I'm reorganizing the mess to make space for building 4 more boards, with pictures and maybe video when I find a box with a few metal tubes in it. I remembered that someone gave me a couple boxes of loose tubes at the Dayton hamfest 2 years ago, I took out the stuff I wanted, then gave away the rest, but these few metal tubes got forgotten until today. I had already pulled the pair of metal 6L6's and put them with the other 6L6 types, but haven't tried them. There were some tubes that were taller than the others. I picked one up and it was a 6AG7 which is a pentode, useful as a driver, but I didn't look much further.
Today I looked. Out of the 10 tall tubes, 8 were metal 6V6's, all were shiny black with no rust......what do I do with these???????
Stick them in the amp, and twist some knobs.....what do you get from some old metal 6V6's? How about 30 watts at clip, 25 watts at 1.1% distortion. The problem with the metal tubes is that you can't tell if they are melting inside, but there is an easy test.....pop some glass tubes into the sockets and watch them.
I want to play these guys on speakers tomorrow, and dig up some glass 6V6GT's to find out what's going on behind that steel curtain.
Today I looked. Out of the 10 tall tubes, 8 were metal 6V6's, all were shiny black with no rust......what do I do with these???????
Stick them in the amp, and twist some knobs.....what do you get from some old metal 6V6's? How about 30 watts at clip, 25 watts at 1.1% distortion. The problem with the metal tubes is that you can't tell if they are melting inside, but there is an easy test.....pop some glass tubes into the sockets and watch them.
I want to play these guys on speakers tomorrow, and dig up some glass 6V6GT's to find out what's going on behind that steel curtain.
Attachments
Last edited:
I did get to stick some glass 6V6GT's in the amp and test them at 30 watts. Nothing was glowing once I found 4 good tubes. Plate dissipation at 30 watts output is 15 watts per tube, a bit beyond the 12 watts spec, but in normal operation you are only going to hit this on loud peaks. I hooked up the speakers and let it play some streaming music from my iPAD for most of Wednesday. No issues, and it did sound nice.
The mail girl brought me my Mouser order yesterday, so I cleared the workbench and set up the cameras. I was planning to spend today stuffing boards, but stink happened.
With about 3 inches of packed snow on the ground, the rain started yesterday.....and hasn't stopped yet. It will rain until late tonight when the rain turns to mush and then snow. 5 to 8 inches, 10 in isolated areas are expected by mid day tomorrow.
This morning I looked outside to see that the previously frozen creek had thawed and overflowed its banks. Water had risen about halfway up the back yard, and the pressure started pushing the water in the saturated ground toward the house. My lab, workroom, and music studio are in the basement which is well below the level of the water.
The neighbor told me that she has standing water in her basement, so I spent the morning dragging expensive electronics the cameras and a lot of other stuff upstairs. The workbench in now piled full of things I didn't want wet.
So far there has been no water intrusion, but the creek is still rising. Flooding has pushed some of the septic tank drain field water into the sump system, stinking up the entire house.
We will have 2 to 4 days of cold and wet before I can get things back to normal. I may set the soldering iron up on a folding table and stuff two boards just so I have 4 to play with. That depends on how today (flood warnings until tomorrow) and tomorrow (maybe snow shovel / blower day) goes.
The first two pictures were taken this morning. The 3rd a couple of days ago.
The mail girl brought me my Mouser order yesterday, so I cleared the workbench and set up the cameras. I was planning to spend today stuffing boards, but stink happened.
With about 3 inches of packed snow on the ground, the rain started yesterday.....and hasn't stopped yet. It will rain until late tonight when the rain turns to mush and then snow. 5 to 8 inches, 10 in isolated areas are expected by mid day tomorrow.
This morning I looked outside to see that the previously frozen creek had thawed and overflowed its banks. Water had risen about halfway up the back yard, and the pressure started pushing the water in the saturated ground toward the house. My lab, workroom, and music studio are in the basement which is well below the level of the water.
