Brand New 1967 Teisco EP-7, Checkmate Amp

Drop dead, new old stock guitar, amp and accessories.

A guitar time capsule discovery. While out trolling the flea marts, pawn and antique shops today, Jon and I ran into this absolutely beautiful 1967 Tesico EP-7. It came with its original matching Checkmate 12 amp, guitar strap and cables. It was entire ’67 Teisco electric guitar starter package, minus the original gig bag (but the seller might have had that hanging around, too). Even though the set was 45 years old, the guitar and amp were as new as the day they came out of the Teisco factory. Someone must have received the set back in ’67 and then locked it on a closet. The nitrocellulose finish was perfectly glossy, the chrome was gleaming, and the rosewood fingerboard and brass frets appeared to never have been played before today. We did hear some hum coming from the solid-state Checkmate 12, but that may have been caused by the super-cheap unshielded guitar cable we were using. The EP-7 sounded just “OK” through it’s little solid-state amp. But when we plugged it into a ’47 Harmony tube amp, those two single coil pickups really began to shine. We were impressed by this little guy. It was the find of the day, and maybe the year.

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.

Features

  • 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

KAY 704 – VANGUARD with VIBRATO
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.

Comments

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

REPLY

alex January 1, 2014 at 9:13 am

Weldon,
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!
~alex

REPLY

big gee February 1, 2015 at 1:56 pm

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

REPLY

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 ?

REPLY

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.

REPLY

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.

VIDEO:

SPECS:

  • 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.

COOL FACTORS:

  • 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 ???.

CONDITION:

  • 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.

PHOTOS:

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Univox UB-250 Bass Amp Video


The UB-250 is a late 60′s solid-state piggy-back (aka mini-stack) bass amp built by Univox in Westbury, New York. These were continuously made through the mid-1970′s, but this is the original design and build from 1969. Although it’s not the loudest of bass amps, it is a vintage cool analog alternative for any beginning bass student.

Sorry for the poor video and audio quality. We really need to work on improving our videos!

1960′s Silvertone 1481 Amp New in Box?!


Holy crap! What an incredible find. Someone is selling on eBay a mid-1960′s Silvertone 1481 tube amp, brand new in the original box. That’s crazy! Original Silvertone tubes inside. Complete with original papers and Owner’s Manual. Even has the original shipping label on the box from the Danelectro factory in Neptune NJ to Sears Roebuck store in Newington Connecticut.

The 1481 was the smallest combo tube amp of the Silvertone family at that time. It was the poor man’s version of the Fender Champ, with one 6V6 tube putting out 7-watts to a single 8-inch Alnico speaker. According to Silvertoneworld.com, the 1481 was a cosmetic replacement to the earlier 1471 and was offered in the Sears catalog up through 1968. It was made in Neptune, New Jersey by Danelectro.

Link to eBay auction: 1960′S SILVERTONE AMP MODEL 1481 NEW IN BOX DAN ELECTRO

Original shipping label from Neptune, New Jersey:

 

UPDATE: This auction has ended. The amp sold for $610.

Gretsch 6170 Pro Bass Amp

Now on eBay

I don’t know the seller or endorse the product, but here is a cool late 60′s bass amp built by Valco for Gretsch. Solid-state rectifier, 12AX7 preamp tubes (I believe?), 6L6 output tubes and a Jensen 15-inch speaker. I have not heard these amps myself, but the seller claims they are similar to the Supro Thunderbolt, which was used by Jimmy Page and Brian Setzer.

Check it out here. Search for more here.

UPDATE: This amp sold for $400.

Silvertone 1420 (Sears 5XL)

Vintage Sears 5XL Silvertone 1420 Guitar Tube Amp


Welcome to our first review. Please consider Tone Gems a resource for vintage guitars, amps and gear of non-repute. We will strive to make each review rich with information and content, including inside gut shots, electrical schematics, audio, video, manufacturer specs and more. Since this is our very first review, please excuse any rough spots. We welcome your comments and feedback. Thanks ~alex.

Quick Info

Summary:  Five watts of hand-wired boutique tube heaven for a fraction of the cost. Lots of midrange growl and creamy overdrive. Great for  jazz, blues, classic and indie rock. Use as a practice amp or at small venues. Perfect for recording.

Likes:  Cheap! Lots of tube overdrive. Awesome speaker. Cheap! Point-to-point hand soldered. Cheap!

Dislikes:  Cheap cabinet materials and shoddy construction. Not loud enough. No safety fuse. Non-grounded power cord.

Surprises:  8-inch Alnico Speaker. Polypropylene caps (Orange Drops!).

Price:  $90.00 from Trade Up Music, Portland Oregon.

Similar Amps:  Silvertone 1420; Silvertone 1459.

