Parsing the Tubelab website and this forum, I see twinklings of a Tubelab Spud SE based on compactrons, dating back to 2008 and fizzling out around 2010 timeframe.
I also see a LOT of other activities in Tubelab's life/career as well as answering our various questions here in TubelabLand. With the Simple P-P taking up what looks like much time, certainly understand if the spud PCB is dormant. Heck, I can't even get around to building out my SSE board due to other commitments.
If Tubelab could look into their crystal ball, would a Tubelab SpudSE PCB be rekindled and available? A spud puffing out more than 3W/ch with a simple build and budget price tag would be suh-weet.
Danke
I also see a LOT of other activities in Tubelab's life/career as well as answering our various questions here in TubelabLand. With the Simple P-P taking up what looks like much time, certainly understand if the spud PCB is dormant. Heck, I can't even get around to building out my SSE board due to other commitments.
If Tubelab could look into their crystal ball, would a Tubelab SpudSE PCB be rekindled and available? A spud puffing out more than 3W/ch with a simple build and budget price tag would be suh-weet.
Danke
I built a Spud which was heavily inspired by Tubelab's SpudSE. You can check it out here: 6LU8 Spud : Neurochrome.com : : Audio
I actually built my prototype Spud using point-to-point wiring. It's certainly possible if you want to go that route. I think the total cost of mine was around $250. That included about $40 worth of walnut for the chassis.
I think a lot of things fell on George at the time the SpudSE was conceived so I suspect it's one of those "too many projects, not enough time" kinds of issues.
~Tom
I actually built my prototype Spud using point-to-point wiring. It's certainly possible if you want to go that route. I think the total cost of mine was around $250. That included about $40 worth of walnut for the chassis.
I think a lot of things fell on George at the time the SpudSE was conceived so I suspect it's one of those "too many projects, not enough time" kinds of issues.
~Tom
Very nice work. Particularly like the 5AR4 in your P/S and the toroid up top for power. The chassis is very nice. I'd seen your website during my initial research and found your CV an interesting read.
Point-to-point is a little beyond my skill level. Modestly handy is about right. Your comment about your entry into tube gear as getting into the "kiddie pool" end is just how I feel. Since I'm a mechanical engineer, I received some university level power engineering for electrical transmission and distribution and did some tower design with Ontario Hydro (when it still existed), but that was many, many moons ago. Understanding 3 phase electricity is, for me, a lot easier than plotting load lines and reading tube datasheets. I've had a few "ah ha" moments in the last few months.
I've just really liked the look of Spuds and the minimalist philosophy of their design. I remember reading something about an ideal amplifier being a "straight wire with gain..." (might've been Bob Carver years ago in an ad for his TFM series transfer function mimic amps) so Spuds seem to approach this type of philosophy.
Hence, the question of Tubelab George. He's got the tools and he's got the talent. I just have to recognize my limitation and the need for a PCB to pull off a tube amp.
Thank you, Sir...
Load lines are a lost art these days. I recall briefly seeing them in the textbook I used in college, but I don't think they were taught. If they were, then I certainly was asleep during those classes...
I got a good amount of information from reading Morgan Jones, "Valve Amplifiers". Also, Electronics 27 is a good read. Jones is probably a bit more accessible, though.
Rather than waiting around for a Spud PCB, I suggest grabbing a SimpleSE board. It's the same circuit topology but with two tubes rather than a double-tube. You can go as simple or as complicated as you'd like. Or as inexpensive/expensive as you'd like. The 5842 can be a little hard to find, but the various tube places on-line (or eBay) should be able to source them.
I had a SimpleSE going in point-to-point wiring at some point. It's a pretty neat amp.
~Tom
Load lines are a lost art these days. I recall briefly seeing them in the textbook I used in college, but I don't think they were taught. If they were, then I certainly was asleep during those classes...
I got a good amount of information from reading Morgan Jones, "Valve Amplifiers". Also, Electronics 27 is a good read. Jones is probably a bit more accessible, though.Rather than waiting around for a Spud PCB, I suggest grabbing a SimpleSE board. It's the same circuit topology but with two tubes rather than a double-tube. You can go as simple or as complicated as you'd like. Or as inexpensive/expensive as you'd like. The 5842 can be a little hard to find, but the various tube places on-line (or eBay) should be able to source them.
I had a SimpleSE going in point-to-point wiring at some point. It's a pretty neat amp.
