax. As previously, I then connected the remaining portion of the "Y" lead, into the Laney Input. This appears to now work exactly as I need it to. Thank you to everyone that has posted comments here, to help me with this. I hope that this post ends up being of help to others, in a similar predicament to myself.

Answer 1

If you have access to a looper pedal, such as the Boss RC series, they have a line in. Connect the pedal to the looper, and then your MP3 player to the line in of the loop pedal.

Answer 2

I'd have thought that merely plugging the player into the input would do the job. The volume can be attenuated via the gain pot on the amp., and also by the volume control on the player. Turn it down initially, as there will be a propensity for lots of sound. The speaker extension output - it may already be switched, and cuts out the internal speakers of the amp. Make sure that you wire either in series or parallel to reach a sensible impedance for the amp. to cope with, especially if the internal speakers are still functioning when others are plugged in.

Answer 3

You can take a passive DI box and run it backwards, or get a specialized box called a ReAmp to do this.

Answer 4

The effects loop on a guitar amplifier is between the preamp (where the gain and EQ controls sit to modify the tone) and the power amplifier (which pretty much just makes everything louder). Your specific amplifier has a multi-channel tube preamp with a solid state power amp.

As your amplifier has an effects loop, you can feed a non-guitar input in through the FX Return input. This has the advantage that the audio is not going through the preamp, which will significantly affect the tone, but straight into the power amp, which tends to have flatter tonal response.

Another advantage of this is that it allows you to play along - some amps have a an effects loop blend control between the dry signal (direct preamp -> power amp) and the wet signal (via FX loop), which you can use to mix the input with the guitar. I have also used this technique to use a single 100W amp for two guitars: one through the pre-amp, one through an external amp simulator into the FX return.