Silvertone 1428 (Sears 60BXL) Solid-State Bass Amp

60-Watts of Transistor Power! (meh)

The Sears 60BXL (labeled as Silvertone model 1428) was a electric bass amp similar in design and appearance to guitar and bass amps built by Danelectro in the late 1960’s. It appeared in the Sears Catalog from 1971 through 1973. According to the catalog, the 60BXL was a two transistor-powered 60-watt (marketing hype) bass amp with a 15-inch speaker. It seems that very few of these amps were sold, maybe because the more powerful 200BXL met the needs of electric bass players.

Not much is known about these amps; they are rarely seen in the wild. Here is an image from the 1971 Sears Catalog.

Page 928 excerpt from the 1971 Sears Catalog

Here is a posting about this amp in the Talk Bass Forum: NAD – 1971 Sears 60 BXL Combo.

Below are some photos courtesy of Chicago Music Exchange and eBay.


Silvertone 1428 Sears 60BXL Electric Bass Amplifier
Courtesy Chicago Music Exchange
Silvertone 1428 Sears 60BXL Electric Bass Amplifier
Courtesy Chicago Music Exchange
Silvertone 1428 Sears 60BXL Electric Bass Amplifier
Courtesy Chicago Music Exchange
Courtesy eBay


Courtesy eBay


Courtesy eBay


Music Man 110 RD Fifty

Music Man 110 RD Fifty Guitar Amplifier

Analog Solid-State/Tube Guitar Amp from the 1980’s

This page (which is a work in progress) is dedicated to the Music Man 110 RD Fifty guitar amplifier, which I recently had an opportunity to play.

Last weekend I was fortunate to make some new friends, hang out, and play some guitar. I had never met these guys before, but we hit it off right away, and it was a great time had by all. Thank-yous go out to our hosts David B, and his wife Elizabeth, who graciously allowed us to invade their home and make noise until the early hours of the next day. And thanks to the other guys for letting me be part of the group. I had no idea I would be in such good company!

During our Saturday night “jam session” (and I use the term loosely), I had the opportunity to play my ’70 Silvertone Mosrite Copy through David’s vintage Music Man amp. And boy, what a great amp that was! It was a Music Man 110 RD Fifty. Similar to the one pictured above, minus the grill fabric, it was the perfect match for my old solid body Surf Guitar with Teisco single coil pups. I simply plugged my guitar into this amp and it immediately started playing beautiful big clean tones with just enough added bite and grit. I loved the sound of that amp so much that I decided to dedicate this page to Music Man, and specifically to the 110 RD Fifty.

Thank you, David!

BTW: If you don’t know what a Mosrite is, then Google it right now!

Some Background

Music Man LogoBack in the mid 70’s a new music company from Anaheim California, called Music Man, hit the scene. This new company was founded by some former Fender employees: Forrest White, Tom Walker, and most notably Leo Fender. Leo himself designed a new line of amplifiers and a new bass guitar for the company. (BTW: The bass guitar, called The Music Man Stingray, is still around today and sold by the Ernie Ball Company.) Some of you reading this will know more than I about Leo Fender, his second guitar and amp company, his Stingray bass, and the Ernie Ball connection, as I am still learning the facts.

The Music Man amps were designed to be clean and LOUD with lots of headroom! They sounded very “Fenderish” (I wonder why?). According to literature, Music Man amplifiers were a unique hybrid design, employing solid-state electronics for the preamp stage, and tubes for the output. Apparently, the 12AX7 tube in the preamp stage is just for the distortion only, but I’m not exactly sure about that? The amps were big on power and built like tanks, to handle the difficult task of traveling professional musicians. Music Man produced amps in several sizes (65-watt, 135-watt, 150-watt) and configurations (combos, heads, cabs).

Music Man 110 RD Fifty with foot switchThe Fifty Series

The Fifty series was introduced in the early 1980’s. The Fifty series included heads and cabs, as well as small combos that had either 10-inch or 12-inch speakers. These amps were packaged different ways. Some had a built-in distortion effect; others had a phaser; but all had real spring reverbs.

Music Man 110 RD Fifty speaker and chassisThe 110 Combo with Reverb and Distortion (RD)

The 110 RD is a compact (but heavy!) 50-watt single-channel combo, with a 10-inch Ceramic speaker, reverb and distortion effects. I read that the designers of the amp were aiming for a clean tone similar to a Fender Blackface Deluxe Reverb, and apparently they hit the target!