~Tom
There have been a lot of strange diversions that have come my way over the last 5 years, and indeed my soldering iron has not been turned on yet this YEAR! However there was a totally unique reason for the death of the spud.....tube sockets. The 6LU8 and the 6LR8 are the same tube except for the base. The 6LU8 has 12 pins and the 6LR8 has 9. I first met these twin brothers when I worked in a TV repair shop in 1968. I made a few guitar amps back then with 6LU8's and other parts from discarded TV sets. The spud amp concept is a similar design, so I made one with an SSE and about half a million clip leads. It worked and sounded reasonable.
Before considering any amp for possible production I investigate the long term supply of parts. Neither of the twins are very common outside the USA. The 6LR8 was in far better supply than the 6LU8 back when I considered making the spud, so that is the tube I chose. I made a PC board and an amp and played with it for a while. At the time PC board mount sockets were not being made yet, but I was assured that they were coming.....from China.
I was looking into a parts kit like the ones I now have for the Simple P-P, and even boiught most of the parts. When the first batch of Chinese tube sockets showed up they were crap. The terminals were too loose for a Noval (.040" pins) and too tight for a Magnoval (.050" pins). The tube socket fiasco went on for at least 2 years and I gave up.
I saw Stan (ESRC) at the Orlando hamfest and he handed me some new production Chinese 9 pin PCB tube sockets that actually fit! It took what 3 or 4 years??????
I have about 100 6LR8's, all the small parts, but never bought any PCB's. Is anyone else still interested in this thing? If so I will have to make a spreadsheet and run a cost analysis to figure out what it would cost.
Back to the not enough time issues......
Tubelab has only made money (and only a few hundred bucks at that) for one of its six years as a corporation. I have worked at the same Motorola plant for 39 years. They have been laying off engineers slowly but constantly over the last 10 years. I have beaten the odds, but sooner or later my number will come up. Tubelab Inc. must be making some money when my employment ends, or it will cease operations. We have been paying $2510 a year in warehouse rent. If that payment did not exist, Tubelab would have been in the black for 5 out of 6 years! So, the obvious must be done.....bye bye stuff.....lots of stuff. Sherri and I have a goal to be out of the warehouse by July even if it all goes to the trash dump.
I have been sorting, selling, tossing, and giving away tons of stuff. I have hit every local hamfest and swap meet selling my stuff, although last week I sold about 300 tubes for $1 each and a bunch of other stuff, but bought a guitar and amplifier......not cool but for $60 I couldn't say no.
The mother of all hamfests is in 34 days 11 hours 5 minutes and 34 seconds, so I will pack up one cubic Honda Element full of stuff and drive it 1200 miles to Dayton Ohio. Then on to West Virginia. Be back on Memorial day. Until then I won't have time for electronics stuff, and the soldering iron will likely stay cold and so will the tubes......After that?????
I guess we're getting a little off topic here, but we're still talking about tubes and the learning experience of building Tubelab equipment.
Join the two mystery points and that's your load line. It wasn't until recently that I discovered (for the 6L6GC) that in the Vp verus Ip the tops of all the sweeps were a straightline that was a typical load line. Came from a vendor's site: Tube amplifiers for high-end audio by The David Berning Company
So, it wasn't until I started treating the output tube like a quarter turn ball valve that I understood that the tube is throttling the power supply (B+) through the load by modulating the grid that things have started dropping into place lately.
Brad
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Things are only impossible until they're not!
And, I can tell you that it is not well explained in most places. Most of the authors seem to skip something vital in their treatment and a load line magically appears on the plate characteristic curves plot...so pick a quiescent point (uh, how?!?), and that gives you one point, then use a plate current value that is your load resistance (selected HOW) divided into the E-sub bb voltage (selection not quite clear).
Join the two mystery points and that's your load line. It wasn't until recently that I discovered (for the 6L6GC) that in the Vp verus Ip the tops of all the sweeps were a straightline that was a typical load line. Came from a vendor's site: Tube amplifiers for high-end audio by The David Berning Company
So, it wasn't until I started treating the output tube like a quarter turn ball valve that I understood that the tube is throttling the power supply (B+) through the load by modulating the grid that things have started dropping into place lately.
Even Master Tube Man Jones didn't explain load lines to my understanding. He jumped into it like everyone will just "get it".
Already have it. Just waiting for more spare time and some budget funds to start the build up.
Brad
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Things are only impossible until they're not!
Seeing that picture of squid-like art that produced a working amp is what caught my eye, George. So, I thought I'd just ask.