The neighbor told me that she has standing water in her basement, so I spent the morning dragging expensive electronics the cameras and a lot of other stuff upstairs. The workbench in now piled full of things I didn't want wet.
So far there has been no water intrusion, but the creek is still rising. Flooding has pushed some of the septic tank drain field water into the sump system, stinking up the entire house.
We will have 2 to 4 days of cold and wet before I can get things back to normal. I may set the soldering iron up on a folding table and stuff two boards just so I have 4 to play with. That depends on how today (flood warnings until tomorrow) and tomorrow (maybe snow shovel / blower day) goes.
The first two pictures were taken this morning. The 3rd a couple of days ago.
Attachments
Last edited:
We have a basement at our primary house, which is rare, because hydrology here is unfavorable to basements.
There is a product, I call it hydraulic cement, that you can use to plug water entry points. You can put this stuff into a hole or seam even when water is actively flowing through it under pressure, and it will set and block the flow. A bigger hole will take more cement and more time, you just work at it a little bit at a time. I've also used this product in commercial buildings with great success on subterranean water. I had a floor, probably six feet below ground, where a new slab was up against a 150 ish year old sandstone field rock wall, and water was pushing through the seam. Stopped it. It works really well. There is a name for it, but hydraulic cement will be enough for the supply house to know what you want. It takes a lot. Get three times what you think you'll need if you try it.
There is also a paint like product that you can brush on that will seal cement blocks to water intrusion. It won't fix holes, you need the cement for that, but normal porosity, it will handle.
For good measure, I put in two sump pumps in the slab to pull water away from the basement area. This only helps if you have someplace else you can pump the water to.
We were getting three and four feet of water in our basement, now it's dry.
Win W5JAG
There is a product, I call it hydraulic cement, that you can use to plug water entry points. You can put this stuff into a hole or seam even when water is actively flowing through it under pressure, and it will set and block the flow. A bigger hole will take more cement and more time, you just work at it a little bit at a time. I've also used this product in commercial buildings with great success on subterranean water. I had a floor, probably six feet below ground, where a new slab was up against a 150 ish year old sandstone field rock wall, and water was pushing through the seam. Stopped it. It works really well. There is a name for it, but hydraulic cement will be enough for the supply house to know what you want. It takes a lot. Get three times what you think you'll need if you try it.
There is also a paint like product that you can brush on that will seal cement blocks to water intrusion. It won't fix holes, you need the cement for that, but normal porosity, it will handle.
For good measure, I put in two sump pumps in the slab to pull water away from the basement area. This only helps if you have someplace else you can pump the water to.
We were getting three and four feet of water in our basement, now it's dry.
Win W5JAG
Last edited:
UPDATE:
It has been snowing nearly every day since I took the pictures in post #66. So far there have been no incidents other than a daily workout with a snow blower, shovel, broom, or all 3.
There were predictions for sub zero weather with no snow today so school was cancelled again. I haven't seen a school bus in a week. Instead we had temperatures that hung around +10 degrees F all day with periods of sunshine and snow showers. More of the same expected tomorrow.
There is currently about 7 inches of snow on the ground. The creek out back merges with another creek and both empty into the Ohio River which is about a foot below flood stage. Sooner or later all the snow is going to melt and the water has to go somewhere. The area where the two creeks merge experienced severe flooding last week and has been evacuated. Temperatures are expected to remain below freezing until next week.
I had set up the cameras to take pictures and video of 4 new boards being assembled. That didn't happen and all the camera equipment and a lot of other stuff is upstairs, and will remain there until the flood threat is over.
I removed the two boards from the test amp. They are being updated to match the latest parts list. Two new boards are being populated to match. After all 4 boards are tested and working, the parts list and schematic will be updated, and posted. The old boards will be returned to the test amp, and the new ones will be used to make a complete amp.
It has been snowing nearly every day since I took the pictures in post #66. So far there have been no incidents other than a daily workout with a snow blower, shovel, broom, or all 3.
There were predictions for sub zero weather with no snow today so school was cancelled again. I haven't seen a school bus in a week. Instead we had temperatures that hung around +10 degrees F all day with periods of sunshine and snow showers. More of the same expected tomorrow.
