Best guitar amps
Four published figures settle most of this, and wattage is the one most likely to mislead you.
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We have not played this gear. Every pick below is chosen from published manufacturer specifications and the arithmetic set out in how we research, which you can re-run yourself.
Four published figures decide an amp: wattage, speaker size and model, tube complement, and whether there is a power-reduction option. Wattage is the one most likely to mislead — doubling power buys about 3 dB, so a 100 W amp is not twice as loud as a 50 W one. The speaker moves the air, and it changes the sound more than most people expect.
Before comparing amps, decide one thing: do you want the amp to make the distortion, or the pedals? That single question eliminates most of the market, and it is covered properly in tube vs solid state.
Best guitar amps
| # | Product | Best for | Price |
|---|---|---|---|
| 01 | No photo BOSS KATANA-50 MkII 50 W into a 12-inch speaker with five amp characters, five effects sections and a Power Control switch. | The most capability per dollar, by a distance | |
| 02 | No photo Fender Blues Junior IV 15 W of EL84 through a 12-inch Celestion — the classic small-club valve combo. | A real valve amp at a sensible size | |
| 03 | No photo Marshall DSL20CR 20 W of EL34 with a half-power setting, a real effects loop and per-channel gain and volume. | Two channels of valve gain with an effects loop | |
| 04 | No photo VOX AC10C1 10 W of EL84 through a 10-inch Celestion, with the Top Boost-style tone circuit. | The Vox chime at the lowest wattage that still fills a room | |
| ! | No photo Positive Grid Spark 40 An excellent desk amp with two 4-inch speakers, which is the wrong tool for a rehearsal room. Skip this one — see why below | Not a stage amp, and frequently bought as one |
Rows link to the full write-up further down this page. Prices come from the live price layer only — where there is no live figure the button reads “Check price” rather than showing a remembered number.
02Published specifications, side by side
| Amp | Power | Speaker | Tubes | Power reduction | Weight |
|---|---|---|---|---|---|
| BOSS Katana-50 MkII | 50 W solid state | 12" | None | Power Control switch | 11.6 kg |
| Fender Blues Junior IV | 15 W valve | 12" Celestion A-Type | 3 x 12AX7, 2 x EL84 | None | 31.5 lb |
| Marshall DSL20CR | 20 W valve | 12" Celestion Seventy-80 | 3 x ECC83, 2 x EL34 | Half power (10 W) | 35.2 lb |
| VOX AC10C1 | 10 W valve | 10" Celestion VX10 | 2 x 12AX7, 2 x EL84 | Master volume only | 12.3 kg |
| Positive Grid Spark 40 | 40 W class D | 2 x 4" | None | n/a | 5.2 kg |
Every figure is the manufacturer's published specification.
03The wattage arithmetic
Perceived loudness scales roughly with the logarithm of power. Doubling the power adds about 3 dB, which is a noticeable but modest change — nothing like twice as loud. Going from 20 W to 100 W is a factor of five, or about 7 dB.
What that means practically: a 100 W amp is not five times as loud as a 20 W one, and dropping from 100 W to 50 W will not make an amp quiet enough for a bedroom. Speaker efficiency, measured in dB at one watt at one meter, varies by several dB between models and can matter more than the amplifier's rating. Attenuator vs master volume works through what to do about it.
BOSS KATANA-50 MkII
The most capability per dollar, by a distance
The number50 W rated output, 47 W power consumption, 11.6 kg. All published by BOSS.
BOSS publishes 50 W into a single 12-inch speaker, five amp characters each with a second variation, and five independent effects sections with three variations each. The Power Control switch reduces the output for lower-volume playing.
The connectivity is what makes it more than a practice amp: a Power Amp In jack, a Rec Out/Phones jack, an expression/control jack, Aux In and USB. You can record from it, run a modeler into its power amp, and control it with a footswitch.
No XLR output and no IR loading, and deep editing needs BOSS Tone Studio on a computer. The front panel gives you the surface only.
| Rated power output | 50 W |
|---|---|
| Speaker | 30 cm (12") x 1 |
| Amp characters | Acoustic, Clean, Crunch, Lead, Brown, each with a second variation |
| Effects | Five independent sections — Booster, Mod, FX, Delay, Reverb — with three variations each |
| Power Control | Switch that reduces output for lower-volume playing |
| Connectors | Input, Power Amp In, Rec Out/Phones, expression/control jack, Aux In, USB B |
| Power consumption | 47 W |
| Weight | 11.6 kg (25 lb 10 oz) |
| What it does not do | No XLR output and no built-in IR loading. Deep editing needs the BOSS Tone Studio software on a computer — the front panel gives you the surface only. |
Specs from BOSS KATANA-50 MkII specifications. We have not used this unit.
Fender Blues Junior IV
A real valve amp at a sensible size
The number15 W, 3 x 12AX7 and 2 x EL84, 12-inch Celestion A-Type, 31.5 lb.
Fender publishes 15 W, three 12AX7 preamp tubes, two EL84 power tubes and a 12-inch Celestion A-Type speaker. That is a proper valve power section driving a proper speaker, which is what the money is for.
The FAT switch is a mid boost with an included one-button footswitch, not a second channel. There is no channel switching and no effects loop.
15 W of EL84 is loud. Loud enough to be genuinely difficult in a small room, and there is no power reduction — which is why the attenuator page exists.
| Power | 15 W, all-tube |
|---|---|
| Speaker | 12" Celestion A-Type |
| Preamp tubes | 3 x 12AX7 |
| Power tubes | 2 x EL84 |
| Controls | Volume, Treble, Bass, Middle, Reverb, Master, FAT switch |
| Weight | 31.5 lb |
| Footswitch | One-button footswitch for the FAT mid boost, included |
| What it does not do | No effects loop and no channel switching — the FAT switch is a mid boost, not a second channel. 15 W of EL84 is loud enough to be a problem in a small room and it has no attenuator. |
Specs from Fender Blues Junior IV product page. We have not used this unit.
