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.

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.

Comments

tomas March 29, 2011 at 4:37 pm

glad you are enjoying it!

nice site, added it to my RSS reader….

REPLY

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

REPLY

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

 

 

Beatles Amp Rediscovered

Vox UL730 Head

The Vox UL730 amp played by George Harrison on the Revolver and Sgt. Pepper’s recordings

The Northwich Guardian reported today that a man in Wicham England discovered that a guitar amplifier he’s owned for awhile actually belonged to George Harrison in the mid-60′s. Apparently that fact went unnoticed for decades until the man took the amp in for repair. The technician discovered Harrison’s identification inside the amp during the repair.

Read the article here: Wicham man finds amp owned by the Beatles

More info about the Vox UL730 Amplifier from www.voxshowroom.com.

Photo courtesy of www.guitargeek.com.

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.

 

How it all began…


This story began a few days after Christmas when my son and I stopped into one of Portland’s music shops, Trade Up Music, to browse the used gear. After checking out Trade Up’s nice selection of guitars, my son spotted a small, funky, beat up amp sitting atop the other guitar and bass amps. It was a simple square box, somewhat plain in appearance. The original green vinyl covering was stretched in a few places and had a few tears. The speaker fabric was splattered with paint and a had hole in it! Because of those “faults,” my son thought it had a certain cool factor and retro personality. And it had tubes inside! Cool… a little tube powered practice amp. Or maybe he could use it on stage, or for recording.

Taking a closer look, I could tell it was one of those unimpressive department store amps of the late 1960’s or early 70’s. Basically the kind of stuff we ran away from (but in reality was all we could afford!). It was a Sears amp, model 5 XL to be exact. Well I thought to myself, “A Sears amp? No way.” Musicians didn’t buy these. Only parents bought these cheap amps, paired with an equally cheap electric guitar, so their kids could start their own noise brigade in the garage.

Anyway, knowing nothing about this amp, I grabbed my smart phone and quickly Googled the amp’s name while still in the store. Not much was found, except for some less than glowing information and commentary found at Silvertone World (a great site, by the way). Still scratching my head, my son decided to buy it for less than $90 cash.

Once we got this guy home and plugged into Jon’s modified tele, all my doubts were replaced with astonishment. What unexpected sounds came zooming out of that plain green box! Jon cranked the volume and the tone knobs. The tubes went into overdrive: somewhat snarly and raspy but under control. Subtle highs, growling midrange, and a whole lot of solid bass. Who knew?!

Have a listen…

Who knew there was an real unexpected Tone Gem hiding underneath that Sears label and ugly green vinyl?

Well, that’s how this whole thing started.

{2 comments}

Randy October 5, 2010 at 7:30 am

Alex, thanks for the insight on the 1420! “Less than glowing” is right, because I’ve never had the opportunity to play through one… now, I know! Mind if I use your mini-review on the site for the 1420 page? Funny how just a little hot wire, vacuum and glass can create a Tone Gem, eh?

alex October 5, 2010 at 9:30 am

Randy, greetings! A privilege to hear from Silvertonium. Thanks for your comments. Please fee free to use as a mini-review. I am currently working on full fledged review pages (complete with specs, photos, video, and audio) for this amp and for the 10 XL (1421), which will be posted in the near future.