I am involved (part of my time) in safety/reliability for petrochem clients and that's always part of the lifecycle cost/design. Understand completely.
I've lived that distress twice in the last three years with major employment losses in Ontario, Canada, including me, twice as one of the last to go both times.
Understand that too. Clearly, however, there is quite a little community here at DIYAudio that thinks the world of your work, so I'm hoping it can continue, since I have just barely arrived at the ground floor.
Has anybody looked into soldering the tubes in, could this be done without damage to the tube? My first thoughts are, you would be fine, I have never tried it though.
Sure tube rolling would be a pain, this could be offset by the ability to use uncommon tubes.
You could even drill the PCB to accept different tube basses, like they do with capacitors.
Sure tube rolling would be a pain, this could be offset by the ability to use uncommon tubes.
You could even drill the PCB to accept different tube basses, like they do with capacitors.
It was commonly done with the tiny subminiature tubes used in military aircraft electronics and hearing aids. I met a guitar preamp about 20 years ago that had the 12AX7's soldered into a little PC board that plugged into the main board so it would fit into a 1U rack cabinet. The company wanted over $100 for a replacement board. I used a propane torch to unsolder the tubes. I cleaned up the board with solder wich and soldered in some new tubes.
I suspect that the bigger tubes with pins through the glass like the 6LU8 and the 6LR8 would get the pins hot enough to stress the solder joints causing them to become intermittent over time.
I went to a technical high school where I was enrolled in a 3 year long 3 hour a day vocational electronics program. It was 1967 - 1970 and our books were old US Army training manuals, and some textbooks printed by Philco. All centered on repair and basic design of electronic equipment built with vacuum tubes! It was here that I learned how to melt them. We learned how to draw load lines. I also quickly learned how to ignore them and squeeze more power out of a tube than the text book says was possible. A2 and AB2 weren't in the text books. Neither was screen drive. It was then that I made the biggest audio amp that I have ever made. It was completed during the summer after high school graduation and made 1200 watts. A lot of audio power for 1970 and it was clean power used for a rock groups PA system. All silicon though (24 X 2N3773).
I was a teenager with no money and I wanted to make loud guitar amps with old TV parts. Who needs a load line when you are using a power transformer for an OPT, you have no idea what the impedance or turns ratio is, you connected 42 speakers together in whatever series - parallel combination made the most noise and distortion was an acceptable and even desirable attribute?
I still do it the same way. I connect a tube to a variable power supply using an oversized OPT. Then I test the power and distortion at every possible load impedance from way too little, to way too much. Then I pick what works the best for the job at hand. The curves in the tube manual seem to never be drawn at the operating point you want to use (especially screen voltage) any your "8 ohm" speaker isn't 8 ohms.
That one even amazed me. I thought it would be a full blown TV jammer, but it never tried to oscillate. I have built some very clean designs that oscillated themselves into meltdown. They usually involved mixing tubes and mosfets though.
I don't think mine has been on this year either. I am BIG time backed up on projects: the DZ kit, the 6146 SSE Rev 2, a new crankshaft damper for a V12 Jag, and more. And, child number 3 is expected in September. This is on the heels of grandchild number 3 that arrived a month ago
. I only bought one tube at my last hamfest, a 6HS6 for $1, and sold about $300 worth. I even sold a bunch of 6AL5's. I would say there is hope, but at the hamfest before last I fell off the wagon and bought probably three dozen NOS TV sweeps. NOS 6BG6's for a buck, what can you do?
It's now looking grim for me AGAIN this year. I had to involuntarily take back a property two weeks ago, and I've decided to gut and remodel the place. Since construction always seems to take twice as long as I think it should, I'll probably be in the big middle of it during Dayton week. I feel if I don't make it this year, it could be a long time before I get another chance
.Win W5JAG
Where would we be without surface mount stuff?
huh? really? I'm struggling to visualize this........vacuum tube hearing aid?
huh? really? I'm struggling to visualize this........vacuum tube hearing aid?
Yep, until roughly the mid 1960s.. The electronics usually lived in a small box about the size Altoids mints come in..
Yes, as Kevin says the user carried a cigarette pack sized box in their shirt pocket that housed a mic, a tube amp, and two batteries. There was a wire to a crystal (piezoelectric) earphone. I had one of them in the early 60's and hacked it into a radio. The tubes are about the same diameter as a pencil, an inch and a half long, need 1.4 volts at 50 ma for the heater and 22.5 volts on the plate. Still have some of the tubes, but they are in the goodbye stack.
