Vintage 1960's Guyatone GA-530A Guitar Amplifier

Japanese-made tube amps from the 60’s represent, in general, one of the great values left in the vintage market. Frequently, you can pick up little combos like this Guyatone (or the Univox U-45B) for under $300. Real vintage tube tone for under $300 (and frequently even lower)? What’s not to love?

This Guyatone, along with coming cheaply and sounding great, is a looker. In white Tolex (or Tolex-like material), this is a stunning looking amp that was a popular model (though not for export) in the Mid-60’s Japanese “Group Sounds” movement. A great amp for chiming Beatles-inspired sounds or tremolo-drenched surf-styled instrumentals, the GA-530A is one to keep your eyes peeled for. It’s a classy looking amp, and one that probably looked just fine gracing the stage of the 60’s Japanese TV show Kachinuki Eleki Gassen (“Electric Guitar Tournament”—a highly-rated audience-participation guitar show…something of a Ventures-inspired proto-American Idol for guitar players—guitars were HUGE in the 60’s in Japan).

Vintage 1960's Guyatone GA-530A Guitar Amplifier

What’s under the hood? It’s a pretty simple and well-made amp. Three 12AU7’s (for preamp, tremolo and phase inverter duties), two EL84’s for output and a solid state rectifier and not much else. The speaker is labeled “Guyatone”, though I’m not sure if it was made by Guyatone or rebranded (there are no codes on it). Whatever its source, this is a sweet-sounding ALNICO speaker in the 20-watt range.

Vintage 1960's Guyatone GA-530A Guitar Amplifier

The sound of the amp is very cool and unique. Where most of the Univoxs I’ve heard are little blues and garage-rock machines, this amp is all about chime and cleans. Part of this, of course, comes from the low-gain 12AU7’s. A 12AX7 has, for instance, an amplification factor of 100. The 12AU7’s have an amplification factor of 17. The amp is voiced for cleans and isn’t (as you might guess from the tube line up) the loudest dual EL84 amp you’ll ever hear. Without mods, you can heat things up a bit with a 12AT7 in the preamp, but anything much higher than that makes it start oscillating and wailing a bit. Without some mods, it’s not going to be a high (or even mid) gain amp.

Vintage 1960's Guyatone GA-530A Guitar Amplifier

However, played clean (which it stays until about 7 on the volume knob), this thing really shines and sparkles. Byrds and Beatle type tunes sound incredible and it takes to a 12-string really well. Chords are articulate and well-voiced and the amp rings like a bell. Pushed into overdrive (from 7-10 on the volume), and the amp retains its trebly voice, but pushes the EL84’s into a Vox-like chime and grind (albeit at a lower overall volume than, say, an AC15).

And, while this combo may lack reverb for true surf tones, it’s got the awesome gritty sparkle to base your surf tone on, along with an absolutely KILLER tremolo. With tremendous range of depth and speed, it’s a very musical tremolo effect. One of the best I’ve heard in ANY amp. Add a ‘verb pedal, and you’re catching a wave!

Vintage 1960's Guyatone GA-530A Guitar Amplifier

Issues? Well, you are going to have a few when you buy a mid 60’s amp for under two hundred bucks. First of all, unless you know how to do relatively simple work like cap jobs and basic trouble-shooting for bad resistors and so on, the trip to the tech could cost more than the amp is worth. So, it’s probably not a great deal unless you know some basic repair and maintenance.

AND, there is a design flaw on this amp. The tubes are not mounted separately on the chassis, as they should be, but, instead, they’re mounted on the printed circuit board. This is problematic for a few reasons—the main ones being that it’s not nearly as study or durable as the proper mounting on the chassis and that it’s much easier for microphonic issues to arise (whether from the tube or the circuit board and then amplified through the tube).

Vintage 1960's Guyatone GA-530A Guitar Amplifier

Also, it’s not nearly as easy to modify a printed circuit board amp as it is on a hand-stuffed circuit board or a point-to-point amp. And you might want to modify this model for a little more gain on the preamp, via a nice 12AX7, pushing the rest of the signal down the chain. Or add a bypass cap to fatten up the sound. Both of these are still easy mods—just not quite as easy as if it were a point-to-point amp with a lot of space to be noodling around in the chassis.