Specs for the Music Man 110 RD Fifty

Mfr: Music Man, Anaheim California
Series: Fifty
Model #: 110-RD-50
Chassis: 1650RD
Power: 50-watts RMS
Speaker: 1×10-inch, Ceramic Magnet
Tubes: Preamp: 12AX7; Output: 2x6L6GC’s
Effects: 3-spring Reverb; Distortion
Accessories: 2-Button Foot Switch
Years: 1981-1983

Schematics for Music Man RD Fifty

Version A

Music Man Chassis RD50, Rev. A (Courtesy of Schematic Heaven)

Version B

Music Man Chassis RD50, Rev. B (Courtesy of Schematic Heaven)

Music Man Hall of ShameA Bit More Character

Now the one I played had a woven wire mesh front grill, so it looked more like this one. But that just added to its character.

More Links

As I work to gather more info about the company and their products, here are some links:

More later (to be continued…)

Music Man 110 RD Fifty Guitar Amplifier



Previous Comments

{ 10 comments… read them below or add one }

Bob September 1, 2014 at 4:23 pm

Hi, Alex
I have a Peavey Musicman model No. 112-RD-50, similar to or exactly the same as the one featured in your article. I remember purchasing mine from American Music, located in Seattle, WA, sometime during the mid to late 70s. So although it’s the spitting image of the one in the article, I did purchase it some years before 1980.

I’m considering selling it and was wondering if you had any idea what it might go for on today’s market?



alex September 1, 2014 at 7:49 pm

Thanks for reading our article. You say “Peavey Musicman” but I believe you are referring to just the original Music Man, not Peavey? I have seen the Music Man 112-RD-50’s selling on eBay from about $550 to $700, depending on condition.


Eddie September 11, 2014 at 6:19 pm

Hey Alex, yup yup yup about your exp with the Music Man 110 RD-50! I know what u spk of, I own two in excellent orig cond & they’re stayin’ with me lol! These 110’s are superb & fly way under the radar of guitar plyrs but I don’t understand why. In big cities like NYC where musicians subway to gigs these little giants are revered. I’m going to try a Celestion G10 vintage in one of them, just for fun.
Keep playin’, Eddie, Toronto, Canada.


alex October 4, 2014 at 9:24 am

Eddie, thanks for checkin in, and telling us about your Music Man. Let us know how the Celestion G10 sounds!



Eddie February 3, 2016 at 7:14 pm

Well, I finally got around to installing the Celestion G10 Vintage speaker (8ohm, 60w) in one of my MM 110 RD 50 amps (have two), only took +1 year lol. Fantastic improvement on ALL sonic levels! Highly recommend this upgrade, do this. Don’t know what took me so long, just stuff i guess.
Super ez too, the speaker & grill removed forward as 1 unit and Celestion screw-holes lined up perfectly. I’ll hang on to stock spkr to keep amp’s originality.
Curious, anybody tried out other spkrs??
Rock on MM brothers! (are we able to upload photos here?)


alex February 4, 2016 at 8:57 pm

Thanks for the update! Sounds like the Celestion G10 was a great choice! And makes sense too, since a lot of the guitar speakers we have available today sound soooo much better than speakers they had in the 70s and 80s. Actually, I believe mfrs back in the 70s and 80s were just making bad choices on the speakers for their amps.

You could try emailing me your photos, I would love to post them here on the site.



Jim October 5, 2015 at 10:50 am

I’m not sure when they started making the 50 watt version but mine is a 1981. I have owned at least 75 amps. This one is a definite keeper.


alex October 6, 2015 at 7:20 am

Hi JIm!
Thanks for that info. Glad to hear that you still have yours! I have revised this page, by changing the dates to 1981-1983, which probably fits the Music Man timeline better.



