12 Technology Drive, Ste.13 East Setauket, NY 11733
Resistors and Capacitors:
The Critical
Components of Tone
RESISTORS:
Usually underestimated as to the contribution they make to tone, these "passive" components make a real difference in sound when carefully selected. Carbon composition resistors were used in most every amp made until the late sixties when they were gradually replaced by carbon film types, a inferior component choice in many ways. Metal film and metal oxide resistors are the standard choice in high-end stereo equipment but do not work as well in guitar amps. Remember that stereo equipment reproduces music, While guitar amps, working with the guitar itself, PRODUCE sound . The warm coloration of carbon comp resistors, often undesirable in stereo equipment, is vital to the sound of a guitar amp.
Metal film and metal oxide resistors impart a slightly brittle tone and a hard aural sheen, especially when a amp is just beginning to distort in the preamp stages, before output stage loading can smooth these undesirable overtones out.
In all audio stages we use carbon comp's in general repair and restoration work. Metal oxide and wirewound resistors are only used in power supply circuits.
Usually underestimated as to the contribution they make to tone, these "passive" components make a real difference in sound when carefully selected. Carbon composition resistors were used in most every amp made until the late sixties when they were gradually replaced by carbon film types, a inferior component choice in many ways. Metal film and metal oxide resistors are the standard choice in high-end stereo equipment but do not work as well in guitar amps. Remember that stereo equipment reproduces music, While guitar amps, working with the guitar itself, PRODUCE sound . The warm coloration of carbon comp resistors, often undesirable in stereo equipment, is vital to the sound of a guitar amp.
Metal film and metal oxide resistors impart a slightly brittle tone and a hard aural sheen, especially when a amp is just beginning to distort in the preamp stages, before output stage loading can smooth these undesirable overtones out.
In all audio stages we use carbon comp's in general repair and restoration work. Metal oxide and wirewound resistors are only used in power supply circuits.
CAPACITORS:
The effect on tone by capacitors cannot be over emphasized. These so-called passive components are actually highly reactive in guitar amp circuits and have a great effect on tone.
Our standard cap for guitar amps is the Mallory 150 film/foil wrap quite similar to the the mylar and paper/foil caps of the past, having a softer response when used in a overdriven preamp circuit and a more musical tone played clean. Orange Drops were the standard replacement for almost any amp cap in the years before overdrive and multi-gain stages. The Mallory's are a bit smoother when handling a overdriven signal and have less harshness in sound compared to O'Drops. On Fender amps we prefer Mallory 150 series caps as they are the closest match to the old Astrons and Blue Mallory's used in most pre-cbs amps. Unless a more "hi-fi" sound is desired this is our choice for classic Fender tone. We have also had good results with SoZo Mustard caps in Marshall Vox, and Hiwatt amps. The blue molded Mallory caps used in Fender Blackface amps rarely fail usually do not need replacement.
We do not use supposed "nos" or recycled old caps in any repair we do. It is our opinion that old dried out caps are just that- old bad parts. The caps we use are chosen to sound like the way original type caps sounded like when new and will give best results after a break in period between 40-100 hours.
The effect on tone by capacitors cannot be over emphasized. These so-called passive components are actually highly reactive in guitar amp circuits and have a great effect on tone.
Our standard cap for guitar amps is the Mallory 150 film/foil wrap quite similar to the the mylar and paper/foil caps of the past, having a softer response when used in a overdriven preamp circuit and a more musical tone played clean. Orange Drops were the standard replacement for almost any amp cap in the years before overdrive and multi-gain stages. The Mallory's are a bit smoother when handling a overdriven signal and have less harshness in sound compared to O'Drops. On Fender amps we prefer Mallory 150 series caps as they are the closest match to the old Astrons and Blue Mallory's used in most pre-cbs amps. Unless a more "hi-fi" sound is desired this is our choice for classic Fender tone. We have also had good results with SoZo Mustard caps in Marshall Vox, and Hiwatt amps. The blue molded Mallory caps used in Fender Blackface amps rarely fail usually do not need replacement.
We do not use supposed "nos" or recycled old caps in any repair we do. It is our opinion that old dried out caps are just that- old bad parts. The caps we use are chosen to sound like the way original type caps sounded like when new and will give best results after a break in period between 40-100 hours.
We do
not routinely change film (tone) caps unless they are
actually defective or have been replaced with improper parts in the past as
these are critical to the sound of a vintage amplifier.
In power supply areas we use high quality high reliability caps from reputable manufactures, not cheapo imports from the far east.
In power supply areas we use high quality high reliability caps from reputable manufactures, not cheapo imports from the far east.