Description The KRELL KBX is a crossover network developed to achieve precise crossover in multi-amp systems. Its designed through speaker manufacturers software, allowing for the setting of crossover frequency, slope, and equalization. Each speaker-specific circuit board is crafted in collaboration, offering custom-made boards to match other manufacturers specifications. These plug-in boards make replacements easy by simply removing the connector.The internal circuit adopts a fully balanced configuration to connect everything from the player to the power amp in balance, emphasizing sound quality with a high-bias, pure Class A circuit design. The output stages low impedance configuration enhances the driving capability of the power amp.Equipped with two 50VA toroidal transformers, the power supply ensures stable power delivery. The chassis is designed as an independent structure to prevent interference with circuits and parts.The KBX typically operates in a 2-channel stereo setup but can also function as a 3-channel monaural system. In this mode, two units are used for separate channels, enabling a dual mono configuration for a 3-way crossover system.Specifications include:Channel Divider SystemSystem Gain: 4dBS/N Ratio: 90dBTotal Harmonic Distortion: Less than 0.01% at 1kHz and 20kHzInput Impedance: 47k?Output Impedance: 10?Maximum Output: 17VDimensions: Main Unit - W483 x H70 x D383mm; Power Supply Unit - W222 x H64 x D286mmWeight: Main Unit - 6.8kg; Power Supply Unit - 3.3kgCondition:The item has been tested and is in good working condition.Included:KRELL KBX Main UnitPSUManual (Copy)DC CableAC Cable (missing earth pin)Original BoxThis crossover operates at 650Hz, enhancing the precision of multi-amp systems with speaker-specific design and plug-in board convenience. The fully balanced internal circuit and low impedance output stage underscore the KBXs commitment to audio excellence. International Buyers - Please Note: Import duties, taxes, and charges are not included in the item price or shipping cost. These charges are the buyers responsibility. Please check with your countrys customs office to determine what these additional costs will be prior to bidding or buying.

I have here a KRELL KBX crossover known as one of the best. The power supply is just fine. This unit was totally recapped by me. All 20 on the main board and the 5 on the x-over board. This one had a bizarre x-over freq so I changed all parts required to create a 24 db slope at 100 hz. This was done by me but via the support of David at Krell and Mike Bettinger of luminous audio. I can now change the frequencies for this unit or any kbx for that matter. All polystyrene or polypropylene caps and metal film 1% resistors. I cleaned the pots with deOxit 5. This is a wonderful example of one of the finest crossovers ever made and in excellent condition. The last photo is the unit showing the new caps on the x-over board at 100 hz. This unit is 100% and ready to roll! A rare find these days.

I have here a KRELL KBX crossover known as one of the best. The power supply is just fine. This unit was totally recapped by me. All 20 on the main board and the 5 on the x-over board. This one had a bizarre x-over freq so I changed all parts required to create a 24 db slope at 100 hz. This was done by me but via the support of David at Krell and Mike Bettinger of luminous audio. I can now change the frequencies for this unit or any kbx for that matter. All polystyrene or polypropylene caps and metal film 1% resistors. I cleaned the pots with deOxit 5. This is a wonderful example of one of the finest crossovers ever made and in excellent condition. The last photo is the unit showing the new caps on the x-over board at 100 hz. This unit is 100% and ready to roll! A rare find these days.

I have here a KRELL KBX crossover known as one of the best. The power supply is just fine. This unit was totally recapped by me. All 20 on the main board and the 5 on the x-over board. This one had a bizarre x-over freq so I changed all parts required to create a 24 db slope at 100 hz. This was done by me but via the support of David at Krell and Mike Bettinger of luminous audio. I can now change the frequencies for this unit or any kbx for that matter. All polystyrene or polypropylene caps and metal film 1% resistors. I cleaned the pots with deOxit 5. This is a wonderful example of one of the finest crossovers ever made and in excellent condition. The last photo is the unit showing the new caps on the x-over board at 100 hz. This unit is 100% and ready to roll! A rare find these days.

I have here a KRELL KBX crossover known as one of the best. The power supply is just fine. This unit was totally recapped by me. All 20 on the main board and the 5 on the x-over board. This one had a bizarre x-over freq so I changed all parts required to create a 24 db slope at 100 hz. This was done by me but via the support of David at Krell and Mike Bettinger of luminous audio. I can now change the frequencies for this unit or any kbx for that matter. All polystyrene or polypropylene caps and metal film 1% resistors. I cleaned the pots with deOxit 5. This is a wonderful example of one of the finest crossovers ever made and in excellent condition. The last photo is the unit showing the new caps on the x-over board at 100 hz. This unit is 100% and ready to roll! A rare find these days.

