I am posting this minor update (from a hotel room with free internet) to add the pictures from the 2006 Mopar Nationals including an entire page of pictures of the 2008 Dodge Challenger concept car. It was announced that production of this car will commence in April of 2008. I have done some minor reorganization of the site to make room for more pages in the future. Everything is still here, although some pages (and their links) now have their own sub page. I have been working on the assembly manual for the SSE amplifier. My return (and the manual) has been delayed by car trouble. Try to find an oil pan for a Volvo in rural West Virginia.
The break in my work schedule lasted for 7 days (I knew that it was too good to be true). The SSE boards are in and three amps are already up and running. I can build these boards in about 45 minutes each, they go together real easy. I am already working on the construction manual. I have gathered about 500 pounds of transformers which will all be tested and the results posted here (two transformers are already done). I will be out of town for most of August, so there will not be much activity until September.
I finally got a break from my relentless work schedule (it won't last) so I have been updating the web site every night. I have added (or finished) several pages in the Tech Pages and Tested and Proven Circuits sections. These pages were created to explain some of the experiments that began as a thread on the diyAudio forums. Some of the material is directly cut from my contributions to those threads. Some additional material has been added.
The SSE section has been updated, and will continue to be updated as more info becomes available. The PC boards are on order. My amp has been stressed tested in several ways, including me playing guitar through it, and plugging it into a Variac and cranking the input voltage to 135 volts while playing rock music at full volume! It is still going strong.
I have added some text and old pictures to the Tubelab SE assembly manual. I sold every assembled board that I had during the time that I was too busy to build any (the past 4 months). The pictures (text too) for the checkout and bias adjustment pages were lost last year. I have finished assembling a new board, and the new pictures will be shot this weekend. I will add them to the site ASAP.
I have added a few more updates and 2 new pages (in a big hurry, so I am sure I messed something up). The Budget SE output transformers and the 6AV5 testing page. I have updated the Tubelab SE assembly manual, but I won't have it finished for a few more weeks. Many of the final assembly and checkout pages were lost, and the board that I used to shoot all of the pictures was sold a few months ago. I have assembled a new board, and am in the process of shooting new pictures.
Tropical storm Alberto has reminded me that I must fix my roof before we get a serious storm. My roof got minor damage last year from hurricane Wilma. All of the roofing companies are booked selling complete re-roof jobs (15,000 to 45,000 dollars!). I can't get anyone to do my "small repair"( $1000), so I must do it myself.
With the last update I added a page of information about my simple single-ended (SSE) amplifier, The email and forum activity related to that project have been outstanding, so I have began a major expansion of that page. The one page is now 4, and more are coming. Some of these pages are not complete yet. When it is all done you will be able to follow along during the entire design process. Some of the new material being added is a direct result of questions asked on the DIY audio forums.
I have reorganized the site so that I can add new pages without having to re-do all of the links and table of contents on all of the other pages. This meant giving more control to Microsoft (Front Page 2003). The previous organization became impossible to manage. It will no longer be possible to have a link to everything from this home page. The menus (links) on the left bring you to a secondary menu page that has links to the individual pages. The news that formerly occupied this space has been moved to the news page.
Number three was a success! I have added several new pages, with more to come soon. Some of the new pages may have little or no content. That is because I mapped out the design of the web site before I finished the individual pages, and I needed to make sure that all of the hyperlinks work. Content is being added as I have time. I sit in front of a computer for 8 to 10 hours a day at work, when I get home, I would rather play with tubes. All of the old pages are still here (some have been updated) and they are still in the same location, so all old bookmarks and links should still work. Email me if I broke anything. I don't claim to be an expert web designer.
The PowerDrive circuit has become quite popular, and I constantly get requests for unique designs. There is no way that I have the time to design, prototype, and test each one of these. I am finishing up a new page that should help you design your own. (Actually I am doing it over, it got zapped when my hard drive died).
Family matters and other commitments have required me to be out of town for many of the weekends so far this year. I now have a work schedule that allows little time for Tubelab. This will continue for the near future. I have tried to set aside one or two evenings per week to answer e-mail. I am currently running about one to two weeks behind responding to e-mail.
I finally have a free weekend. We are ready for the demo at work, and I have just finished building the new Tubelab SSE (simple single-ended) PC board. It rocks! I have been blasting this thing with everything from Roberta Flack to Metallica. It is hard to believe that I am listening to $18 output transformers. If I don't find anything wrong with this in a few days, I'm sending the board out for duplication.
I have tested the first prototype of the new Tubelab SSE (simple single-ended) amp design. It works quite well but there was not enough gain for every application. I have fixed the gain problem by using a CCS load on the driver stage. Now I can reach clipping in triode mode on a quiet CD at less than full volume. This change requires a new PC board design. Our demo at work has been moved up to May 30. The web site still will not upload.
I am back at home, and the new web site will not upload. I have found out that I must have a prototype design ready to demo on June 15 at work. I finished the PC board layout before going on vacation. Now I have less than 2 months to get them populated (1200 parts on a 3 inch by 7 inch board) and debug the design. Looks like there will be no time for Tubelab.
I have gone as far as I can with the web site, since I don't have all of my files with me to finish the technical pages. I started the PC board layout for a new amplifier design. It is a simple single-ended design that is geared for the novice builder, but has the features and sound quality of a high end amp. I was originally planning to use the 6AV5 sweep tube but I have been informed that it is not available outside the US. The new design uses any of the popular audio pentodes (6L6, EL-34, KT-88) in triode or UL mode.
I took the laptop with me on vacation. I am designing a new version of the Tubelab web site. I attempted to reorganize the web site so that I could manage it better. The original site was made up of several individual pages that were linked together by a menu system that I made by hand and pasted on to each page. This allowed total control, but became unmanageable as the site grew. It was also the source of the broken links. The new site is built using Microsoft Front Page 2003. It will either work better, or not at all, only time will tell.