There is currently about 7 inches of snow on the ground. The creek out back merges with another creek and both empty into the Ohio River which is about a foot below flood stage. Sooner or later all the snow is going to melt and the water has to go somewhere. The area where the two creeks merge experienced severe flooding last week and has been evacuated. Temperatures are expected to remain below freezing until next week.
I had set up the cameras to take pictures and video of 4 new boards being assembled. That didn't happen and all the camera equipment and a lot of other stuff is upstairs, and will remain there until the flood threat is over.
I removed the two boards from the test amp. They are being updated to match the latest parts list. Two new boards are being populated to match. After all 4 boards are tested and working, the parts list and schematic will be updated, and posted. The old boards will be returned to the test amp, and the new ones will be used to make a complete amp.
Nice new boards George! Maybe in a few years I can afford to buy some more parts & your PCB's. I posted a link to this site over at AK when you announced the new boards, and hopefully that will help you sell more!
Your winter pics look like around here (since the middle of Nov.)
We just get cold 500 miles north/central of the US boarder at this time of the year with temps lately hitting -37C /-35 F overnight. Last few days have warmed up to the temps your mentioning during the day which is about -10 C I believe. Back to -20 C or colder next week or -5 to -10 F! 26 inches of snow so far which the snowmobilers like. Ice has been thick enough on the surrounding lakes for ice fishing since fairly early in Dec.
Your winter pics look like around here (since the middle of Nov.)
We just get cold 500 miles north/central of the US boarder at this time of the year with temps lately hitting -37C /-35 F overnight. Last few days have warmed up to the temps your mentioning during the day which is about -10 C I believe. Back to -20 C or colder next week or -5 to -10 F! 26 inches of snow so far which the snowmobilers like. Ice has been thick enough on the surrounding lakes for ice fishing since fairly early in Dec.
Last edited:
I usually recommend something like my SSE for a first project since it's pretty much a build it, plug it in and play, type of design. There are no adjustments needed. An amp like this will require testing and adjusting things like bias and balance with the system powered up, and a KT88 amp tends to run at 400 to 500 volts.
If you are not in a big hurry, watch this thread for a while. I plan to build up an amp or three using these boards and document the build with photos and video.
The part where you have to adjust a live amp will be done on video since it's the biggest hurdle for many builders, and the most dangerous. I have made it somewhat easier by using multiple cheap meters connected to the amp before powering up to remove much of the risk.
I plan to offer a power supply board (in the works now) and maybe some output tube boards (if there is a demand for them) to simplify the build process.
Great project for tube beginners; and a fine sounding amp too.
Great idea George!
Another good idea. If the power board can support the TSE, I guess that will make things a bit easier for TSE builders too.
They can be ordered now, but there could be a short restock delay once my current supply runs out.
I don't have the ability to access my web site at this time, so nothing has been posted there in a few years. I bought a batch of these boards in 2015 but they sat in a box after moving twice and partly rebuilding my lab. Tubelab sales have not paid the bills in the last two years, so I was seriously thinking of shutting down last year.
My wife is now working part time, and since I turned 65 the $2500 per month health insurance bill is gone, so our economic situation is improved. Nobody here is going to hire a 65 year old engineer who designed cell phones and police radios for 40+ years, so I'm going to see what I can do with Tubelab this year.
I made this statement in post # 29:
I can sell these boards. For now the only construction info is what's right here. The boards are $25 USD plus the usual $8 shipping in the US, and $15 international for up to 4 boards.
And the usual how to order statement that's on the web site in post #32
I have sold 10 of these so far, built 4, and have 21 left. I plan to populate 2 more once the flood threat has cleared and I can set the expensive stuff back up in the basement.
I have the material to build at least 3 amps using these boards, probably 5 without spending more than $50 total, so I plan to do this over the next few months and detail it here. I will order a new batch of boards as soon as I am sure there isn't any need for changes.
