Right, Tubelab Inc. has never made any money. As long as I still have my full time engineering job, thats OK. This does mean however that my day job gets priority (especially now that Sherri is unemployed), and I can't dig too deep financially into a new project until the last one has paid for itself. This recession delayed the purchase of the Simple P-P boards by several months.
The Spud SE boards and the Octal Driver boards are waiting for funds. If the Simple P-P does well, one of them will get done early next year.
Not quite.
I just returned from my trip up north this afternoon. I didn't get as far with the construction manual as I had planned since we had one trip to Pittsburgh planned on Monday the 19th. It turned into 3 all day events, which resulted in Sherris mother being removed from the clinical trial that was keeping her cancer from spreading. We must now decide on a new course of treatment, which will probably result in one or more trips back up north before the end of the year.
We returned home because I must be at work tomorrow. I have not received any email or phone calls from my co-workers (unusual) so I don't know what to expect. Things were pretty hectic before I left, so I may be working long hours to get caught up.
Sherri will be here for at least two weeks, so she will organize the parts kits. They will be ready before the instructions!
Most of what I have was written in the back seat of a car or a hospital room. Nothing was done in sequence since I had to use what I took with me. I tried to guess what I would need before I left, but didn't always get it right. Many pages were written when I didn't have a PC board with me to look at (can't bring all of that stuff into a hospital). I started on a page and worked on it until I was missing some information, then I started another one.
I will attempt to organize my randomness and take a few more pictures during this week and next weekend (assuming a realistic work schedule). If this goes well I should be able to post the first cut of the PC BOARD manual next Sunday evening (+/- a few days) on the web site. At this time anyone and everyone can look over the instructions and offer their creative input.
That covers the assembly of the PC board itself. The manual will not be complete without the information needed to assemble a complete amplifier. Well I wasn't smart enough to load Visio on my laptop before I left so the connection diagrams are not done yet. I have started the construction of two different amplifiers using the Simple P-P board. They will be posted as they are built.
The boards are slightly larger than the others, but to make it easy for my feeble accounting skills (and a few customers who can't seem to add) I have kept the price the same, $35 plus shipping. I still have to have a long conversation with Microsoft (Excel) to figure out the price of the parts kit (my spreadsheet already has 4 pages), but I will throw out a guess that it will be $65 to $75. There are still a few unknowns right now that could mess up that number since I haven't figured out my true cost of some parts.
The parts kit will include all of the parts that go on the PC board, except the tubes themselves. You will still need to purchase your own transformers, chassis, connectors (input, speaker, and IEC), switches and volume control if desired. The PC board components provided are the exact same ones that I used to build the boards for the instruction manual (I bought hundreds of all of the small parts). I should be able to put everything in the small flat rate box from the USPS, which means no extra shipping charge when the board and parts kit are ordered at the same time.
Only being slightly larger than SimpleSE I take it they are mono boards, or ?
OK - I will be waiting for your signal and then will read it all as fast as I can and send any markup - whether any will be *creative* or not -- that'll be your call
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I tried, but I broke the socket! Guess I will need a bigger hammer.
Then I guess that it would be cruel to tell you that I was in the pool yesterday after mowing the lawn (needed all year long here).
I expected that work would be a bit hectic after being gone for 2 weeks, but it has gotten a bit more demanding. I usually try to avoid being in the "critical path" but I now have several sections of a new custom IC to evaluate (which involves designing some hardware and writing some code) before the next pass goes out (December). This means that I have been at work until late (7 or 8 PM) every night. I am still spending most of my free time working on the manual lately, except for last weekend. Last weekend we decided to take the weekend off since we knew that I would be at work until late on my birthday. We needed to blow off some steam.
The Simple P-P manual is progressing a bit slower than I planned, and I haven't had the time to integrate any of it into the web site yet. Two amps are being constructed for the manual, but the only time I have had to work on them is my Thursday night wood shop class. One should be done in two more classes if there are no more screw ups (I drilled the top plate wrong). I still don't claim to be a great amp builder. My amps all work, but vary from UGLY to OK.
Don't worry, January will soon be here. I remember last year's warning:
Oh my goodness! It won't be chilly for just a short while, it's going to last for several hours. Get your hat and gloves ready. I wonder if you'll need a shirt?
