spritzer Posted January 13, 2018 Report Posted January 13, 2018 It's warm to the touch, not hot at all. I've had the first one running 24/7 now for a few weeks and no thermal issues at all. 1
johnwmclean Posted January 13, 2018 Report Posted January 13, 2018 4 hours ago, spritzer said: It's warm to the touch, not hot at all. I've had the first one running 24/7 now for a few weeks and no thermal issues at all. ... yeah with an ambient temp of -10 . Really nice details and loving the miniature size.
sorenb Posted January 13, 2018 Report Posted January 13, 2018 2 hours ago, johnwmclean said: ... yeah with an ambient temp of -10 . Really nice details and loving the miniature size. With those heatsinks, output Stage current is probably around 5-6mA ... miniature doesn't come free
Mach3 Posted February 2, 2018 Report Posted February 2, 2018 Hello, everyone. Need some advice, does anyone know a supplier in Australia or Oceania that produce a toroidal transformer for the KGSSHV for Australian 240V voltage? Got an uncompleted KGSSHV from the states and there's only 1 117V primary winding so I can't bridge 2 117V to make 234V
spritzer Posted February 2, 2018 Report Posted February 2, 2018 I have plenty of 420VAC transformers (for the 450V KGSSHV) with dual primaries but shipping to you would be killer...
Mach3 Posted February 3, 2018 Report Posted February 3, 2018 Entertain me please. What's the cost to ship to Australia postcode 3030
spritzer Posted February 3, 2018 Report Posted February 3, 2018 43$... gotta love shipping lumps of steel. 1
SeaWolf Posted February 3, 2018 Report Posted February 3, 2018 Still though, your two locations are about as far away as you can get.. that considered, I thought it would be more.
spritzer Posted February 3, 2018 Report Posted February 3, 2018 The post here can be pretty reasonable but for some they are an utter pain. Anything with tracking is 20$ plus... even if i send a single resistor...
Mach3 Posted February 4, 2018 Report Posted February 4, 2018 14 hours ago, spritzer said: 43$... gotta love shipping lumps of steel. That's not so bad, can you PM me the cost for the transfer thanks.
powertoold Posted March 30, 2018 Report Posted March 30, 2018 If I were to parallel the 180 ohm resistors (with 390 ohm) to 120 ohm equivalent to increase the output current, would I also need to rebias the amp? Thanks!! Sorry to bump this thread
powertoold Posted April 13, 2018 Report Posted April 13, 2018 This is probably a ridiculous question (I know little about circuits and DIY), but doesn't the 580v bias come from the power supply? If I'm only changing resistors on the output stage to increase the current, why would a rebias be necessary? This is for a 500v off board version, which I'm just trying to increase the output current on. Someone tell me it's a bad idea
JimL Posted April 13, 2018 Report Posted April 13, 2018 The 580V voltage is for the headphones - this is sometimes called biasing the headphones. When you change the resistors on the output stage you have to adjust the currents in the output stage so that the output sits at zero volts with respect to ground - this is referred to as biasing the output stage. These are two separate things that are not related to each other except that they are sometimes referred to with the same term - "bias." 3
powertoold Posted April 14, 2018 Report Posted April 14, 2018 Just to be clear: Turn off and unplug amp for 5 minutes Change the output bias resistors Turn on amp and leave on for 10 minutes Ensure the + and - for each channel at the Stax plug is as close to 0V as possible by screwing the Balance screw on the respective channel board. Ensure the + at the Stax plug and ground (will need to find a ground lead on chassis) for each channel is close to 0V by screwing the Offset screw on the channel board. Done? Thanks!
powertoold Posted April 15, 2018 Report Posted April 15, 2018 I was able to parallel the resistors to an effective 125R and double checked it using my multimeter. I checked the Balance and Offset voltages before and after the procedure, and they were essentially the same (~0v). I didn't have to adjust the pots at all. Did I do something wrong? The amp sounds essentially the same, with the volume being similar at the same positions on the knob. ?
powertoold Posted April 15, 2018 Report Posted April 15, 2018 Scratch that, I was on AC rather than DC ? After lowering the output bias resistors and increasing the output current, is the volume supposed to be louder? It seems similar in terms of loudness to me.
spritzer Posted April 16, 2018 Report Posted April 16, 2018 Volume has nothing to do with the output stage bias so no. 1
powertoold Posted May 9, 2018 Report Posted May 9, 2018 (edited) At lower volumes, do balance and offset voltages that are farther away from zero make a bigger difference vs higher volumes? For example, my 500v kgsshv is usually ~2v away from 0 for balance and offset. If the left channel is negative 2v and right channel is positive 2v, would that be audible at low volume and not higher volumes, or is it always 4v/500v difference at any volume, which is less than 1% between the channels? Edited May 9, 2018 by powertoold
sorenb Posted May 9, 2018 Report Posted May 9, 2018 <10V offset isn't a problem. Engaging the servo should quickly get you <1V
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