Tone library / Johnny Cash / Fulsome prison blues

Fulsome prison blues amp settings — Crate GX-15R

The Johnny Cash guitar tone for “Fulsome prison blues”, dialed in for a Crate GX-15R with a Doner Seeker designer series. Original studio version, Sun Records single (1955)

Original rig

Fender Esquire through Sears Silvertone amp, Sun Studios tape slapback delay (~130ms), flatwound strings

Clean, twangy, percussive country tone with tight palm-muted bass notes and bright single-note leads

Amp settings — Crate GX-15R

Knob	Setting (0–10)
Gain	2
Bass	4
Mid	5
Treble	6
Presence	0
Reverb	3
Master	5

Don’t have a Crate GX-15R? Match your own rig →

Guitar

PICKUPbridge TONE7 VOLUME10

Signal chain

01Digital Delay (RECOMMENDED — not currently owned)

RECOMMENDED — Set delay time to 80-130ms with only 1-2 repeats at lower volume than dry signal. A Boss DD-3 or Donner Yellow Fall (~$30) will get you there. Without this pedal, the tone is 60% complete — the slapback is essential to the Sun Records sound.

Time 3 · Feedback 2 · Level 4

Why these settings

The Crate GX-15R is a solid-state practice amp with limited headroom and a brighter, thinner voice than the original warm Silvertone tube amp. Gain stays at 2 to keep it dead clean — any breakup destroys the percussive clarity. Treble pulled back to 6 (vs typical 7-8 recommendation) because the GX-15R's solid-state preamp gets harsh quickly. The built-in reverb substitutes partially for the room ambiance, but you genuinely need a slapback delay pedal to nail this tone.

PRO TIPPalm mute aggressively on the low strings right at the bridge saddles — the muted notes should have clear pitch, not just a thump. Luther Perkins' whole sound is defined by that tight 'chunk' on beats 1 and 3 with the bass notes ringing briefly through the slapback. Use a medium-stiff pick and strike close to the bridge for maximum twang.

Get this tone on your amp

These settings are for a Crate GX-15R. ToneAdapt matches any song to whatever amp, guitar and pedals you own — first match is free.

Get ToneAdapt on Google Play

More tones for the Crate GX-15R

Animal I Have BecomeThree Days Grace

Find your amp

Browse

Crate GX-15R settingsALL SONGS FOR THIS AMP Johnny Cash tonesALL SONGS Tone libraryEVERYTHING

Song, artist and gear names are used to identify the tone being matched; ToneAdapt is not affiliated with or endorsed by the artists or manufacturers mentioned. Settings are AI-generated starting points — trust your ears.