From the PDF: http://www.tripath.com/downloads/TA2024.pdf
16 is the point beyond which damage will occur... 8.5 to 13.2 is apparently the range in which the device will function. So according to them, it will stop working beyond 13.2 volts, but this would seem to be an exaggeration.
Anyways, it runs great on the Yamaha adapter - I personally can't hear any difference between it and battery power.
16 is the point beyond which damage will occur... 8.5 to 13.2 is apparently the range in which the device will function. So according to them, it will stop working beyond 13.2 volts, but this would seem to be an exaggeration.
Anyways, it runs great on the Yamaha adapter - I personally can't hear any difference between it and battery power.
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Power Supply Voltages
I do not think it is good for the chips to run these high voltages. Someone posted somewhere that the 12 volt 1000 ma supply from Radio Shack runs about 14.5 volts.
If you do not mind, please unplug the power supply and measure the unloaded output. The SI is a very low power draw when not playing.
I am thinking of buying one of the Yamaha supplies, it has to lower than the 13.8 supply sold by Parts Express.
One thing though, the SI does sound nice when run at 18 volts! My speakers are 100 dB efficient, and 15 ohm.
George
bwbass said:
I do not think it is good for the chips to run these high voltages. Someone posted somewhere that the 12 volt 1000 ma supply from Radio Shack runs about 14.5 volts.
If you do not mind, please unplug the power supply and measure the unloaded output. The SI is a very low power draw when not playing.
I am thinking of buying one of the Yamaha supplies, it has to lower than the 13.8 supply sold by Parts Express.
One thing though, the SI does sound nice when run at 18 volts! My speakers are 100 dB efficient, and 15 ohm.
George
Well, I use this at work, and all we had in the shop was an old Mura analog meter... it's nearly as big as one of my speakers, and dwarfs the T-amp!
According to that it was 12 volts DC right on the nose.
Anyways, since the amp just plain stops rather than fades out when the voltage gets too low (as would be expected from a digital amp), how would the sound be improved by a higher supply voltage anyways?
As I understand switching amps, you're just turning on and off the (full) supply voltage in a time scale proportional to amplitude in order to approximate the sound source waveform. I can see it being louder with more supply voltage, but as long as the switching circuit is in a voltage range to function properly, the "quality" of the sound should be the same, right?
Forgive my newbieness with digital amps, I just want to understand!😱
According to that it was 12 volts DC right on the nose.
Anyways, since the amp just plain stops rather than fades out when the voltage gets too low (as would be expected from a digital amp), how would the sound be improved by a higher supply voltage anyways?
As I understand switching amps, you're just turning on and off the (full) supply voltage in a time scale proportional to amplitude in order to approximate the sound source waveform. I can see it being louder with more supply voltage, but as long as the switching circuit is in a voltage range to function properly, the "quality" of the sound should be the same, right?
Forgive my newbieness with digital amps, I just want to understand!😱
Has anyone thought of this?
What about making a power supply based on this $5 toroidal tranny from PE
http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=129-082
With a minimum of parts it could be a killer PS solution, much better than any wall-wart, plus maybe even cheaper. PE probably has all the parts needed.
What about making a power supply based on this $5 toroidal tranny from PE
http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=129-082
With a minimum of parts it could be a killer PS solution, much better than any wall-wart, plus maybe even cheaper. PE probably has all the parts needed.
By the time you rectify the AC to DC the output will be over 18v.
Nice toroid though...we have to think of something for it...
Nice toroid though...we have to think of something for it...
Lo Duca
I ordered a Lo Duca 12v 1700 ma supply from Best Buy for 19.99 online and picked it up on the way home from work this afternoon.
It measures 12.03 volts unloaded. This sounds more like it. Until my next batch of SI amps arrives I will not try the 18 volt supply from PartsExpress. Do not want to press my luck.
I am listening to another amp now, but will give the SI a listen later. It will be interesting to compare the LoDuca supply, high power AA's, and the battery from my daughter's Power Wheel Motorcycle. It is a 7.4 AH 12V SLA.
btw, the Best Buy had four more of the Lo Duca's on the rack.
George
bwbass said:
I ordered a Lo Duca 12v 1700 ma supply from Best Buy for 19.99 online and picked it up on the way home from work this afternoon.
It measures 12.03 volts unloaded. This sounds more like it. Until my next batch of SI amps arrives I will not try the 18 volt supply from PartsExpress. Do not want to press my luck.
I am listening to another amp now, but will give the SI a listen later. It will be interesting to compare the LoDuca supply, high power AA's, and the battery from my daughter's Power Wheel Motorcycle. It is a 7.4 AH 12V SLA.
btw, the Best Buy had four more of the Lo Duca's on the rack.
George
>>By the time you rectify the AC to DC the output will be over 18v. Nice toroid though...we have to think of something for it...
Sure you will have about 18 volts after the rectifier, but throw on a LM317 regulator and just pick what voltage you want to send to the amp.
Sure you will have about 18 volts after the rectifier, but throw on a LM317 regulator and just pick what voltage you want to send to the amp.
I would never disagree on power supplies with a guy named DCDave😉
Besides- that's a good point!
Besides- that's a good point!
Input Impedance?
Ok, another question:
Does anyone have a spec on the input impedance of the T-amp? I want to make a Passive Line Level Crossover for it ( http://www.t-linespeakers.org/tech/filters/passiveHLxo.html ) so this little amp doesn't blow my little Tang Band drivers trying to pound out low bass.
Anybody?
