n_maher Posted June 25, 2010 Report Share Posted June 25, 2010 That looks fantastic Inu! Can someone explain to an idiot about the TRS jack though? It's the panel bearing for the shaft extension kit, looks a lot like the front a Neutrik jack so the mistake is understandable. Quote Link to comment Share on other sites More sharing options...
Craig Sawyers Posted June 25, 2010 Report Share Posted June 25, 2010 Based on the assumption that KG's knob is 1/4" (waits for the inevitible comments...), since the panel bearing specced is for 1/4" rod, I need to transition from 1/4" rod to 6mm shaft for the DACT. I've therefore bought a 6mm shaft coupler (Rapid Electronics), and will ream half the length out to 1/4". I could of course turn the 1/4" rod down to 6mm at one end, if I had a lathe (but I don't), so adapting the hole size in a coupler is much easier. Quote Link to comment Share on other sites More sharing options...
Inu Posted June 25, 2010 Report Share Posted June 25, 2010 I used http://www.custompowdercoating.com/ They did good job with reasonable price (less than $200 for all). Yes, I placed R81 and R82 on the back. Quote Link to comment Share on other sites More sharing options...
Craig Sawyers Posted June 25, 2010 Report Share Posted June 25, 2010 I used http://www.custompowdercoating.com/ They did good job with reasonable price (less than $200 for all). Yes, I placed R81 and R82 on the back. Did they mask casework areas that are in electrical contact? Quote Link to comment Share on other sites More sharing options...
swt61 Posted June 25, 2010 Report Share Posted June 25, 2010 It's the panel bearing for the shaft extension kit, looks a lot like the front a Neutrik jack so the mistake is understandable. Ah, that makes perfect sense. I couldn't for the life of me figure out how a TRS jack was going to work on an electrostatic amp. So the shaft goes into the bearing and back to the attenuator, gets locked down into the attenuator, and then the knob goes onto the shaft end? Very nice setup, wasn't aware they worked that way. Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted June 26, 2010 Report Share Posted June 26, 2010 Well pretty close. The shaft is machined single piece out of the knob material. Then there is a coupling right behind that to the extension shaft, and another coupling to the pot. Depending on which pot you get, the second coupling needs to be a different diameter on the pot end. The picture posted previously showed this. http://gilmore.chem.northwestern.edu/t2chassis29.jpg Quote Link to comment Share on other sites More sharing options...
swt61 Posted June 26, 2010 Report Share Posted June 26, 2010 Ah, thanks Kevin. That's an elegant design! Quote Link to comment Share on other sites More sharing options...
Inu Posted June 26, 2010 Report Share Posted June 26, 2010 I need to order another 450V 680uF. Won’t fit if height is 50m/m, need 45m/m. The edge of front panel touches the head of capacitors. Panasonic 450V 680uF (35mm x 45mm) is out of stock... Craig, How about your EPCOS caps? Quote Link to comment Share on other sites More sharing options...
Craig Sawyers Posted June 26, 2010 Report Share Posted June 26, 2010 I need to order another 450V 680uF. Won’t fit if height is 50m/m, need 45m/m. The edge of front panel touches the head of capacitors. Panasonic 450V 680uF (35mm x 45mm) is out of stock... Craig, How about your EPCOS caps? Maximum EPCOS height above the board is 47mm. How about slightly shorter spacers? Specced ones are half inch, so would 10mm work better? Quote Link to comment Share on other sites More sharing options...
Craig Sawyers Posted June 26, 2010 Report Share Posted June 26, 2010 Well pretty close. The shaft is machined single piece out of the knob material. Then there is a coupling right behind that to the extension shaft, and another coupling to the pot. Depending on which pot you get, the second coupling needs to be a different diameter on the pot end. The picture posted previously showed this. http://gilmore.chem.northwestern.edu/t2chassis29.jpg I wondered what the second coupling was - that is a really neat design, and keeps visible shaft grub screws completely out of the equation! With the fancy Alps, you have to go *up* from 1/4" to 8mm, whereas with the DACT you need to go "down* to 6mm. Quote Link to comment Share on other sites More sharing options...
Craig Sawyers Posted June 26, 2010 Report Share Posted June 26, 2010 Maximum EPCOS height above the board is 47mm. How about slightly shorter spacers? Specced ones are half inch, so would 10mm work better? Scratch the 10mm comment - the board height is fixed by the heatsink bracket position. Quote Link to comment Share on other sites More sharing options...
Craig Sawyers Posted June 26, 2010 Report Share Posted June 26, 2010 Another UK source of UNC fixings, including black, in various headstyles and 1/8" length increments http://www.modelfixings.com/ Quote Link to comment Share on other sites More sharing options...
