Every tube amplifier has a preferred speaker impedance: usually, this is something in the neighborhood of 4 Ω or 8 Ω. The preferred speaker impedance of tube Wurlitzers are as follows:

What is a patent? A patent is a form of compromise. When you patent an invention, you must describe it in detail: specifically, enough detail that someone with a background in your industry would understand how to recreate your invention just by reading the patent application. In return for this valuable information, you are given the exclusive legal right to make and sell your product for a certain number of years. If someone else makes or sells your product during the time period covered by your patent, you have the power to sue them for patent infringement.

We are very excited to announce that our collection of Wurlitzer service manuals are available for download!

The Wurlitzer service manuals are a valuable resource in restoring Wurlitzer keyboards. Although they are not perfect, they contain a lot of interesting, useful, and historically important information. The 112 claims that it is not a guide on servicing pianos in “ten easy steps” (condescending air-quotes theirs!), but it kind of is. You should read the service manual corresponding to your Wurlitzer — and maybe even a few others, since a lot of the information can be applied across models.

When you repair an amplifier, you have two choices. You can bring it back to its original state by fixing only what is broken. Or, you can improve the circuit by modding it.

There is a lot to love about an amplifier that is in fully-functioning, but original, condition. When using a vintage amp, you are playing music on a slice of time. You are combining two different musical periods in a way that is impossible to replicate with any other gear. It’s basically time travel.

The only true difference between 140-series and 145-series Wurlitzers is the amplifier. Both keyboards were released in the 1960s and represented a total redesign of the Wurlitzer electronic piano. Wurlitzer overhauled the mechanical action, revised the cabinet, and — for the first and only time — manufactured two parallel styles of amplifier: a solid state amp (the 140/140a/140b) and a tube amp (the 145).

A customer brought this Rhodes in for restoration. It had been in storage for some time, and he asked us to bring it back to optimal playing condition.

The instrument was out of tune, missing most of its tolex, and suffered from a sloppy, unresponsive action. It had clearly been well-used for a while, and then at some point it had been put away and not used at all. Overall, though, it was in good shape, because all of its fundamental parts were present and more or less functional. That is, the wood parts weren’t warped, the plastic parts hadn’t deteriorated, and nearly every pickup worked. It was a great candidate for restoration.

The 206a is the student-model Wurlitzer. It shares all the same cosmetic features of its professional counterparts, except - appropriate for the classroom - everything about it is just a little less exciting. Instead of dramatic black, here we have friendly beige. Instead of four speakers, we have two. Instead of vibrato, we have the self/ensemble knob.

This vintage tube amp was removed from a Wurlitzer 700 electronic piano. It’s is the same amplifier as a Wurlitzer 120…unfortunately. The 120 had very limited cabinet space, so that’s why the physical design of the amp is so cramped. On the other hand, the 700 had a cavernous cabinet that could definitely have handled a larger amp chassis. Oh well: that ship has obviously sailed.

The Wurlitzer 120 amplifier represented a total redesign from the previous Wurlitzer model, the 112. The upside is that the amp is a lot smaller, so it fits nicely in the smaller, lighter 120 cabinet. The downside is also that the amp is a lot smaller. It’s missing many of the features that make the Wurlitzer 112 so magical. Regardless, it’s still a great vintage tube amp with a lovely, classic tone.

These photos are from a batch of four student model Wurlitzers that we recently picked up. All arrived in amazing condition, with very few rips or scuffs and immaculately clean interiors. With just a little restoration, they became excellent and highly playable examples of early 200 Wurlitzers. Only one is still available.

The filter capacitors in many amps are mounted in a metal can, which can be an obstacle to successfully recapping the amp. These days, filter cans are only made in a limited values, so it's hard to find the exact match. Mounting the caps outside of the can is another option, but finding the space can be tricky. Removing the can can leave a giant hole, which can allow dust to enter the chassis over time. So, what's the best way to replace can-style filter capacitors?

Originally, Wurlitzer built amplifier chassis just big enough to fit the components they needed. This left some interior cabinet space unused. There is nothing wrong with this design choice, but there is a lot of interior cabinet space that can be utilized should one (like, say, us) were to design a brand new replacement amplifier to go inside the Wurlitzer.

Whenever you think about modifying a vintage electronic piano, you should think about two things. Is the mod reversible? And, if not, am I actually improving the keyboard?

A Wurlitzer electronic piano has been around for decades. Clearly, Wurlitzer did something right when they manufactured them, because even after all these years they are still desirable. It is important to avoid performing impulsive mods that will irreversibly change the keyboard. Think it through. Consider whether the mod enhances the function of the keyboard. Consider whether there is a less invasive way to reach the same goal.

In the classroom, multiple student-model Wurlitzers were connected to each other via the two ports on the back. This connection allowed each Wurlitzer to communicate with the teacher console. It also linked each Wurlitzer to the mains wiring so that they could power on in the first place.

When we’re thinking about buying a Rhodes, there are a few criteria that we use to judge potential purchases. We’re mostly concerned about how much work the Rhodes needs to become playable - and if you want your Rhodes to be a functional keyboard and not just a moderately inconvenient buffet table, you probably care about the same things we do.

In Part I of our guide on fixing hum, we listed some easy fixes. In Part II, we’ll go into further detail on techniques that require some prior electronics experience to execute. It’s worth checking out Part I first, because it listed some simple, non-invasive things that you should always be tried before diving into the amplifier’s circuitry. For the purposes of this article, we’ll assume that you already tried everything in Part I. This includes:

Before we start, a disclaimer: hum should be addressed on a case-by-case basis, because every vintage amp is special and degrades in its own way. What cures one amp may not work for another. That said, reading this guide should give you a good starting point on how to address your own hum problems. This guide is pretty basic and going to assume that the only piece of test equipment that you have is a multimeter.

The heaters of your vacuum tubes are one of the most critical parts of your amplifier. A well-designed heater circuit is quiet and unobtrusive: truly an unsung hero of any quality amp. On the other hand, flaws in a heater circuit can produce noise.

Wurlitzer tube amps are in fact very similar to guitar amps.

But before we talk about that, let’s back up a little. The Wurlitzer itself is very analogous to an electric guitar: the heart of both instruments is a pickup that converts vibration into an electrical signal that is ultimately sent to an amplifier. In a guitar, the amplifier is almost always external, but a Wurlitzer’s amplifier is tucked into the body of the instrument.

An effects loop opens up many, many tonal possibilities in your Wurlitzer. Some of the earlier Wurlitzers have a reputation as a one-trick pony. The 112, for instance. How many people on forums have opined that it’s good for that one Ray Charles sound, and that’s it? Three people? Four? That’s not the point. The point is that, once you give the 112 an fx loop, it now has an unlimited amount of sounds.

But what sounds, specifically, should you plug into your Wurlitzer’s effects loop?