Still, you want perfect for under two hundred clams? These are great-sounding, great looking little tone machines. And while the build quality may not equal Fender or Marshall (or even Univox), they are still pretty easy to fix and modify, and you can’t beat a little 12” combo with two EL84’s jangling and grinding for this kind of price. The Guyatone GA-530A is worth checking out—if you can find one!

Vintage 1960’s Guyatone GA-530A Guitar Amplifier from MyRareGuitars.com

Class A tube guitar amps. Everyone’s heard the term. It’s generally associated with higher-end amps in support of an amp maker’s claim that their product sounds “better”.

I’ll leave the debate as to which is better to others. What I want to discuss is what Class A really means and, from the pet peeve perspective, to debunk many amp manufacturers’ claims that their products are Class A when clearly they’re not! You may be surprised at how many amp makers falsely claim Class A operation. So, let’s review, in practical terms, what Class A really is and learn a simple rule of thumb you can use to spot operating class BS!

There’s no denying that Class A amps have different tonal characteristics when compared to the more common ClassAB amps. However, as with anything related to tone, “better” is in the ear of the beholder. There are plenty of butt kickin’ amps out there of both classes.

What does “Class A operation” mean? Technically, it refers to where on a tube’s operating curve, it’s biased. That’s it. Bias a tube one way and it’s operating in Class A, change the bias and it’s in ClassAB.

Of course, there are always technical details that complicate things. In this case, the complicating detail is that tubes biased to operate in the Class A “zone” require a lower voltage supply. Otherwise, they’ll quickly fail. Enough tech stuff, no need to worry about that. I mentioned it to avoid a misperception that you can simply take your amp to a tech for a 5-minute re-bias job and you’re in Class A land. Can’t happen. Fundamental changes to your Class A/B amp would be required to lower the voltage and otherwise set it up for Class A operation. Back to regular programming!

Fixed vs. cathode biasing is another “Class A” related misconception. Many believe that if an amp is cathode biased it is Class A. Not true. An amp can be A or A/B and fixed or cathode biased. Again, it depends on where the tube is biased on its operating curve not how it is biased.

Another factor in the myth is that if an amp has a “single-ended” power tube configuration it is Class A. Conversely, so the myth goes, if an amp has a push-pull power tube configuration it is Class A/B. Once again, the operating class of the amp is not defined by the power amp configuration. It is true that many (most?) single-ended amps are, in fact, Class A. But, on its own “single-ended” does not define an amp’s operating class. An amp can be Class A push-pull or Class A/B single-ended or vice versa.

The technical difference between single-ended and push-pull power amps are perhaps a topic for another article; I mention it here because they are common terms and often enter into the Class A vs. Class A/B confusion.

I mentioned above that Class A amps sound different from Class A/B amps. To review, Class A means the tubes are operating in a different part of their operating zone as compared to Class A/B. Two important things happen as a result. First, tubes operating in Class A produce more even harmonic content. Second, they produce less power.

Tubes biased to operate in Class A/B produce more odd order harmonics. Generally, even order harmonics sound more pleasing than odd. That’s why Class A and Class A/B sound different. However, as I mentioned earlier there are MANY GREAT sounding Class A/B amps. Don’t get unnecessarily biased toward Class A amps (amp builder’s humor – HAHA!).

The fact that a Class A amp with the same power tube configuration as a Class A/B amp produces less power leads us to the simple rule of thumb you can use to check whether an amp is really Class A: just compare the power tube configuration to the claimed output power rating of the amp.

Here are the guidelines I use to tell if an amp’s manufacturer doesn’t have their facts straight:

*Some smaller Class A/B Fenders (e.g. early Princetons and Deluxes, etc.) that feature two 6V6s are rated around 15 watts – later examples are in the more typical 20+ watt range.