bruce November 29, 2015 at 10:30 am

the date built is on a white sticker under the top back panel on the right
year/month like 83/3
i fell so deep in love with the amp i put an ad in VG mag and acquired 10
some heads/10’s/and 112’s
the last editions show a more wedge shaped cabinet ..wider at the bottom ,
harder to tip over …. first ones….no wedge shape at all
revision e models have a mid shift rocker instead of the clean/distortion rocker in the
center of the panel i have a 112 and a head both with this set up and they both have black grills the head was originally a half stack with a closed back 1 15 bottom
i also had a white rev e half stack
it also came with a closed back 1 15 bottom
in both cases i sold the bottoms and used all sorts of other cabs with these heads

these amps are fixes bias no need to worry just change the power tubes as needed

sovtex 12ax7 lps is a secret weapon for the amp enhancing smooth creamy sustain
the 2 110 models i acquired were equipped with JBL and EV speakers
a cool pair of amps for sure
the EV magnet was cut along the top to fit under the chassis no way a home made fit .. it must have been built for the amp at ev

leo took a 110 to g&l with him and it was in his office there to test guitars

GOD bless leo and the rd 50


alex November 29, 2015 at 11:05 am

Thank you for all that valuable information! Great to hear from people who were there, playing their gear! (I was in college, broke, and still hadn’t begun playing seriously) Your contribution will make this page on the 110 even better! Since I wrote this article, I have passed on several, but still intend to get one in 2016!



Kay Vanguard 704 with Vibrato

Kay 704 Vanguard Vibrato

“A Briefcase Full of Blues” – The World’s First All Solid-State Guitar Amp

Quick Info

Summary: 1965 5-watt solid-state combo amp with built-in vibrato effect; 8-inch Alnico speaker; seven Germanium transistors and five Germanium diodes. Point-to-point hand soldered. Perfect little amp for practice or recording.

Pros: Vintage 60′s tone. Extremely compact and portable design. Vintage Germanium transistors and diodes. Simple chassis layout.

Cons: Cheap, lightweight construction and paper-thin fabric covering (but hey, it’s lasted this long already).

Surprises: This old school amp designed more like a tube amp than a solid-state amp. The 8-inch Oxford Alnico speaker sounds great! Awesome vintage vibrato circuit.

Value: Street prices vary by condition and demand, but the price of these continues to rise.

Similar Amps: Kay 700, 705 and 706 of similar vintage. It’s possible, but not certain, that there may be some similar Kay-built amps with a Truetone (Western Auto) label.

Introducing the Kay Vanguard Series

In 1962, the Kay Musical Instrument Company of Chicago introduced the Vanguard line of guitars and amps. That new line included the Kay Vanguard Amplifier with Vibrato, Model 704 (Model No. K-704). The Vanguard 704, along with other Vanguard amp models 700, 705 and 706, were the world’s first mass-produced all-transistor (solid-state) guitar amplifiers. While some transitional hybrid amplifier circuits had previously existed, which paired solid-state electronics with traditional vacuum tubes, Kay was the first company to offer a full line of exclusively solid-state amps to market in ’62. The Vanguard 704 was part of that line and was frequently seen offered with the Kay Vanguard solid-body electric guitar.

A marketing advertisement from 1965 says that the K-704 was built with seven transistors and five diodes.

A Compact Design

In contrast to the heavy, boxy, amplifiers of the 1950′s, the engineers at Kay set out to create a new series of amps styled for the Modern Space Age. The new Vanguard Series was designed to be compact, lightweight, sleek in appearance. Finished in a rad two-tone pattern, the tapered vertical design had a top mounted control panel, and a cabinet barely deep enough to house the speaker and chassis. The new look was unique for a guitar amp of the day and remains unique today. However, the lightweight cabinet materials made it more prone to excessive wear and tear. Therefore, not many of these amps have survived.

The Controls

The Vanguard 704 features three instrument inputs into a single channel; a volume control and a tone control. The power switch is built into the tone control knob. The vibrato controls include speed, strength, and a jack for a foot switch. A sturdy brass handle is ready to go places.

Old Germanium, New technology, Old Circuit Design

What really makes the Vanguard 704 interesting today is its 1960′s Class A amplifier design and chassis layout. Since solid state technology was still relatively new at the time, the Kay engineers built the preamp, vibrato and the output circuits similar to the old tube circuits, except using Germanium transistors and diodes substituted for vacuum tubes. Because of this design the K-704 sounds akin to its tube cousins of the day. Based on traditional tube amp design of that period, the vacuum tubes were replaced in the hand-wired circuits with seven Germanium transistors and four diodes. The old Germanium transistors sound a little “looser” than the newer Silicon versions, which make them perfect for these low wattage amps. However, Germanium never could handle the heat and raw power of higher watt amps. But Germanium still has a following and is used in low voltage applications, like custom built effects pedals.

