I just changed the resistors to get a new output voltage. I think you can use a LM317 calculator like this one to get the new resistor values:
http://www.electronics-lab.com/articles/LM317/
Other than that, and going with a wall-wart, nothing else was changed.
http://www.electronics-lab.com/articles/LM317/
Other than that, and going with a wall-wart, nothing else was changed.
lushds said:
The small size is the issue. I tried the straight core and the torriods. The 2100 series Miller choke is just too large and heavy.
Found some nice aircore chokes for loudspeaker crossovers. They use copper foil. These are sweeter than any tied up to now. I suspect this is an area where the 41 hz boards beat the eb-2024 and other with the little bobbin chokes.
I have read that the aircore do not filter the hash as well as iron cored. This is a grey area to me, may be true or it may be crap.
The sonics seem much better with aircore. It is the bass, much riper and full with the air core. The highs maybe just a little tamed. These measured 10.3 - 10.5 uH on my LCR meter.
George
I had sent an email to tripath asking about the output chokes. They basicly said to use low mu type 2 powdered iron cores (toroids).
I think that is what 41 Hz uses as well. I think this would be an "upgrade" to what is stock on the Teac and SI units. But they need to be removed and measured for high level distortion to be sure.
BTW, you can't bridge the outputs, but you may be able to "parallel" them - feed same signal to L R inputs, and tie L and R +/- speaker outs together. Just make sure the speaker outputs are in phase before you hook it up this way - there was a warning about out of phase speaker outputs on another SI mods website. Not sure if the extra current or separation would buy you anything, unless you are running 4 ohms or below.
More info to come as I play.
Bob
I think that is what 41 Hz uses as well. I think this would be an "upgrade" to what is stock on the Teac and SI units. But they need to be removed and measured for high level distortion to be sure.
BTW, you can't bridge the outputs, but you may be able to "parallel" them - feed same signal to L R inputs, and tie L and R +/- speaker outs together. Just make sure the speaker outputs are in phase before you hook it up this way - there was a warning about out of phase speaker outputs on another SI mods website. Not sure if the extra current or separation would buy you anything, unless you are running 4 ohms or below.
More info to come as I play.
Bob
BFNY said:
here is the email and reply from support@tripath.com
Bob
----------------------------------------------------------------------------------
Subject: Re: inductor recommendations w/ TA2050 parallel mode
Date: Wed, 8 Jun 2005
Hello,
Type 2 cores are still the best, both from a performance standpoint, as
well as being very cost competive, if not the most inexpensive solution for
these type of powers.
The parallel design uses a T68 core, which is adequate for this design,
as shown by the very good performance. If you wanted to increase the core
size, then the resistive (I2R) losses will be decreased, and the
damping factor would increase since you could use less turns and a higher guage wire.
We have not used air core inductors for many years. Basically, the
type 2 core has such a low permability (obviously larger than aire) that the
peak current handling and saturation limits are more than we need.
I am only aware of 1 commercial design using an air core.
----- Original Message -----
Sent: Tuesday, June 07, 2005 6:01 AM
Subject: inductor recommendations w/ TA2050 parallel mode
> Hi;
> I'm looking for guidance on high quality inductor recommendations
> for use with the TA2050 in parallel mode for 4 ohm output.
>
> I can use MPP, iron powder cores and wind on these, but need
> guidance on *size* of core, and best type to use for low distortion
> output.
> An old app note mentioned type 2 low u iron powder as best. Does
> this still apply? Emphasis is on quality, not economy here.
>
> Also comments on using air core inductors.
Thank you very much, gentlemen (in particular Mike and George), for this highly informative thread. I have ordered two SIs which are currently on their way and I will modify them following your advice. I will let you now how it worked out and most probably ask for more details as I start ;-)
Panomaniac, the image of the circuit you posted in your post #20 of this thread seems incomplete. The lower part of the image seems to be missing. Could you post it once again? Thanks!
Once again: Great job and thanks a lot.
Mick
Panomaniac, the image of the circuit you posted in your post #20 of this thread seems incomplete. The lower part of the image seems to be missing. Could you post it once again? Thanks!
Once again: Great job and thanks a lot.
Mick
Hey!
