Tag: Audio

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Bucking Transformer

I built a bucking transformer for use with older tube amplifiers. Did you know that back in the day the voltage in the US was 110v!  Yeah who knew!  Its in the mid 120v range hovering around  123V-124V in my house in NJ. I have CT’s logging the power at my main breaker in my main panel so I have a log of this over time. This higher then design voltage takes it toll on old transformers and components. It can cause the bias voltages on the tubes to be higher and leads to tube wear and premature failure that I want to avoid.  I can buy an off the shelf step down transformer or variac’s but they are expensive, big and ugly. It’s also no fun!  I decided to go the DIY route and use a small 12v AC transformer to buck the voltage. The transformer I’m using is a $40 fairly cheap 12v center tapped one off Amazon. It’s not some exotic crazy expensive transformer hand wound by Franciscan monks with silver wire built somewhere in Europe.  The trick is to wire the secondary out of phase with the input voltage on the primary.  If you do this properly the two voltages will subtract from each other and you get the following:

      • 120V – 6V = 114V
      • 120V – 12V = 108V

If you wire it in phase you will get the opposite.  The voltages will add together and you will get a higher voltage.  This is called a boost transformer

      • 120V + 6V = 126V
      • 120V + 12V = 132V

This is a pretty neat trick and pretty cost effective.  You don’t need such a big ass transformer because it’s not handling the full voltage of the load! Pretty cool right! If you would like to know more let me know and I can post pictures and a wiring diagram to help you build your own.  I mounted it in a small metal project box I got off Amazon.  IEC inlet on one side and regular household receptacle on the other side. I removed the tie on the hot side of the receptacle and wired it so that one plug is at 114V and the other is at 108 making it pretty versatile.  I grounded and fused it as well for safety.  I find it runs cool while powering a Dynaco ST-70 for hours.

Well time for bed.  Happy building!

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Dirac Live on MiniDSP

I know this is sacrilegious in audio circles but I decided to put a MiniDSP between my source and pre-amp in my desktop nearfield listing rig.  It makes a huge difference, like not subtle it’s huge!  You can easily A/B it by disabling Dirac on the MiniDSP.  If you have anything that can do Dirac room correction you owe it to yourself to just give it a try.  You will need a calibrated mic, mic stand and and about an hour to run the software and place the mic around the room.

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Record cleaning

I have been trying to come up with the perfect process to clean records. I think I found it! I was thinking about one of the fancy ultrasonic cleaners but what I found is perfect. Here how I do it if your interested.  First you are going to need a few things. One is kinda pricy but not anywhere near a ultrasonic unit.

      1. Okki Nokki record cleaning machine (any vacuum style cleaner will work here)
      2. Okki Nokki record cleaning solution
      3. Revolve record cleaning solution
      4. Distilled water
      5. ClearAudio cleaning brush
      6. Revolv goat hair cleaning brush
      7. Small spray bottle.
      8. High quality microfiber cloth
      9. Milty Zerostat
      10. DS Audio ST50 stylus cleaner
      11. Mofi Master Sleeves
      12. Mofi Archival Sleeves

This process will make the vyinal dead quiet with almost no pops and clicks. It does involve a bit of work but I find it enjoyable.

Step 1
Make sure the platter on your Okki Nokki is clean and dust free. No sense in putting a record on a dirty platter and pressing that dust in the grooves. Place your record on the platter and tighten down the record clamp.

Step 2
Add distilled water into your spray bottle and wet your brushes. Both the Revolv goat hair and the Clearaudio brushes. Don’t put them on the record dry.

Step 3
Start the platter in CCW direction on the Okki Nokki. Add the Okki Nokki cleaner to the surface of the record. Now use the goat hair brush. When I see light bubbles I change directions to CW and start the vacuum. Suck up the dirty fluid and add fresh. Brush again with the goat hair brush until you get some small bubbles.  Once you do vacuum up the solution.

Step 4
Do the same thing as step 3 with the Revolv solution. You will not get bubbles however. Use the ClearAudio brush. You will notice that the he water doesn’t bead, it sticks and spreads out.  Do both directions and vacuum between directions.

Step 5
With the Okki Nokki platter spinning CW spray the surface with a light coat of distilled water then vacuum it up. Remove and repeat step 1-5 for side 2.

Step 6
With record off the Okki Nokki hit it with the ZeroStat gun I give 4 trigger pulls. One in the center about 6 inches away, and then a triangle starting at the top, then left then right. Now it’s ready to play.

Step 7
Before you play clean your stylus with the DS Audio ST50. Place it on the platter and drop the arm into it twice.  Now you are ready to listen. Enjoy the fruits of your labor!

Step 8
When done listening place your record in a mofi master inner sleave and put your jacket in a mofi archival sleeve.  I slip the inner sleeve in the back of the jacket to prevent ring ware.

That’s it. If you try this let me know how it goes! Happy listening.

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Latest project completed

Finally finished a project I have been dragging my feet on for awhile.  The surround on my Vandersteen’s midrange detached.  I have tried  my hand at re-foaming speakers before and didn’t have very good luck with it.  I decided to remove the drivers are send them back to Vandersteen.

Model 3’s without the sock installed

Above is me testing them once I got the drivers back and re-installed.  Richard Vandersteen really is brilliant with this design.  Everything is well build but he saves so much money on the finishing just covering it with a sock and some fancy top and bottom plates!

Model 3's with sock installed
Model 3’s with a new sock installed

 

Above you see them under test after I installed the new socks and top and bottom plates.  They sound as good as ever even without proper placement.  Still working on getting this system back up and running.  I have some really nice vintage amplification going on them soon and my highly modified Rega P3 as the main source.

 

 

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Roon Nucleus Plus Music Server

Does anyone out there have any experience with the Roon Nucleus Plus music server?  It looks like a really cool device!  I will be finally setting up a proper listening room in the coming months and I think the Roon music service really brings something to a digital collection. The server itself is kinda expensive and I can probably do the same thing under a Linux VM but sometimes it’s nice to just have something turnkey that just works without having to mess with it.  I think audio equipment should be that way so that is why I’m thinking about adding it to my setup.

If anyone has anything to say about this please chime in!