I have here a KRELL KBX crossover known as one of the best. The power supply is just fine. This unit was totally recapped by me. All 20 on the main board and the 5 on the x-over board. This one had a bizarre x-over freq so I changed all parts required to create a 24 db slope at 100 hz. This was done by me but via the support of David at Krell and Mike Bettinger of luminous audio. I can now change the frequencies for this unit or any kbx for that matter. All polystyrene or polypropylene caps and metal film 1% resistors. I cleaned the pots with deOxit 5. This is a wonderful example of one of the finest crossovers ever made and in excellent condition. The last photo is the unit showing the new caps on the x-over board at 100 hz. This unit is 100% and ready to roll! A rare find these days.

I have here a Krell KBX that was made for Avlar in the 90s. The crossover point seems to be about 125 hz 24 db per octave. I can change the frequency for a fee if desired. There is a slight noise coming from the right ch of the sub out. Krell can repair this. However, Krell cannot change the freq of the x-over. I have the original power supply as well. They bring well over $500 as-is.

I have here a KRELL KBX crossover known as one of the best. The power supply is just fine. This unit was totally recapped by me. All 20 on the main board and the 5 on the x-over board. This one had a bizarre x-over freq so I changed all parts required to create a 24 db slope at 100 hz. This was done by me but via the support of David at Krell and Mike Bettinger of luminous audio. I can now change the frequencies for this unit or any kbx for that matter. All polystyrene or polypropylene caps and metal film 1% resistors. I cleaned the pots with deOxit 5. This is a wonderful example of one of the finest crossovers ever made and in excellent condition. The last photo is the unit showing the new caps on the x-over board at 100 hz. This unit is 100% and ready to roll! A rare find these days.

I have here a Krell KBX that was made for Avlar in the 90s. The crossover point seems to be about 125 hz 24 db per octave. I can change the frequency for a fee if desired. There is a slight noise coming from the right ch of the sub out. Krell can repair this. However, Krell cannot change the freq of the x-over. I have the original power supply as well. They bring well over $500 as-is.

I have here a KRELL KBX crossover known as one of the best. The power supply is just fine. This unit was totally recapped by me. All 20 on the main board and the 5 on the x-over board. This one had a bizarre x-over freq so I changed all parts required to create a 24 db slope at 100 hz. This was done by me but via the support of David at Krell and Mike Bettinger of luminous audio. I can now change the frequencies for this unit or any kbx for that matter. All polystyrene or polypropylene caps and metal film 1% resistors. I cleaned the pots with deOxit 5. This is a wonderful example of one of the finest crossovers ever made and in excellent condition. The last photo is the unit showing the new caps on the x-over board at 100 hz. This unit is 100% and ready to roll! A rare find these days.

I have here a Krell KBX that was made for Avlar in the 90s. The crossover point seems to be about 125 hz 24 db per octave. I can change the frequency for a fee if desired. There is a slight noise coming from the right ch of the sub out. Krell can repair this. However, Krell cannot change the freq of the x-over. I have the original power supply as well. They bring well over $500 as-is.

Martin Logan / Krell KBX Crossover This is the Martin Logan branded Krell KBX crossover designed for the Martin Logan Monolith speakers. It is extremely hard to come by with the Martin Logan branding so do not miss out on this incredibly rare opportunity. This unit comes with the original packaging and power supply. This unit has been fully recapped and is ready to go to a new home. Check out my other listings.Feel free to ask any questions.I ship items only to buyers with signature required on items above $750.NOTE: Returns not accepted.

I have here a Krell KBX that was made for Avlar in the 90s. The crossover point seems to be about 125 hz 24 db per octave. I can change the frequency for a fee if desired. There is a slight noise coming from the right ch of the sub out. Krell can repair this. However, Krell cannot change the freq of the x-over. I have the original power supply as well. They bring well over $500 as-is.

I have here a KRELL KBX crossover known as one of the best. The power supply is just fine. This unit was totally recapped by me. All 20 on the main board and the 5 on the x-over board. This one had a bizarre x-over freq so I changed all parts required to create a 24 db slope at 100 hz. This was done by me but via the support of David at Krell and Mike Bettinger of luminous audio. I can now change the frequencies for this unit or any kbx for that matter. All polystyrene or polypropylene caps and metal film 1% resistors. I cleaned the pots with deOxit 5. This is a wonderful example of one of the finest crossovers ever made and in excellent condition. The last photo is the unit showing the new caps on the x-over board at 100 hz. This unit is 100% and ready to roll! A rare find these days.

I have here a Krell KBX that was made for Avlar in the 90s. The crossover point seems to be about 125 hz 24 db per octave. I can change the frequency for a fee if desired. There is a slight noise coming from the right ch of the sub out. Krell can repair this. However, Krell cannot change the freq of the x-over. I have the original power supply as well. They bring well over $500 as-is.

I have here a KRELL KBX crossover known as one of the best. The power supply is just fine. This unit was totally recapped by me. All 20 on the main board and the 5 on the x-over board. This one had a bizarre x-over freq so I changed all parts required to create a 24 db slope at 100 hz. This was done by me but via the support of David at Krell and Mike Bettinger of luminous audio. I can now change the frequencies for this unit or any kbx for that matter. All polystyrene or polypropylene caps and metal film 1% resistors. I cleaned the pots with deOxit 5. This is a wonderful example of one of the finest crossovers ever made and in excellent condition. The last photo is the unit showing the new caps on the x-over board at 100 hz. This unit is 100% and ready to roll! A rare find these days.