Thank you for replying and for the information. I can imagine the flood threat has been really disruptive. This is from that massive rain last Friday? I spend a lot of time in upstate NY, and ice jams and high water have been a real problem. I hope the danger passes soon and no permanent damage affects you.
A bunch of us around here will be glad to see the Tubelab get active again. I sincerely hope it's a big success for you.
I have to figure out which project to tackle first. I was thinking of a SSE rigged up as a headphone amp, since I have downstairs neighbors who won't let me listen to music at night in my bedroom, even quietly. I have too many parts lying around not to build something soon...
It has been below freezing for over 2 weeks. The creek in our backyard was frozen over several inches thick. There was about 5 inches of snow covering the yard and the frozen creek when the rain started. The ice melted enough to jam up the creek and flood our back yard. My unfinished lab is in the basement, so I dragged most of the movable expensive things like cameras, computers and other electronics upstairs or piled it up on all the workbenches.
The rain left, and the snow returned. Yesterday the snow left and the cold returned, near zero for two days. There is a layer of ice covering the creek, and 6 inches of snow on the ground. The creek empties into the Ohio river which is 7 inches below flood stage. The stuff stays where it is for now.
I cleared a small corner of the workbench today for a day of soldering. There are two new boards that will see power tomorrow, and the existing pair now have exactly the same parts as the new pair. The old boards get tested first.
Attachments
I got sidetracked today when I opened a box that's been packed for several years. It was full of Russians....tubes that is. There were a lot of "one of a kind's" and unmatched pairs like a wafer base Sovtek 5881 and a regular base Sovtek 5881, but some good stuff.
There were 4 Electro-Harmonix EL34's with TubeStore matching stickers. 3 number 42's and a 27. Not quite a matched quartet, but I wired up the old driver boards and plugged them in. They sounded nice with 450 volts on the plates, and 350 on the screens. I listened to them for about 20 minutes because something far more interesting had caught my eye.
There were 6 total Sovtek 6550WA's from the late 90's. There were two matched pairs with matching stickers dated 1998. I was buying these from the original Triode Electronics to build guitar amps back then. These things would eat everything I threw at them without blowing up. So how would four 20 year old Sovteks take some fresh abuse?
I stuck them into the amp, set the plate supply on 525 volts, the screen supply on 400 volts cranked it up and fed it everything from Norah Jones to Metallica. They laughed it off. I noticed the screen supply current meter bouncing north of 100 mA (all 4 tubes) on loud music when the EL34's were installed. I never saw the screen supply bounce above 50 mA when the 6550's were fed loud Metallica at full tilt.
I have been hesitant to use the GE 6550's in an amp since they are rather pricey today. I could sell them for enough $$$$ to build a whole amp! The old Sovteks are a different story, especially when I have 2 spares. I may test them in triode mode and do a side by side test against the GE's when I get a chance.
There were 4 Electro-Harmonix EL34's with TubeStore matching stickers. 3 number 42's and a 27. Not quite a matched quartet, but I wired up the old driver boards and plugged them in. They sounded nice with 450 volts on the plates, and 350 on the screens. I listened to them for about 20 minutes because something far more interesting had caught my eye.
There were 6 total Sovtek 6550WA's from the late 90's. There were two matched pairs with matching stickers dated 1998. I was buying these from the original Triode Electronics to build guitar amps back then. These things would eat everything I threw at them without blowing up. So how would four 20 year old Sovteks take some fresh abuse?
I stuck them into the amp, set the plate supply on 525 volts, the screen supply on 400 volts cranked it up and fed it everything from Norah Jones to Metallica. They laughed it off. I noticed the screen supply current meter bouncing north of 100 mA (all 4 tubes) on loud music when the EL34's were installed. I never saw the screen supply bounce above 50 mA when the 6550's were fed loud Metallica at full tilt.
I have been hesitant to use the GE 6550's in an amp since they are rather pricey today. I could sell them for enough $$$$ to build a whole amp! The old Sovteks are a different story, especially when I have 2 spares. I may test them in triode mode and do a side by side test against the GE's when I get a chance.
