Hypex nCore/UCD transconductance - Current Output - amplifier

[Windforce85]

Windforce85,

I have not checked it in reality with Class-D, yet. I will be doing it soon and I will update my results here in this very thread.
I am jumping on the Class-D full-bridge version and implementing load current feedback is not as straight forward in full-bridge.
Either way, I'll post my results.

P.S. I have implemented this in Class-AB with tremendous results!! But that is not what you want...I know.

I have seen your current amplifier - good thing! As I already have bunch of amps I will try to drive DXT tweeters through simple resistors and I'm going to post some measurements. Will see if it benefits or not.

 

[bimbla]

Current Drive

You should be able to 'HEAR' the different immediately! So much so that it will make you say that you need not do any measurements.
Another big feature of current drive is that it inherently adds short circuit protection.

Can we have a volunteer who has a DIY Class-D amplifier UCD or Non-UCD and who wishes to test the mod for current drive? All you need is a 0.15E to 0.33E 3W/10W resistor?

 

[Windforce85]

Wow! I will place 15-Ohm resistor to the amp output in series with tweeter and boost my buffers gain to the max to obtain necessary voltage swing to the V/I conversion. And I will prepare another pair of tweeters with direct-driven UCD (unbuffered) to make a comparison. Only unbuffered UCD can give liquid and spacious treble with kind of musical 'flow' unobtainable with any solid state buffer engaged. Regarding your current-drive mod to the amplifier - Is this mod related with disassembling of post-filter control loop of the Hypex UCD? If only it could be done extrnally! I could mod it to current-output at the subwoofer channel where x-over is at 70 Hz. It should avoid any unstability but I need to solve out how to make accelerometer servo. I feel that building servo and current drive on sealed subs could make marvellous things to the bass! 🙂 W22EX midrange is class on its own so I can't see much benefit here .

 

[bimbla]

Wow! I will place 15-Ohm resistor to the amp output in series with tweeter and boost my buffers gain to the max to obtain necessary voltage swing to the V/I conversion.

Yes, its a quick way of testing it. However, remember, in this case, there is no feedback and hence no inherent short-circuit protection.

Is this mod related with disassembling of post-filter control loop of the Hypex UCD? If only it could be done extrnally! I could mod it to current-output at the subwoofer channel where x-over is at 70 Hz. It should avoid any unstability but I need to solve out how to make accelerometer servo.

If you could post/ PM me the circuit of the amp you have, I can suggest you the mod. In every probability, it should be external.

W22EX midrange is class on its own so I can't see much benefit here .

You never know until you try it!