If the marketing hype shows output power near or above these ratings and it says the amp is Class A – there’s something wrong! If the output power is a fair chunk lower, the amp is most probably Class A. Simple!

Next time you read a guitar mag have fun by checking the tube configuration, power rating and operating class claims of your favorite amps. You may be surprised at what you find!

Class A Tube Amps: Marketing Hype vs. Reality from MyRareGuitars.com

Airline 18-Watt Handwired Combo Amp

In addition to my monthly rants and raves here in Guitarticles, I also donate some experience and opinions in the design and development of many EASTWOOD guitar models. So, last month Mike Robinson of Eastwood Guitars sent me a prototype of his new Airline 18-Watt Handwired Combo Amp for review. The AMP is scheduled for release in October. Despite UPS’ efforts to the contrary, it arrived in perfect condition with a black – almost “bedliner” looking covering – a different take from the usual Tolex treatment. This material is very tough and cleans up nicely. The Airline sported an Emminence Red Coat speaker which looks to me to be a copy of a Celestion Vintage 30, which by the way is one of my favorite speakers. The controls on the Airline are simple a volume, a tone and a three position switch. The switch seems to fatten up as you go from position 1 to position 3, a great addition when going from single coil to humbucking pickups. I reported to Mike immediately that I thought the knobs – which were original 1960’s Airline knobs – are not my cup of tea, perhaps some chrome knobs?. I also thought that the pilot light, on/off, and standby switches also looked chinsey. But hey, he asked me to take this baby for a TONE test drive, not a fashion show, so now let’s get down to the sound.

I plugged the amp in and was expecting it (with its dual EL84’s) to sound like a Marshall with that classic compressed signature sound. It did not; I initially thought that the speaker was the difference but upon playing the amp more I realized that this amp was indeed a different bird. First off the Airline is a cleaner amp with more headroom then the Marshall. The Airline seems to be a bit louder than its British counterpart, hence the clean headroom. The Marshall sounds best when turned up all the way, revealing its signature sound. A sound that is fat, and compressed, with a fair amount of Marshallesque high end. You cannot get that sound from the Airline, but what you do get is a more versatile amp that sounds very good at any volume setting. It’s lively and strong in its sound. The three position switch is also a nice addition. The amp held its head up nicely when paired with my Blackface Pro Reverb in a live A/B setting.

Where the amp really shines is when you plug a few different guitars in. My Les Paul sounded great at the first of the three tone settings on the Airline. The amp replicated the classic bluesy Les Paul sound very well. And due to the headroom the Airline has, it also handled a few different pedals I plugged in impressively well.

But, when I plugged in a Strat the amp really, really shined. The guitar sounded full and nasty at amp and guitar on 10, but when I started to turn the amp down to about 6 it cleaned up w/ a funky tone that was amazing. Now the flood gates opened, I started trying all different combinations amp on 10 guitar on 5, position 1 through 3 on the tone selector, different pickups!, I was there for about two hours getting truly breathtaking sounds, all with different degrees of chunk/clarity and sustain even at moderate volumes. Before I knew it, it was sunrise and I went to bed thinking about other guitars I would have to try next day.

After a midday cup of “Joe” the Airline got fed a steady diet of my favorite Eastwood guitars, the Sidejack, Delta 6, P90 Special, and the Saturn all yielded similar results, the Airline revealed their versatility and tonal possibilities without pause.

It’s not a fancy looking boutique amp with piping and a brushed golden aluminum faceplate. It, like its guitar namesake, is a retro looking niche offering featuring unusual angles and colors. However, where most niche AMP’s turn out to be one-trick ponies, this versatile AIRLINE delivers, big time!

The Airline is a point to point custom shop handmade amp with a versatile sound, Made in Canada, quality workmanship and a well matched speaker. With most of it’s competition at a street price in the $1,800 range, the AIRLINE holds ground and offers an uncommon versatility. But, knowing Mike, we won’t have to pay that much! Right?

Verdict: I LOVE THIS AMP!!!

Gear Review: Airline 18-Watt Combo Amp from MyRareGuitars.com