UPDATE ! My Sharp GF-9000

[BoomBoxDeluxe]

YAAAAAAAAAAAAYY!

Some years back, those that know me from S2G may remember me reporting that my Sharp GF-9000 had a line-in problem, that resulted in the music only coming through rather quietly........even with the vol turned up to the max.


Well people! I have finally figured out this box! It turns out that............

To use the line-in on this box, is a bit more complex than most other boxes, as it has one of those DIN sockets, and not an RCA-input (the two RCAs on the back of a GF-9000 are for phono-level input, and not line-level sources like CD player/MP3/MD)

So, I have an adaptor-cord that has a DIN plug on one end, and four RCA plugs on the other. Two are inputs and the other two are outputs.

Which two plugs do I use? Well this is where things went wrong. You see, the GF-9000 box is one of those that doesn't have an AUX switch, and so, you have to run the tape deck in order to get anything through the line-in. Where I was going wrong, is basically, I was only pressing PLAY on the tape deck. On one set of RCA plugs, I was getting nothing, and on the other two? There was music, but rather quietly. I assumed that there was something wrong with the box, and as such, this box has never had too much use........Until recently, that is!!!

With the Sharp GF-9000, you have to PRESS RECORD to get the line-in to work!!

Not only was I using the wrong set of RCA plugs, but I was only pressing play. D' oh!

So yes! I have now got my Sharp GF-9000 working now, by using the correct set of RCA plugs on the end of the adaptor cord, *AND* pressing REC on the tape deck. The music is coming through very loud........excessively loud!!!


...........I think I have hit another problem with this box. The problem has now gone the opposite way. The music is way too loud!

I am not talking about volume level here.....Its way distorted at any volume!!!!

I have a CD player that has RCA line-outs on it. Most other boxes I have can connect directly to these, and all works well. With the GF-9000, the music is excessively distorted. I think that my GF-9000 has an overly-sensitive input jack.

Even if I set the rec mode to 'manual' and turn down the rec level all the way to zero, it doesn't affect what comes out of the speakers, and it still remains distorted real bad!


What would be the long-term solution to this?


For now, what I have to do, is use the headphone output on the CD player. For this, I need a connector lead that has headphone plug on one end, and two RCA plugs on the other. I then couple these to the other two RCA plugs on the other lead, of which has the 5-pin DIN plug on the other, and this goes into the boombox.

With the headphone socket on the CD player, I can control the 'power' that goes to the boombox, but I have to have the vol control on the CD player turned almost to zero, and it comes out VERY LOUD on the GF-9000. There's also a catch.....On quiet parts of music, there's a lot of hiss, like a badly recorded tape.




Overall though, this is one loud box!



..........But what would be the long-term solution for an over-sensitive input jack? Using all of these different connection leads, and getting the vol control just right, and listening to music with a lot of hiss in it, really takes the shine off using this box, but that hasn't stopped me from giving this box a damned good exercising over the past week!!!

In the last seven days, this box has had more use than in the past two or three years!!


If you have a long-term solution to an overly-sensitive input jack, and it isn't too difficult or expensive to sort out, then I would like to hear your solution to this.


Thanks for reading!


-BoomBoxDeluxe.

 

[BMoney]

try adjusting (lowering) the record level?

 

[Superduper]

I don't have or ever seen a GF-9000 in real life but it's hard to imagine a top box like that doesn't have an aux function. Many older boomboxes do have a phono in function. I suspect that is the case with you.

Your line-in is a line-level input which is correct but is for Record only. The phono input can be used as an aux-in but the problem is that phongraphs output very low signal levels. Inside the boombox is circuitry called a phono amp that amplifies the phono signals to line-level. You are overloading the phono inputs which is why it's way too loud and distorted.

The solution is to use a phono to line converter. They are available commercially or you can make one. That should solve your problem.

 

[BoomBoxDeluxe]

Hi there! Thanks for your replies.

Firstly.......... Adjusting the record level doesn't make any difference to the sound coming out on the speakers it is still way distorted.

Next............ I am *NOT* using the phono-in sockets. I am using the Line-in, which is in the form of a 5-pin DIN socket.


Its just that the input on this box is overly sensitive. I don't know why.

I am not recording tapes here..........I am just playing CDs through the boombox. Most of my other boomboxes are OK with my CD player's line-out connection. Its just that the GF-9000 seems overly sensitive.


OK........what's next? Any more ideas / solutions / fixes?


-BoomBoxDeluxe.

 

[Superduper]

Hi there! Thanks for your replies.

Firstly.......... Adjusting the record level doesn't make any difference to the sound coming out on the speakers it is still way distorted.

Next............ I am *NOT* using the phono-in sockets. I am using the Line-in, which is in the form of a 5-pin DIN socket.


Its just that the input on this box is overly sensitive. I don't know why.

