Sansa Fuze through AVR - low volume

[pzaur]

Alright, anyone got a cheap way to increase the volume output of this setup?

Sansa Fuze connected to Sony HTiB receiver (at one school) and a Technics receiver (at the other school) via y-cable. I have to crank it to just below max to get any real volume out the dang thing with either receiver. I don't have any volume issues when a CD/DVD player is used.

It has to overpower an elementary band...

Notes:
1) I've already looked into increasing the natural volume of the sound files with no luck because the files end up being clipped. They're already as loud as can be.

2) Volume on the Fuze is all the way up.

3) It's at a school and the budget is in the s****er.

-pat

 

[Adam]

Hey, Pat. That surprises me that it would sound so quiet even with the volume on the Fuze all of the way up. Have you tried a different cable? Just a thought.

Also, the manual mentions that you can set the volume to "Normal" or "High" under the System Settings.

 

[TLS Guy]

Alright, anyone got a cheap way to increase the volume output of this setup?

Sansa Fuze connected to Sony HTiB receiver (at one school) and a Technics receiver (at the other school) via y-cable. I have to crank it to just below max to get any real volume out the dang thing with either receiver. I don't have any volume issues when a CD/DVD player is used.

It has to overpower an elementary band...

Notes:
1) I've already looked into increasing the natural volume of the sound files with no luck because the files end up being clipped. They're already as loud as can be.

2) Volume on the Fuze is all the way up.

3) It's at a school and the budget is in the s****er.

-pat

Presumably you are using the headphone jack as the output, is that correct? How loud do headphones play?

I don't understand the Y connection, that would give mono from one channel.

I assume the output is via 1/8 micro stereo phone jack, so you would need a stereo micro phone plug to R & L RCA plugs. That is not a Y connection, but a discreet two channel connection.

If you are connecting as I have outlined, then you will have to build another stage of amplification from a dual op amp chip. That is a very simple circuit with very few parts. The biggest cost would likely be the case to put it in and the wall wart to power it with. So I'm sure the total cost would be less than $20.

 

[Seth=L]

I've never experienced such an extreme problem with my Sansa Clip, a lower model, and I find it unlikely the output of the Fuze would be lower than the Clip. I've used it as a line source because it plays FLAC, and while it's output is reduced compared to most fixed line outputs it's enough for me to get considerable output from regular stereo equipment. A cheap Audiosource preamp could boost the output, or a cheap headphone amplifier would do the trick as well, at least in terms of increasing the output.

 

[lsiberian]

Alright, anyone got a cheap way to increase the volume output of this setup?

Sansa Fuze connected to Sony HTiB receiver (at one school) and a Technics receiver (at the other school) via y-cable. I have to crank it to just below max to get any real volume out the dang thing with either receiver. I don't have any volume issues when a CD/DVD player is used.

It has to overpower an elementary band...

Notes:
1) I've already looked into increasing the natural volume of the sound files with no luck because the files end up being clipped. They're already as loud as can be.

2) Volume on the Fuze is all the way up.

3) It's at a school and the budget is in the s****er.

-pat

I wonder if you could boost the signal between the system and Sansa.

 

[j_garcia]

If you are using the headphone out, most likely the output voltage is too low for the receiver/amp you are sending it to. I agree with the headphone amp or preamp if this is how you have it connected.

 

[pzaur]

If you are connecting as I have outlined, then you will have to build another stage of amplification from a dual op amp chip. That is a very simple circuit with very few parts. The biggest cost would likely be the case to put it in and the wall wart to power it with. So I'm sure the total cost would be less than $20.

The audio actually comes through both speakers using a good ol' y-cable with the headphone plug to r/l rca plug. The total volume, with both volumes all the way up, is at a decent level after rechecking it today in an empty room with no elementary band playing. The problem is that it just isn't loud enough with 50 budding instrumentalists playing woodwinds, brass, and percussion. Just listening, acceptable with both volumes cranked. With the band playing, no-go.

The amp idea intrigues me a great deal. I have no idea what a "dual op amp chip" is. I'm assuming the "op" means "output" at this point. Can you guys lead me to schematics of what I'd need to do this build?

