Jump to content
Heritage Owners Club

American Vintage Cheese Amps...


212Mavguy

Recommended Posts

Not all of the really cool vintage amps to have are the super well known popular ones. Back in the sixties, amp makers were building amps with very little money spent on components, low parts count, etc, marketed as budget amps to begin with, these amps were cheesy right from their origin except...the wiring and choice of circuit design provide some real foundation for amazeballs tones with some of these old designs. Worth the time I've spent and then some, the brands Harmony and lesser known, almost cultish Lectrolab amps were both designed and built out of the same building, that entity called Sound Projects Company (Interesting name choice!) in Cicero, Illinois. I am not positive but am pretty sure early Supro and possibly early Danelectro amps came from that same company as well, they built amps for several different labels! You can tell by the parts used, the choice of transformers, the layout, and the lead dress across the various brands and models.

 

I first became aware of Harmony amps because of a chance encounter at someone's home, a guy living there toted one of his late father's amps out of the basement, we fired it up and it did not sound happy, but since it was passing some signal I emptied my wallet, 151 bucks literally fluttered down from my shaken wallet onto the coffee table for a '62 Harmony H-306A 1/12 combo minus the footswitch. I called it the rescue amp. The covering is a mottled dark blue imitation of Mother of Toilet Sea coloring of cheesy thin, not even tolex vinyl covering. Going to have to figure out a new name for it now...

 

Why is this amp cheesy? well, to start out with it had an inexpensive Jensen p12r in it, the baffle board and cab bottom are made out of 3/8 inch thick compressed paper board, the chassis is make of thin sheet metal, and the iron looks small, especially the output transformer, it's not much bigger than in a Fender Champ.

 

I removed the chassis and found mostly pure point to point wiring, but surprisingly, instead of a rat's nest, there were nice, military style right angle bends in the lead dress, simple to access with room to work on. The schematic is printed on a piece of paper on the inside of the cabinet back baffle...it was wet stained but still readable, fluid had been running down from what was probably a spilled beer which likely led to the resistor frying in the first place, a possibly alcohol-fueled gig death??? There were two 12ax7's for the preamp, a 5y3 rec tube, a pair of 6v6's and a wierdass looking 6sh7 metal jacketed tube to drive the footswitchable bias modulated tremolo. I found a fried and cracked resistor by sight, replaced it, fired it up again and dang, it sounded pretty decent for what it was, surprisingly so.

 

The Sound Projects Company built amps are modder's dream platforms. I've had three of their designs, Harmony H-306A, Harmony 420 1/15 combo, and a Lectrolab R600C.

 

The best part about a vintage cheese amp is that crap is stress free to make it less crappy. So I gave my rescue amp the Frank-en-Champ treatment. There were setbacks along the way but here's what I ended up doing over a two year period bit by bit besides retubing all NOS.

 

I stuck an additional 33 microfarad/400 volt axial electrolytic cap in parallel with each of the three nodes of the stock can cap, more than doubling the capacitance from stock. This amount is way above what the hifi weenies say is safe to do with a tube rectifier, well, BS on that, it works just fine this way and provides some serious bottom grunt without the farting noises on the low notes. Some of the amp builders swear that if you put too much filtering in the power supply, the amp won't sing and sustain as well. Maybe on some circuits but not this one. It's cathode biased and runs the power tubes at near 100% all the time, with this circuits lower power section voltages, real class A territory and the sounds reflect that, this amp wants to sustain and sing even ordered harmonics for days. So in this case the extra filtering helped with no adverse effects.

 

Once it was running, I yanked the cheesy Jensen and put in a REAL speaker, a late 40's early 50's original cone 20 tube watt rated Altec 600b full range hifi speaker. It was much more musical, rich and full sounding than the stocker, not even close. This is the forerunner of the 417's used by Randall Smith and Alexander Dumble in their early amps that Carlos Santana played through.

