Audibly mine is absolutely fine, when there is nothing playing there is just complete silence. With music playing it shows great definition and clarity, and even some bass!
A spectrum analyser might reveal something, but I'm not concerned because I can't hear it!
I only used a laptop supply because I had one spare and it's output voltage was perfect. It's small size is a massive bonus also.
A spectrum analyser might reveal something, but I'm not concerned because I can't hear it!
I only used a laptop supply because I had one spare and it's output voltage was perfect. It's small size is a massive bonus also.
bongoman said:
which one?, I realize the importance of power supply..., I have one board coming so like to get hold of the proper PS.
gychang
I'm using an IBM Thinkpad 16V supply, but that's on the edge of what the board can take so just be careful!
Can anyone help with adding a Microphone input on this amp? I know the ohms and voltage are different than, a typical IPod output. What would have to be added to be able to do this?
BTW - I got my 1st amp and you guys are right it does sound pretty good, right out of the box...
Mike
BTW - I got my 1st amp and you guys are right it does sound pretty good, right out of the box...
Mike
I'm no expert, but I think it depends what kind of microphone you are thinking about using (condenser, moving coil etc).
If it's a very low level input you need some kind of preamplifier stage to get the voltage up to a level that the amp can handle. I'm guessing that unless you have some kind of preamp in the microphone that you will need something. Adjusting the ratio between R7/R8 and R13/R14 adjusts the amplifier gain on this board, check the TA2024 datasheet for info on the gain setting. I really doubt it will go low enough however.
I have replaced R8 and R14 with 10K metal film resistors, replacing the original 22K so that the amp can handle both high level inputs (squeezebox), and now also gives enough gain to use with my MP3 player (Creative Zen Vision:M). I found that before I had to really crank the MP3 player output up and it was still quiet, but now it's ok.
Audio1st, do you have any feedback on removing those output stage caps, I may be imagining it but the top end might be a little overpowering now. I'm probably just imagining it
If it's a very low level input you need some kind of preamplifier stage to get the voltage up to a level that the amp can handle. I'm guessing that unless you have some kind of preamp in the microphone that you will need something. Adjusting the ratio between R7/R8 and R13/R14 adjusts the amplifier gain on this board, check the TA2024 datasheet for info on the gain setting. I really doubt it will go low enough however.
I have replaced R8 and R14 with 10K metal film resistors, replacing the original 22K so that the amp can handle both high level inputs (squeezebox), and now also gives enough gain to use with my MP3 player (Creative Zen Vision:M). I found that before I had to really crank the MP3 player output up and it was still quiet, but now it's ok.
Audio1st, do you have any feedback on removing those output stage caps, I may be imagining it but the top end might be a little overpowering now. I'm probably just imagining it
Thanks Bongoman,
I'm testing the amp to see how well it holds up under extended run times at full power. After a 45 min, of playing heavy bass music, I topped out at around 203°F Does anyone know the Tripath temp shutdown? Most songs are around 175-185°F (@100% on the IPod)
Audio question - I'm running 4 ohm coax speakers along with a 8 ohm tweet crossed over at ~4,000 Hz. Running 4 ohm and 8 ohm in parallel is 2.6667 ohms. When I crossover the highs does this change things? When I mean to say, don't I only have to worry about ohms on the woofers? Example, if I ran two 4 ohm woofers in parallel?
Mike
I'm testing the amp to see how well it holds up under extended run times at full power. After a 45 min, of playing heavy bass music, I topped out at around 203°F Does anyone know the Tripath temp shutdown? Most songs are around 175-185°F (@100% on the IPod)
Audio question - I'm running 4 ohm coax speakers along with a 8 ohm tweet crossed over at ~4,000 Hz. Running 4 ohm and 8 ohm in parallel is 2.6667 ohms. When I crossover the highs does this change things? When I mean to say, don't I only have to worry about ohms on the woofers? Example, if I ran two 4 ohm woofers in parallel?
Mike
From the TA2024 datasheet...
Over-temperature Protection
An over-temperature fault occurs if the junction temperature of the part exceeds approximately
155°C. The thermal hysteresis of the part is approximately 45°C, therefore the fault will
automatically clear when the junction temperature drops below 110°C.
Does your board trip out? An over-temperature fault will cause it to stop playing and start again once the chip cools, whereas over-driving the chip won't start playing again.
I am going to connect the MUTE pin to the FAULT pin I think, it's starting to get annoying having to reset the board manually every time I accidentally over-drive it. Apparently connecting these pins together will trigger an automatic "reboot" in the event of an over-current condition!
Over-temperature Protection
An over-temperature fault occurs if the junction temperature of the part exceeds approximately
155°C. The thermal hysteresis of the part is approximately 45°C, therefore the fault will
automatically clear when the junction temperature drops below 110°C.
Does your board trip out? An over-temperature fault will cause it to stop playing and start again once the chip cools, whereas over-driving the chip won't start playing again.
