You’ve probably all heard that the 1970s was a difficult decade for most guitar manufacturers. Martin experienced the same strain during those years. '70s Martin guitars tend to have a lousy reputation, such that their values are probably as low as they'll ever get. This does not mean that '70s Martins are to be avoided. They can be some of the best sounding guitars out there and can be bought for reasonable prices. There are few other instances in which you'd be able to find a 40 year-old, top-of-the-line dreadnought from one of the best companies in the world for under $2,000. Now is an excellent time to buy a vintage '70s Martin.

When the '60s folk boom was in full swing, people wanted to buy good quality instruments. All of the guitar manufacturers were struggling to keep up with orders and high-end Martin was no exception. Supposedly, during this period you had to order your guitar before it was built, rather than going to a shop to choose one out of several hanging on the wall. Martin went from producing 7,403 guitars in 1965 to producing 22,636 in 1971; in a mere 6 years, their production numbers more than tripled. A large number of the 163,887 guitars produced from 1970-79 were fantastic instruments that were built without flaws. However, there were a small number which suffered from what’s generally considered the result of poor quality control. Even during this difficult period, Martin was producing guitars of excellent quality, especially considering that some of the big competitors of the day, like Gibson, were sometimes selling factory seconds.

The only real quality control issue that Martin experienced in this period was that some of the bridges were misplaced, resulting in poor intonation. It is rumored that a simple yardstick-like piece was used to place the bridges, and one out several used was about a ?" too short. This issue can be righted by moving the original bridge back, installing a new bridge, or by filling and re-cutting the saddle slot in the original bridge. Each of these alternatives has pros and cons, and it is best to discuss the differences between them with your luthier.

Bridge Plates

Guitars from this period tended to have large (3?") East Indian Rosewood bridge-plates. The traditional Martin has a small (1?") maple bridge-plate. A large bridge-plate does not help tone and many '70s Martins sound good in spite of their enormous bridge-plates. This is something that can be changed out by a qualified luthier. However, a replacement bridge-plate will decrease a guitar’s originality and thus its value, even if it sounds better as a result. A few models introduced in the late '70s had the smaller maple bridge-plates (HD-28, M-36 and M-38).

Indian Rosewood
The factor that has had the most significant effect on value for Martins is the switch from Brazilian Rosewood to Indian Rosewood in the back and sides of style 21 and above guitars. With the supply of Brazilian Rosewood drying up, many manufacturers made the same shift in the early '70s.  For Martin, the change happened in late 1969, but there have been a few isolated instances of Brazilian Rosewood showing up on 1970 Martins. Brazilian continued to be used on the fret-boards of style 18 Martins as late as 1971. Today use of Brazilian Rosewood is limited to special edition or custom shop guitars.

Pickguards

During this period (and others), Martin applied finish on top of the plastic pickguards. Over time, the plastic would shrink, pulling the top with it. This caused what is referred to as a "pickguard crack." Typically, these cracks happen along the grain of the top and on the side of the guard that is closest to the center seam (often called a b-string crack), they don’t go any farther (north or south) than the bridge or soundhole rosette. However, Occasionally these cracks can happen on the other side of the guard, creating larger cracks. If left un-repaired, they can run the whole length of the guitar.

Necks

Martin started using adjustable truss-rods in 1985. Everything they built prior had a non-adjustable truss-rod, and in the 70’s the truss rod consisted of a ?" square tube. Over the years, the tension from the strings will pull the neck forward. On some guitars (more commonly those with the square-tube truss rod), the neck will bow forward, otherwise referred to as having "too much forward relief." This issue can be corrected in a number of ways, but the most common and successful method is to do a compression re-fret. A compression re-fret is where larger tang widths are used to push against the fret-board, straightening it out. If a guitar needs new frets anyway due to excessive fret-wear, this isn’t much of an additional cost. The trick is finding a luthier who knows how to correct this particular issue on a Martin neck.

Also, as the decades pass, the neck will actually begin to compress into the body. In this process, the neck angle will change, making the action far too high to play anything except standard cowboy chords. Years ago, the thought among some repair folks was to shave down the bridge in order to compensate for the higher action. This repair almost always makes the original bridge unusable, and it doesn’t fully address the problem. The proper way to right this issue is to reset the neck, which involves removing the neck from the body and setting it again at a proper angle. This is an expensive repair and should be considered when inquiring about a vintage Martin guitar.

Questions to ask when looking to buy a ‘70s Martin

Has the neck been re-set? If so, when was it done and by whom?

Regardless of the answer to this question, it is good to ask for photos of the neck heel (a poor reset can be obvious if the neck heel has glue visible), and the bridge/saddle. The saddle should be somewhat above the bridge, and the bridge should have a nice, rounded shape in the middle that rises a good bit above the "wings." If the saddle is shaved down all the way, then either the guitar hasn’t had a reset or it is due for another. Yes, a guitar may need to have more than one neck reset in its lifetime. Neck resets are par for the course when you have a vintage flat-top.
Is the neck straight, and is there any forward relief?

Many private sellers won't know about this issue, but it is good to ask anyway.

Are there any cracks in the guitar, including pickguard cracks? If so, where are they and have they been repaired?

A "b-string" pick-guard crack should by no means be a deal breaker. They are incredibly common on old Martins, and it’s not necessary to have them repaired (unless they are really large or they are bothersome to you as an owner).

If there are cracks that have been repaired, how was the repair done; were they cleated and/or was there any finish applied over the cracks? Any finish touch-up will hurt a guitar’s originality factor and thus value.

Does the guitar still have its original finish?

A refinished '70s Martin should be a relative bargain. However, the general rule that a refinished guitar is worth 50% of an original one doesn’t always apply here. For example, a 1975 D-18 that is valued at $1500 in original condition is worth more than $750 if it has been refinished but is perfect otherwise.

Always try to get detailed photos of every area you are asking questions about. Most sellers are happy to oblige and can post the extra photos to their ad if you don't end up buying the guitar.

What to Pay

When looking for 1970's Martins, you will mostly encounter dreadnoughts on the used market.

D-18's are great mahogany guitars and usually the least expensive, ranging anywhere from $1200 or less for a project, to $2000 for something really nice and needing very little.

D-28's are more the flagship model for Martin, and they can be more expensive. These range from $1500 for a good project to $2200 for something very nice (sometimes with asking prices higher than that).

D-35's tend to have strong bass and a unique sound due to thinner top bracing. These are very versatile guitars, typically priced in the range of $1500 to $2000.

Any dreadnought higher than a style 35 will be significantly more money. They are harder to find, and thus more difficult to pin down an actual price.

For some reason, the 0, 00 and 000 body sizes are harder to come by in the '70s, and it is difficult to get a read on their value. Generally, they should be in line with the values of their dreadnought counterparts. The 000's are going to be more expensive than the 0's.
12-strings are often up for sale, and typically have a lower value than their 6-string brethren. The D12-20's and D12-35's are sloped-shoulder dreadnought 12-fretters and the D12-18 and D12-28 are traditional dreadnoughts with 14 frets clear of the body.

Don’t be afraid of 70’s Martins. They were solid, well-built guitars, and with a little tweaking, can blow just about anything else out of the water. It is wise to understand the repairs and adjustments necessary to make them sound and play their best. If the repairs are done correctly, you will have a sweet old Martin that will hold its value together for as long as you want to own it.