Marshall DSL20CR
Two channels of valve gain with an effects loop
The number20 W with a 10 W setting, 3 x ECC83, 2 x EL34, 12-inch Celestion Seventy-80, 35.2 lb.
Marshall publishes 20 W with a half-power setting, three ECC83 preamp tubes and two EL34 power tubes into a 12-inch Celestion Seventy-80. EL34s are the British mid-forward voice and they are the reason to choose this over an EL84 or 6L6 amp.
Two channels — Classic Gain and Ultra Gain — with independent gain and volume, plus a Resonance control and a genuine effects loop. That loop is the practical advantage over the Blues Junior: time-based effects have somewhere to go.
The half-power switch takes it to 10 W, which is about 3 dB. That is a real reduction and it is not bedroom volume. The reverb is digital and there is one level per channel.
| Power | 20 W, with a half-power (10 W) setting |
|---|---|
| Speaker | 12" Celestion Seventy-80 |
| Preamp tubes | 3 x ECC83 |
| Power tubes | 2 x EL34 |
| Channels | Two — Classic Gain and Ultra Gain — with per-channel gain and volume |
| Extras | Digital reverb, effects loop, Resonance control |
| Weight | 35.2 lb |
| What it does not do | The half-power switch takes it to 10 W, not to bedroom volume — this is not a power scaler. The reverb is digital and there is only one reverb level per channel. |
Specs from Marshall DSL20CR product page. We have not used this unit.
VOX AC10C1
The Vox chime at the lowest wattage that still fills a room
The number10 W RMS, 2 x 12AX7 and 2 x EL84, 10-inch Celestion VX10, 12.3 kg.
Vox publishes 10 W RMS, two 12AX7s and two EL84s into a 10-inch Celestion VX10, with Gain, Volume, Bass, Treble and Reverb.
The master volume is the practical feature. It lets you drive the preamp without the power section at full output, which is how you get any of this amp's character at a manageable level.
No effects loop, no channel switching, and no attenuator. The 10-inch speaker is a genuinely different instrument from a 12 — tighter, less low-end weight, more upper-mid presence.
| Power | 10 W RMS, all-tube |
|---|---|
| Speaker | 1 x 10" Celestion VX10 |
| Tubes | 2 x 12AX7 preamp, 2 x EL84 power |
| Controls | Gain, Volume, Bass, Treble, Reverb |
| Connections | One normal input, one external speaker jack |
| Size / weight | 520 x 210 x 410 mm, 12.3 kg (27.1 lb) |
| What it does not do | No effects loop, no channel switching, no attenuator. 10 W of EL84 with a master volume is still a loud amp before the power section does anything interesting. |
Specs from VOX AC10 Custom product page. We have not used this unit.
Positive Grid Spark 40
Not a stage amp, and frequently bought as one
We are not picking this as a general-purpose amp. Positive Grid publishes 40 W class D into two 4-inch speakers, 33 amp models, 43 effects, Bluetooth audio and a USB recording interface. For practicing at a desk it is genuinely very good.
The specification that decides it is the speakers. Two 4-inch drivers cannot move the air a 12-inch does, and no amount of wattage changes that — a class-D 40 W into 4-inch cones is not comparable to 15 W of valve power into a 12.
Buy it as a practice and songwriting tool, which is what it is designed to be. If it needs to compete with a drummer, buy something in this list with a 12-inch speaker.
| Power | 40 W class D |
|---|---|
| Speakers | 2 x 4" custom designed |
| Amp models | 33 |
| Effects | 43 — noise gate, compressor, distortion, modulation/EQ, delay, reverb |
| Connectivity | 1/4" guitar input, 1/8" aux in, 1/8" headphone, Bluetooth audio, USB recording interface |
| Size / weight | 350 x 180 x 190 mm, 5.2 kg |
| What it does not do | No effects loop and no external speaker output. The 4" drivers cannot move air the way a 12" can — this is a desk and sofa amp, not a rehearsal-room one. |
Specs from Positive Grid Spark 40 product page. We have not used this unit.
04The tube complement, briefly
- EL84 — Vox and the Fender Blues Junior. Breaks up earlier, brighter, chimier. Less clean headroom for a given wattage.
- EL34 — the Marshall DSL20CR and most British amps. Mid-forward, aggressive when pushed.
- 6L6 — most American amps and the EVH Iconic. More clean headroom, scooped and tight.
- 12AX7 / ECC83 — the same tube under two names, used in the preamp of nearly everything here. Count is a rough proxy for gain stages.
05What we did not include
Nothing above about $1,500, because at that level the interesting comparison is against a good amp plus an attenuator or a load box, and that is a different page.
No 100 W heads. For anyone not already gigging large rooms, 100 W is headroom you will never use and weight you will always carry. Combo vs head and cab covers when that changes.
Frequently asked questions
+ What is the best guitar amp for most players?
+ How many watts do I need?
+ Does speaker size matter more than wattage?
+ Is a modeling amp good enough for gigs?
Sources
Related on Fret & Fuzz
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Top pick: BOSS KATANA-50 MkII
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Headroom, not gain. Why solid state is genuinely competitive here, and which amps have the jacks that matter.
Best Pedal Platform pick: BOSS KATANA-50 MkII
Best practice amps
Speaker size sets the ceiling and the headphone output decides the rest. Four practice amps on published specs.
Best Practice Amp pick: Positive Grid Spark 40
Should you upgrade the pedal or the amp?
One five-minute test with the pedals switched off decides it. Plus the cost comparison nobody totals up.
Top pick: BOSS KATANA-50 MkII
