Earspeakers

Well I was trying to help guys, sorry I bothered. Too late to delete the thread, just ignore it then.

never mind

Anybody have a spare board set? Anybody thinking of running a new board set?

Right, I keep remembering the pro bias incorrectly Separate output drive sections. So folks regularly hook up multiple headphones simultaneously with no issues? Or, when would a amp not be able to handle multiple 'phones?

I was thinking of doing same. Do tell, how'd you wire it up? Could you put up a table?

Actually why not just tap off the Pro bias pin (assuming a dual output amp) with the network above? Two equal resistors will drop the voltage by half, and 230V is close enough to half of 480V, assuming the bias pin is correctly set to 480V or thereabouts. Different question, with multi output Stax amps, are the ports all simply wired in parallel? That'll double the capacitance if equal ear speakers are attached for one thing.

Thanks Spritz, of course a simple voltage divider. Nice bit with a filter cap. Like so?

I've got a couple normal bias Staxen I'd like to build an amp for, any ideas for any simple mods to make a normal bias KGST? Edit: apologies if this is a simple mod, I've done searches but what comes up is for going the other direction (normal->pro)

Actually here's the best reference for Active Loads The active load is the red line, compared to the blue which is the usual resistive load. The curve spacing is much more even on the active.

I always use a variac, bring it up slow, put clips on the output and watch what it does as you come up, go slow and test intermediate points too. Having multiple DVM's helps.

Thanks, that was my guess, no problem.

I meant in the sense of do you have vendors and design files? If we could call somebody up and get a clone of your design that would be ideal.

Thanks, I tried every search I could think of and didn't find it. Mouser is like a big haystack sometimes and all those parts little needles

Hey does anybody have a source for the .1uF/1000VDC film caps in the KGST power supply? The lead spacing is approximately 18.3mm and Mouser/Digikey seems to stock only 22mm leads

Beautiful Geoff. Is that design one others could use?

I had it described to me as fixing the operating point due to the high effective impedance. A resistor lets the tube slop it's operating point around, but a CCS nails it to a point on the chart, which is probably why they sound so good.

Yes the repair was somewhat more than the headphones, but cheaper than taking a working Lambda and tearing it apart. It's fine, these are hard to find these days. To tell you the truth I'm not sure I'll even like them. I went to headphones to get away from from speakers after all. The sound stage bothers me not at all, in fact I like it because it sounds like I'm a musician playing in the group (I'm a lifelong classical musician). But, I've fallen hard for Stax, after having given up on decent audio reproduction for about 10 years. I have to hear what they sound like. Also have the 4070 coming in, and a 009 and a 007 for comparison Otherwise I'm not interested in farting around with 007-mk1, 404's or whatever else.

The circuit diagram show plain resistor loads on the input drivers, any reason those aren't CCS's? A simple LM317 load kills any resistor in my tests.

Dunno the specifics. Do you know the operating point of the BHSE & Megatron EL34s, 400VDC or below?

Alignment? What are the gotchas? I'm also getting a quote from a Stax repair shop.

Hi Spritz, I just ordered a normal bias Sigma off eBay with a defective driver. No problem with repairing, is the procedure to buy a Lambda and take it apart? Any special tips otherwise?

Definitely, but it's the only one for sale at any rate (I keep writing 6S4A wrong for some reason) I'm on the list for the next run, he's drained the world supply of 450V/100uF caps apparently ...

That was my exact reaction, to a 307/SRM-323S! Hasn't changed one jot since, just that I appreciate more deeply how good these are as I listen to more recordings. I'm a classical only guy (musician), why bother with anything else? Placed an order for the BHSE shortly thereafter to save a spot in line.

I was just wondering about this. What operating point are KGST 6C4's and Megatron and BHSE EL34's at?

Brilliant, just what I was looking for. I didn't want to buy an old smelly tube tester again, the tracer is perfect. Hm, is there anything that a regular tester will measure that the tracer doesn't?