 

Next, I yanked out the original tone caps and stuck in some Russian military paper in oil ones, following original values except on one or two instances.

 

I had previously gutted an old Magnatone (pair of 6v6')s PA head that I was never going to be able to repair, some nice parts came out of that amp including very beefy power and output trannys. So I looked at the way that that little baby cheesy OT on the Harmony was sitting so close to the power tubes and getting cooked while the amp was running, and yanked it. There was no room for an output transformer weighing at least four times as much as the stocker, so I did what I did with the Frank-en-Champ and put the Mongo iron in a convenient bottom corner of the cabinet and ran extended leads to it. Looks messy, sounds fantastic. Again, more richness in the bottom and more harmonic content. The amp has more clean headroom, and can get louder dimed now, which is rather addicting since 10 class A watts won't cause earbleed through a 1/12 cabinet no matter what you put in it.

 

Next, I found a Lectrolab R600C on fleabay. It was basically the same chassis, circuit and layout using different rectifier and tremolo driver tubes and having a pair of cathode biased el84's. I did the same thing, NOS retube, beefed the power supply caps and replaced similarly as before the tone caps, did not replace the OT (yet). For a speaker replacement I removed the original Jensen c12r and found a very nice 50's vintage JBL 123 with a paper dust cap. It's very full in the bottom and lower mids, and a bit darker than the Altec on top. This amp now does not sound like it has a pair of el84's in it. Too big, fat and sweet, not thin raspy, scratchy and snarly enough to sound like any el84 amp ever made today, especially some of the Chinese built ones filling the big box sellers' shelves, oh wait, am I brag ranting a bit here? sorry.

 

The Third Sound Projects amp is similar to the Supro Thunderbolt, only an additional tone control separates the two circuitwise, both are 1/15 combos, but the cabs are differently shaped. It's the Harmony 420. I did it up the same way and stuck a JBL MI-15 speaker in it. I sold it to a very happy harp player. That is one fantastic blues amp.

 

But this morning I hooked up the el84'ed Lectrolab and the 6v6'ed Harmony out of the left and right outs of my TC Nova multi fx pedal and found an amazing set of sounds unlike others, simliar yet different enough between the sides to sound amazingly huge, sweet, and oozy as trying to lick two chocolate dipped ice cream cones at the same time, melting out from under the coating onto your fingers...gooey, rich, fattening, messy and delicious. Woooooooeeee! Stereo class A amps... one 6v6, the other el84 with similar circuits., hit that volume pedal swell, turn on the singing, pulsating trem on one of them, let the singing carry on. The three little Green cheek and Sun conures (Parrots), my secret tone consultants who dance and sing when the playing's good and bite the back of my neck when it sucks (really!) were going noisily nuts and bouncing all over their cages like nobirdy's business, so I'm definitely on the right track. What they like at home goes well at the gig 100% of the time. And I really dig their low consultant's fees along with the immediate feedback.

 

The Lectrolab is a very rare bird to find, but used Harmony H306A's go for between 300 and 400 bucks on fleabay occasionally, and cheaper in pawn shops or local Craigslists...they are low in demand under the radar vintage American cheese, prime tone monster circuits begging to be redone with some beef replacing some of the cheese, they become modern production amp tone slayers...for potentially less money than expected, definitely less than a boutique amp, which is the only thing that will keep up with these in the tone department...

 

nobody is building amps today in quantity that sound like or as good as these old circuits do, period.

 

Do any of you have any, possibly similar, Vintage Cheese amp stories?

Link to comment
Share on other sites

I recently scored one of the stinkiest of all cheese amps...a Silvertone 1457 Amp-In-Case.

 

No colorful stories to be told about this vintage cheeser. But it's a cool novelty. Not much room for big iron, but it's a great conversation starter.