I'm new and form germany... sorry for my bad english ;-)
i want to modificate my sonic impact... i want to use a power supply which i found in my work-room. its a 15V 40VA power supply! Is it possible to use ist for the amp or is it too much power for the amp?
greetings form germany!
nifan (= no idea for a name ;-))
I'm new and form germany... sorry for my bad english ;-)
i want to modificate my sonic impact... i want to use a power supply which i found in my work-room. its a 15V 40VA power supply! Is it possible to use ist for the amp or is it too much power for the amp?
greetings form germany!
nifan (= no idea for a name ;-))
Any 12-13.5 volt regulated power supply that can provide at least 2 amps should work. You could base it on a LM317 (which can only do ~1.5 amps continuously, with proper heatsinking), or you could go for one of the various low drop out regulators, or the LM338.
There's about 5,000,000 schematics on the internet for power supplies.. Just heed their warnings if you're working with line level voltages.
There's about 5,000,000 schematics on the internet for power supplies.. Just heed their warnings if you're working with line level voltages.
Maybe this is a silly idea.....
If you want to replace C10 you have said you encounter problems due to the limitted space on the board. Therefore, eg. in post #8 you suggested to use the panasonic fm 680uF cap which fits in the original place.
Well, why dont you just put the cap in the same place but on the bottom of the board? Then you have no limitations due to L3 to L6 and you can use (almost) any size of cap (you may have to bend the contacts a little bit if they are too wide). In that case, what capacity would you suggest for best sound?
Mick
If you want to replace C10 you have said you encounter problems due to the limitted space on the board. Therefore, eg. in post #8 you suggested to use the panasonic fm 680uF cap which fits in the original place.
Well, why dont you just put the cap in the same place but on the bottom of the board? Then you have no limitations due to L3 to L6 and you can use (almost) any size of cap (you may have to bend the contacts a little bit if they are too wide). In that case, what capacity would you suggest for best sound?
Mick
Mick_F said:
As to your cap question, I used a low ESR 105 deg. Sanyo that was intended for computers. It is 1000uf @ 16v. I laid it on its side on the bottom. I also added another one on its side directly at the chip input on the bottom. This one is on the other side of the power switch and wiring so is much more effective. The + lead is connected between the 2 surface mount caps that are there and the ground lead is connected right next to this to the ground with all the holes in it. I made a little L bend in the end of the lead and surface mounted it with a generous amount of solder. This seems to help as well but after working with an amp3 board from 41Hz I think the inductors have to be replaced to get much better sound out of these things. After some point it isn’t worth going further. Improvements get smaller and smaller and seem to take more effort to do. The stock amp 3 with off board quality input caps is that much better than the SI with all the mods. I have both and can do a direct A/B. Don’t get me wrong, the modified SI is very good, just that the amp3 is better and more powerful. Measured 9.5 watts @ 13.5 volts applied with .06% THD into an 8 ohm load. There also is the heat issue with the new board and the chip not soldered down. This one seems to be a show stopper.
Roger
For those who have heavy mods in mind ...
Hi everybody,
my humble suggestion for those who would like to make heavy modifications to their 5066 t-amp ....
There's a kit on sale on the web which is similar to the t-amp, uses NO SMD components (it uses the TA2020 chip. with the usual legs ...) and is quite easy to build or modify.
Take a look at the kit at this link ... http://www.diyaudio.com/forums/showthread.php?threadid=60046&highlight=
I bought it after burning my t-amp with my solder iron. For me it's almost impossible to make reliable solderings and desolderings on such tiny resistors without actually buring them, but maybe it's me ...
By the way, I built the kit above in less than an hour, and actually modified it afterwards (different gain) with no problems.
Hope this helps somebody.
Hi everybody,
my humble suggestion for those who would like to make heavy modifications to their 5066 t-amp ....
There's a kit on sale on the web which is similar to the t-amp, uses NO SMD components (it uses the TA2020 chip. with the usual legs ...) and is quite easy to build or modify.
Take a look at the kit at this link ... http://www.diyaudio.com/forums/showthread.php?threadid=60046&highlight=
I bought it after burning my t-amp with my solder iron. For me it's almost impossible to make reliable solderings and desolderings on such tiny resistors without actually buring them, but maybe it's me ...
By the way, I built the kit above in less than an hour, and actually modified it afterwards (different gain) with no problems.
Hope this helps somebody.
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