Big Tripath power fun on ebay

[theAnonymous1]

So, who is going to be the first to try and go high current with this amp?

Looks like all that is needed is four more output devices and a diode and resistor for each one.

OK OK, why do I always have to be the guinea pig.

 

[serengetiplains]

You *could* pick up an input transformer and provide (nicely exact) opposing phase signals for bridged operation. Just a thought.

High current! Fantastic!

HF edge on my amp has largely disappeared, in part because I rid the circuit path of connectors, replaced with soldering. The volume pots are obvious sources of grunge. I might bypass all input circuitry altogether, so:

DAC (cap coupled) ---> LDR pre ---> input cap ---> Tripath pins.

This would be to experiment blind as I don't have the time to figure out the circuit, with my mediocre figuring skills, to then make appropriate adjustments etc. But I don't expect my experiments to generate smoke, ahem.

 

[theAnonymous1]

Tom, I tried the source ---> caps ---> input pins thing and you end up with some nasty hum. I tried different grounding schemes and nothing seemed to help so I went back to using the input board.

I got happy for a minute after my last post, I remembered I still have the output devices from my failed DCP501 venture. I was hoping they would be the same, but they are W34NB20 and not the needed W38NB20. I'm not sure if deadtime would need to be adjusted either.

 

[serengetiplains]

Anonymous, to what did your input ground tie in that config?

 

[theAnonymous1]

I tried just about everywhere there was a ground. I even tried PIN 1(AGND) of the chip.

I don't know, give it a shot. Maybe you'll get lucky and I was overlooking something.

 

[serengetiplains]

An, did you disconnect that parallel (blue, underside) wire from the volume pot to the main board? I wonder if that was looping something.

 

[theAnonymous1]

Yes, it got disconnected. That wire carries the signal for the auto on function(I believe). It's funny, I have three of these amps and that wire was a different color in each one; blue, red, and grey.

 

[serengetiplains]

Did you test if your ground buzz was a system interaction between, say, amp and pre? Don't mind the questions, you probably checked everything.

 

[theAnonymous1]

Yeah, the buzz was there even with the inputs completely shorted. It was strange, I couldn't figure it out.

Like I said though, give it a shot, you might get different results. It's easy enough to do.

 

[jeffrae]

Green Fault on Power

Hello,

I have two of these amplifiers..

Well I had a picnicand used these two drive my Beater Cerwin Vegas

I was constantly pushing these amplifier into fault where they would switch off.. They didn't feel warm at all.

I swear my single AudioSource Amp3 can handle party mode with less problems.. I usually don't drive my amps hard... once in awhile it happens though....

I heard no clipping (Unlesss going to fault it the amps way of preventing the amp to clip..

 

[theAnonymous1]

Most likely an over-current condition. I didn't bother looking at the oc resistor values when I had my amps open. Maybe the over-current is set on the "conservative" side.

 

[jeffrae]

Yeah IT was really strange because it was still sounding excellent.

Just a little embarrassing when I had to reset the amplifiers.

I have noticed one wierd thing......

These amps do very very well with my (don't laugh) bose 901s.

For some reason they thrive on that crossoverless design.

I though boses silly eq would have drove the amp to clip the way the low end is boosted.

 

[serengetiplains]

I've wired my amp direct-in to the Tripath input pins, so:

DAC --> capacitor --> Lightspeed attenuator --> capacitor --> Tripath pins.

I do get a nice roar of 60/120Hz humming. Interestingly, when I disconnect the power supply to the Lightspeed, the humming disappears. I'm guessing a ground loop is the cause. Any thoughts anyone?

 

[john65b]

I don't know too much about the Tripath TA0104, but I have built two lightspeeds - the Tripath chips may not like the tied signal grounds on the lightspeed - are they floating or tied grounds? Try tying/untying them to see if that helps...

 

[serengetiplains]

John, the signal grounds are untied at the Lightspeed from the Lightspeed power supply. DAC ground is of course tied to the Tripath ground. Because the buzzing disappears when the Lightspeed is unplugged, I'm thinking the buzz is a ground loop between DAC and Tripath chip. Anonymous had the same problem connecting directly to the Tripath input pins.

 

[theAnonymous1]

I will be revisiting this route soon. Well, not exactly the way I had it before. I plan on adding a circuit for DC coupling like I did for my AMP32......

http://www.diyaudio.com/forums/showthread.php?s=&threadid=107628

Signal path will be DAC ---> AMP7T input board ---> DC coupling/buffer board ---> TA0104 input pins.

 

[jeffrae]

Hi All,

Well I just fired up my AudioSource Amp Three and it is making me think that the Amp Seven (Tripath) Amplifier is overrated for power or something.

My single Amp Three Blows away my two Amp Sevens bridged to mono.

Actually it is in the bass realm. For some reason my Amp Seven's do not like to be driven hard with Bass heavy material.

The Amp Three will amplify anything I throw at it..

I don't know.. I am happy with my Amp Seven.. I wonder if this is another reason why they never made it retail.

They couldn't beat teir analog amps.

 

[theAnonymous1]

Jeff, I opened one of my amps up to do more modding and took a look at the over-current resistors for you. The resistors (3.9k) are R27 and R26 in the blow pic.......

You can try changing these to a lower value and see if the amp still goes into protect. The Tripath datasheet says you can even set them at 0R, but this is not recommended as the amplifier will not have any over-current protection and would attempt to drive a short (KABOOM!).

BTW, A DC coupled AMP7-T comming soon......

 

[dweekie]

BTW, A DC coupled AMP7-T comming soon......

I thought you were going to go easy on the mods.....

 

[theAnonymous1]

I have OCD.