eXStatA Build Thread II
Jul 25, 2010 at 2:28 PM Post #62 of 588
OK, so it's desoldering time.  Happy to do so, actually, as it seems that I will be close to +/- 320V with the WHT-GRY connection.  Thanks.
 
(I will watch my head, Beefy....)
 
atsmile.gif

 
Jul 25, 2010 at 4:11 PM Post #63 of 588
You might just be hearing some vibration because the tranny isn't bolted down. I use the McMaster-Carr PVC mounts, but any dampening should be fine (teflon or fibre washers, etc), but I bet when everything is bolted down, you won't hear it.
 
Jul 25, 2010 at 5:08 PM Post #64 of 588
Yesss!  You guys are good.  With the WHT-GRY 115V 60HZ connection, I now have the following  readings:  Rails are +306.3 and -303.0.  T1 is +351.2 and T3 is -349.6.  Thank you very much! 
 
So, why is there an increase in these values when using less voltage from the transformer?
 
My son is certain now that his hum (I still can’t hear anything) is coming from the transformer.  So, I guess we’ll wait and see what happens once it’s bolted down and the amp is connected.
 
Jul 25, 2010 at 6:03 PM Post #65 of 588


Quote:
Originally Posted by rbarth /img/forum/go_quote.gif
 
So, why is there an increase in these values when using less voltage from the transformer?


Transformers work as on 'fixed' ratios of how much they change the voltage.
 
A transformer with a 125V primary and a 250V secondary will increase the voltage 2x. So if your line voltage is 120V you get 240V out.
 
A transformer with a 115V primary and a 250V secondary will increase the voltage 2.17x. The same 120V line voltage becomes 261V out.
 
Jul 25, 2010 at 9:07 PM Post #68 of 588
The teflon and gold pin connectors were definitely a custom build from Luvdunhill, and Kerry has emulated this somewhat.
 
I have 22 of the original Amphenol connectors (now made by WPI) which I 'found' after shipping all the tubes while looking for some other parts. These were graciously donated by Frank Cooter, and I will pass them on (limit 2 each)... SHOULD have sent a pair with all the tubes, but had honestly forgotten these.
 
My (very) bad.
 
Please PM me for the connectors - but, customs forms really, really suck.
 
Again, my bad guys.
 

 
Jul 26, 2010 at 6:22 AM Post #70 of 588
Jul 26, 2010 at 9:12 AM Post #71 of 588
Those are correct - if you can source locally, that is your best bet. Looking at a package to OZ (and East) if we can work out logistics of a single ship from here. I have about 16 left, as of this morning, and will hold all other requests until we sort the Oz builders, as they asked first, and I should have sent some there with the tubes.
 
Jul 26, 2010 at 5:48 PM Post #73 of 588
I am now wiring and need some help with the following:
 
(1)  I understand that the positive and negative signals connect to the input pins on the pot and then go from the output pins on the pot to the corresponding terminal blocks on the amp board.  What I’m not getting is how to connect the two input ground wires coming from the XLRs to the common pins on the pot and then to the two input ground terminals on the amp board. (I’m using a quad pot so obviously there are four common pins.)
 
(2) There is an fourth, unnumbered pin on the XLRs that I’m also uncertain about.  Is this the ground for the XLR connector?  If yes, where I do ground it to?
 
Jul 26, 2010 at 9:20 PM Post #74 of 588
Are you using two 3-pin xlr connectors? Or 4-pin jobbies?
 
If 3-pin there is a wiring diagram on the exstata website that shows this wiring.
 
Jul 26, 2010 at 9:50 PM Post #75 of 588
I used the one specified on the BOM   It has three pins in a triangular shape numbered 1, 2 and 3 and one smaller, unnumbered tab on top of them that has a small hole in it.  I have checked the wiring diagram and regret to say that I am not experienced enough to determine whether the answer to my question is there.  I have never wired a balanced connection before.  In the past, I have wired the ground from the inputs to the the pot I was using and then ran it from there to the amp board.  Is this the same case with balanced inputs?  If yes, I have two ground wires and four common tabs on my pot.  How do I connect this?  
 
 

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