According to the pots, it’s a 1965 model. Completely original. A 5-watt wonder. It’s circuits and layout are traditional for the period, but seven germanium transistors and four diodes in place of the traditional vacuum tubes. A single front-loaded 8″ Oxford Alnico speaker. Not a whole lot of lower mid-range. But then again, no low end speaker flab either. The tone kinda reminds me of Led Zep. Mild overdrive at full volume from my Gretsch 5120 humbuckers. Growling, howling overdrive from my Silvertone 1445 with Teisco single coils.

Vibrato, CCR, and The Midnight Special

The vintage Germanium powered vibrato circuit stirs up a deep swirly tremolo that simply sounds awesome. The Kay Vanguard with Vibrato is perfect for nailing that stirring, swelling, sound that Creedence Clearwater Revival played on songs like The Midnight Special and Run Through the Jungle, and other great CCR recordings.

If you are a fan of that vintage 60′s and 70′s tremolo, then this effect alone was worth the price of this unit.


  • Compact, ready-to-go “suitcase” design.
  • Two-tone fabric over wood construction.
  • Five watts output.
  • 7 Germanium transistors.
  • 4 Germanium diodes.
  • 8-inch Oxford “Heavy Duty” Speaker with Alnico magnet.
  • One channel.
  • Three inputs.
  • Vibrato speed and depth controls; foot switch.
  • Volume and tone controls.

Specifications – Kay 704

Model Number 704A
Serial Number 9366
Manufacture Date 1965
Type 8″ Combo Amp
Output (Peak or RMS) 5 Watts, Peak
Pre-Amp Transistors 2N2613, 2N408 and 2N591 Ge PNP BJT, RCA USA
Vibrato Transistors 2 ea. 2N408 Ge PNP BJT, RCA USA
Power Transistors 2 ea. 2N545 Ge PNP BJT, Motorola USA
Speaker Configuration 1 x 8″ Rear Loaded
Speaker Oxford 8ES-9 Alnico Magnet
Speaker Code 465-510 (10th month of 1965)
Baffle Board 1/4″ Plywood
Impedance 8 Ohm
On-Board Effects Solid-State Vibrato
Footswitch Yes
Controls Volume & Tone
Inputs 3 Instrument Inputs
Channels 1
Cabinet Construction 3/8″ Plywood
Cabinet Covering/Color Fabric
Dimensions (WxHxD) 14″x17″x6″
Weight 8 lbs.
Power 120V AC

Schematic Diagram and Parts List for the Kay 704A

Original factory schematic diagram as photographed from inside the 704 chassis.

Original factory Bill of Materials (or, “parts list”) as photographed from inside the 704 chassis. Notice that transistors Q1, Q2, Q3 and Q4 are all Germanium transistors made in the USA by RCA and Motorola, as well as diode D1.

Additional Resources

Links to additional information.

Photos: See more photos here.


weldon January 1, 2014 at 12:04 am

i had a 704 kay amp and kent guitar in the 60s they were new—–i had to pawn them to move away–i found a kent guitar and now looking for the amp-can you help thanks weldon bent


alex January 1, 2014 at 9:13 am

Thanks for stopping by the website. 704 amps are hard to come by these days. Not many survived the 1960′s. Ebay is probably your best bet, as I see a few show up there each year. Craigslist another option. Good luck!


big gee February 1, 2015 at 1:56 pm

I have one of these 704 Kay in great condition for sale make an offer


Tom J April 7, 2015 at 4:28 pm

I have a Heater II reverb amp type 58 with the tag that says “Manufactured by beautiful girls in Milton, Wis.
under controlled atmosphere conditions”.
Can you help me get a schematic ?


alex July 26, 2015 at 9:58 pm

Hi Tom.
That reverb unit was made by OC Electronics and was used in many amplifiers sold by Sears, Wards, etc. in the late 60′s early 70′s. I don’t know if a schematic is available, but you might try Schematic Heaven.


Kalamazoo Model 1 Solid State Guitar Amp

Kalamazoo Model 1 Solid-State Guitar Amp

A great little clean tone amp with real vintage vibe. Why practice on a modern digital piece of (insert your favorite phrase here) when you can play a pure analog classic on the cheap!

Here’s a great little solid-state analog-powered practice amp for electric guitars. Around 5 to 10 watts of power into a vintage 10″ American speaker with Alnico magnet. These little Kalamazoo amps were produced in Kalamazoo, Michigan (of course!) in the 1970’s next to their larger Gibson siblings, and were very well built compared to other inexpensive amps of that era. All real plywood construction and baffle board; no pressed fiber board. This one gets plenty loud for practice, or small gigs. Like most solid-state amps of that era, it produces a clean tone all the way to up full volume. You will need to add a good pedal to get that tube-like distortion, like a BOSS DS-1, a Tube Screamer, or my personal analog preference a vintage DOD Overdrive.



