MXR · Distortion+ · 1974–1984 (MXR); reissued by Dunlop as the M104
The Distortion+ was one of MXR's first pedals, part of a trio that followed the Phase 90 in 1974. It's about as simple as a dirt pedal gets. One op-amp boosts the signal and two germanium diodes clip it, with only Output and Distortion knobs and no tone control. Turning up Distortion adds treble along with gain. Dunlop's own history credits it with the distortion on Blizzard of Ozz, and Dunlop later built a signature model after its engineers measured Randy Rhoads' own pedal. Jerry Garcia used one for his distortion in the late 1970s, and Dave Murray of Iron Maiden has used one since the early 1980s. The logo went from script to block around 1976, but the circuit didn't change, so a script unit is a collector's choice more than a tonal one. The DOD 250 Overdrive is a near twin. For playing, a Dunlop M104 gives you the same two knobs with an LED and a power jack. For collecting, look for a clean yellow Rochester box with its stock diodes.
It's one of the most modified pedals around, so swapped diodes, added switches and replaced parts are common. Old units also get scratchy pots, worn footswitches and corroded battery snaps.
Buying guide
To play one, buy a Dunlop M104, which keeps the same two knobs and adds an LED and a power jack, at $70 to $85 delivered here. About 27 are for sale by our count and most ask $85–170 delivered, which is mostly Rochester-made MXR units, and we'd pay $148 for the one titled 1981. Script-logo units from before about 1976 ask $277 and up, but the circuit didn't change with the logo, and MXR units made before 1981 run on a battery only. It's one of the most modded pedals around, so ask for a gut shot showing the two germanium diodes, and compare photos on the 1980 block-logo title that three listings share.
$69.70est. delivered
The lowest delivered Distortion+ at $70, a Dunlop M104 from a 99.9% US seller. It isn't titled tested, so ask for a clip with Distortion low, then high.
MXR M104 Distortion+ Guitar Effects Pedal P-30983
$148.00est. delivered
Titled 1981, so it's a Rochester-era MXR from the first year with a power jack, at $148 delivered from a 99.9% US seller, inside the band. Ask for a gut shot to confirm the stock germanium diodes.
MXR Distortion Plus Vintage 1981 Guitar Effect Pedal
$84.98est. delivered
An M104 with its original box at $85 delivered from a US seller. It has the same two knobs as the original, plus an LED and a power jack for a pedalboard.
MXR M104 Distortion + Effects Pedal ORIGINAL BOX (PD4048968)
$159.99est. delivered
Titled tested and working, and it comes with the box, an adapter and a battery. At $160 from Japan it's priced like an MXR original, so ask whether it's an M104 before paying that.
MXR DISTORTION+ Distortion Pedal Yellow Tested & Working w/Box Adapter/Battery
$277.08est. delivered
Titled 1970s script logo, at $277 delivered from a 99.9% US seller, about $190 under the other script here. The circuit matches the block version, so you're paying for the logo and the age.
Vintage 1970s MXR Distortion + Script Logo - Guitar Effects Pedal
Delivered prices include shipping as eBay quoted it to a US address on Oct 10, 2026. Many sellers charge by distance, so your total may differ. eBay shows yours before you pay.
Snapshot
Checked . Some may have sold.
Delivered prices include shipping as eBay quoted it to a US address on Oct 10, 2026. Many sellers charge by distance, so your total may differ. eBay shows yours before you pay.
Used$69.70est. delivered
$57.00 + $12.70 shipping
Buy It Now$57.00
Good buy
Dunlop M104. Not titled tested. In the US.
Seller: bjboydent
99.9% positive
Used$148.00est. delivered
$140.00 + $8.00 shipping
Buy It Now$140.00
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Good buy
Titled 1981, so it should have a power jack. In the US.
Seller: backyard-guitars-plus
99.9% positive
Used$84.98est. delivered
$69.99 + $14.99 shipping
Buy It Now$69.99
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Good buy
Dunlop M104 with its original box. In the US.
Seller: pawndepotllc
99.6% positive
Used$159.99est. delivered
$139.99 + $20.00 shipping
Buy It Now$139.99
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Good buy
Titled tested and working, with box, adapter and battery. Ships from Japan.
Seller: k5_japan
99.8% positive
Used$277.08est. delivered
$269.99 + $7.09 shipping
Buy It Now$269.99
Good buy
Titled 1970s script logo. Ask for a gut shot.
Seller: gratefuldays
99.9% positive
Used$160.00est. delivered
$145.00 + $15.00 shipping
Buy It Now$145.00
Our take
Titled 1979, so it runs on a battery only. In the US.
Seller: hookaroon-pickaroon
100% positive
Used$150.00delivered
$150.00 · free shipping
Buy It Now$150.00
This seller takes offers, and many sellers accept less than the asking price.
Fine if you might miss it? Send an offer first. Someone else can still buy it while you wait for a reply.
Want it for sure? Use Buy It Now.
Check the seller
Two srz_audio listings use the same title. Compare photos before you buy.
Seller: hitthegroundrunninpaul
100% positive
Used$468.99est. delivered
$449.00 + $19.99 shipping
Buy It Now$449.00
Priced high
Script logo, about $300 over the band.
Seller: ralleysprr4nhf
100% positive
Prices change daily. The live eBay search shows everything listed now, including anything new since Oct 10, 2026.
See every listing on eBay ↗eBay searchPlenty of used pedals turn up without a power supply. Check the power line in the specs above, then match the voltage and plug before you buy one. This searches Amazon for the usual kit.
Search power supplies ↗Amazon searchDOD · DOD 250
Overdrive250
Specs and what to check →
ProCo · RAT
DistortionRAT2
$150–$340 typical ask
Boss · Boss compact
DistortionDS-1
$130–$220 typical ask
MXR · Micro Amp
BoostMicro Amp
$80–$230 typical ask