I would just add one thing by saying that ideally you'll want to keep the wires from the regulator to the board as short as possible to ensure the best regulation. If you look at the datasheet for the LT1083 you'll see this mentioned along with some other things to keep in mind if you do put the regulator next to the amp pcb. I have some decent transformers laying around but I'm opting to get a Plitron toroidal transformer to see just what this little amp is capable of 😉
john65b said:
I'd beware of any computer power supplies. Almost all of them are switching power supplies, and you'd only add the switching harmonics on top of the ones the amp already generates. I'd say that going with a linear PSU is your best bet with these little guys.
A LM317, LT1083/4/5 or LM338 based PSU should suffice.
Subwoofer outs for $30 amp upgraded
Has anyone wired up a set of subwoofer outs for their upgraded t-amp as of yet? I am in the process of building a chassis for one and am planning to add a pair of passive outs from the new Potentiometer. I will be using the amp with my Full Range Coral Mini-Monitors and a sub. I fired up the bone stock version without the sub and they sound great together. Id just like to have a little more low end when watching a movie.
Any help would be great!
Kerry
Has anyone wired up a set of subwoofer outs for their upgraded t-amp as of yet? I am in the process of building a chassis for one and am planning to add a pair of passive outs from the new Potentiometer. I will be using the amp with my Full Range Coral Mini-Monitors and a sub. I fired up the bone stock version without the sub and they sound great together. Id just like to have a little more low end when watching a movie.
Any help would be great!
Kerry
Re: Re: Subwoofer outs for $30 amp upgraded
OK, i think i figured that out :^)
Now i want to know what box you put them in and see pictures.
dave
planet10 said:
OK, i think i figured that out :^)
Now i want to know what box you put them in and see pictures.
An externally hosted image should be here but it was not working when we last tested it.
dave
Sorry to go OT about the Corals . . .
Send me your e-mail and I will take some fotos of the speakers and send them. Basicaly they are 9x6x7Boxes with a 1.5 diameter by 2.75 inch long port tube. The enclosures are solid oak and the internals are wired with Silver coated copper. They are really beautiful sounding. They just don't have much below I would guess 80 to 90 Hz. I have paired them with an 8 inch mirage subwoofer and they sound really good together. Lots of depth and a tremendous sound field for their size. BTW the port and box tuning was done by ear with no software. So what sounds good to me may not work for you.
Send me your e-mail and I will take some fotos of the speakers and send them. Basicaly they are 9x6x7Boxes with a 1.5 diameter by 2.75 inch long port tube. The enclosures are solid oak and the internals are wired with Silver coated copper. They are really beautiful sounding. They just don't have much below I would guess 80 to 90 Hz. I have paired them with an 8 inch mirage subwoofer and they sound really good together. Lots of depth and a tremendous sound field for their size. BTW the port and box tuning was done by ear with no software. So what sounds good to me may not work for you.
Nice corals! 😎
I've got a couple sets of these I plan to mate to SI amps, too. Please share your pics!
I've got a couple sets of these I plan to mate to SI amps, too. Please share your pics!
Sorry for the hijack but I too have the Corals. Here is what I played with last night. The Coral is running 1000 to 10000Hz. planet10 dave thinks I am under using the value of them. It's hard to disagree, they are a great little driver. If this sounds half ways good, I will ask him to do the doctor dave treatment on them. ie: Puzzle Kote, phase plug and damping.
Cal
Cal
Attachments
motherone said:
Thanks Motherone. I have been looking for a couple more for several weeks. Ordered two from eFunctional today. They show as in-stock. We shall see.
This little amp is amazing. It could change the whole industry if they take notice... or even if they don't 🙂
Best,
Paul
planet10 said:
I am asking the MCM 6.5 to run from 100 to 1000. I think I need the Coral up a little higher for power handling. I'm using a 6dB XO. Were it not for that, I would be happy to run them down to 300. Remember this is my first non-two way speaker in quite some time. So instead of just going for a three way, I decided to break with tradition and go wild with this one. Egads, it's a four way! Say it's not true.
Oops, more hijacking I guess.
Cal
Coral Mini-Monitors
I took the pictures tonight however I can't find the cable to download them off my digital camera. I will try and get these on in a couple of days.
Kerry
I took the pictures tonight however I can't find the cable to download them off my digital camera. I will try and get these on in a couple of days.
