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AFD #35
Hot Rodded Plexi Series
50W amplifier
Page 1: ...1 AFD 35 Hot Rodded Plexi Series 50W amplifier ...
Page 2: ...t take a rocket scientist to figure out the top hatted cigarette smoking inspiration for this amplifier Simply put the tone on that landmark album helped bring back the rock in rock and roll The tone is aggressive yet sweet and musical Although most closely linked with that album in particular the tones the AFD 35 provides lend it to all sorts of hard rock tones where both great rhythm crunch and ...
Page 3: ...aker cable 4 Set the OUTPUT SELECTOR to the match the impedance of your speaker cabinet 5 Set all rotary controls on the front panel to 12 00 clock face 6 Set PKR control to the middle right position 7 Set Channel to the up position 8 Set Master at just above minimum 9 Set front panel POWER switch in the 1 position down position with adjacent STANDBY switch in the 0 up position for 30 seconds to a...
Page 4: ...BLE control 9 OUTPUT MASTER control 10 CHANNEL 2 way toggle switch 11 GN2 GAIN 2 control 12 PKR PEAKER 3 way toggle switch 13 GN1 GAIN 1 control 14 FOOTSWITCH instrument jack 15 INPUT instrument jack INDICATOR will illuminate when the AFD is powered by turning the front panel POWER toggle switch to the ON position If INDICATOR does not turn on check your power cable connections and then the fuse o...
Page 5: ...e amplifier This volume configuration is unique to most amplifiers and occurs after the phase inverter in the power section We will save you the nerdy details and tell you that this type of volume will give you much of the feel and tone of a cranked amplifier but without the unmanageable volume Use this in conjunction with the OUTPUT MASTER to set both the volume level and degree of power amplifie...
Page 6: ...t can be used to add sparkle and gain to your tone In the middle position PKR is defeated In the UP position it boosts upper mid and high frequencies and adds noticeable gain With the toggle switch in the DOWN position it boosts extreme high frequencies and adds less gain boost than the UP position In conjunction with an active PKR lower GN1 settings will also trim the bottom end This high frequen...
Page 7: ...END of the effects loop Plug the input of your effects unit or interface device ex C lator Klein ulator into this jack using instrument cable FX RETURN instrument jack can be used to directly interface the power amp of the AFD thereby bypassing the preamp and using the amplifier as a power amplifier Conversely this is usually used as the RETURN of the effects loop Plug the output of your effects u...
Page 8: ...llows user to further control the power and response of the amplifier In 100W position the power section is in pentode operation and provides greatest headroom and dynamics In 50W position the power section is in triode operation This not only reduces output power but compresses attack softens high frequency transients and provides a softer attack MAINS IEC cable inlet plug a suitable IEC power ca...
Page 9: ... BIAS JACKS AND ADJUSTMENT From left to right V1 12AX7 ECC83 input stage 1 and gain stage 2 V2 12AX7 ECC83 gain stage 3 V3 12AX7 ECC83 gain stage 4 and tonestack driver V4 12AX7 ECC83 phase inverter for power amplifier V4 6550 V5 6550 ...
Page 10: ... jack V5 2 Blue solid arrow probe jack V6 3 Green arrow probe jack GROUND 4 Orange dashed arrow bias adjustment potentiometer shaft To measure your power tube bias carefully follow these steps with the amplifier in OPERATE and connected to a speaker load not doing so may damage your amplifier ...
Page 11: ...4mV 8 Adjust bias adjustment orange dashed arrow SLOWLY until your DMM reads approximately 55mV see calculations below To calculate bias there are two pieces of information you need to know your amplifier s power tube plate voltage and the published value for maximum plate dissipation for the power tubes used in your amplifier To save you some time and energy here are those two values Approximate ...
Page 12: ...asing your amplifier Extremely high voltages are present and vacuum tubes reach high temperatures during use The risk of electrical shock and or skin burns should ALWAYS be kept in mind Therefore bias at your own risk and only while paying attention and taking all precautionary measures Biasing should only be done on a clean workbench with no distractions Do not wear loose clothing or any jewelry ...
Page 13: ...atching of impedances and or an overloading of the effect unit itself Most rack mount units have different input impedance than pedals and thus can sometimes function fine without a buffer before them In addition some of these rack mounted effects can pad the volume they receive preventing it from overloading Pedals do not have proper input impedance or padding ability and therefore do not play ni...
Page 14: ...l free to experiment with different tubes of the same type in your Yeti though I ve read that the components used in this type of amplifier are really important What is inside my Yeti We use a combination of parts custom made for us to our specifications power transformer output transformer choke high temperature low ESR electrolytic capacitors and those used in our British series 1 2W carbon comp...
Page 15: ...l straight from the EFFECTS LOOP SEND jack 10dB or 4dB While not exact 10dB is a better approximation than 4dB The actual output level will depend on your settings particularly the volume controls 4dB is usually reserved for recording P A equipment with balanced connections ...
