There’s a lot of information (and confusion) out there regarding the constant debate over tube amplifiers versus solid-state amplifiers. Everyone has their own preference, but in general, most professional players agree that tube amplifiers are superior. Let’s look at why that is the case and compare how both tube and solid-state amps are constructed and function.
Note: With a few exceptions (looking at you, gorgeous Roland JC-120), I am firmly planted in the Tubes-Are-Better camp. I’ll be as unbiased as possible in discussing the pros and cons of each, though.
Overdrive Tone:
The real conflict between tubes and solid-state swirls around the way that each product produces distortion and overdrive. When an audio signal enters the amp, it gets amplified by either tubes or transistors. Transistors are smaller, more cost-effective devices that have a cut-off point. When the incoming signal gets loud enough to reach that threshold, the transistor clips the signal, or cuts off the tops and bottoms of the audio waveform. This gets further amplified by other transistors and eventually results in a distorted sound at the output.
Tubes don’t have a cut-off point in the sense that they clip the audio signal more gently, as if in a curve. This results in a more organic, smoother sounding distortion that most people find more desirable. There’s also the addition of even-order harmonics with tube amplification, which means that faint distorted frequencies ring out at higher octaves of the fundamental note. These harmonics aren’t produced with transistorized circuits, and their inclusion rounds out and enriches the overall audio signal.
The lack of hard cut-off point with tubes results in the touch sensitivity that many players enjoy. You’ll often see this referred to as “edge of breakup”, meaning that, under the right conditions, the instrument can be played without distortion when the strings are picked lightly, and with distortion when they are strummed with more force. This trick is more difficult to achieve with transistors. What’s more, tube overdrive and distortion creates a natural audio compression that helps the audio signal sound richer, warmer, and fatter, especially at high volumes.
Speaking of high volumes, tube amps need to be relatively hot to work properly and sound their best. Most tubes sound anemic and hollow at low volume, where transistor circuits do just fine at a whisper. A lot of players don’t have the luxury of knocking the walls down with added volume.
Durability:
Tube amps are much more fragile than solid-state. Tubes are made of glass and hold an internal vacuum. Even though they are protected by the amp’s cabinet, a wrong bump or smash can break a tube. Tube amps also run on significantly higher internal voltage than solid-state, and although the components are rated to handle the current, it’s still a lot of energy running around and causing stress. Solid-state amps can usually be thrown off a moving truck and still function (please don’t try this at home!), but problems at the component level are more difficult to diagnose when they arise.
Repair:
Unfortunately, most solid-state amplifiers are built to be disposable. It’s much more challenging to fix a broken solid-state amp, and hourly repair costs can quickly balloon when the required fix is complicated. When solid-state amps fail, it usually is a matter of weighing the cost of repair versus putting that money towards a new amp or better model. The transistors that amplify the signal in solid-state amps require more connected components to function correctly, and the circuit boards are always more populated and intricate. In digital circuits, proprietary chips may be involved that can only be replaced from the manufacturing company, not repaired.
On the other hand, tube circuits involve larger and fewer components. The tubes do all of the heavy lifting, so in a super simplified sense, the other components are just carrying current and making the necessary connections to help the tubes do their job. Most tube amps are designed with future repair or modification in mind. In short, it seems like most solid-state manufacturers don’t want you to repair the product, while most tube manufacturers know that you will eventually.
Realness:
Tube amplification was invented before solid-state, so the natural progression of technology is that solid-state will forever try to capture, emulate, and improve on the sound of tubes. Has it happened yet? Many players including myself would argue no, not at all. Solid-state sounds close to the real deal, especially with digital modelers, but that extra five percent of je ne sais quoi is what has yet to be accurately captured. The combination of even-order harmonics from an amp’s tubes, plus the volume saturation, plus the physical act of moving air in the room from the speaker is, as of now, the missing piece from solid-state products.
Cost:
There’s no bones about it: tube amps are far more expensive than solid-state. This is because the tubes themselves are costly on a parts-level, plus tube amps require expensive output transformers whereas solid-state usually relies on transistors to do the job in the output section. Tube amps that have onboard effects like tremolo, true vibrato, and reverb usually have extra transformers, chokes, and tubes for those sections as well. What’s more, tube amps that are intended to last decades are often hand-wired or constructed with point-to-point wiring, meaning that all internal components are easily accessible and visible in case a repair is needed. Building an amp in this fashion requires literal hands-on work, so labor costs are higher.
Mojo:
Guitars and cars are always compared, so a tube amp is like a classic American muscle car and a solid-state is like a brand-new vehicle that just came off the line. You may find enjoyment in both, or you may prefer one over the other. At the end of the day, your amp should be like your guitar – it should make you want to play more! I find that tube amps have extra mojo and “coolness” that gets me excited to pick up my instrument and play some tunes. Your goal is always to find that piece of gear that makes you want to do the same.
I hope that this helped shed some light on both sides of the eternal tube versus solid-state debate! Let us know if you have any questions, and if you’re interested in your own custom tube amplifier, check out our custom amps page!
