A Buyer’s Guide for Purchasing Old Amps – Dave Boze

An increasing number of amplifiers are being purchased today over the Internet without the new owners seeing or hearing them before they agree to buy. Most of these transactions involve old amps (Fenders, Ampegs, Marshalls, Voxes, etc.) and aside from the varying descriptions offered by the sellers, who really knows what may be going on inside these cream puffs? What potential surprises should a prospective buyer look for? What are the questions you need to ask before you buy? Well, fellow Tonefreaks, let’s get to the heart of these important questions with expert tech Dave Boze.

Over the past 10 years we’ve seen amps go from relative obscurity as prized appliances, tone machines, and collectibles, to highly sought-after and very expensive vintage “instruments.” Prices have in some cases increased several times over what they were 10 years ago!

Back in the mid to late 80’s when the vintage guitar boom was just starting to come into it’s own, most people didn’t give much thought about amps. A lot of people paying big dollars for vintage guitars were bedroom players and collectors, and they didn’t care as much about creating a special sound, since most of these vintage guitars were going to be played at home. Those of us who were still gigging on a regular basis had never really left the tube amp world, or we had re-discovered tube amps after acquiring a really bad taste for solid state. Slowly but surely, more people started to grasp the fact that the entire chain in the search for tone is rooted in the combination of an electric guitar and an amplifier. As for me, I still think that a great amp with a so-so guitar is more desirable than a terrific guitar with a mediocre amp!

As many of the most desirable vintage guitars have become increasingly rare and expensive, it was inevitable that amplifiers would attract the attention of collectors, but has only been within the past 2 years that the collecting frenzy has truly caught up with vintage amps.

Now that the word is out, the potential for some unpleasant problems exists. You’ll notice that most vintage instrument dealers won’t sell an amp with a warranty, for example. Why? Well, aside from the fact that amplifiers can be unexpectedly temperamental even after having been serviced, shipping can wreak havoc on an amp, even in the absence of any visible signs of damage. And unfortunately, a lot of people don’t pack amplifiers properly. So the mint, just serviced, killer amp that you bought on Ebay could arrive looking mint and sounding like a cat on fire! For packing tips, refer to the section in Mark Baier’s interview on page 6, and then confirm and clarify your expectations with anyone who may be shipping an amp to you in the future.

Looking Under the Hood

If you want to a buy one of the more valuable and collectible models, it is crucial to know what you’re getting “under the hood.” For example, blackface control panels can be bought today for $80 along with some new grill cloth and poof— someone’s silver face amp worth $500 is now cosmetically transformed to a blackface model worth $1,200. Does this go on? It must. Transformers can be changed (and they often are) speakers reconed, cabinets recovered and even new cabinets aged and recovered to look 30 years old. Would someone really do that? Think of the money involved when you’re dealing with a $2,800 Vibroverb or a $4,000 ’59 Bassman. Now, I’m not crying wolf and telling you that everyone who has an amp for sale is out to screw you, but sometimes I wonder if many of the sellers of all of these suddenly hot amps know if the amp they are selling is “original.” The point is…I’d want to know before I spent $1,000 or more on an amplifier, or anything else. So know what you’re buying, or pass!

When it comes to evaluating an amp before you buy, there are several critical things you want to verify to the best of your ability. Amps are different from guitars in that changed parts in guitars will usually reduce the selling price, but changed, missing, or altered parts in amps can be hard to detect and they can dramatically alter the tone of the amp (as well as the selling price, if you know.) Some things are more important than others, and in some cases an altered amp may even be more desirable than an original! More on that in a moment…

The Cabinet

Does it have the original covering? Is the tolex or tweed in good condition? Tweed is tough to recondition, but black tolex can usually be brought back to life with a little know-how. Even if the covering is shot and unsalvageable, you may wish to consider buying the amp at a bargain price and having it professionally restored. I run across a lot of amps with missing back panels. Not to worry, you can get some made if needed, and they will look perfect.

Transformers

One of the key components in the classic sound of old tube amps is the way that the original transformers were made. Most were manufactured using paper bobbins and the coils were carefully interleaved together to allow the maximum transfer of sound. You’ll find that in almost all new boutique amps, transformer construction is quite similar to those found in vintage amplifiers of yesteryear. To me, original transformers have been a very important consideration, especially in 1950’s amps, since exact repro copies were more difficult to find. Having said that, a much better selection of new reproduction transformers is now available and they are very close to OEM transformers. In regard to power transformers, it is critical that the voltages match the specs of the original, and in output transformers, you certainly want to have the correct impedance to match your speakers and similar construction to the original to produce authentic vintage sound. Virtually all transformers are dated, so you can verify their originality.

Speakers

Original speakers can be a significant benefit to tone, or not, and almost always a determining factor in price. Most people who really know amps will tell you that the sound of an original Celestion in a Marshall, a Bulldog in a Vox, or a Jensen in a Fender is the sound that defines those amps.

Reconed speakers are highly variable. Be cautious in this area, because I have heard some reconed speakers that sound fantastic, and others that sound horrible, depending on the type of voice coil and paper that were used. There are also instances when original speakers may not be desirable. In an effort to reduce costs, Fender stopped exclusively using Jensen speakers in the mid 1960’s. To me, this was a huge mistake and it serves as an example of what happens when bean counters and corporate profits get in the way of good old solid American engineering. I personally believe that Oxford speakers, and to a lesser extent CTS speakers, offered inferior tone compared to Jensens. I have worked on hundreds of amps that had these speakers in them and in my opinion they sound fairly lame compared to the tone of an original (or the recent vintage reissue) Jensens. In these cases, if the original Oxford speakers were gone, I wouldn’t lose too much sleep over it. A new speaker can dramatically enhance the sound of many amps, sometimes even those with their original speakers.

Internal Circuitry

This is an area rife with controversy, but here’s my 2 cents worth:

Electronic parts wear out, primarily as a result of age, use, and heat. Also remember that in the 1950’s, electronic parts were not manufactured to nearly the same tolerances that they are today; plus or minus 20% was the norm for some parts. Electrolytic capacitors definitely have a shelf life, and when they leak, they can wreak havoc in an amp in terms of tone and noise, and they can even cause transformers to fail. With time, coupling caps can leak DC into tone circuits – not good. Power resistors can drift, especially those that are near a heat source, and when they do, they can disrupt voltages throughout the amp, negatively affecting tone. Some manufacturers used cheap parts to cut costs (the brown chocolate drop coupling and tone capacitors are an example). So, if some parts are changed, that can be a good thing.

Tubes

Original tubes are in almost all cases absolutely worthless unless the amp was hardly ever played. Occasionally, I’ll see lots of life left in original tubes, but for the most part, an amp that has been played will need new tubes. Tubes are mechanical components that wear out.

Grille Cloth

The new repro cloth is very good and you can even acquire aged cloth now. Contrary to what anybody tells you, Fender never used black grille cloth on any Tweed, Brown, White, or Black tolex amp (from the 1950’s through 1970’s).

Don’t get too hung up on “changed” amps that you intend to play – especially if you have access to a good amp tech. Just be aware that originality should normally affect the final purchase price. Most players have silverface Fender amps converted to blackface circuits because doing so tremendously improves the tone. So here’s a case where an altered amp actually has more value than if it was in original condition.

Above all, keep in mind that amps are for TONE! I’ve heard many absolute beaters produce the most fabulous tone that you could imagine. As a player rather than a collector, I get much less hung up on cosmetic condition and internal changes as long as the amp is running great and produces killer tone. But it is important to know what you’re buying, particularly when you’re dealing with an amp you haven’t seen or heard, and won’t, until it’s yours.

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