-pat

 

[pzaur]

I've never experienced such an extreme problem with my Sansa Clip, a lower model, and I find it unlikely the output of the Fuze would be lower than the Clip. I've used it as a line source because it plays FLAC, and while it's output is reduced compared to most fixed line outputs it's enough for me to get considerable output from regular stereo equipment. A cheap Audiosource preamp could boost the output, or a cheap headphone amplifier would do the trick as well, at least in terms of increasing the output.

It's definitely a unique problem since the end goal is being able to be heard over 10 to 12 year olds playing instruments.

-pat

 

[TLS Guy]

The audio actually comes through both speakers using a good ol' y-cable with the headphone plug to r/l rca plug. The total volume, with both volumes all the way up, is at a decent level after rechecking it today in an empty room with no elementary band playing. The problem is that it just isn't loud enough with 50 budding instrumentalists playing woodwinds, brass, and percussion. Just listening, acceptable with both volumes cranked. With the band playing, no-go.

The amp idea intrigues me a great deal. I have no idea what a "dual op amp chip" is. I'm assuming the "op" means "output" at this point. Can you guys lead me to schematics of what I'd need to do this build?

-pat

Pat, here is an opamp calculator.

Go to topology and bring down the menu and click on non-inverting. This gives you an opamp with two to one gain, and up to 4.5 volts out which should be plenty.

Vin is the inline voltage of 5 volts DC, this is pretty usual for opamp chips. You would need a dual linear audio opamp chip for stereo. These are plentiful and cheap, usually around 50 cents. To power it I would get a wall wart of about 8 to 12 volts and then get a 5 volt output regulator IC chip, and put a 5 volt 25 mfd cap across the output and ground.

Vref is your input and Vout the output. The downward facing triangle is ground.

That circuit will do what you want.

 

[TLS Guy]

Pat, here is an opamp calculator.

Go to topology and bring down the menu and click on non-inverting. This gives you an opamp with two to one gain, and up to 4.5 volts out which should be plenty.

Vin is the inline voltage of 5 volts DC, this is pretty usual for opamp chips. You would need a dual linear audio opamp chip for stereo. These are plentiful and cheap, usually around 50 cents. To power it I would get a wall wart of about 8 to 12 volts and then get a 5 volt output regulator IC chip, and put a 5 volt 25 mfd cap across the output and ground.

Vref is your input and Vout the output. The downward facing triangle is ground.

That circuit will do what you want.

I have had one more thought about this. Does this device run headphones OK? What is the source of the recordings you are committing to the Sanza Fuse? I ask this because if you are recording uncompressed material to this device, then this will reduce the average level significantly. If you are doing this you will need expensive pro equipment to reproduce this under your circumstances. If you are going to do what you want, then a very healthy dose of dynamic range compression needs to be applied.

By the way opamp stands for operational amplifier.

 

[pzaur]

Thanks for the op amp definition. I really had no clue. The only music I'm running through it comes off the student's method book for band, Essential Elements 2000. The files are all in mp3 format.

I also discussed this with two of my buddies who work in the engineering field and they both suggested an op amp right off the bat.

The Fuze drives headphones with no problem and it really is loud enough in the classroom when the band is not playing. I'm trying to make the volume loud enough so it will be heard by all members of the group when everyone is playing. Fifth and sixth grade instrumentalists are just freakin' loud. We're working on their volume controls....of course they believe the "Louder is better" motto.

-pat

 

[TLS Guy]

Thanks for the op amp definition. I really had no clue. The only music I'm running through it comes off the student's method book for band, Essential Elements 2000. The files are all in mp3 format.

I also discussed this with two of my buddies who work in the engineering field and they both suggested an op amp right off the bat.

The Fuze drives headphones with no problem and it really is loud enough in the classroom when the band is not playing. I'm trying to make the volume loud enough so it will be heard by all members of the group when everyone is playing. Fifth and sixth grade instrumentalists are just freakin' loud. We're working on their volume controls....of course they believe the "Louder is better" motto.

-pat

Does the program that you edit and transfer the files to the Sansa Fuze allow you to compress the dynamic range? If it does that will solve your problem. The fact that your unit plays headphones loud, tells me that your problem is excess dynamic range with reference to your application.