I am going to connect the MUTE pin to the FAULT pin I think, it's starting to get annoying having to reset the board manually every time I accidentally over-drive it. Apparently connecting these pins together will trigger an automatic "reboot" in the event of an over-current condition!
No, after 1 hour going strong... Never shut down. So I should be good to ~300°F , very cool... I might have to worry about the solder melting before the thermal kicks in 😉
Have you removed C3 and C24? If you haven't then I strongly that you do, it makes a very obvious improvement to the treble.
Not yet, I have another one on order, just incase 
Louder or better clairity? Is it as simple as pulling it on one end and heating up the other end with a solder gun?
Louder or better clairity? Is it as simple as pulling it on one end and heating up the other end with a solder gun?
Removing those components won't make it go any louder really, but as standard the boards sound muffled due to those two capacitors acting as a low-pass filter on the inputs. Certainly removing them won't cause you any problems, if you can do it safely.
I would recommend just heating the whole component up if you don't have a fine point (<1mm tip) soldering iron, then dragging it off the SMD pads that it's sitting on while it's hot. Often adding a little more solder can help to get the whole thing hot and aid removal. Once it's gone make sure that the SMD pads aren't bridged with the left over solder.
I would recommend just heating the whole component up if you don't have a fine point (<1mm tip) soldering iron, then dragging it off the SMD pads that it's sitting on while it's hot. Often adding a little more solder can help to get the whole thing hot and aid removal. Once it's gone make sure that the SMD pads aren't bridged with the left over solder.
It seems OK so far, I find Eva Cassidy's Songbird CD has some high notes that can screech if you get it wrong. Clear and smooth still.
I guess this Amp is going to take a while to settle down and will probably sound worse before it reaches it's best..
The bag of SMD's (fleas), arrived today with 2 of their 8watt amps (only asked for one). Thought they might be suitable for headphones or pre amp? (they have a single speaker ground)..
Only ordered Boxing Day😀
The photo is to show a comparison to the Tripath board, inductors are a lot bigger..
Cheap Toys, good service..
Attachments
Hey bongoman,
Still working with the 16V power supply? I have a board on order and I have an old thinkpad power supply that I want to use but the voltage scares me.
I also have a 250W powersupply from a 1U server. Anyway to use that?
Still working with the 16V power supply? I have a board on order and I have an old thinkpad power supply that I want to use but the voltage scares me.
I also have a 250W powersupply from a 1U server. Anyway to use that?
Yep, still working great from the 16v supply! My guess is that the absolute maximum quoted on the datasheet is fine and it might go higher if the cooling is up to it.
I just measured my supply and it's 16.5v when running! 😀
I connected to the FAULT pin to the MUTE pin through the MUTE resistor and it works great. When the amp over-drives, it cuts out momentarily and then resets itself.
I've also sorted out my over-drive and power LEDs and replaced the tank cap with a slimmer Frako 4700uF/16V.
I think I'm done messing around with this little amp now. Time to find a box.
I just measured my supply and it's 16.5v when running! 😀
I connected to the FAULT pin to the MUTE pin through the MUTE resistor and it works great. When the amp over-drives, it cuts out momentarily and then resets itself.
I've also sorted out my over-drive and power LEDs and replaced the tank cap with a slimmer Frako 4700uF/16V.
I think I'm done messing around with this little amp now. Time to find a box.
An externally hosted image should be here but it was not working when we last tested it.
Received mine yesterday. Sounded dull out off the box.
Will follow advise of bongoman, to remove c3 and c23.
Will follow advise of bongoman, to remove c3 and c23.
These make a very good headphone amp!
These make a very good headphone amp. All you do is put a 220 uf capacitor (paralled with a 1 uf film) between the + outputs for the left and right channels and then connect the common (sleeve) connection of the headphones to ground. Orient the + terminal of the capacitor towards the amplifier's + terminals (away from the headphones). The capacitors are needed because there is a voltage of about half the power supply present between any output terminal and ground.
They sound pretty good-a bit hissy but not bad at all, actually.
For the price, a steal!
In theory you could hook up two headphones to one amp by using both the +and - outputs-each with its own blocking capacitors of course. The only caveat is that the headphones would be 180 out of polarity with each other.
These make a very good headphone amp. All you do is put a 220 uf capacitor (paralled with a 1 uf film) between the + outputs for the left and right channels and then connect the common (sleeve) connection of the headphones to ground. Orient the + terminal of the capacitor towards the amplifier's + terminals (away from the headphones). The capacitors are needed because there is a voltage of about half the power supply present between any output terminal and ground.
They sound pretty good-a bit hissy but not bad at all, actually.
For the price, a steal!
In theory you could hook up two headphones to one amp by using both the +and - outputs-each with its own blocking capacitors of course. The only caveat is that the headphones would be 180 out of polarity with each other.
bongomann
dullness is now gone. sound much better.
will let it burn in for a couple of days.
then see what to do further.
dullness is now gone. sound much better.
will let it burn in for a couple of days.
then see what to do further.
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