boomana Posted May 4, 2009 Report Posted May 4, 2009 I having the technical knowledge of a dead mouse, I can only be envious of such a meet. Looks like you had fun, and am looking forward to impressions and more pics.
luvdunhill Posted May 4, 2009 Report Posted May 4, 2009 I having the technical knowledge of a dead mouse, I can only be envious of such a meet. Looks like you had fun, and am looking forward to impressions and more pics. I dunno about impressions at this meet. Steve was impressed by the current FOTM-ness of short skirts... other than that, I don't remember many. Your avatar did come up though, as well as a HD800 sighting...
boomana Posted May 4, 2009 Report Posted May 4, 2009 I meant impressions of final projects. Further meet impressions might scare me a bit.
naamanf Posted May 4, 2009 Report Posted May 4, 2009 heh, yeah it works just fine, but I had to fine tune a few parts to also support all the way down to the low bias phones. No need to cut traces, etc. though I looked at my original prototype and the values were right there... RTFM Fired up Als and it was at like 1050 V or something and I was worried my meager 1kV meter was going to go before I had time to grab the trimmer and stop turning.. Obviously, I couldn't just turn it off, way less exciting that way.
spritzer Posted May 4, 2009 Report Posted May 4, 2009 Yeah about the bias supply... could you send me the BOM, Marc?
Nebby Posted May 4, 2009 Report Posted May 4, 2009 There's a good bit of capacitance there, but otherwise it's about right I too was a bit surprised at how large it really needs to be when I looked into building one.
luvdunhill Posted May 4, 2009 Report Posted May 4, 2009 I had no idea the F5 was so huge I suppose you didn't see my F4 in the other pictures. In fact, Steve's build is very compact. The boards are very small.. It's just the caps and toroid that are large. I think it's quite the nice size actually. There's a good bit of capacitance there, but otherwise it's about right I too was a bit surprised at how large it really needs to be when I looked into building one. 148,000uF is about the minimum here, given the current demands of the circuit and the fact that it's just a simple CRC supply.
luvdunhill Posted May 5, 2009 Report Posted May 5, 2009 well, Steve I got one channel up and simmering now. Probably have 1-2 hour wait until I'm happy with the bias. I'm right at 1.3A on this side and will probably push it a bit more. I have a 1 ohm test load waiting and willing to make this thing sweat, plus this is the only way Spritzer's ears will perk up
Nebby Posted May 5, 2009 Report Posted May 5, 2009 As usual, my ignorance was showing and you were right luvdunhill. How toasty is the heatsink at 1.3amps running thru it?
luvdunhill Posted May 5, 2009 Report Posted May 5, 2009 As usual, my ignorance was showing and you were right luvdunhill. How toasty is the heatsink at 1.3amps running thru it? not too bad. I can hold indefinitely one of the fins that is right over one of the output devices. I'll track down my thermocouple. I'm probably going to leave it this way, because A.) Steve is planning for this to primarily power the K1000 (I have no idea what the impedance of these things drops down to, but it cannot be too low) and B.) those trim pots are impossible to get to, so I have the heat sink tipped up on it's side, which hinders convection and I'll probably need to readjust later anyways. The variac came in very handy. I was able to adjust the output of the unregulated CRC supply to the nominal +-24V, which wouldn't have been possible otherwise since I'm only running a single channel at the moment.
luvdunhill Posted May 5, 2009 Report Posted May 5, 2009 The bolts that secure the output devices is right at 61C.
spritzer Posted May 5, 2009 Report Posted May 5, 2009 Danm, that F5 in clearly needed. I have a 1 ohm test load waiting and willing to make this thing sweat, plus this is the only way Spritzer's ears will perk up
luvdunhill Posted May 5, 2009 Report Posted May 5, 2009 Danm, that F5 in clearly needed. 1 ohm soft clips at +- 10A
spritzer Posted May 5, 2009 Report Posted May 5, 2009 Holy crap!!! Has anybody ever tried using the F5 to drive a reactive load such as a Quad ESL?
luvdunhill Posted May 5, 2009 Report Posted May 5, 2009 Holy crap!!! Has anybody ever tried using the F5 to drive a reactive load such as a Quad ESL? damping factor is 80. Here's a pic of the 1 ohm performance from NP:
luvdunhill Posted May 5, 2009 Report Posted May 5, 2009 Looks like I need some moar heatsinks soon... If you go down this route, let's talk.
spritzer Posted May 5, 2009 Report Posted May 5, 2009 You know I will bug you about it. I need to finish a few ESP amps though before I can start to work on that.
Duggeh Posted May 5, 2009 Report Posted May 5, 2009 Holy crap!!! Has anybody ever tried using the F5 to drive a reactive load such as a Quad ESL? I'd like to submit my application for funding for this research. Onthingaudio will want the cheque within the month.
spritzer Posted May 5, 2009 Report Posted May 5, 2009 Your application has been received and is being processed. Since this was outsourced to SP, then it could take a while.
Duggeh Posted May 5, 2009 Report Posted May 5, 2009 What's the rate for installation of extra blackgates onto my money?
luvdunhill Posted October 1, 2009 Report Posted October 1, 2009 Looks like round two may begin this weekend
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