Inu Posted June 28, 2010 Report Share Posted June 28, 2010 Maximum EPCOS height above the board is 47mm. How about slightly shorter spacers? Specced ones are half inch, so would 10mm work better? The space between PCB and edge is 49m/m so your EPCOS are safe. I uploaded more pics. Quote Link to comment Share on other sites More sharing options...
nattonrice Posted June 29, 2010 Report Share Posted June 29, 2010 Just got my traffos =D Oh and fuck me my mouser bill is rather weighty... Birgir, did you get your chassis parts? Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted June 29, 2010 Report Share Posted June 29, 2010 Birgir did get his chassis parts evidently i messed up on one of the stax jacks... Quote Link to comment Share on other sites More sharing options...
nattonrice Posted June 29, 2010 Report Share Posted June 29, 2010 In that case let the obligatory "pics or ban" comments begin! Was there a problem with the replication? Quote Link to comment Share on other sites More sharing options...
Craig Sawyers Posted June 29, 2010 Report Share Posted June 29, 2010 Just got my traffos =D Oh and fuck me my mouser bill is rather weighty... Birgir, did you get your chassis parts? FWIW my total Mouser bill was Quote Link to comment Share on other sites More sharing options...
spritzer Posted June 29, 2010 Author Report Share Posted June 29, 2010 Here is a quick snapshot I took before I packaged it all up again for storage. The heatsinks look great, beyond great even but the other panels are a bit flat. Also notice the small marks on each end of the panels which go right through the finish. Yeah, one of the Stax jacks is messed up but I'm too tired to take a picture of it. Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted June 29, 2010 Report Share Posted June 29, 2010 Not sure what happened with the stax jack. it may have been one of the first 3 that i did, and maybe i machined it a bit too fast. From now on i will test the fit before i ship any more stax jacks. The problem with teflon is that it likes to get out of the way of the end mills as it is being machined. Maybe i bumped the speed knob... It will be replaced. When i send birgir his "custom pure titanium" knob. Hopefully the material for that will be in the end of this week. Yep we are at the silly stage... Need to find a 2 inch cube of aged lignum vitae. Quote Link to comment Share on other sites More sharing options...
n_maher Posted June 29, 2010 Report Share Posted June 29, 2010 Need to find a 2 inch cube of aged lignum vitae. GENUINE LIGNUM VITAE Wood Turning Spindle Blank Lathe - eBay (item 190409818674 end time Jun-30-10 17:55:49 PDT) You might be able to work around the heart check. Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted June 29, 2010 Report Share Posted June 29, 2010 I don't believe the moisture content for one second. I have lots of lignum vitae here, after you take the wax off, it usually takes about 10 years for it to be usable and it shrinks well over 10%. My wonderful hardwoods store went out of business last year, so no more of the exotic stuff for me till i find some place else where i can look at the stuff first. Quote Link to comment Share on other sites More sharing options...
luvdunhill Posted June 29, 2010 Report Share Posted June 29, 2010 I always test the AC out of all transformers first. And unloaded power draw checking for shorted turns did you test the transformers with a load as well (rated maximum load or actual load?) Also, thanks for the transformer specs. Could you also give us the maximum gauge that each lead can be (so, pad diameter) and the maximum lead length we need? Quote Link to comment Share on other sites More sharing options...
luvdunhill Posted June 29, 2010 Report Share Posted June 29, 2010 .. and one more thing. Is there a preferable relationship to the primary entry point and the secondary exit point on the toroid? 180 degrees? 45 degrees? Quote Link to comment Share on other sites More sharing options...
Craig Sawyers Posted June 29, 2010 Report Share Posted June 29, 2010 did you test the transformers with a load as well (rated maximum load or actual load?) Also, thanks for the transformer specs. Could you also give us the maximum gauge that each lead can be (so, pad diameter) and the maximum lead length we need? One additional thing that is worth mentioning to a transformer manufacturer is that some of the windings float at high DC. Specifically the heater windings to the EL34's (-500V), and two of the HT transformer windings are referenced to -560V or -500V. So those windings in particular need an insulation barrier - just overlaying one secondary over another probably won't work (it *should* in principle, because winding wire is good for more than that - but not if any insulation is compromised through nicks during winding, or just thinned because of winding pressure). Quote Link to comment Share on other sites More sharing options...
kevin gilmore Posted June 30, 2010 Report Share Posted June 30, 2010 I tested at 10% over maximum rated load (which is dc because its pure class A) out of the power supply with a stack of resistors. The leads out of the high voltage transformers are 14 inches long. And yes you have to tell them to do 600 vac wire for all of the transformer windings. Which SumR does anyway i think. Quote Link to comment Share on other sites More sharing options...
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