Ok, another question:
Does anyone have a spec on the input impedance of the T-amp? I want to make a Passive Line Level Crossover for it ( http://www.t-linespeakers.org/tech/filters/passiveHLxo.html ) so this little amp doesn't blow my little Tang Band drivers trying to pound out low bass.
Anybody?
Re: Re: Getting rid of the pot & battery supply tip
Sorry, just had a brainstorm and searched this thread for "impedance" ... does 10k input impedance on the T-amp sound right to everybody?
MEXXX said:
Sorry, just had a brainstorm and searched this thread for "impedance" ... does 10k input impedance on the T-amp sound right to everybody?
10k is what it measures.
That is what I measure. This is with the pot disconnected and going from that input to ground.
If you are going to drive it from a solid state source this should be fine. A tube circuit most likely will not like the 10K loading. That is unless it is a 6080 tube or something like that.
The spec sheet from Tripath recommended a 2.2 ufd cap in the input. The way I am measuring it I cannot see a cap in the input. If there is one there, the series impedance after it has to be factored in for calculating crossover values.
George
bwbass said:
That is what I measure. This is with the pot disconnected and going from that input to ground.
If you are going to drive it from a solid state source this should be fine. A tube circuit most likely will not like the 10K loading. That is unless it is a 6080 tube or something like that.
The spec sheet from Tripath recommended a 2.2 ufd cap in the input. The way I am measuring it I cannot see a cap in the input. If there is one there, the series impedance after it has to be factored in for calculating crossover values.
George
I have been tinkering with many power supplies for the SI 5066 including the 12V walwart I got from RS. Seemed like there should be a better sounding option than the 8 AA batteries or the 12V motorcycle battery. I tried a 12 volt 1 amp, 1.5 amp and an old 12 volt 1.8 amp powersupply that was came from an old laptop (glad I didn't throw it away!!). I noticed the sound seems punchier and more alive with the higher current (duh - should this surprise me??)
I also noticed the 1 amp tripped out the amp at higher volumes...the sound eventually came back after 5 minutes or so.
Anyway, got to thiking, my spare computer power supply has a 12 volts/16 amps connection I can jimmy rig to the SI...I think you know what I'm thinking... any advice before I blow up my amp?? Speak now!!
I also noticed the 1 amp tripped out the amp at higher volumes...the sound eventually came back after 5 minutes or so.
Anyway, got to thiking, my spare computer power supply has a 12 volts/16 amps connection I can jimmy rig to the SI...I think you know what I'm thinking... any advice before I blow up my amp?? Speak now!!
BTW, these little guys work great in a car running at <13.8v. It was powering 6.5" mids and tweeters through a passive xover and I was astounded at how loud it was. The two I have running my home setup use a 13.8v 10amp good old fashioned regulated supply and they love it.
john65b said:
You might want to measure the voltage being outputted by all those supplies. The rated voltage and actual can be a long way apart. Like you, I have tried three power supplies, a 12 volt SLA, and two kinds of AA.
In my system it should not be so critical, the power demends are much less than a watt. But all sounded different. The 13.5/30 1 amp supply from RS was the worst. It was causing some ringing that caused headaches after a few hours. The higher current supplies and batteries did not do this.
George
Re: Purchasing an SI AMP
I was in the same boat but with (3) on backorder thru PCMall since December.
Got the package from Sonic direct in 5 days. Opened it up and found the T-amp with speakers and a backpack....along with a note that said FREE SPEAKERS!!!
😀 😀 😀 Very cool of SI😀 😀 😀
kerryvh said:
I was in the same boat but with (3) on backorder thru PCMall since December.
Got the package from Sonic direct in 5 days. Opened it up and found the T-amp with speakers and a backpack....along with a note that said FREE SPEAKERS!!!
😀 😀 😀 Very cool of SI😀 😀 😀
OK, I just found out about these little beauties today. I ordered two for me and one for a friend from eCost, and they're allegedly due to ship like February 18. I think I'll hold my breath and see how that works out....
...or maybe not. 😉
Anyway, we're looking for a stable power supply that will let this amp hit bass notes hard, but without exceeding some voltage limit which will croak (that's a technical term) it.
How about adding a car stereo stiffening capacitor on the power supply? I'm talking something like this: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=50547&item=5749196007&rd=1
Make sure the conductors from the cap to the board are large enough, and stand back....
...or maybe not. 😉
Anyway, we're looking for a stable power supply that will let this amp hit bass notes hard, but without exceeding some voltage limit which will croak (that's a technical term) it.
How about adding a car stereo stiffening capacitor on the power supply? I'm talking something like this: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=50547&item=5749196007&rd=1
Make sure the conductors from the cap to the board are large enough, and stand back....
I was going to wait to post about it until it was built, but I plan on using one of Linear Technology's Low Dropout Voltage Regulators for a rock solid supply voltage and ample current capability (specifically the LT1083). Should make for a good combination when all is said and done. I'll be sure to post the results here when it's finished 🙂
If you're still looking for a sub-$30 sonic impact, check out this site:
http://store.yahoo.com/efunctional/sit5066.html
I purchased two here for this price a while back ($20.46). They show that they still have them in stock as well.
Good luck!
http://store.yahoo.com/efunctional/sit5066.html
I purchased two here for this price a while back ($20.46). They show that they still have them in stock as well.
Good luck!
Here is a supply design of mine that I modified to use the LT1083 as suggested by BWRX and changed resistors to give +13.1v out. For a tranny I would go with the $5 Parts Express toroidal (129-082) with the secondaries in series yielding 14VAC. It doesn't say the output current, but given its size I'd say it would be fine. This design should give great results.
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