Then wire the 2 tap to the ext speaker jack. User manual for the IBS amps (790kB). Photograph of an IBS 5510 bass combo. Most importantly the tone gets rougher and rawer with more mids and higher frequencies, aka presence. If you think your tone is too bright or harsh or you’re seeking a mellow and nice clean tone, you probably want to keep the NBF loop. Each channel has individual volume and effects sends with channel 4 also having additional bass and treble knobs.
The whole dynamic area can be within a narrow interval, i.e. 2 and 2.5. These amps require a careful touch when dialling in the reverb, which irritates us. This special «heavy duty» cabinet was fitted with 4 100W 12″ speakers. The JTM50’s In 1966 Marshall switched to EL34 tubes. To reflect this the JTM45 panels were changed to JTM50 panels.
The diode rectifier will feed your amp’s filter caps with a higher and “faster” DC voltage compared to a tube rectifier. Don’t confuse this amp with the older Artiste’s from the 1970’s. The preamp is solid state, only the power amp uses tubes. Different speakers may alter the tone significantly in the Pro Reverb, as in all amps. A set of Celestions give you a Britsh Marshall color with strong mids, while traditional Jensen-style speakers give you the classic Fender tone. The amp will play louder than before given the same volume knob setting. See Viva Analog’s Marshall Amps page for technical information on modding your Marshall. They were Marshalls first venture into solid state country.