 

vintage-1964-silvertone-1457-electric-gu

Link to comment
Share on other sites

That is exactly "it" right there, except your Dano is a true vintage collector piece, unlike my cheese amps. Can you imagine what a line out from that Dano would sound like through a FOH board or big tube amp? It would be as easy as running the speaker output into a Weber MASS attenuator/dummy load/balanced line out like mine, from that unit into where ever. Some boutique builders charge huge bucks to build one-three watt tube amps that double as effects units when not connected to speakers. Look at what you have...hehehe it's awesome.

Link to comment
Share on other sites

Mavguy, do you have any pics of that Harmony?

 

I have an H305 ( I think ) that needs some TLC

 

it has a nice Jenson speaker, and a pair of 6V6's...2 channels, a few 12AX7's

 

 

ok I am going to read your post now....that's a whole lotta words ( cue the Zep riff :D )

Link to comment
Share on other sites

hahaha that was an excellent read!!

 

"alcohol-fueled gig death" sounds like a great title for a song

 

I like your tone Parrots...hilarious!

 

 

my amp is made of that compressed cardboard as well. let me go dig it up

Link to comment
Share on other sites

I recently scored one of the stinkiest of all cheese amps...a Silvertone 1457 Amp-In-Case.

 

No colorful stories to be told about this vintage cheeser. But it's a cool novelty. Not much room for big iron, but it's a great conversation starter.

 

vintage-1964-silvertone-1457-electric-gu

 

When those came out they seemed like zero cool factor, and now, total cool factor.

Link to comment
Share on other sites

Bolero, take that chassis out and look at it. then look at the original schematic glued on the back of your back baffle board, It's simple and I bet it shows what voltages were at the different places in the guts when it was made. Look for blackened resistors first. Chances are that the original filter can cap is still good. I'm not sure if the 305 has the trem circuit and atwo channel four hole preamp, but as it sits it will be one freaking wailing blues amp with some real American mojo in it's tones' bones. Once you get it up and running you can start messing with the guts if you feel like it.

Link to comment
Share on other sites

That Silvertone looks very, very much like Sound Projects built it. There are many similarities to my Lectrolab and Harmonys. When that vibrato is going, does the blue glow in the 6l6's pulsate in brightness? If so you have the bias modulated tremolo, very rare in today's amps.

Link to comment
Share on other sites

What are these tubes?? I see two 6L6's, a rectifier, and what appears to be a 6V6 second from the right. Can't identify the other members of your valve choir.

 

post-2247-0-20197100-1436915090.jpg

#1 from the left is original and all the print is worn off, I have no idea what it is. #2-6 (from the left) all have 6L6GC written on them. The two with the red bottoms are from China.The others are original. #7 is a 6V6. I'm not sure what # 8 is. It is also original. It is a cool amp but very delicate. They were cheaply made construction wise. With the stereo components it picks up a lot of ambient noise. I use an Archer AC line interference filter between the amp and power source when playing. I have a 1957 Danelectro that pairs quite nicely with it. Very cool early Duane Eddy and Ventures type tones.

Link to comment
Share on other sites

Bolero, take that chassis out and look at it. then look at the original schematic glued on the back of your back baffle board, It's simple and I bet it shows what voltages were at the different places in the guts when it was made. Look for blackened resistors first. Chances are that the original filter can cap is still good. I'm not sure if the 305 has the trem circuit and atwo channel four hole preamp, but as it sits it will be one freaking wailing blues amp with some real American mojo in it's tones' bones. Once you get it up and running you can start messing with the guts if you feel like it.

 

thanks!!

 

 

I picked this up after playing one in a shop, the shop one sounded great i was getting some nice EC/bluesbreakers sounds out of it

 

I have no idea why it was pulled apart/shelved. will def check it out!

 

genericmusic, I didn't know they even made 80-100w silvertones...it must be a 2x12 combo?

Link to comment
Share on other sites

OK!

 

You have the real deal here! This is a great one! It will be quite a bit simpler inside than mine. It will sound decent stock, but will respond very well to upgrades. The simplest circuits have the potential to sound fantastic, if not as versatile as more complex designs in execution.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...