JVC RV-B70 line-in

[neko]

I couldnt fint anything about adding line-in to those old kabooms. So i decided to do it on my own.
Before ive done anything


After opening You can see radio module on the top left


Oh great, the pins are signed so its easy to find out which pins are audio signal in GND RCH LCH


Now the only thing i have to do is cutting the signal tape and divide the signal, one from radio module and one from line-in mini jack socket
For this im gonna use 3ch switch.
Hmm doesnt look so good from inside


But from outside alot better


And now its done i can finaly plug in mp3 to it



one more thing, some mp3 players have very strong audio signal out and when You add full volume the sound in jvc will be distorted. You need only to turn volume little down on your mp3 and it will be ok
PS; sorry for my bad english

 

[blu_fuz]

There are people that do that same thing to their OEM car stereos. I have been wanting to do that to my '04 Chevy Silverado for awhile now.

Nice job.

 

[teamstress]

I didn't know there was a Kaboom without a line in feature.

 

[Superduper]

I didn't know there was a Kaboom without a line in feature.

I was just thinking the same thing, but good job, nonetheless.

 

[BMoney]

Good work Neko!

 

[monchito]

I didn't know there was a Kaboom without a line in feature.

I was just thinking the same thing, but good job, nonetheless.

 

[neko]

I didn't know there was a Kaboom without a line in feature.

I was just thinking the same thing, but good job, nonetheless.

I also thought all of them have line in

anyway, theye already prepared for future modofications. Like theres already place for tape mechanism, but this model didnt had it yet

 

[Superduper]

No line in OR tape either? Must be a prehistoric version of the kaboom. At least, it looks like a kaboom.

 

[lazanas]

Nice job!

 

[Retro Addict]

That's a strange Kaboom, I've never seen that model before. It's strange to see an early one without a cassette deck. My RV-B90 has a cassette deck. Your's must be a cheaper model, not such a bad thing though, cause Kabooms pump more bass than any mass produced portable stereo EVER.

 

[vikingsdiditfirst]

Hi! I found this exact model at a garage sale, and I've been planning on making this exact mod ever since. I have some questions, does this "kill" the radio function? Would it be possible to keep the radio function and simply add a line in? Thanks in advance

 

[Superduper]

That's why he put a switch on the back -- so he can switch from radio and aux-in.

 

[stormsven]

Nice job dude. I use to have 4 boomblasters from different types and all of them had a line in. Yours is a strange one . But worthy job. love this machines from JVC for trying to save the boombox glory .

 

[markh]

Hey just picked up a rv-b70 of my own and looking at repeating your ace mod
question how did you go about connecting to the ribbon cable? did you simply cut, expose and tape along and has this proved durable?
and any thoughts on your signal quality compared to a fm transmitter setup
cheers!

 

[neko]

Hey just picked up a rv-b70 of my own and looking at repeating your ace mod
question how did you go about connecting to the ribbon cable? did you simply cut, expose and tape along and has this proved durable?
and any thoughts on your signal quality compared to a fm transmitter setup
cheers!

I did cut ribbon cable and expose wires, but i soldered cables before i wraped them with tape to make them safe
And fm transmiters are really good right now so its easier to use one than adding mini jack-in.

 

[goodman]

Good work!!!

one more thing, some mp3 players have very strong audio signal out and when You add full volume the sound in jvc will be distorted. You need only to turn volume little down on your mp3 and it will be ok

Hm, this is very strange... I check 3 MP3 players, volume is on max, but output level is so lower.
In electronics sites found assembled preamplifier with TL 082.
The gain is determined by the value of the resistor in the feedback.
The picture shows how to connect:

I decided to embed this preamplifier in one of my boomboxes.
I found a place to mount the board.

When I finished, it's time to tests.
The level indicators show the radio level +3db.
For this output level of player, volume is on 40%, equalizer is off or flat.
Now, the sound is good!!!