This 1979 Guyatone EX1 amp is very rarely seen outside of Japan. It was most likely built and sold for the domestic market only. I found this one in a used music store in Portland, Oregon and suspect maybe a U.S. service man or woman brought this amp over from Japan.
The EX1 is an analog, single channel, solid-state amp with 20 watts of power, a 12-inch speaker, overdrive and reverb. Gain and volume controls, high and low EQ, reverb depth. Normal and overdrive inputs, headphone jack, pilot light.
I had this one serviced by Audio Synapse in Portland, and had a new reverb tank installed, as the original was ineffective.
This amp is bright sounding to begin with, and the 12-inch speaker by Tokyo Sound Co. only makes it brighter. I replaced the original with a Peavey Neo and that added a lot of lower end.
Update: Just added some new shots of the chassis, tubes, board, Orange Drop caps, Fisher speaker, etc.
The Original 40XL
This page is dedicated to photos of our ’69 Silvertone 1422, also known as the Sears 40XL. We recently acquired this amp and found it to be one of the nicest 40XL’s we’ve seen in many a year. This Made-in-USA amp is totally original, right down to it’s late 60’s dark olive vinyl, green sparkle grille cloth, and a 12-inch Alnico magnet made by Fisher. The only cosmetic damage we could find is a bump (dimple) on the cabinet edge, right side of the control panel, and a chip off one control knob.
The 1422, or 40XL, was marketed by Sears as a 40-watt, 12-inch, combo tube amp for guitar. It features two separate input channels, and built-in reverb and tremolo. The reverb and trem are controlled by a dedicated foot switch. Sears advertised these as 40-watt combo amps. But in reality, the two 7189 power tubes put out around 20-watts or less. In fact, the features and chassis layout suggest that it could be an American copy of a the mid-60’s Marshall Model 1974, which was an 18-watt combo using two 6BQ5’s (EL84’s).
Summer of ’69
This amp was built, sold, and first played in the Summer of ’69. The code on the CTS potentiometers read “137-6919.” Decoded, that means “137” = Mfr’d. by CTS; “69” = Year Mfr’d. (1969). “19” = Week Mfr’d. (2nd Week of May).
How Does It Sound?
Well, it’s a loud 18 to 22 watts, that’s for sure. HUGE in the mid range, solid in the bass range, but not too sparkly or chimey at the high end. Poor speaker sounds like it’s wearing a heavy wool sweater. And there is a noticeable 60-Hz hum. But we will dig into it and find out what’s wrong.
Major improvements! We took the chassis out of the cabinet, cleaned and tightened all the loose connections, and relocated one unshielded cable sitting too close to the transformer (will completely remove that later). Now, the amp is almost silent when idling, the 60-Hz hum is completely gone, and frequency response at the high and low ends have improved!
These photos are little rough, and I hope to upload some better ones in the near future.
From the tail end of the vacuum tube era, a real Tone Gem in the genre of garage band tone.
Editor’s Note: This is Part One of a two part series on modifying the Silvertone 1421 guitar amp. This article is a work in progress, so please check back for additional info and updates.
The 1960’s Silvertone 1421 Combo Tube Amp (also originally sold as the Sears 10XL) is a great little vintage tube amp. It’s compact size makes it easy to carry to practice or a to small venue. It’s low 10-watt tube output (actually, closer to 5-watt) is perfect for the recording studio. It has two instrument inputs going into one channel, volume and tone controls, and a fantastic 12AX7 tube tremolo circuit, playing out to an 8-inch speaker. The sound here is definitely in the garage band category, but you can coax some great sounds out of this little guy.
The all-tube version of this amp was made from 1968 to 1972, and was later replaced with a all-transistor (solid-state) version in 1973. I picked this one up off eBay a few years ago. It’s a 1970 model and is all original, except for the brown speaker grille fabric (which is ugly!).
Below is a photo of my Silvertone 1421 after it first arrived. The vinyl covering, the controls, the faceplate were all in excellent condition for its age; no tears or scratches. The original vinyl handle was flexible and intact. The only problem this amp had was a stuck (frozen) power switch. I replaced the bad switch with a new heavy-duty toggle, and replaced the old two-prong power cord with a new grounded cord. When I powered it up for the first time it was amazingly quiet for an old tube amp.
