Sears Silvertone Hi Fi to Guitar Amp Conversion


When we received this Sears Silvertone amplifier, it had no knobs, tubes, input jacks, or power cord. It had started its life as a hi fi amplifier to complement a record player. We looked at the all-tube circuit and saw the potential for a unique, one-of-a-kind guitar amp. 

In the 50s and 60s, Sears advertised to practical suburbanites on a budget. For most products, Sears was the more affordable alternative, but the convenience of their department stores and their mass advertisement efforts made it seem like shopping at Sears was simply a wise pit stop for the upwardly mobile. Sears sent out enormous semi-annual catalogs depicting happy families, perfectly-coiffed housewives, men at leisure, and, of course, thousands and thousands of products for sale.

Consider the teenage newlyweds in Chuck Berry's "You Never Can Tell," who "furnished off an apartment with a two room Roebuck sale." It's evidence of their limited income, but also of their practicality. Either way, it hardly cramps their style: 

They had a hi-fi phono / Boy did they let it blast / Seven hundred little records, / All rock, rhythm and jazz

Sears products prioritized function over form, which is evident in the design of this amp. Utilitarian in shape, with a boxy silhouette and minimalist front panel, this is an amplifier that wouldn't draw too much attention in the average midcentury living room. Although we'd currently consider it a statement piece, think about how it would have fit in the year it debuted. Remember, we're talking about the golden age of Formica. On-trend colors included bright yellow, avocado green and electric blue. High-pile carpets, wood paneling, and patterned wallpaper abounded. Although amp is a knockout today, it was definitely a wallflower in its youth. 

So, it was a pleasure to put this amp on its own upward trajectory by converting it from a staid budget hi fi accessory into a powerful tone machine. We tweaked the circuit to better suit a guitar signal. We also added a three-prong cord and an input jack (the original input was not only hardwired, but severed when we received it). Because the original 6X5 tube is notorious for blowing transformers, we popped in a Weber copper cap WX5. This is a solid-state replacement designed to simulate the forward conduction resistance curve of the tube it supplants. It sounds fantastic, but does slightly diminish the volume in comparison to an actual 6X5 tube. Despite this, the amp is excellent for recording and intimate performance settings. Because the Weber copper cap is a drop-in, non-destructive solution, you can always swap it for a 6X5 tube - but we really recommend sticking with the Weber. 

Further Reading

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