 

[TLS Guy]

Pat, I had not realized how sensitive these ear bud headphones had become! I guess I'm really slipping behind the times. These modern phones like the Shure Ear Buds, produce 119db with 1 mwatt into 36 ohms. By my calculations that means a device like the Sansa Fuze only needs to have an output voltage of 190 mV (0.19V) to blast your eardrums out.
Now line voltage is a volt. So you actually need 5:1 gain.

So in the op amp calculator RF sets the gain if you change RF to 40 K you will have 5:1 gain. So if the device outputs 190 mv then it will send just under 1 volt to your receivers. That will be plenty enough to drive them into clipping.

The program will tell you that output voltage of 4.5 volts is exceeded, however you will not get more than a volt out at full program modulation, and that will be perfect.

So my first thought was correct. I second guessed myself because I could not believe that a device that could drive a headphone would not fully drive a line input. No wonder the device has such long battery life. Resticted output has to be the trade off for that, and explains what you have observed. At least we have got to the bottom of it. How things change!

 

[pzaur]

Pat, I had not realized how sensitive these ear bud headphones had become! I guess I'm really slipping behind the times. These modern phones like the Shure Ear Buds, produce 119db with 1 mwatt into 36 ohms. By my calculations that means a device like the Sansa Fuze only needs to have an output voltage of 190 mV (0.19V) to blast your eardrums out.
Now line voltage is a volt. So you actually need 5:1 gain.

So in the op amp calculator RF sets the gain if you change RF to 40 K you will have 5:1 gain. So if the device outputs 190 mv then it will send just under 1 volt to your receivers. That will be plenty enough to drive them into clipping.

The program will tell you that output voltage of 4.5 volts is exceeded, however you will not get more than a volt out at full program modulation, and that will be perfect.

So my first thought was correct. I second guessed myself because I could not believe that a device that could drive a headphone would not fully drive a line input. No wonder the device has such long battery life. Resticted output has to be the trade off for that, and explains what you have observed. At least we have got to the bottom of it. How things change!

Am I sure glad you understand that stuff. I've got a basic grip on the concepts and am still lost! I'll see if I can find the output voltage for the headphone jack on the Fuze. It has to be listed somewhere...

-pat

 

[Adam]

Pat, the info on the thread linked here might be of value to you. In short, the headphone jack at 100% volume is supposed to be the same as the line out (if you had a dock), and a firmware update came out late last year that was supposed to help with quality from the headphone jack.

 

[pzaur]

Pat, the info on the thread linked here might be of value to you. In short, the headphone jack at 100% volume is supposed to be the same as the line out (if you had a dock), and a firmware update came out late last year that was supposed to help with quality from the headphone jack.

It still clips with the volume all the way up on the Fuze and cranked volume at the receiver. My Fuze is new as of July '09. I'll have to double check the firmware revisions. Mine was purchased in July and probably has the most recent revision.

-pat

 

[TLS Guy]

It still clips with the volume all the way up on the Fuze and cranked volume at the receiver. My Fuze is new as of July '09. I'll have to double check the firmware revisions. Mine was purchased in July and probably has the most recent revision.

-pat

I think we are finally at the bottom of things. Take a look at this thread from the Sanza forum. The headphone output is optimized for 16 Ohm impedance.

When connected to the Sanza dock the headphone output is disabled and a healthy line output is available from the 30 pin connector. So it seems you need a dock to get a true line output. No wonder you have been having clipping problems!

 

[pzaur]

This amp has been suggested by my buddies here. Any pros/cons over the aforementioned one?

I'm not gonna mess with modifying a dock (at this point...)

-pat

 

[TLS Guy]

This amp has been suggested by my buddies here. Any pros/cons over the aforementioned one?

I'm not gonna mess with modifying a dock (at this point...)

-pat

That amp is a 5 watt power amp. You need a voltage amp, in other words a preamp. However I think we have established that there is a healthy line out from the dock, but not the device itself. You should be able to solve your problem with a dock.

 

[pzaur]

You should be able to solve your problem with a dock.

The biggest problem with the dock situation is the only one I can find is on Amazon right now and Griffin Technologies doesn't list it on their website.

I haven't done a ton of searching other places at this point. The headphone amp is going to be built just so I can say, "Hey! I built this and it works!"

-pat