Inline Amplifier For Aux

[djh3]

Well after using the Aux input quite a bit I have decided that it needs a boost. Here is my issue. I use the Aux port (split with a y-cable so I can use more than one item ie:GPS and Phone). but to get anything to come over it seems I have to make it "play" from that item at full volume. Phone for sure as it tells me I'm goning to blow my eardrums out. It had to played just as loud when it was simply connected to the aux port by the cassette deck, so I dont think its because of the added wires.

If Iuse my boostaroo inline it is much better and sound is better also. But that also means I have to find someplace to attach it and change batteries etc. So I tried to find a battery elminator or figure out a way to build one. Then I ran across this "mini amp" that by what I can read should fit the bill. All I have to do is put it in a raio shack project box, seal it and connect to 12v under the fairing and connect the y-cable.

So can any of you smarter than me guys tell me if it will work?

Here is the Boostaroo specs

Input: One 3.5mm (1/8") Stereo Jack

Impedance: 5K Ohms @ 1Khz

Output: Two 3.5mm (1/8") Stereo Jacks

Impedance: 5.5 Ohms

32 mW increase per channel @ 32 Ohms

12 dB boost per channel

THD (Harmonic Distortion): less than 1.0%

Frequency Response: 20 to 20,000Hz +/- 3 db

Signal to noise ratio -110db

[videoarizona]

Hmmm..if I read the specs right, that is a 10 watt amp....not a pre-amp. That has almost as much power as our little amps on the bike.

So no...that may not work well. You are looking for a pre-amp to up the input voltage a teeny bit. You also need to look into the impedence as that will change the frequency curve...ie...what the music will sound like.

 

Something similar to this would be better:

 

Load Impedance: 10K Ohms - Reference Voltage: 1V

Input Sensitivity/Impedance/PHONO 3 mV / 50K Ohms - T.H.D: 0.08 for 1 KHz 3 mV Input - Output Level: 2V

S/N Ratio (A-WTD): 70 dB - Frequency Response: 20 Hz ~ 20 KHz ±2dB

The problem is that the above is for a phono pre-amp...a record player...so that may be the wrong impedence. But that is more of what you need....to increase the voltage to maybe 2 volts output...not 10 watts. Although I bet one of the guru's here could help you build and "H" pad type thingie to bring the voltage down and the impedence where it needs to be.

 

I would go with a 12 volt battery eliminator circuit and your boosteroo...easy to make/buy...

david

[djh3]

Not so easy. They do make a 12v model now, but its like $60. I read a bunch of ideas on how to knock the voltage down for the boostaroo, but then it get muddy as to how much of a resistor I need. Readon thread gave specs of something like 9 (amount I need to drop to)/amp=ohm But the spec of the boostaroo is not stated. So its a guessing game. I didn't figure it was much on that little amp that is run bu 2 ea AAAA batteries (they are pricey buggers when you find them) So I went with 9/.05 and got 180 ohm. Couldnt find a 180 ohm resistor listed at radio shack, but I think if you make a combo (100+30+50) and solder all together at one point that makes it what you need. The next problem would be making the connection on the unit. Maybe a piece of wooden dowel with contacts on the ends?

They do make some simular board amps like the one I had linked with rheostats. Something like this. I kind of hate to but though had crossed my mind to remove the beloved tape deck and put one of these in if I found one to fit.

[videoarizona]

I was thinking something like this:

 

http://www.philmore-datak.com/mc/Page%20246.pdf

 

First unit pictured...

 

or this:

 

Volume and Tone Control Preamp Kit K8084

 

Tons of stuff out there like this....tiny, 12volt powered and simply increases the signal a tad...

 

d

[Bob Myers]

Dion, this is what you need, it will accept 4 inputs. Use the priority input for the GPS,etc and main input for your music, patch to the input in of your stereo and you can tailor each item to a specific audio level.Mix-It Products

[djh3]

Dion, this is what you need, it will accept 4 inputs. Use the priority input for the GPS,etc and main input for your music, patch to the input in of your stereo and you can tailor each item to a specific audio level.Mix-It Products

That is wayyy more than I was looking to invest in this project. I mean heck I can buy a new boostaroo that is 12v powered for around $60 I was just looking for an inexpensive say under 20 fix.

[Motiv]

Just wondering out loud. If something like this would work for you.

iStream DockFree Bluetooth Audio Receiver, Black, Aluratek, AIS01F

Of course your GPS will need to be Bluetooth capable.

[Bob Myers]

Search a little, I bought 2 of them from a guy in Washington, freight cost more than purchase price of the 2!

[Bob Myers]

One on ebay for aboutl half price of new; Mix IT2 Original Pocket Size Audio Mixer Amplifier for MP3 GPS SAT Radar | eBay

[Bob Myers]

The boostaroo should do what you want but doesn't appear to be an amp of much output, just 20Mw. There is a model that has a 5v input, easily used on a bike with a cig lighter plug in USB adapter or a dash mounted dedicated USB outlet, I have one of these on my VUlcan, it worked for several years without fail, paid a lot more than this for it too, same brandMotorcycle 12V USB Cigarette Lighter Power Port Integration Outlet Socket | eBay

 

I put this in sidecar for Tina to charge and listen, etc without swapping cables constantly;

Dual USB Charger and Socket Panel Mount Marine 12 Volt Boat Jack Power Outlet | eBay

[djh3]

Motiv: not necessarily looking to go Blutooth. And I dont own an I-anything. But I would like to find something to conver the CD player cable to something usable. My player has been out since Oct, and I just have not put it back in.