Kerry
In reference to earlier posts about wall warts, I found this 2.4amp, 13.5V one at part express for 4.50 each. Would the extra amps make any difference, good or bad, all else being equal? I have no idea what kind of current would be overkill for the amp. (yes, i'm a newb😀 )
http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=129-068
http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=129-068
I'm not an expert, but generally:
More amps is better- amps are just what it COULD put out.
Its too many volts might kill it, but 13.5 volts is fine
BUT, These wall wart type power supplies seem to vary all over the place in their true voltages. Often they put out more volts than they are rated to compensate for the voltage dropping under a significant load. A regulated supply shouldn't do this, but we don't know if its regulated or not.
The problem is that the amp draws so little power that the voltage of the supply might not drop as much as it would under higher load, thus endangering your amp. That said, I suspect it will be fine, and the price is right.
The knowledgable person would find out the power the amp draws, set up an equivalent resistor load on the powersupply, and THEN measure the voltage at the supply output.
Others might just hook it upand see if it blows up or not. It probably won't, and you are rising only 20-30 dollars.
PS
It appears our beloved amps are being discontinued, they are no longer listed on the company website. While we think that sales must be great because we are all ordering them, the general public may not be interested in buying amps without speakers, for their portable players, and they might in fact not be big sellers.
More amps is better- amps are just what it COULD put out.
Its too many volts might kill it, but 13.5 volts is fine
BUT, These wall wart type power supplies seem to vary all over the place in their true voltages. Often they put out more volts than they are rated to compensate for the voltage dropping under a significant load. A regulated supply shouldn't do this, but we don't know if its regulated or not.
The problem is that the amp draws so little power that the voltage of the supply might not drop as much as it would under higher load, thus endangering your amp. That said, I suspect it will be fine, and the price is right.
The knowledgable person would find out the power the amp draws, set up an equivalent resistor load on the powersupply, and THEN measure the voltage at the supply output.
Others might just hook it upand see if it blows up or not. It probably won't, and you are rising only 20-30 dollars.
PS
It appears our beloved amps are being discontinued, they are no longer listed on the company website. While we think that sales must be great because we are all ordering them, the general public may not be interested in buying amps without speakers, for their portable players, and they might in fact not be big sellers.
Kepler said:
I'm with Variac on it. I think what he was trying to say was that whether or not this thing will destroy your SI depends on whether or not it has good regulation on the DC side of things. If it is a regulated power supply, it shouldn't matter what kind of load you put on it up to the 2.4 amp limit -- it should stay within a certain percentage of 13.5 volts.
However, if it's unregulated (more likely), then you're probably going to wind up having the voltage creep higher as the load decreases. This means that it puts out 13.5 VDC @ 2.4amps, but puts out 20 VDC @ 300ma, which I think is close to the idle draw of the SI.
Variac said:
As they say, all good things must pass. But they are still available on the www.SI-5.com website. Just as part of the 69.95 SoundPAX speaker system.
I purchased a 5066 two weeks ago for 45.00 delivered. and the SoundPAX system with carrying backpack is what showed up.
The speakers are very nice, but maybe not everyones cup of tea. Todays 70.00 price is getting close to the price of a Tripath EB-2024B Evaluation board. But I have had zero luck in getting a response on purchasing a couple of these. Maybe someone could group buy some if they can get a response from Tripath.
The evaluation board looks to be a big step up in build quality compared to the 5066, and is designed to play full range.
George
How many around here have heard the TEAC $99 3 channel (with the secret 4th channel) Maybe its time to try it. There are some comments that it isn't quite as good as the SI, but I have my doubts- heck it could be better, and more power.
I guess one way to remedy the possible 20v dc at 300ma would be to make a voltage regulator to hook the wall wart to before feeding it to the amp. Would it even be worth it having the 2.4A vs. 1.7A wort?
Variac said:
This is on my to-do list, after I finish up my SI's.
Kepler said:
If you used a low-dropout regulator, depending on the dropout voltage, you could get it down to 12v or so from the 13.5, and have it fully regulated.
A LM1084 regulator would probably work for this (1.5v dropout voltage), unless I totally misunderstand how LDO Regulators work.
However, at that point, you may as well just make your own regulator with one of Digi01's boards. I'm using some 2.4A 15VAC wallwarts from allelectronics.com.
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