No matter your tone shaping needs – from tasteful EQ sections that help shape it to models with built-in drive for metal bands – there is something suitable to meet them all.
Hybrid amps combine the best features from both worlds by pairing a tube preamp with a solid-state power amp. They tend to be lighter and require less maintenance than pure tube amplifiers.
Tube vs. Solid-State Amps
Solid-state amps and tubes are two main categories of amplifiers, respectively. Tube amps tend to produce warmer sounds with more harmonic distortion and natural “life.” Furthermore, tubes respond more readily when you hit harder on your strings as this will increase distortion while soft playing will result in cleaner tone for greater consistency in tone quality. It gives these unique amplifiers their distinctive sound that many guitarists appreciate.
Solid-state amps tend to be much crisper and consistent. They’re much better at handling transients and peaks, which is especially crucial when playing bass guitar as the lower frequencies need more amplification power than higher ones. Furthermore, these amplifiers may lack some of the harmonics which add warmth to their tone, leading some to perceive less “character.”
Another difference between the two types of amplifiers is their susceptibility to wearing out over time, leading to leakage of internal components as they wear away, creating problems in bass amplifiers used frequently. Furthermore, tubes can be very costly to replace.
Therefore, if your budget is limited or if you require something that will outlive a tube amp, solid-state bass amplifiers could be your ideal choice.
Also available are hybrid amps which combine both tube preamp and solid-state power amp elements into one system; these hybrid amps are commonly known as “ss-tb or ss/tb amps.” Mesa WD-800 and Ampeg Mini CMD 121P are two such amps; both solid state basses with tube preamps designed to handle up to 4 ohm loads, feature an input for 1/4″ cables, outputs capable of supporting 8-ohm speakers, control knobs such as gain, volume, four band EQ settings and two filter knobs; power switches can also be found on the back as well as switches that enable effects loop and tuner out.
Sound Issues
If your amp sounds dull, harsh or lifeless you should seriously consider changing amplifiers. Your power tubes could have reached the end of their expected lifespan and need replacing; some guitarists replace their tubes every two years regardless of sound quality; others treat them like car oil – waiting until it starts wearing thin before replacing it.
An effective way to test whether the issue lies within power tubes is to run your amp with one tube disconnected at a time. If this fixes it, most likely there is something amiss with preamp tubes or components upstream of power tubes that needs attention.
One other possible cause may be a broken power tube screen resistor. If this fails open with infinite resistance, its output of the entire amp drops significantly; replacing this tube would correct this issue but will likely alter the sound quality significantly.
An amp that produces rumbling noise is usually not capable of handling the low frequencies from a bass guitar correctly or there may be an improper connection between amp and speaker.
If this is the case for you, adjusting or replacing the speaker wires could be all it takes. Furthermore, cleaning all connectors could also help; if all else fails you could take your amp in for repairs.
Hum is one of the primary issues with tube amplifiers and may result in noise or buzzing when input jack shunt switch is not properly in contact with its tip connector, or there is a significant voltage differential between power tube cathode pins and plate pins. A fixed bias circuit coupling cap (usually electrolytic) may also contribute to this hum. To test for its function, alligator clip in an extra cap in parallel with your original and see if that reduces or eliminates it; otherwise replace old cap immediately if not. Leakage from within an active power tube could potentially produce significant noise that even threatens power tube screens – an alligator clip-in test would allow you to check its workings!
Buying a Hybrid Amp
Hybrid amps offer a combination of tube and solid-state circuits in their design. Most often they combine a valve preamp with a solid-state power amp for optimal tone production as well as powerful volume production – ideal for bass players looking for the best of both worlds!
There is a range of hybrid amplifiers on the market today, from low budget Chinese products to higher end designs. Most perform admirably when first purchased; however due to poor thermal management and subpar components they will often cease functioning within one year; typical examples being Indeed G2, Bravo, Miridiy, and Muse-style copies found on eBay as examples.
When searching for a hybrid amp, the first thing to keep in mind is what sounds you prefer and its purpose – be it home use or stage performance. Once that decision has been made, decide how much gain you need: turning up gain will louden the signal – ideal for rock and metal guitarists but difficult to control at higher gains settings.
Consider whether or not you require distortion settings; if not, a clean hybrid amp should do just fine for you; otherwise it would be worthwhile exploring tube hybrid amps that offer both distortion options as well as clean tones.
Consideration should also be given to how many channels you require when purchasing a hybrid amplifier. For instance, if two channels is all that’s necessary for you to play your instruments properly then purchasing either a half stack or small combo should do just fine, while for those needing additional channels either larger combo or even full stack may be more suitable options.
If you’re uncertain of which amplifier to purchase, renting different models first could provide invaluable guidance in selecting an amp that best meets your needs while saving you money from purchasing unnecessary gear.
Maintenance
Bass guitars require lower frequencies than electric guitars, and so bass amps must be designed specifically to handle low-frequency sound waves. Bass amps typically feature louder speakers with higher power output as well as features tailored specifically to handling bass frequency sound input.
Many bass amplifiers today are hybrid designs, featuring both a tube preamplifier and solid state power amplifier for optimal tone with improved reliability and light weight. Some hybrid bass amps even incorporate bypass switches for their tube preamps so players can switch over to using solid state when their tubes fail or there are technical issues with them.
Combo bass amplifiers (also referred to as “combo” amps) are smaller amps that combine a preamplifier with tone controls, power amplifier and speaker in one integrated unit. Combo amps are most suitable for bassists performing acoustic or soft rock genres that do not necessitate high stage volumes; more powerful combo amps may be preferred by bassists performing other genres that do require high stage volumes.
Separate amplifier heads known as “amp heads” provide bassists with another great option to customize their rig by mixing and matching different models and brands of preamplifier, equalizer and power amplifiers. Furthermore, separate amp heads and cabinets make replacing components that become defective easier as this doesn’t necessitate taking out their entire rig like with combo amps.
Some professional-grade bass amps feature a crossover feature that divides the bass signal into low and high frequency components for use with appropriate speakers and speaker cabinets, respectively. This gives bassists more control over sound quality by customizing their EQ settings according to venue or performance conditions.
Bassists without their own amplifier rig can make do with using regular guitar amps, though the risk of damaging its speaker due to low-frequency signal increases with each bass guitar use. To minimize this danger, bassists should only plug their instrument into amplifiers designed to accommodate low frequencies; furthermore they should consider turning down their volume settings in case of gig performances.