  • Built in 1971.
  • Somewhere between 5 and 10 solid-state watts.
  • One channel.
  • Two instrument inputs.
  • Volume, tone/on-off switch, red pilot light.
  • Black vinyl “tolex” covering.
  • Nice, vintage 10″ Alnico speaker.
  • No tremolo or reverb on this model.


  • Vintage, pure analog, solid-state guitar amplifier.
  • Made in Kalamazoo, Michigan – the home of Gibson at that time – where they took the art of building great guitars and amplifiers seriously.
  • Classic, made in USA, Alnico magnet speaker. Kalamazoo speakers always sounded great!
  • Not your modern mass-produced digital garbage manufactured off-shore by ???.


  • I have gone thoroughly through this amp and played it for hours.
  • All wiring, components are original and in good condition.
  • Everything functions as it should, and this amp is very quiet when idling.
  • It still has the 2-prong power cord, but works just fine.
  • No major cosmetic damage.
  • Some slight separations of the tolex vinyl at some corners, but have to be up close to notice.
  • Some light surface scratches on the control panel, again, can only be seen up close.
  • There’s just a bit of looseness in the speaker fabric.


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A Briefcase Full of Blues

Kay 704A Guitar Amp with Tremolo

1965 Kay 704 Vanguard Vibrato

Find the full review here: Kay 704 Review

The Kay 704 Vanguard with Vibrato was the world’s first all transistor solid-state guitar amp, introduced by Kay Musical Instruments in 1962. Based on traditional tube amp design of that period, the vacuum tubes were replaced in the hand-wired circuits with seven germanium transistors and four diodes.

I bought this from a guy on eBay. According to the date codes found on the potentiometers, it’s a 1965 model. Completely original. A 5-watt wonder. A single front-loaded 8″ Oxford Alnico speaker. Not a whole lot of lower mid-range. But then again, no low end speaker flab either. The tone of this amp makes me think of Led Zep. Mild overdrive at full volume from my Gretsch 5120humbuckers. Fantastic OD howl from my Silvertone 1445 with its Teisco single coil pickups. The solid-state vibrato circuit is simply amazing! The vibrato effect alone was worth the price.

See more photos of the Kay 704 Vanguard Vibrato here.


tomas March 29, 2011 at 4:37 pm

glad you are enjoying it!

nice site, added it to my RSS reader….


alex March 30, 2011 at 8:07 am

tomas, thanks for visiting the site! ~alex

glassdog March 2, 2012 at 4:27 pm

I have the same vanguard amp was wondering Its worth having someone look at it. It has some issues with the sound. It mostly crackles It was given to me by a relative. thanks


alex March 2, 2012 at 4:59 pm

@glassdog, thanks for visiting the site. Personally, I like these amps a lot, and they are getting much harder to find. I do my own repairs to save $. I would definitely recommend having someone look at it to at least estimate the damage and repair cost. But I wouldn’t recommend spending very much to repair it. $75 to $100, max, and that’s pushing it. Unless yours is in pristine physical condition – and most are not! Good luck! ~alex



First Solid-State Guitar Amplifier

Kay Vanguard 704 Vibrato
Courtesy Mass Street Music

Lucky me! I was looking for a vintage solid-state combo amp to use at practice, and to give my trusty tube Silvertones a rest. Just scored this one off ebay today for cheap! The very first solid-state guitar amp was introduced by Kay Musical Instruments in 1962. Can’t wait for it to arrive.


Roger McGuinn and the Regency TR-1

Long before iPods, CD’s and Walkmans there was the transistor radio.

The advent of the transistor radio is integral to the history of rock and roll. The first transistor radio, the American-made Regency TR-1, arrived on the scene in 1954 about one year before the Sony transistor. In this video Roger McGuinn, founding member of The Byrds, tells how he received his first transistor radio and how it inspired him to become a musician. The rest of course is history, as The Byrds became one of the biggest groups of the 60′s and transformed rock music with their own style called folk-rock.

More info:

Regency TR-1 Transistor Radio History

Roger McGuinn’s Home Page

Roger McGuinn’s Transistor Radio Collection

Roger’s Transistor Radio Collection