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Tribute 3000
I just finish Tribute 3000. Here are some measurements. The amplifier behaved wonderfully from the first switch on. The sound? I have a smiley face right now when i listen to it. All tests are made with +/-52V and 8 ohm load.
I just finish Tribute 3000. Here are some measurements. The amplifier behaved wonderfully from the first switch on. The sound? I have a smiley face right now when i listen to it. All tests are made with +/-52V and 8 ohm load.
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Aha interesting.
You mean that Tribute is a mutch better amplifier compared to Vhex?
Hi Thimios,
Sorry for delay - too many things are happening here ))
OK - I ran some sim tests. Well, testing with 100R resistors is not really good here as the feedback network is rather low-inpedance, loading the VAS too much. But anyway, the sim shows an issue exactly in 22MHz area in this case.
Let's do the following for the beginning:
1) Short D1, D4 with the pieces of wire;
2) Replace C11, C12 capacitors with 100pF ones;
3) Remove C15 (47pF).
Then power-on and see the behavior. 22MHz problem is expected to disappear. If we still have some issues, it would probably make sense to solder a simple 2-transistors follower to the output of the board to see it in the conditions close to the ones with OPS in terms of the impedance matching. But let's see what it shows with no buffer first.
Cheers,
Valery
Don't worry Valery,take your time.
I haven't test as stand alone only.
Connecting this to OPS i take a smoke zobel resistor and some REALLY HOT protective resistors(instead of fuses) position.
BTW i will try the modifications soon.
Well, that's no surprise with such an oscillation
But don't worry - we will win the game against it
I don't worry,i'm sure for for the win!Well, that's no surprise with such an oscillation
But don't worry - we will win the game against it
Hi Valery,
I am redoing the distortion measurements, i am more carefully this time, i am using shorter wires from my sound card interface to the load and Tribute 3000. I am also using 64-bit FFT to get a cleaner graph. You can see in the pictures what i am obtaining. Are you sure that you measured 0.008% for Tribute 3000?
I am redoing the distortion measurements, i am more carefully this time, i am using shorter wires from my sound card interface to the load and Tribute 3000. I am also using 64-bit FFT to get a cleaner graph. You can see in the pictures what i am obtaining. Are you sure that you measured 0.008% for Tribute 3000?
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You seem to have a better build than me
My H3 is noticeably higher, however, both builds don't show any significant higher order components, which is important.
Confirmed - a very fine amplifier