Hey it was 31 to 36 degrees and raining for 7 days when I was in West Virginia last month. I guess my bodies thermostat is messed up (and getting worse) because people gave me strange looks walking around in a T shirt and flip flops. It warmed up to 60 the day I left. I have a thick denim long sleeve shirt for Decembers trip, real shoes too. They was sufficient last year.
This is the second year in a row where I have loaded up on cheap clothes during the winter up north. The girl in the Old Navy store remarked "you are not from around here are you" when I loaded up an entire shopping cart full of shorts, tank tops and T shirts from the clearance rack (still wearing my T shirt and flip flops). The cart full cost me $34. I can wear that stuff all year round here.
I have a 6CW5 amp running here. It uses the Antek 1T200 power transformer($29), and a Triad C-24X choke($8). Both of these are technically a little small but the amp sounds good although I only get about 14 WPC. The transformer and choke get warm, but not hot. I put oversized caps in the power supply in an attempt to get a few more volts, but I only got 3 more volts, so it probably isn't worth it. I picked these parts because I already had them. I plan to get a 2T230 to try but I just haven't had the time lately. I know from previous experiments that the 230 volt secondary will produce too much B+ for most 6CW5 tubes, so some experimentation with the capacitor values will be needed. There is a possibility that the 2T230 may not work at all, so the 1T200 is the safest bet for now.
I am in the process of building a chassis for this amp in wood shop class. It uses some surplus OPT's so it will be a good sounding low cost amp. I also have an EL84 version powered by a Hammond 372HX. I am trying to make a nice chassis for this one, but I screwed up the first one, and started over.
I have started on another extremely low cost amp using the Simple P-P board with 6CW5's. It is very similar except that it uses dumpster power toroids for OPT's, no choke, the Antek 1T200, and the cabinet is a wooden box that originally came full of car care products. The whole "car care kit" cost $6 on the discount rack in a "dollar store" in Ohio. All of the transformers go inside the box, so it isn't too ugly.
Post a pic when you're finish if you don't mind, i feel curiosity about what can you learn in those classes.
I'm also finishing a wood chassis for a PP, i would post mine in about a week so you can laugh about what i didn't learn.
So far the "natural" finish is being a nightmare, can't get it right...
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I am taking pictures during the build of three different amps to be posted on the Tubelab web site.
I started out taking a beginning woodworking class at a local middle school about 4 years ago. The beginning class required construction of at least two mandantory projects (a tool box and a lawn chair) to demonstrate the safety and technique needed to "graduate" to the intermediate class. Each class ran 8 weeks (one night per week) and cost $70. The classroom was full of woodworking equipment that was about 20 years old. It was all professional quality and well maintained. It took me 3 or 4 classes to graduate. There was about 8 to 10 students with full time teacher supervision. No one could run any dangerous equipment with out the teachers direct supervision.
Intermediate woodworking came next. A few more students, a little less direct supervision. Build anything you want. No playing with the table saw (a 5 HP monster!) unless the teacher was looking over your shoulder, but anything else was fair game. The teacher is very knowledgeable in woodworking, but didn't know what a vacuum tube was. I did about 3 trips through the intermediate class where I made a few amp chassis of less than stellar quality. Many were just tests to find out what I could or couldn't do. I was informed that I could graduate to the advanced class next term, so I signed up.
Just as the class was starting the local school board decided to close the community school program due to budget. Game over (about 2 years ago). I bought a budget table saw and a few other swap meet tools, but I don't have any space to use them in the garage, and it is just too hot and humid here for me to set them up outside for about 10 or 11 months of the year.
Late last year I got a call from the old teacher asking if I was still interested in taking the advanced class. It would now be offered at a high school about 10 miles away. It now costs $100 for 8 weeks, and when we got there we found that none of the equipment worked. The class room wasn't even being used during the day.
Fast forward to today. Most of the equipment has been fixed. The school has hired a new teacher to actually teach wood shop to high school students during the day. The new teacher is there for every class so that our teacher can show him how to teach wood shop. I now look at this as a shop rental event with a room full of experts to answer my dumb questions. In a previously locked room, I have discovered some metal working equipment. in disrepair of course. I even fixed the sheet metal shear, and sliced several amp top plates from a 2 by 4 foot piece of aluminum.
So, I believe that there could be a lot to learn from one of these types of classes, IF you can find one that has a good teacher and some good equipment. The current budget situation in the US and South Florida will probably kill this class, or continue to raise the price until it isn't worth it. The current enrollment is now below the minimum class size, so it could be soon.