INTRODUCTION Immediately following WW II, there was very little in the way of truly high fidelity amplification equipment available to audio enthusiasts. But then came D.T.N. Williamson's Landmark design that introduced the Williamson amplifier to the world in the May, 1947 edition of Wireless World. He revisited his creation in a followup article in August of 1949, and by that time, the British design caught the attention of Mr. David Sarser and Melvin Sprinkle, who were so impressed with it that they introduced an Americanized version in their article which appeared in Audio Engineering in November of 1949. Dubbed the "Musician's Amplifier”, it sported a large (for its power level) Peerless OPT, and made a splash in the audio world that is still felt to this day. In 1952, Heathkit, who already had audio amplifier kits on the market, decided to really up their game with their audio products, and introduced the W1-A1 two chassis basic amplifier kit, which was a near exact copy of the Sarser and Sprinkle version of the Williamson amplifier. The OPT that Heath used was notably smaller than that used by Sarser and Sprinkle, but it was still a genuine Peerless unit none the less. Independent of these developments, were David Hafler and Herbert Keroes of Acrosound Transformer fame, who released their original Ultra-Linear OPT in November of the year prior. Powering the screen grids from taps on the OPT primary winding (an idea originally suggested but never exploited by the Brits), it too made an equally big splash as that of Mr. Williamson's design a few years earlier. With both the Williamson amplifier and Ultra-Linear output stage seen as monumentally huge advancements in the audio scene, the idea of marrying the two concepts together was hatched in short order. By June of 1952 the wedding had occurred, with Hafler and Keroes publishing their article on converting the original Williamson amplifier to Ultra-Linear operation. The Williamson amplifier originally employed a triode output stage, but by changing the OPT to the (now) famous Acro TO-300 Ultra-Linear OPT, power output was increased, yet with no deterioration of the Williamson's other fine attributes. Sarser and Sprinkle took note of this development, and immediately started experimenting with using the (originally unused) intermediate primary winding taps provided on the Peerless OPT they specified for their version of the Williamson amplifier to power the screen grids of the output tubes. While the taps were not located exactly where Hafler and Keroes specified for true Ultra-Linear operation, they were close enough to make the experiments worthwhile. The results were conclusive enough that this change, along with some other less significant changes, formed the basis of their followup article the very next month in July of 1952 entitled "Gilding the Lily" -- the lily being the original Musician's Amplifier they had introduced less than three years earlier. It was a period of rapid change in the fledgling early days of high fidelity, where you had better not blink, or you'd miss the next great advancement coming along. Now Heathkit, not wanting to miss out on all of this advancement, immediately sourced a new and larger OPT from that offered in the W1-A1, since that transformer had no intermediate primary winding taps. The new transformer they chose was larger, but still not as large as the original piece specified for the Musician’s Amplifier (Peerless S-265Q). However, as an Altec Lansing 20-20 Peerless model 16277, it had intermediate primary winding taps, and they were located at the same position as those on the S-265Q (50% of the winding). With this new transformer, the use of its primary taps to power the screen grids, and a change to new, tight tolerance 5881 output tubes and 5V4G rectifier tube, the W-2M was born in January of 1953. In the owner's manual for the W-2M, Heath references Sarser's and Sprinkle's Gilding The Lily article, and how the improvements outlined in it with tapped screen grid operation were incorporated into the new W-2M amplifier. It is that amplifier that is the subject of this thread. However gilded as it might have been over Heath's original Williamson offering, the design of the W-2M still leaves a lot of sonic performance on the table versus what it is capable of delivering. This is not meant to slam Heath, nor its efforts with the W-2M. After all, they were simply following the efforts of Sarser and Sprinkle, who themselves were following the efforts of Williamson. Most of the items to be discussed relate to the (soon to become) low and high frequency stability issues of the design, which when unchecked, have a marked influence on the audible presentation of any amplifier. At the time of the W-2M, much was still being learned regarding the performance criteria of a global NFB design, let alone even defining what good stability was. So Heath was hardly alone in this concern. Additionally, in executing the W-2M, Heath strangely (or wisely depending on your point of view) did not follow some of the Gilded Lily's recommendations -- which was certainly their choice, but the lack of any discussion regarding the issues involved leaves its users at a disadvantage. On the other hand, there was an improvement that Heath made of their own accord in the W-2M, that Sarser and Sprinkle likely would have discussed in their Gilded article, had their test procedure not masked the concern addressed. And, there were even two versions of the W-2M as well. But all of this will be discussed in due course. One last point I'll mention in this opening salvo: This re-gilding effort was not born out of any desire to re-engineer a piece of audio history simply because it could be done, or for want of something to do. Neither was this an effort to make it into something it is not. Rather, every effort has been made to preserve what it is, retaining the best of its performance attributes, while making stability improvements to the design that really should be considered as mandatory: Depending on how a loudspeaker load is or is not connected to the W-2M, it is at best a marginally stable design, displaying either sustained LF or HF oscillation under certain conditions, with the ever present possibility of damage to HF driver elements always being high. At the very least, such instabilities will really muddy any LF sonic presentation, and degrade the clarity of HF transient information as well. This is only made worse then by today's highly dynamic sources, that provide significant energy in frequencies close to where these instabilities reside. Therefore, the goal was not to chase better sound for the sake of the chase. However by properly addressing the stability issues of the design -- if only to provide for safer operation of the amplifier and the HF drivers it powers -- better sound will definitely be the result. For now however, a few pics are presented of my W-2M shortly after I received it, and which became the target of this re-gilding effort. Whoa boy! The adventure begins. The person who constructed this unit clearly had little experience building electronic kits, as the picture shows. Besides the creative lead dress, none of the retaining rings for mounting the tube sockets were ever properly snapped into place, so that in an upright position, they could easily fall down around a socket's terminals, shorting them together, to ground, or both. It definitely made it interesting trying to remove any tubes from their sockets. In fact, the resistor providing B+ power to the preamp socket was almost certainly burnt to a crisp due to this issue. It’s a wonder that the transformers weren't fatally damaged with such lack of construction detail. Incredibly however, they were all good, and all of the connections were correct as well — mounting rings not withstanding. At one time then, this model of kit construction may have actually operated -- or not. The history of a kit piece can be interesting to say the least. The pic shows the unit after I had snapped all of the socket retaining rings into their properly seated position, and first started the process of completely rebuilding it (input cap has been removed). Next up, we’ll start getting into the regilding discussion. Next time. Dave Below: Could use just a little tidying up! Below: Check out the interesting matched set of tubes this baby came with. They both tested just fine!