TA8215AH not sure where to start...

[mattthegamer463]

I bought two of these Toshiba TA8215AH 30W x 4 channel amplifier chips, but I'm struggling to figure out how to use them from the datasheet. I've been unable to find a project or schematic that uses them and I'm basing everything off the test circuit given in the datasheet.

http://www.datasheetcatalog.org/data...shiba/1386.pdf

Does anyone know anything about these chips? I hooked one channel up to my power supply and gave it a shot, I managed to get very distorted audio out of my speaker, but I used no components other than the chip and speaker.

I'm not sure about volume control (pot on the input signal(s)?) and I'm not sure about how to keep the THD down because at 18W the THD is 10%, which is beyond brutal.

Also, in the test circuit they show resistors and caps on the output signal, but I have no idea what kind of wattage resistors to use, or what kind of caps it wants (little 0.1uF ceramic disks surely would be too small for that power?) and where does speaker XOs play into that?

I'm just new at these chips and audio in general so if I could get some pointers or some links to literature that will help me out that would be much appreciated.

[1moreamp]

These were used in car stereo head units back in the early 90's Sony, Kenwood and a few others.
Don't know if the come anywhere close to whats out and about nowadays, but I doubt these could keep up with some of the newer chip amps on the market.
In car HU's they burned up rather nicely leaving badly burned and charred skeletons to remove. As I recall there were no large resistors used in the car radio's with these, and ceramic disk caps were not a size issue either. Hope this helps,,, these are rather old and seldom scene in use nowadays

[pacificblue]

Originally posted by mattthegamer463
I managed to get very distorted audio out of my speaker, but I used no components other than the chip and speaker.

None at all? You need to connect something to the mute and stand-by pins, and there should be a capacitor at the RIP pin. What power supply did you use?
Build it according to the test circuit. Add a 2,2 µF MKP capacitor before the input pins (after the potentiometer) for DC protection and give it another shot.

Originally posted by mattthegamer463
I'm not sure about volume control (pot on the input signal(s)?)

You need one. Try a 10 k log potentiometer.

Originally posted by mattthegamer463
I'm not sure about how to keep the THD

Don't play it loud.
Seriously, if you want to keep THD low at high output power, increase the supply voltage, and use high impedance speakers. But don't worry too much about it.

[QUOTE]Originally posted by mattthegamer463
Also, in the test circuit they show resistors and caps on the output signal, but I have no idea what kind of wattage resistors to use, or what kind of caps it wants (little 0.1uF ceramic disks surely would be too small for that power?) and where does speaker XOs play into that?[QUOTE]
They are Zobel networks that counteract oscillation. 1/4 W resistors and 100 nF ceramic discs will do, because there is little power going through them. Being in parallel to the speaker terminals, they do not interact with the cross-over at all.