hotrodding a Dayton DTA-2 (sonic impact) amp

[budget minded]

a while back, i bought a couple Dayton DTA-2 DIY modules as i refused to deal with paypal like ALL higher power module (& lepai) dealers make you do so i reluctantly settled on the lower power power modules to replace my similarly rated (and probably the same exact amp) sonic impact.

when i bought the module, i was expecting it to be a simple plug & play deal & didn't realize it needed assembly. in particular, i noticed that the choke coils need to be hand wound. when i tore my sonic impact apart, i noticed that there were maybe half a dozen windings in the toroid. would there be any advantage to adding extra windings and even making a true full toroid when i build the amps? my understanding is that they filter transient spikes. might doing so make the amp sound warmer or increase it's durability?

would upgrading the capacitors that bridge the speaker jacks make any difference either?

if i have to settle on a puny 10wpc amp when i REALLY want a 50wpc, is there anything i can do to make this one either sound better or last longer?

[4season]

Visit this site, click "Input Mods" and check out Version 2 ("Just the caps ma'am"):
http://www.michael.mardis.com/sonic/start.html
You can leave the rest stock. The output inductors and filter caps as supplied by the factory actually work pretty good, and I don't think there's much to be gained by mucking about with these.

[nightanole]

The output inductors are for filtering out the class t switching noise. You can mess with them, like switching to bigger units and different cores, but you need to keep the turns the same. Its also the reason why you cant hook them up to headphones, a filter for a 4-16 ohm load is not going to work on a 64ohm pair of cans

[MuaDibb]

Does the "stealth version 3" accomplish the same thing as version 2, just from a different point on the board? It seems like that would be an easier mod for me. If it doesn't do the same thing, what are the differences in the two mods?

[nightanole]

v3 bypasses everything on the board and all your replacements are air wired, mainly because they are huge. v2 trys to use the existing input points and stock component locations.

Both do the same thing.

For caps i recommend either 1 of these:
Dayton Precision 1% Metallized Polypropylene Capacitors at Parts Express

or if you have the space, several of these:
Dayton Film Caps at Parts Express

your cut off freq needs to be 3 ocaves lower then your lowest freq. so your input is 20k so do the math:

Guitar Pedals: R-C Filter Calculator

you only need 1uf to play down to 30hz or so, 2.2uf is good for 14hz, very low. To big of cap and your highs will be attenuated.

[MuaDibb]

Originally Posted by nightanole

v3 bypasses everything on the board and all your replacements are air wired, mainly because they are huge. v2 trys to use the existing input points and stock component locations.

Both do the same thing.

For caps i recommend either 1 of these:
Dayton Precision 1% Metallized Polypropylene Capacitors at Parts Express

or if you have the space, several of these:
Dayton Film Caps at Parts Express

your cut off freq needs to be 3 ocaves lower then your lowest freq. so your input is 20k so do the math:

Guitar Pedals: R-C Filter Calculator

you only need 1uf to play down to 30hz or so, 2.2uf is good for 14hz, very low. To big of cap and your highs will be attenuated.

Thank you for the answer, very much appreciated. Just one more question though, in the V3 there are two pics that show the mod.

Sonic/Tripath

One shows Electrolytic caps with a value of 2.2uf and the other shows some Auricaps with a value of 7uf. I have both values on hand as I do some speakerbuilding, so which should I use?

Ok I went back and just noticed it does say 2.2uf they just have a different cap in the picture.

[Saturnus]

Originally Posted by nightanole

your cut off freq needs to be 3 ocaves lower then your lowest freq. so your input is 20k so do the math:

Unless you want to take advantage of the filtering naturally but even as a sub cut filter SQR 2 of the intended audible range is probably the closest you should aim for in an input filter, if you need more precise filter than that calculate a 2nd order L-R filter and take the highest filter frequency on the passive side and the lowest on the input side.

[nightanole]

On the passive output, the output torroids and the speaker act as the LR filter. What is a SQR 2 of the audible range? I was just shooting to make the 90 degree shift in freq to happen before the lowest note.

[Saturnus]

SQR 2 = Squareroot of 2 ~ 1.44

[planet10]

Originally Posted by Saturnus

SQR 2 = Squareroot of 2 ~ 1.44

SQRT 2 = Squareroot of 2 ~ 1.414159...

dave