The retro thing...
Could such a thing be Frankenstein'd into a retro portable headphone amp?
Battery technology using NiMH or Lithium Ion/Polymer could provide quite a nifty power source. Would the mighty Tubelab be into seeing how much power he could thump through a helpless, nearly used up pencil shaped tube? That would make an excellent, excellent YouTube video...TubeLab Meets Bobby Darren in The Time Tunnel and bends time with a microtube.
With a 'leatherette' pleather case, an old pair of Radio Shack 100-in-1 electronics experiments earpieces and you've got one jazz-hands, unique-as-all-get-out box around your neck. Guaranteed to break the ice at parties. I think I want one already.
Back on topic though, did I see right that the website change? Spud on hold until further notice?
The size, shape and config of the spud just resonates with me...
~Squiff
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Things are only impossible until they're not...
Could such a thing be Frankenstein'd into a retro portable headphone amp?
Battery technology using NiMH or Lithium Ion/Polymer could provide quite a nifty power source. Would the mighty Tubelab be into seeing how much power he could thump through a helpless, nearly used up pencil shaped tube?
That would make an excellent, excellent YouTube video...TubeLab Meets Bobby Darren in The Time Tunnel and bends time with a microtube.With a 'leatherette' pleather case, an old pair of Radio Shack 100-in-1 electronics experiments earpieces and you've got one jazz-hands, unique-as-all-get-out box around your neck. Guaranteed to break the ice at parties.
I think I want one already.Back on topic though, did I see right that the website change? Spud on hold until further notice?
The size, shape and config of the spud just resonates with me...
~Squiff
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Things are only impossible until they're not...
That shouldn't be too hard, but the sound quality would likely suck. I was a 10 or 12 year old kid at the time, and essentially wired a crystal radio set where the microphone was. I could get a few stations, but the popular music station has its tower in the Atlantic ocean with mega power. They were (and still are..560 KHz AM) easy to pick up with a coat hanger and a diode. I thought it was cool to have a radio that I "made" but sound quality???? What does it take to hear the Beatles or Elvis on AM radio???? Does it beat todays iPOD?????? Do you care if you are a kid?
All these tubes are still around and cheap. Many are microphonic, have low gain and very limited power output (tens of milliwatts). Look up 6418.
With todays LIPO power I would look into the subminiature tubes that were used in aircraft at the same time. Here you get an oxide cathode, 90 to 150 volts of plate capability and 1 to 3 watts of dissipation. They can be coerced to fit into an 8 pin round IC socket too. Look up 5718, 5636, 5840 and 6021.
I looked into using them for a guitar amp that fits INSIDE the guitar. I want battery power but at least 2 watts output, so I will still use a 7 pin miniature tube for output......if I ever find time to build it.
I have been going through the website removing all traces of the name that uses the word Simple and the common abbreviation for Single Ended. That design now must be called the SSE due to copyright issues. In the process of hastilly removing and renaming things I have busted many links. I am now trying to fix them. It's these kind of things and the warehouse deal that have kept me from working on the Spud, or ANY tube designs this year. It will be an indefinite time before I get to play with electricity again.
I will look them up, but the datasheets and curves will still look like latin to me. However, would it be wise to have 90 to 150 volts hanging around my neck where I am the path to ground in the even of a fault and my heart and major organs are in the path of flow? It would be retro cool to own and operate a unique piece of kit like that though, potential fidelity issues aside.
I am one of the most recent guilty parties of using the defunct term. Will do my best to stick to SSE in future.
Having read a little history on your site and here on diyAudio, it was only my eagerness talking. Zero intent to add pressure to your situation. Heck, I can't even get around to purchasing the passive components for my SSE board, let alone the iron or fab a chassis. That's on hold now as I will be saying b-bye to colleagues at week's end, tightening the budget further. Economy sucks North of the border too. Second time for me in the last three years. Unless I move to the oil patch out West, short dry spell for me too.
~Squiff
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Things are only impossible until they're not
Sorry to hear that. I have worked in the same Motorola plant where I started 39 years ago. There are layoffs every year, yet there are new young faces too. Most of my friends are gone and it's only a matter of time for the rest of us old farts.
I have lived in South Florida for 59+ years. I will leave here when my number comes up at work. Hence the preparations for a big move and the associated "stuff reduction plans".