I have here a KRELL KBX crossover known as one of the best. The power supply is just fine. This unit was totally recapped by me. All 20 on the main board and the 5 on the x-over board. This one had a bizarre x-over freq so I changed all parts required to create a 24 db slope at 100 hz. This was done by me but via the support of David at Krell and Mike Bettinger of luminous audio. I can now change the frequencies for this unit or any kbx for that matter. All polystyrene or polypropylene caps and metal film 1% resistors. I cleaned the pots with deOxit 5. This is a wonderful example of one of the finest crossovers ever made and in excellent condition. The last photo is the unit showing the new caps on the x-over board at 100 hz. This unit is 100% and ready to roll! A rare find these days.

I have here a KRELL KBX crossover known as one of the best. The power supply is just fine. This unit was totally recapped by me. All 20 on the main board and the 5 on the x-over board. This one had a bizarre x-over freq so I changed all parts required to create a 24 db slope at 100 hz. This was done by me but via the support of David at Krell and Mike Bettinger of luminous audio. I can now change the frequencies for this unit or any kbx for that matter. All polystyrene or polypropylene caps and metal film 1% resistors. I cleaned the pots with deOxit 5. This is a wonderful example of one of the finest crossovers ever made and in excellent condition. The last photo is the unit showing the new caps on the x-over board at 100 hz. This unit is 100% and ready to roll! A rare find these days.

I have here a KRELL KBX crossover known as one of the best. The power supply is just fine. This unit was totally recapped by me. All 20 on the main board and the 5 on the x-over board. This one had a bizarre x-over freq so I changed all parts required to create a 24 db slope at 100 hz. This was done by me but via the support of David at Krell and Mike Bettinger of luminous audio. I can now change the frequencies for this unit or any kbx for that matter. All polystyrene or polypropylene caps and metal film 1% resistors. I cleaned the pots with deOxit 5. This is a wonderful example of one of the finest crossovers ever made and in excellent condition. The last photo is the unit showing the new caps on the x-over board at 100 hz. This unit is 100% and ready to roll! A rare find these days.

I have here a KRELL KBX crossover known as one of the best. The power supply is just fine. This unit was totally recapped by me. All 20 on the main board and the 5 on the x-over board. This one had a bizarre x-over freq so I changed all parts required to create a 24 db slope at 100 hz. This was done by me but via the support of David at Krell and Mike Bettinger of luminous audio. I can now change the frequencies for this unit or any kbx for that matter. All polystyrene or polypropylene caps and metal film 1% resistors. I cleaned the pots with deOxit 5. This is a wonderful example of one of the finest crossovers ever made and in excellent condition. The last photo is the unit showing the new caps on the x-over board at 100 hz. This unit is 100% and ready to roll! A rare find these days.

I have here a spare power supply from a Krell KBX crossover. It works fine. It will also power Krell preamps from the same era.

I have here a KRELL KBX crossover known as one of the best. The power supply is just fine. This unit was totally recapped by me. All 20 on the main board and the 5 on the x-over board. This one had a bizarre x-over freq so I changed all parts required to create a 24 db slope at 100 hz. This was done by me but via the support of David at Krell and Mike Bettinger of luminous audio. I can now change the frequencies for this unit or any kbx for that matter. All polystyrene or polypropylene caps and metal film 1% resistors. I cleaned the pots with deOxit 5. This is a wonderful example of one of the finest crossovers ever made and in excellent condition. The last photo is the unit showing the new caps on the x-over board at 100 hz. This unit is 100% and ready to roll! A rare find these days.

I have here a KRELL KBX crossover known as one of the best. This one however was in storage for years in a shed. A bunch of dust inside and signs of humidity. It works but is quite noisy. The controls need a good cleaning and perhaps cleaning the entire board and re-flowing all solder joints. This would take a long, long time so I am selling as-is. No power supply. Unsure of the crossover freq. The badge on the front is from a speaker co that Krell was commissioned to provide custom crossovers for. Seems to be around 100HZ 24 db per octave. I can actually change the frequency for you if the unit is ever brought back to life.

I have here a KRELL KBX crossover known as one of the best. The power supply is just fine. This unit was totally recapped by me. All 20 on the main board and the 5 on the x-over board. This one had a bizarre x-over freq so I changed all parts required to create a 24 db slope at 100 hz. This was done by me but via the support of David at Krell and Mike Bettinger of luminous audio. I can now change the frequencies for this unit or any kbx for that matter. All polystyrene or polypropylene caps and metal film 1% resistors. I cleaned the pots with deOxit 5. This is a wonderful example of one of the finest crossovers ever made and in excellent condition. The last photo is the unit showing the new caps on the x-over board at 100 hz. This unit is 100% and ready to roll! A rare find these days.