The knobs and faceplate were in great condition. The handle was still flexible and firmly secured to the cabinet. But the original toggle switch stuck (frozen).
Front view showing the replaced grille cloth over the original baffle board and speaker.
Rear view of cabinet. You can see the new grounded power cord that I added.
The Sears product label on the rear panel showing the model number and vacuum tube layout.
A view of the chassis through the back panel vent.
Photo of the cabinet interior, showing the chassis and the original 8-inch speaker made by CTS.
A closer view of the chassis.
The 8-inch speaker with ceramic magnet made by CTS (code 137).
Another view of the chassis, showing the power transformer, the filter capacitor can, the output transformer, and the tubes. The on-baord tube complement is one 6X4 Rectifier tube, two 12AX7 tubes for preamp and tremolo circuits, and 7189 power tube.
Here is the baffle board removed from the cabinet. The board was nothing more than 1/8″ thick Masonite.
Here is the cabinet with the baffle board removed.
This great little combo tube amp was built by (who?) and sold through Sears and Roebuck in the late 1960′s and early 70′s. It was originally sold as the Silvertone Model #1421, and in later years as the SR 10XL, and lastly as the Sears 10XL. Oh, the photo of this amp looks innocent enough, but, this is one serious sounding tube screamer. And you won’t usually find them as nice as this one!
Summary: A 10-watt tube combo with tremolo and 8-inch speaker. Hand-wired. Lots of midrange growl that transitions into a creamy overdrive. Great for classic and indie rock, jazz, blues, country and rockabilly. Use as a practice amp or at small venues. Perfect for recording.
Pluses (+): Vintage British, Vox-like, valve sound in an affordable practice amp. Compact and lightweight.
Minuses ( – ): Cheaply constructed lightweight cabinet and thin vinyl covering. The original grille cloth was fragile, and most are completely deteriorated by now. Loud enough for a small venue (i.e. coffee shop) but not for anything larger.
Surprises: 1) The 7189 output tube! This is the higher plate voltage version of the EL84 tube made famous in British amps of the 60′s; and 2) The 8-inch Oxford Alnico speaker sounds great!
Value ($): Depends on the condition and market demand. I have seen them run from $100 to as high as $500.
Similar Amps: The original 1960′s Vox AC4 practice amp. Nothing else in the Silvertone line is similar.
The Complete Silvertone 1421 Review
(Stay tuned… this section under construction)
The 1421 Photo Gallery
This amp is in fantastic condition for it’s age. It even came with the factory original vinyl dust cover. It is all original, except that I replaced a broken power switch, and then replaced the old 2-prong power cord with a safer grounded cord. The tubes, chassis, speaker, cabinet and finish are all in perfect condition — sans for the cigarette-sized hole burned into the original grille cloth (not by me, it came that way!).
The Sears 10 XL was sold through Sears and Roebuck in the late 1960’s and early 70’s. The 10 XL is a single channel, 10-watt (peak) combo amp for electric guitar with a very cool built-in tube-powered tremolo effect.
This little amp first appeared in the 1969 Sears Catalog as a 10-watt tube-powered amp and, transformed into to a solid-state amp around 1972, and then discontinued in 1973. The label on the rear panel identified this model as Silvertone 257.1421100.
The photo of this little amp looks innocent enough. But don’t let the its appearance fool you! This is a serious sleeper of a tube amp, and sounds fantastic. Perfect for your next garage band. And you won’t usually find them as nice as this one!
Summary: A 10-watt tube combo with tremolo and 8-inch speaker. Hand-wired. A classic garage amp! Starts out loud and stays there. Comfortable at full volume playing in a garage, but will blow you out of your bedroom. Lots of midrange and natural tube overdrive. Highly responsive and touch sensitive to player’s technique; so a talented strummer can get a wide variety of tones and sounds. This amp lives mostly on the treble end of midrange, but depending on the speaker can growl and howl on the low-E notes. Great for classic and indie rock, jazz, blues, country and rockabilly. Use as a practice amp or at small venues. Perfect for recording.
