takin'bout guitar amp schematics

/HOME /GUITAR AMP /bgnr_xtc

CLEAN 2nd

Prohibited no permission reprint

The clean channel step it is 2nd.
The boost switch has been added to the standard 1 step amplifiers of cathode bias resistance 1.5k and plate load resistance 100k.
As for the boost circuit adjusting the attenuation, with the system which puts out the boost effect, only zone above 11dB boost is done from the mediant limits.

R7 1.5k Cathode bias resistance. Fender standard value

R8 100k Plate load resistance. Fender standard value

R9 1M When the boost switch TURNING ON, changing partial pressure ratio with the combination with R11, resistance in order to put out the boost effect. Even with boost ON as for the signal having been attenuated, as for damping ratio - 13dB

R10 3.3M Amount overpowering with the combination with R11, it has been attenuated the signal. With boost OFF damping ratio - becomes 24dB

R11 220k At the time of boost off amount overpowering with the combination with R10, it is attenuated the signal, at the time of boost ON including also R9, it decides partial pressure ratio

C7 22u Cathode bias resistant by-pass capacitor. fc=4.8Hz

C8 0.022u Cutting direct current, the condenser for connection with next step which passes through just interchange. With boost off fc=2Hz. With boost ON fc=6Hz. In any case the extent which does not become problem it has become low frequency

C9 1000p At the time of boost ON just above approximately 130Hz boost the condenser for HPF in order to do

C10 12p At the time of boost off high resister waiting compensation easy the condenser of for the sake of. When the high resistance of 3.3M and the like you use, zone of high resister deteriorates with influence of input capacitance of the vacuum tube of the next step. This way when the condenser of small capacity is added, deterioration of zone can be revised.

SW2 * Boost switch. Because with boost OFF - - it is 13dB with 24dB and boost ON, 11dB of the finite difference reaches the boost quantity

R7	1.5k	Cathode bias resistance. Fender standard value
R8	100k	Plate load resistance. Fender standard value
R9	1M	When the boost switch TURNING ON, changing partial pressure ratio with the combination with R11, resistance in order to put out the boost effect. Even with boost ON as for the signal having been attenuated, as for damping ratio - 13dB
R10	3.3M	Amount overpowering with the combination with R11, it has been attenuated the signal. With boost OFF damping ratio - becomes 24dB
R11	220k	At the time of boost off amount overpowering with the combination with R10, it is attenuated the signal, at the time of boost ON including also R9, it decides partial pressure ratio
C7	22u	Cathode bias resistant by-pass capacitor. fc=4.8Hz
C8	0.022u	Cutting direct current, the condenser for connection with next step which passes through just interchange. With boost off fc=2Hz. With boost ON fc=6Hz. In any case the extent which does not become problem it has become low frequency
C9	1000p	At the time of boost ON just above approximately 130Hz boost the condenser for HPF in order to do
C10	12p	At the time of boost off high resister waiting compensation easy the condenser of for the sake of. When the high resistance of 3.3M and the like you use, zone of high resister deteriorates with influence of input capacitance of the vacuum tube of the next step. This way when the condenser of small capacity is added, deterioration of zone can be revised.
SW2	*	Boost switch. Because with boost OFF - - it is 13dB with 24dB and boost ON, 11dB of the finite difference reaches the boost quantity