Amp mods

Tube amp mods

Our amp mods change boring factory amps to singing musician friends. We always try to dig a soul from amp and we want change reaction on player's style changes. We mainly want to create fat rock sounds with warm singing leads - that's our idea to leave tube amp sing your soul and brain through your fingers, guitar and tube amp.

Of course the best for mods are amps with full tube signal paths, but ask us with your specific demands.


We modded a lot of amp from Marshall, Engl, Mesa, Bugera, Peavey, Laney etc. Every time we want to find solution somewhere on the crossroad of your idea and technical possibilities of your amp. You can hear some examples of our mods on our pages or on our YT channel.

Select from amp's mark from the top menu. We can create your specific mod for known amps or for your different amp.

Randall modifications

Prices for Randall mods are approx. 80-100 Eur (w/o shipment), it depends on many factors, mainly on elaborateness.

Randall RD45

Cheap chinese amp sounds little bit sterile, but 4rockers preamp modification changes it to typical metal machine with good sound profile for typical metal backings. (v. 4/2016)

Randall RH50T/RG50T

This cheap amp is too sterile for our taste. But we can make sound with more punch in the middle, better for metal players...

Peavey mods

Peavey line covers all music styles, from country and blues to higain metal amps. The typical task is mod of higain amp (like 5150), because it sounds good while playing standalone, but often is too fizzy or his overgained sound is deleted by another amp in the band. We can mod preamps to give more meat&balls to sound of these amps, change power amp settings etc.

Prices for Peavey mods are approx. 100-130 Eur (w/o shipment), it depends on many factors, mainly on elaborateness.

Peavey Valveking

Valveking is based on Classic line, it's better to mod this amp for hard&heavy... This is huge mod on both preamp and power amp, but amp is ready to rock after mods...

Peavey 5150 II

Here you can hear one short video from my job on 5150 II. This amp is copied in Bugera line 626x, just visit Bugera section on this website to hear differences from original sound. I cannot add original sound before mod due to my error, when the original sound was distorted by camera. This video was taken after preamp mod, so you can hear less fizzy sound, not so overgained.

Other tube amp mods

There are a lot of specific and sometimes strange requests on tube modifications. We can modify some Chinese products, old amps from Ex-communist countries, boutique amps or no-name made by amateurs.

Jet City JCA-50

This chinese amp was designed by Soldano and signal path evokes hot rodded Marshalls (aka Soldanos). Clients called to 4rockers with higain requests, less brittle sound. Check this video with first modification of JCA-50:


You can hear old legendary amp MV-3 from East Germany in the next video. Our mod contents super boutique parts, but also topology mod, where Matchless meets East Germany. Sounds awful for jazz players!


Rebuilding noname amplifiers

Maybe you have a noname old tube amp... not functional, demaged, but with OK mechanical parts... We can upgrade your amp to new level, insert new high quality boutique level parts. The result is perfect sound of almost new amp with lower price. Sometimes we hear here in 4rockers sentences like "Damned, this one has better sound that both my original old Marshalls from 70's!" (one client said this in August 2014)

Other boutique amp mods

A lot of amps could be repaired, modded, improved... There is no limit...



Another world are Chinese amps. Chinese engineers can calculate part values, but forgot to hear their products. We can mod these amps, but elaborateness is higher...

Ashton Viper VP100

Price of these individual mods changes piece by piece...