My corner of the web
Anything to do with the High-End Audio hobby.
Take a look at these EL-34’s from NessTone. I think they are OEM by Shuguang in China which I thought was a pretty good factory.
What is the brown stuff? It’s not getter, the top is nice and silver where the getter is. It looks like a burn on the glass but I don’t know from what or why. I have to on all 4 tubes. They run and sound fine. Bias is dead on. Are the tubes dying? Something else? I don’t have that happening on my JJ’s they are nice and clean. Weird…
Had to install a new AC in my moms room and then was planning to go to Long Island. Had some last minute changes so ended up back home. Put on some tunes and continued digging into my Audible Illusions project.
I remove the old capacitors, some of them really look like candy! Hard to find equivalents of some of them. I ended up putting back 4 of the orange drop caps because I was not able to find new ones rated at 800VDC. They test ok and from what I have read they tend to last unlike electrolytics.
I replaced the the big Mallory caps ( aluminum ones in the picture) with some super nice but way smaller in physical size AudioNote caps! I had some challenges getting them to fit since the Mallory’s were way larger in diameter but I was able to come up with a solution. I also had to go to the super old spec sheets to decode the polarity. The older caps used symbols not a simple positive or negative mark. Turns out the case is negative and the symbol(s) are positive.
AudioNote caps are a little bit expensive but I think this unicorn of an amp is worth it. And yes they are real, didn’t source them from e-bay. Got them from the Parts Connextion. The amp had a hard life in the past. Looks like it had a violent failure that took out some of the traces on the circuit board. I found it with some bodge wires. Very sloppy work. Here is what I did:
I also tried to make it less obvious with this attempt.
I think the second one looks more stock, if you don’t really inspect the board you can’t see it. Very happy with the results. When I got this amp it was covered in nicotine residue on the top and tons of flux residue on the bottom. Still have cleaning to do but it’s looking alot better. Maybe in the future I will get a bigger ultrasonic that can accept a fill size board. That would be alot easier then the IPA and q-tip method I have been using!
Going to start on the case and other bits and bobs next. I will get all the jacks and binding posts into my small ultrasonic to get the years of crud off. I also have to clean the bias meter, bias pots and tube selector switch. They need some TLC but nothing Deoxit can’t handle. Will post more when I can, for now happy listening!
This happened a few weeks ago. I had just sat down to listen to my second reference system . I built it with some vintage but super high end gear. I powered up and gave the amps a few minuets to come up to temperature. Drop the stylus and after a few notes a horrendous scratchy static comes out at full volume! Like holy fucking shit volume! I immediately power down and notice smoke coming from the driver tube area on the power amp. Something seriously wrong just happened! I’m not exactly sure what but I do know it was bad. Since I’m still new at the repair hobby and because this amp is really nice I decided to take it to someone who’s worked on them before. I didn’t want to risk turning it into a doorstop and the voltages in it are frankly terrifying.
Just found out today the extent of the damage and I think I’m pretty lucky! The previous owner changed the fuse from a 2 amp to a 7 amp so it could have been really really bad. John the tech thinks that I might have accidently shorted out the leads and caused this shit show. 🙂 I can’t say for sure but it seems passable since I’m using spade lugs and not banana jacks on my speaker cables. The binding posts on this amp are also all metal making it even easier to cause this type of failure. John sent me pictures of the damage and it looks like I smoked a few parts in the driver section but its not that bad thankfully and fixable! It’s getting repaired now and I should have it back in two to three weeks.
John tested all the tubes and found that my power tubes tested pretty bad. Two of them are actually really really bad which has me a bit bummed out over. They are all relatively new PSVANE KT88’s. This is my first time dealing with Chinees tubes so I don’t know what I can expect in terms of life expectancy but I hoped for over a year. They did get good reviews online and I really loved the sound but I decided to order a new matched set of 8 Sovtek 6550we’s. I tried KT88’s and know the sound signature pretty well so now I’m excited to see what 6550’s will do to the sound and I know Russian tubes will last much longer.
Well that’s about all I have for today. Happy listening!
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:
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
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!
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.
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.
Just got a crusty old Dynaco ST-70 tube amp off e-bay to rebuild. It’s a project I’ve wanted to do for a long time. It’s amazing that you can still get replacement parts for something so old. The unit I got is in good shape electrically, but needs a new chassis. The chrome is old and pitted with rust here ans there. The output transformers also need a nice coat of paint too. Going to listen to it for awhile then do a transplant into a new chassis. It will. Give me the opertunity to replace older components while I’m in there.
I have been looking over the schematics and it’s a really simple design. Elegant simplicity that has stood the test of time. Will take some pictures when I get the chance. Plan on using it on my main workstation. Currently using an Emotiva integrated amp but I think it’s more interesting to use a preamp and amp here. Going to use a cheap Schitt amp for now and maybe get a vintage Dynaco pre-amp to rebuild later on down the road. I have also been eying a Dynaco Stereo 400’s on e-bay but that’s way down the road.
Want to get more into repairing old vintage equipment. Might hit some estate sales and garage sales this year and see what I can find… Not much in terms of deals in e-bay… Most people know what they have. Someday maybe a Sanusi AU X11! That’s a grail for me. Anyway that’s enough for now.
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.
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!
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.
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!