I am not recording tapes here..........I am just playing CDs through the boombox. Most of my other boomboxes are OK with my CD player's line-out connection. Its just that the GF-9000 seems overly sensitive.


OK........what's next? Any more ideas / solutions / fixes?


-BoomBoxDeluxe.

It sounds almost like you are inputting a signal through the line-out's and not the line-in's. I recommend that you use an appropriate phono to line-in adapter and use the phono inputs. Is the legends in japanese? You might be mixing them up or the DIN connector pins might not be assigned to correspond with the boombox correctly. The fact that the record level adjustment is not working highly suggests to me that the wrong signal path is being used. Distortion is a problem and I would stop using that method immediately.

 

[Radio raheem]

Your sound is distorted for one simple reason the gf9000 is desighned for a record player to be connected nothing else, thats my guess

 

[2steppa]

Your sound is distorted for one simple reason the gf9000 is desighned for a record player to be connected nothing else, thats my guess

Yep. Mine has tape/radio/phono selector buttons.

I imagine the DIN socket is wired to a phono preamp stage not a line level one.

I used a converter on mine, sounded ace

 

[BoomBoxDeluxe]

OK people.....

So you're saying that the DIN socket is at phono level and not line level?

That would be silly, because this box does have dedicated RCA inputs that are marked 'Phono'.

Why have the DIN and RCAs at phono level, when the RCAs can be phono and the DIN at line level?

I will have to try something else.

Maybe, for my next experiment, I will try connecting a turntable upto this box through the DIN socket, and seeing what happens.

My turntable has a built-in phono stage, so tostart with, I will try the turntable, with the output from it going at phono level.

I will report back soon, and let you know what it sounded like. While I also have the turntable going, I will also try it through the dedicated RCA inputs too.


Thanks for the feedback so far,

BoomBoxDeluxe.

 

[Lasonic TRC-920]

To me, it sounds like the device your are playing your music with, that is going into the DIN has the volume set to high. Is there a volume knob on your mp3 player or what ever you are using to supply your music to the boom box? I'd try turning that down. Maybe set the volume to 75%.

 

[BMoney]

no it's not that. the gf9000 was made when mp3 players didn't exist. its inputs are phono inputs. it sounds like crap because the RIAA equalization is amplifying the signal like it would a stylus. until he just accepts this fact, and gets himself a line/phono converter, it'll continue to sound like crap. but he continues to "test" it out like nobody has experienced this problem before.

 

[BMoney]

like this:

http://www.mcmelectronics.com/product/50-7240

mp3 players output something like 2 volts.
phono inputs can only handle like 0.15 volts.

(norm explained it to me in depth)

using it the way he's using it will damage the circuitry in the gf9000. it's just a matter of when.

 

[restocat]

Good answers, sounds lie the easiest thing is to just stop what your doing and go buy the adapter

 

[2steppa]

It's not just the sensitivity of the phono input, it's also the fact it applies an equalisation curve (RIAA standard) to the sound to compensate for the vinyl tonal balance applied before the records are cut. So even reducing the input level to a point that it doesn't distort will sound appalling.

The 9000 doesnt have a native line-in capability, so it will never work in that configuration.

The converters really do work well

http://en.wikipedia.org/wiki/RIAA_equalization

 

[Superduper]

'Tis true.

 

[BoomBoxDeluxe]

OK.....I suppose that I am just going to have to buy the adaptor device which lower a line-level device down to phono.

At present, this box continues to disappoint me. I still can't figure out why Sharp made both of the inputs at phono level! :annoyed:

Take for example, the Sharp GF-777. This has one set of RCA inputs, with a selectable Line/Phono switch. Great!

Even my QT-90 has this set-up, as does the GF-767.

...........And the GF-9000? Two inputs. A DIN socket, and RCAs..........BOTH AT PHONO LEVEL! :annoyed: :annoyed: :annoyed: WHY?!


Well, if bMoney has recommended this device, and that it will lower a line-level device for a phono input, then I guess that this is the way that I am going to have to do things.


Thanks for pointing out this device. Let's hope that they ship to the UK!


-BoomBoxDeluxe.

 

[BMoney]

good luck man. i really think it would solve your problems. if not, there's something else wrong. let me know if you need help. i can send you one if you can't find a UK supplier.

 

[BoomBoxDeluxe]

By bMoney:

i really think it would solve your problems. if not, there's something else wrong

What I will do, is to try the experiment with the turntable.........If it works well with a turntable outputting at phono level, then this will confirm two things:

(1) The box is working OK, and that I haven't damaged it (in my experiments, I have been very careful!)

(2) Also, that both of the inputs are (annoyingly) at phono level, and that I will need to buy the device, or something equivalent.

I will do the turntable experiment mainly for point one above. If there is something really wrong with the box, then I will need to look into that (I am not sure how, though!)

I will post updates on the turntable experiment soon...........Stay tuned.


-BoomBoxDeluxe.