Here are a few things to watch out for when buying second hand valve amps. Valves are very old technology and so valve amps inherit the unreliability of old tech. Keep in mind the 6L6 output valve was launched on the market in 1937. Just think about driving a car today that was designed in 1937 and is unchanged today. Cars back then broke down all the time and dissolved in the rain. So don’t get your amp wet !
Buying from a store
If you are buying second hand valve amps from a bona fide store you will get a warranty and it has to be fully working so you are protected. But what if you are buying privately? I am not suggesting that folks selling privately are crooks but there are some things to look out for that ensure you are getting a good deal and not a lemon that costs you money after you buy it
The obvious one to watch out for is amps that have been modified. My own rule of thumb is that modified amps under 20 years old should sell for a bit less than an untouched amp. You have no idea who did the mods and if they are too a good standard. Safety can be compromised!
If the owner tells you that some mods have been done then you need to know the specifics of what the modification are so that you ,or a qualified amp tech, can reverse the mods.
With amps over 20 years old and certainly vintage amps, their value can be more heavily impacted if they are modified. This includes speakers and component changes. Acceptable mods are those done to bring the amp to modern safety standards. You don’t want to go up in a blue light in the middle of a gig. Entertaing but life threatening !
A good example is the mains voltage selector on early Vox AC30’s. These are dangerous . A good mod is to fix the amp on say 230 volts internally and leave the original disconnected mains selector in place. It is important to keep the cosmetics as original as possible. You need to discount the price to cover the costs of mods that are done and use this to haggle on the price.
Make sure you do some checks to see if that 1965 amp really is a 1965 amp. Have a look online and check pictures of the amp from that era. There are many good sites that help you figure out the date of manufacture using the serial number. A word of caution is that amp manufacturers in the early days tended to not consistently follow their own planned serial number system but at least it is a guide. You can use speaker serial numbers, transformer serial numbers as a cross check with the amp serial number.
Here is a page of Fender amps Fender Amp Serial numbers and general guides on appearance with different dates
Early Vox amps are notoriously difficult to date. Here is a link that may help
Try and check what valves are in the amp. Do they look fresh with nice clear writing on them? Do the output valves look burned due to the heat. Some owners change the valve line-up and this is easy to return to stock by inserting the correct valve types.
It is always asking if the capacitors ( the electrolytic capacitors ) have been replaced in amps over 20 years old. Mains hum can be the sign of capacitors in the power supply being less effective than they were. ( but keep in mind failing valves can also cause mains hum). If they are replaced,
Buying from auction sites
I hear a number of stores of folks buying amps unseen on auction sites ( you know who I mean !).
You have always to ask yourself why are they selling the amp? In many cases the new owner has a nice amp but the valves are worn. They are getting mains hum, crackling an popping, etc etc.
Some amps can have a lot of valves inside inside. A little 22 watt Fender Deluxe Reverb has 10 valves inside and that is not a cheap kit. Check out the price of the valve kit and use that as a bargaining chip if the owner tells you the valves were last fitted when the Human League were at number one.
Is the seller a pro musician gigging every night of the week or are they a bedroom player or some in between? A heavily gigged amp can look pristine as it goes to bed in a flight case every night, and an amp that doubles as a bedside table might be dusty but it will hopefully be lightly used. It is important to make a judgement.
A harder one to answer is just how reliable is the model of amp you are considering. Is it an amp that is simple to repair ( = cheap repairs) or at the other extreme Mesa Boogie which have to go back to the official service centre at the other end of the country? It is worth checking out the forums to see what faults folks are seeing on their amps.
I hope this list helps. I am sure I have probably missed a few pointers on buying second hand valve amps and let us know and we will add them to this blog Just get in contact if you want to ask us a question.
We have a wide range of valves and are always happy to advise on what will sound best in your amp and what also fits with your playing style. Checkout our store now