The 5XL Review

At first glance the Sears 5XL guitar amp would be easy to disrespect, even considering it’s legacy in the line of original Danelectro/Silvertone guitars and amplifiers. And why not, it’s a Sears, right? Well, that’s where you’d be wrong. We recently discovered this 5XL at Trade Up Music, a local music shop in Portland (see posting: How It All Began…). It was dirty, dusty inside, and a little beat-up. It appeared to be all original, except for two replaced vacuum tubes, and was fully functional. Later, we discovered that someone must have upgraded the capacitors with new Orange drops (more on that later).

My son Jon, who likes to play alternative and indie stuff, thought this amp would be a perfect match for his 1950′s Gretsch Electromatic or his newer custom modified Telecaster. I was not initially impressed. But boy was I wrong, and he was right!

The 5XL is an all-tube amplifier producing a modest 5-watts of peak power through a single 8-inch speaker. It has one channel, two instrument inputs, and separate volume and tone controls. The cabinet is built from cheap pressed board and the speaker baffle is 1/8-inch thick Masonite. It is clad in an equally cheap, thin green vinyl that stretches and tears easily.

At lower volume this amp has a clear, clean sound and decent frequency response. But with only three tubes pushing 5-watts it’s more fun to dial this puppy to 10! At that level it’s easy for the player to control the output and vary the tone from clean to full distortion.

This amp is also friendly to effects pedals. It sounds really good with a decent analog delay or analog reverb pedal.

Video of the 5XL

How good does it sound? See and hear for yourself. Here is Jon playing his modified Squier thinline Tele through the 5XL. Hope you have a good set of speakers connected to your computer.

Who built the 5XL?

The tube version of the 5XL was sold by Sears in the United States from about 1969 through about 1972. It was Sears entry level into their line of guitar amps. But the original manufacturer of the Sears 5XL is hard to nail down. I have seen several different builds of the Sears 5XL amp on eBay and elsewhere on the web. Up until 1968 or so, the Silvertone line of electric guitar amps were built for Sears by the Danelectro company of Neptune, New Jersey. In fact, the 5XL is identical in electronics and appearance to the earlier Silvertone 1420 and 1459 amps that were built by Danelectro. But Danelectro was purchased by MCA in 1967 and was, unfortunately, out of business by 1969. This particular sample appears to have been built in December of 1968, so it’s possible that it could be a Danelectro original. But I suspect that even later models were built for Sears by others, maybe using leftover Danelectro parts?

UPDATE: I recently noticed that the schematic diagram for the Harmony H303A is nearly identical to the Silvertone 1420 and Sears 5XL. So it might be possible that these were built for Sears by Harmony. However, I thought Harmony was struggling to stay open around this time as well?

UPDATE 2: This basic amplifier design was used throughout the radio and musical instrument industries for decades. Which makes it even harder to pin point the factory of origin.

The 5XL Chassis

The amplifier is a hand-wired, point-to-point, single-ended Class A amp. The chassis layout and construction is standard to Danelectro/Silvertone design dating back to 1950’s. It is very similar to the Silvertone 1430 chassis, except that it has a separate tone control and a voltage isolation transformer which the 1430 lacks. Apart from some replaced tubes, this chassis has all its original parts including the big paper-oil-wax filter capacitor. Amazingly, this amp is still quiet while running. The three vacuum tubes (thermionic valves) used here are: one 12AU6 for pre-amp, 5OC5 output, and a 35W4 tube rectifier. Curiously, we believe someone replaced all the original capacitors with newer polypropylene film capacitors (Orange Drops!) which may have something to with the usually smooth tone of this sample.

A close up view of chassis showing the Orange Drop caps and volume pot. The stamped 7-digit code on the pot indicates it was manufactured by CTS (code 137) on the 48th month of 1968.

The Speaker

Sears used a lot of cheap parts. No exception here. But for some reason this original 8-inch speaker made by Fisher with an Alnico magnet sounds great!

Conclusion

Even though this little amp is as basic as it gets, it simply excels at what it does. And that qualifies the 5XL as a Tone Gem. Perfect for recording jazz, blues or rock. And perfect for the player looking for that alternative indie sound. But fare warning: manufacturing quality of this amp was inconsistent and not all samples found today will be built like or sound like this one.

Specifications – The Sears 5XL

SEARS 5XL
Model Number 257-1420(1100?)
Serial Number ????
Manufacture Date Dec. 1968
Type Combo
Output (Peak or RMS) 5 Watts, Peak
Pre-Amp Tubes 1 x 12AU6
Power Amp Tubes 1 x 50C5
Tube Rectifier 35W4
Speaker Fisher 8″ Alnico
Speaker Code 6392 (printed on cone)
Speaker Configuration 1 x 8″
Baffle Board 1/8″ Masonite
Impedance 16 Ohm (?)
On-Board Effects None
Footswitch None
Controls Separate Volume & Tone
Inputs 2
Channels 1
Cabinet Construction 3/8″ Pressed Board
Cabinet Covering/Color Vinyl / Olive Green
Dimensions (WxHxD) 16″x16″x6″
Weight 8 lbs.
Power 120V AC

Schematic for the 5XL

I’m working on a new schematic diagram for this amp which I will add here later. In the meantime the schematic of the Silvertone 1430 (shown below) is somewhat similar to the 5XL, except that the 5XL adds a tone control and has no safety fuse! Diagram courtesy www.freeinfosociety.com.

