Hi there guys!
It's working, but not as good as i wish
I bought a 24V/1A PSU, but the darn thing gets me 1V ripple on the speakers. I've tryed 3000uF (didn't have more caps at hand) but the noise dropped very little with a ripple of 300mA.
Bought a couple of 12V SLA batteries, they are charging in the mean time. Even discharged, i connected them and heard no hum, so that excludes ground loops.
Any ideas as for how much capacitance must i add to the PSU, and necessary ripple voltage?
I can hear the music, and sounds good, except for the loud 50Hz hum :S
It's working, but not as good as i wish
I bought a 24V/1A PSU, but the darn thing gets me 1V ripple on the speakers. I've tryed 3000uF (didn't have more caps at hand) but the noise dropped very little with a ripple of 300mA.
Bought a couple of 12V SLA batteries, they are charging in the mean time. Even discharged, i connected them and heard no hum, so that excludes ground loops.
Any ideas as for how much capacitance must i add to the PSU, and necessary ripple voltage?
I can hear the music, and sounds good, except for the loud 50Hz hum :S
Listening impressions
Ok, here are my listening impressions:
Mosfets running at 0,5A
B+ aprox. 23V
Test CD -> Groove Armada, Vertigo.
Tracks -> Chicago, If everybody looked the same, I see you baby.
Crystaline mids and highs, fast bass - not much envolving - excellent imaging and detail.
I have tryed 3 valves: PCC88 (7,2V filament), ECC88 and ECC86.
Apart from an almost indistinguishable less gain from the PCC88 (due to the heater being fed with 6V), all the valves proved similar.
PCC88 and ECC88 seemed to have a a little bit better highs while the ECC86 had a bit more punch on the bass. All three showed signs of audible distortion on the last quart of the volume potenciometer travel (25K).
In my KT88 amp i went through 3 valve makes untill i found one that pleased me. Same here. Try different valves until one satisfies you
The amplifier for comparison is the refered KT88 UL amp (Mikael Abdellah circuit), which has a much more envolving atmosphere, the sound shows more body. That's the way i like to listening to music, to feel and being able to "hold" it.
I sometimes listen to other amps at high levels due to this reason, i can't feel it. Of course, that knackers your ears fast
If only this hybrid had a less fast bass, it would be perfect. But that's Sand showing up, maybe, or the valves at these low voltages.
LED biasing for the Mosfets ought to be interesting
Ok, here are my listening impressions:
Mosfets running at 0,5A
B+ aprox. 23V
Test CD -> Groove Armada, Vertigo.
Tracks -> Chicago, If everybody looked the same, I see you baby.
Crystaline mids and highs, fast bass - not much envolving - excellent imaging and detail.
I have tryed 3 valves: PCC88 (7,2V filament), ECC88 and ECC86.
Apart from an almost indistinguishable less gain from the PCC88 (due to the heater being fed with 6V), all the valves proved similar.
PCC88 and ECC88 seemed to have a a little bit better highs while the ECC86 had a bit more punch on the bass. All three showed signs of audible distortion on the last quart of the volume potenciometer travel (25K).
In my KT88 amp i went through 3 valve makes untill i found one that pleased me. Same here. Try different valves until one satisfies you
The amplifier for comparison is the refered KT88 UL amp (Mikael Abdellah circuit), which has a much more envolving atmosphere, the sound shows more body. That's the way i like to listening to music, to feel and being able to "hold" it.
I sometimes listen to other amps at high levels due to this reason, i can't feel it. Of course, that knackers your ears fast
If only this hybrid had a less fast bass, it would be perfect. But that's Sand showing up, maybe, or the valves at these low voltages.
LED biasing for the Mosfets ought to be interesting
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