I haven't built the N-channel one yet, so I don't know. I am waiting for 6L6 to make one of his famous illustrated build guide and hold my hand through this difficult process. I will start ordering some nice caps and if nothing happens I will start the build on my own.
It would be my dream amp setup.
More V-Fet P-channel goodness from 270Hz and up. More V-Fet goodness. - YouTube
More V-Fet P-channel goodness from 270Hz and up. More V-Fet goodness. - YouTube
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Sometimes it's alarmingly easy to overlook the obvious fix. You can install a second SPST switch. Call is Switch-new.
Now Switch-old disconnects the filter PCB from the SMPS power inlet jack, and Switch-new operates the coil of the thump mitigation relay.
At power-up: (1) flip Switch-new to "SPKR-MUTE" position. (2) flip Switch-old to "ON" position. (3) Wait five seconds. (4) flip Switch-new to "SPKR-PLAY" position.
At power-down: (1) flip Switch-new to "SPKR-MUTE" position. (2) Wait five seconds. (3) flip Switch-old to "OFF" position.
Presto, thumps totally eliminated from both turn-on and turn-off events. And you didn't have to modify the filter PCB at all. Two of the PCB connecting pads on the filter PCB are wired to Switch-old, and the other two of the PCB connecting pads are wired to Switch-new. Pretty simple.
Now Switch-old disconnects the filter PCB from the SMPS power inlet jack, and Switch-new operates the coil of the thump mitigation relay.
At power-up: (1) flip Switch-new to "SPKR-MUTE" position. (2) flip Switch-old to "ON" position. (3) Wait five seconds. (4) flip Switch-new to "SPKR-PLAY" position.
At power-down: (1) flip Switch-new to "SPKR-MUTE" position. (2) Wait five seconds. (3) flip Switch-old to "OFF" position.
Presto, thumps totally eliminated from both turn-on and turn-off events. And you didn't have to modify the filter PCB at all. Two of the PCB connecting pads on the filter PCB are wired to Switch-old, and the other two of the PCB connecting pads are wired to Switch-new. Pretty simple.
I did, but recently removed it, for better quality. The midrange horn (and technically the treble horn as well, but it also has a passive highpass in the form of 20uF caps, which neatly results in a 2nd order highpass together with the ribbon transformers inductance at the preordered 4 ohm tap) is highpassed electronically (BW48dB) at 270Hz so it would require a big one. Are you saying I should put it back?
Plan is to let two compression drivers share one V-Fet amp and let the Raal have its own V-Fet amp and a much less deep horn, that doesn't cut treble as much, even if I love it the way it is with a tad treble EQ boost. And maybe an F6 or SissySIT to handle midbass. I hear F6 is more rock and roll than a SIT.
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I was thinking along the same lines Mark Johnson, but would it not be easier to just have the separate switch toggle a direct connection of the output to the star ground, skipping a delay circuit and relay control altogether?
Certainly the circuit provided by NP minimizes the thump without having to put thought into the power up-down procedures, but audio-nervosa being what it is...
Certainly the circuit provided by NP minimizes the thump without having to put thought into the power up-down procedures, but audio-nervosa being what it is...
Am I making a hen out of a feather? This is the life of owning high sensitivity speakers. The Anticlimactic turn-off Pop! - YouTube
My compression driver diaphragm right now: You're Tearing Me Apart, Lisa! The Room - YouTube
Wait, so you have both the P version AND the N version? How did you manage that? Lucky fellow! Didn't think that was possible.
I have done some moderate cap rolling, mostly on the Dreadnought and Bulwark FE boards. I did make one substitution on the original FE board – a 220 uF Elna Silmic in place of the 1000 uF output coupling cap.
The 0.33 uF Wima is a good polypropylene part. It has 5mm lead spacing, which will make it difficult fit alternate components. I’m not inclined to roll this one.
The big 10,000 electrolytic on the OS is a good Rubycon. Best thing here is to keep this and bypass it with a Nichicon KW series 220 uF or 470 uF on the underside of the PCB.
We have a builders thread in place for more discussion.
The 0.33 uF Wima is a good polypropylene part. It has 5mm lead spacing, which will make it difficult fit alternate components. I’m not inclined to roll this one.
The big 10,000 electrolytic on the OS is a good Rubycon. Best thing here is to keep this and bypass it with a Nichicon KW series 220 uF or 470 uF on the underside of the PCB.
We have a builders thread in place for more discussion.