Silvertone 1430 Schematic

Additional Resources

Links to more info surrounding the 5XL…

 

{5 comments}

Ty Stites February 18, 2012 at 10:05 am

See also schematic for the Alamo Capri which is very similar. You might want to add that as an update. ( I can e-mail you one if you like).
I bought a “5 XL” on e-bay that needs to be repaired/restored. It does NOT say Sears on it anywhere (however, the back is missing…) but has a big Danelectro logo on the grille. It does say “5 XL” on the front panel but where you sometimes see a Sears logo on the front panel there is a logo that looks like an atom or something (???). Anyway, I was wondering if you ever found another schematic. Most of the wires in this one have been cut – I have no idea why as it appears that all the original components are still in place despite all the wires being cut (??!). Anyway, this one has TWO chassis mounted transformers (wires cut) which appear original which I do not see in your pics. It has the output transformer on the speaker like in your pics. Three trannys total. (??…)
Any help would be greatly appreciated!!
Love your site. Keep up the good work!
Thanks.

alex February 18, 2012 at 12:47 pm

Ty,
Thanks for stopping by and leaving your comments. What you are describing sounds odd to me. To the best of my knowledge, Danelectro did not market a 5 XL amp with a Danelectro badge on it (that would be news to me). The logo that looks like an atom is actually a Sears-Roebuck (SR) logo from that era. I have two amps with that logo. It sounds like you have a mixture of things going on there (a frankenamp?). Could it be possible that someone before you took it apart and added the Danelectro logo? The transformers you describe definitely sound to me like someone’s custom modification. Could you email to me some photos? That would be great. ~alex

alex February 18, 2012 at 12:59 pm

Also, thanks for the tip about the Alamo Capri. The schematic does look similar, and it uses the same tubes. I will research that further. Thanks!. ~alex

Scott June 7, 2016 at 11:47 pm

I have been slowly hot rodding one of these little amps for a while now. I have recapped/potted, traded out the OT with a Hammond, and replaced the cheapy 8″ speaker with a Jensen p10r. I’ll tell you what, for blues harmonica it is a tone monster. To play with a band I just stick a microphone in front of my speaker and let the PA do all the heavy lifting. I have a few big tube heads and combos, but I still plug into the hot rod 5xl every time.

alex June 10, 2016 at 10:18 pm

That sounds awesome! Thanks Scott for sharing that info about your 5xl.

~alex

 

1960′s Vintage Ads for Kay Electric Guitars & Amps


Kay Musical Instruments of Chicago was the first company in 1962 to manufacture guitar amps that were 100% solid-state electronics. Here are some vintage advertisements from that time period.

The first ad, Transistorized Amplifiers, I found as a JPEG somewhere on the Internet years ago. Unfortunately I can’t remember where I found it, and can no longer find the source to give proper credit. If anyone knows, please give a shout. The second ad, Kay Vanguard, features the 1966 Kay Vanguard Electric Guitar and 704 Vanguard Amp, and was purchased from a seller on eBay.

Transistorized Amplifiers — An Exclusive

• Space Age Technology and Design

Published 1965. Triumph of top designers, engineers–and Kay! . . . Makes all others obsolete!

A real break-through in guitar amplification… Brought to you FIRST BY KAY. These Space Age transistorized amplifiers have so many long-hoped-for advantages, no serious musician will rest until he has one. First, they eliminate the annoying microphonics of vacuum tubes, giving you  stable, uniform true sound never affected by vibrations or voltage variations. What a boon for recording artists! Here, too, is reliable performance that eliminates tube-changing annoyance… performance that can be counted on through the most exacting engagements. And here is the most instantaneous sound with no need for warm-up or standby switch. Note, too, the new Kay easy-to-reach slant control panel and exclusive tapered cabinets. Then add to all this Space Age efficiency the further advantages of lighter weight and compact beauty of design and you’ll say Kay transistorized amplifiers deserve all the honors.

Kay Vanguard Electric Guitar and Amplifier

• Professional Sound & Style… On a Budget

Published 1966. Kay presents the most professional sound in an electric guitar and amplifier ever offered for under $200…

You can sound like the “pros” and look the part with this beautiful new Kay Vanguard Vibrato Electric Guitar and Vibrato Amplifier… And you get the exclusive “Thin-Lite” neck with adjustable truss rod for lightning fast action, vibrato tailpiece (for modern sound effects), 6 keys on one side, separate tone and volume control, adjustable rosewood bridge, inlaid position markers, shaded cherry red finish… Kay Musical Instruments— Division of Seeburg Musical Instruments, 2201 W. Arthur. Elk Grove Village, Ill. 60007.