You just skip over all that unimportant stuff to get to the typical operating conditions. Here you look at the power output, load impedance (what OPT to use) and the B+ and current. The power output listed for the 6418 is 2.2 MILLIWATTS. Even through a headphone, you are going to need a hearing aid to hear the hearing aid......NEXT.
90 to 150 volts is max rating. These little guys will usually work on 2 or 3 9 volt batteries. I haven't seen one of those hearing aids in maybe 30 or 40 years. I think they are rather scarce today. The brand name was Sonotone. They go back to the 1930's and are still in business. Google for some interesting history.
In sense, it's a silver lining for me. The engineering company I work for is currenlty rocked by national and international scandal and investigation, so I won't miss that. You're quite right that the challenge is when friends leave.
Pursuing a Zen life in line with the principles of Feng Shui and minimalism is a noble goal. Please don't tell me you're coming North. Some of us hearty northerners NEED winter just to survive the onslaught of a dozen "dog days" of sticky, humid weather in August every year. One of my buddies in Pensacola, FL used to live in Louisiana and characterized the weather there as..."imagine putting on a snowmobile suit and fur hat, then getting into your attic in the middle of summer to ride 5 miles on an exercise bike. THAT'S what just standing here in Lafayette feels like."
Just thought of the novelty. My wife's two aunts both wore one of these.
Will Google and thanks for the tip. If you, or anyone you know is a car guy, dragging particularly, then you should Goole "Turbonique Drag Axle". Spin off from an ex-NASA employee who shared a portion of your philosophy, but he did not back off a bit. Google it, you'll see what I mean.
I do hope that you get some bench time soon. I always feel a little lost when I'm unable to play.
Thanks for the well wishes.
~Squiff (aka Brad)
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Things are only impossible until they're not
Well that depends on how you define "North". I was born in Miami and have neven lived any further north than Fort Lauderdale. Both of those areas have made Forbes Magazine's 10 worst places to live list for the past 2 years. We inherited a house in Moundsville West Virginia about 250 miles south of the Toronto area. I have seen pictures taken out the window of the RIM plant in Waterloo during winter. I am not up for that yet.
We lived in Miami and didn't have air conditioning until I was in High School. I can't imagine that now. My internal thermostat seems to have tilted to the point where I dont like going outside from July to September.
I have gone to the house in West Virginia every winter for the past 10 years. The cold doesn't bother me as much as the Florida heat does. Of course there isn't near as much of the white stuff as you guys get.
I have taken trips down the 1320 ever since I got my first car in 1970. Unfortunately the local strip was closed in the name of progress about 20 years ago. The closest strip is now 70 miles away. One of the things I will probably sell is my 500 HP 1973 Dodge Challenger.
I remember the Turbonique from a write up in Hot Rod magazine some time ago. Old car guys will remember Andy Granatellis turbine car at the Indianapolis 500. It walked away from the field and was headded toward victory when a bearing failure in the transaxle killed it. As with many new technologies the sanctioning bodies were afraid of it so they legislated it out of existance. That is what's happening now with electric cars in the NHRA.
Hey George, become a snowbird, then you can keep your hobbies! Lot's of people here sure do it, of course the winters can be too long & I don't look forward to them like you with the hot humid weather.
Didn't mind the winters so much when I was young (they were colder then too) & actually this past was one of the warmest winters I've seen here except for 87-88.
My youngest brother just 3/4 /HR North of Toronto figures he'll go to FL for the winters when he retires.
Most people from here go to Texas & Arizona, though I have heard of California and Mexico as other popular places besides Florida. Popular to go out to BC too, but has gotten too expensive!
One thing about the winters here and out west is it's very dry most of the time so it isn't as bad as it is out east (Detroit-Windsor to Montreal all I've experienced) where it's warmer, but damp which makes it feel much colder.
I remember that Turbonique article too. Wild stuff!
Didn't mind the winters so much when I was young (they were colder then too) & actually this past was one of the warmest winters I've seen here except for 87-88.
My youngest brother just 3/4 /HR North of Toronto figures he'll go to FL for the winters when he retires.
Most people from here go to Texas & Arizona, though I have heard of California and Mexico as other popular places besides Florida. Popular to go out to BC too, but has gotten too expensive!
One thing about the winters here and out west is it's very dry most of the time so it isn't as bad as it is out east (Detroit-Windsor to Montreal all I've experienced) where it's warmer, but damp which makes it feel much colder.
I remember that Turbonique article too. Wild stuff!
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