Pluses (+): Vintage 1960’s tube sound in an affordable practice amp package. Compact and lightweight. Tube powered tremolo that is other-worldly!
Minuses ( – ): Typical department store construction; lightweight cabinet and vinyl covering (it’s a Sears amp!). The original fabric grille cloth was fragile, and therefore most are completely deteriorated by now. Not really loud enough for a big venue, but still perfect for those small and intimate gigs (i.e. coffee shop).
Surprises ( ! ): 1) The 7189 output tube! This is the higher plate voltage version of the EL84 tube found in British valve amps of the 60’s; and 2) The 8-inch Oxford Alnico speaker sounds great!
Value ($): Depends on the condition and market demand. I have seen them run from $150 (beat up and not working) to as high as $500 (too much!).
Similar Amps: Unique, nothing else in the Silvertone line is similar. Preamp tube (12AX7) and power tube (7189 version of EL84) used in the 1960’s Vox AC4.
The Sears XL Story (as best I know it)
The Sears 10 XL was a member of the Sears XL Series of amplifiers that first appeaed in the late 1960’s and ran through the mid-1970’s. The XL Series followed the venerable Silvertone 1400 Series (1472, 1482, 1483, 1484, 1485) from the early to mid 1960’s. The XL Series ranged from the little 5 XL (3-tubes, 3-watts) to the giant 200 XL (200-watts solid-state).
Before the XL Series, the Sears Silvertone 1400 line up of amps was designed and built by the famously efficient and economical Danelectro Company of Neptune, New Jersey. Danelectro was founded by the pioneering electronics engineer and builder Nathan Daniel. Nate Daniel specialized in building quality musical instruments and gear at reasonable prices. Danelectro built and supplied all the guitar amps to Sears and Roebuck from about 1958 to 1968. In 1966 founder Nate Daniel sold his company to MCA, and unfortunately by 1969, MCA had to shut down the operation and thus the original Danelectro Company no longer existed.
From about 1968 to 1972 the smaller amps in the Sears XL Series (the 5 XL, 10 XL, 40 XL) continued to be hand-wired tube amps. But by 1973 the entire XL line – except for the little 5 XL – had transitioned to all solid-state electronics. Exactly who built these XL amps for Sears remains a uncertain. We have speculated that the 5, 10 and 40 XL’s were still built in New Jersey with left-over parts from the defunct Daneletro.
The chassis of the 10 XL is all hand-wired point-to-point electronics with a 6X4 tube rectifier, a 12AX7 preamp tube, a 12AX7 tremolo tube circuit and a single 7189 output power tube. The amp has volume and tone controls, Tremolo speed and intensity controls, two 1/4″ guitar input jacks, and one 1/4″ tremolo foot switch input jack.
The loudspeakers that came in the Sears 10 XL varied throughout production. All speakers were 8-inches in size. But the manufacturer and type of speaker varied. This particular model has an 8-inch speaker made by Oxford with an Alnico magnet, which perfectly compliments the lower output level of the 7189 power tube, and sounds great in this amp. Some other 1421 models were made with speakers from the CTS or Fisher factories, and by my account, those all had ceramic magnets instead of Alnico.
The Baffle Board and Grille Cloth
The baffle board is typical Silvertone quality: 1/8″ pressed board (Masonite). That just helps to establish this amp’s personality. The original silver, gold and green sparkle fabric that covers the baffle board is quite delicate, and in most cases rotted away over the years. Thankfully, somehow the original fabric survived on this model.
The 10 XL Photo Gallery
This 10 XL is in fantastic condition for it’s age. It even came with the factory original vinyl dust cover and tremolo foot switch. It is all original, except that I replaced a broken power switch, and then replaced the old 2-prong power cord with a safer grounded cord. The tubes, chassis, speaker, cabinet and finish are all in perfect condition — sans for the cigarette-sized hole in the original grille cloth (not by me, it came that way!).