Bob: what about this type amp. Connect inline of 3.5 aux cable and stash under the fairing. I dont have room for anything on handlebars.

[Bob Myers]

Wonder what the amp draw is on that? Claimed output power and advertised 1% THD makes it sound like discreet ttl stuff, not MoSFet. bet it'll pull 5 or 6 amps easily.

If amp draw is less than 5 then you'll likely be satisfied with it, as you are basically using it as a preamp, right?

 

I dumped Sirius last month, loaded up a 16G sd card with music and use it in my GPS(old Nuvi780), it works fantastic on the Goldwing and in my car using the Aux input. No ground loop hum, no hiss. As best I can ascertain the output on the MP3 player internal to it is less than 20Mw output.

 

You only need a slight boost to bring your add on up to the level you desire, so the boostaroo may be best bet. The one I linked has 5v input, use it with one of the 12v to 5v USB converters wired to only be live with key on and you should be doing exactly what you wanted in the beginning. I'd guess total investment to be under $35 for that setup.

[Bob Myers]

One thing I would be scared of using either the amps you linked is they are actually feeding a bit of voltage into your receiver device, unregulated, no way to attenuate the output other than by the volume of your player device. Could get ugly if it spiked when you first turn your player on.

The boostaroo uses 2 AA batteries, right? It would be quite easy to solder a pigtail on the terminals, feed that from a voltage regulator such as a Drock(Amazon.com: DROK® 12V to 3.3V 3A 10W DCDC Buck Power Converter Low Voltage Regulator Waterproof: Electronics ) and maybe even glue this into the battery compartment. If so, this would be an $8.00 cure for the problem, you already know the boostaroo will do what you want

 

Here is a regulator that is even cheaper, but not isolated=Amazon.com: Keedox® DC/DC Converter 12V Step Down to 3.3V 3A Power Supply Module, Non-isolated: Electronics

[djh3]

Those look like the ticket. Exactly what I was trying to find. the bootaroo works fine. What seems like enough extra volume to help the devices get "over the hump" so to speak. It adds a little bass and clears the treble up some. I dont know how but it just sounds better.

My thought would be to maybe drill a couple holes in the battery door and feed the wires in and solder to contacts. Then cover it in heat shrink maybe to keep out moisture. (Bootaroo) and tie wrap everything under the fairing. Does this one match the same specs you are talking about? Have to wait on a boat ride for it, but what dont you any more?

[Bob Myers]

Yes, that'll work fine. I would likely do the $8.00 one though if i were buying, it is supposedly isolated, meaning you won't have a ground loop feedback problem when you feed it 12v from the bike. Never seen one that was adjustable, seems like a good idea, but the boostaroo has a voltage regulator internal any way to trim the voltage down so batteries seem to last longer.

Put a one amp fuse in line, and connect to a switched outlet. I loved the way the Kawa's triggered the headlamp, it didn't come on until it sensed a charge from alternator, i tapped that point to trigger a relay to turn on all things I added to my Vulcan.

[djh3]

Where do I look for "isolated" What is supposed to be isolated.

[Bob Myers]

The first one I linked is supposedly isolated, the second one states it is not. The one you linked did not say but it looks like one on Amazon that said it is not. In my limited experience with adding stuff to bikes I find that most equipment is barely filtered well enough to keep the alternator noise or ignition noise out, sometimes adding another bike powered device will add lots of noise, or what is called a "ground loop feedback". An isolated power supply does not guarantee it will be quiet but the chances are better it will be.

In a power supply an isolated supply means the power lead is routed through either an optical isolator or transformer, as well the negative lead is coupled in a similar manner. In theory this keep noise in the electrical system to a minimum.

Remember back a few years ago when Radio Shack sold stuff other than telephones? They had a device called a 12V line filter that was a 3" black square box with 4 wires, 2 in, 2 out. It was nothing but a small 1:1 transformer on each input lead, and a filter capacitor on output side. Things have shrank a might since that was used.

[djh3]

I remember back in the day when you had spark plug wires I use to run solid core ones. Man did they play heck with the radio, and I installed some coil looking thing to eliminate noise. I had to install something like that on the 900 vulcan when I put a radio and stuff on it because it picked up a bit of buzz. that piece looked like an M80 with wires. Of course now I cant find anything at the Shack except the $15 job. Black box looking thin sort of like you described. think I'll go ahead and order the part. What the heck, if it buzzez like crap I can find a filter.

Well sent a couple questions out to sellers on these 2 PSU This one and this one. sort of partial to the second one, it looks a bit more robust.

Edited January 30, 2015 by djh3

[Bob Myers]

Description of first one say it is "synchronous rectification", means it use a MoSFeT instead of diodes for voltage reduction,positive line is filtered/regulated, negative is not. Second one does not say, but bet it is the same. Makes no difference, whichever you want, they'll booth do the same job

[djh3]

Guess I will wait a bit and see if they get back to me. I sent a message to them both to see what they said. I thought I had another noise filter in tool box somewhere. Maybe I will take another stab at looking for it.

[Bob Myers]

There is a good probability you won't need it. The player itself is not bike powered is it?

[djh3]

NO I use mainly the phone (sometimes its pluged in to charge) or the GPS which is plugged in for charge. Or if I use the MP3 it is battery powered.

[djh3]

So ordered up the part. ended up with this one. If it dont work, oh well will have to skip the fries next time or something.

[videoarizona]

Looks good. Sealed unit, lots of overprotection. Best choice.....agreed.

 

I may have to get one just for grins!

david

[djh3]

I am going to try to remember and do a short write up with some pics. Problem is I am usually about ready to button it up when I remember "Oh yea I was gonna......."