Hi Can anybody help me either build them or buy them, I have 2 restored HD770's that I don't have Xovers, I have the PDF that shows the diagram but I am not experience to know how.
Hi, if no-one near you volunteers, go to the nearest tv/radio repair shop with that pdf. It has all the component values and layout plan, piece of cake for a pro to make them!
Speaker layout is old-fashioned and far from optimal by today's standards, but xo looks pretty good, there is lots of knowhow behind it.
Speaker layout is old-fashioned and far from optimal by today's standards, but xo looks pretty good, there is lots of knowhow behind it.
Could be done but would cost you a pretty penny. A ton of parts and the L-pads could cost a lot if you could find the right ones
Agree - that would be a pricey crossover.
Have you tested all four drivers in each speaker to see if they are functional?
Best make sure they are before proceeding further.
Have you tested all four drivers in each speaker to see if they are functional?
Best make sure they are before proceeding further.
Good!
Hope a local enthusiast will turn up to build your crossovers for the price of a few beers!
It won't be a problem sourcing those crossover components (or their nearest current equivalents).
Hope a local enthusiast will turn up to build your crossovers for the price of a few beers!
It won't be a problem sourcing those crossover components (or their nearest current equivalents).
Peterma, you don't say what your problem building them is. Is it finding parts, reading the schematic, soldering?
Some assume expensive. The coils beside the drivers are high resistance. This can mean cheap, even a spool of cheap thin hookup wire might do the job 😛 . The caps don't have to be polys, electrolytics can sound very good. The L-pads can be replaced with resistors.
What parts d you have lying around that might be useful.
Some assume expensive. The coils beside the drivers are high resistance. This can mean cheap, even a spool of cheap thin hookup wire might do the job 😛 . The caps don't have to be polys, electrolytics can sound very good. The L-pads can be replaced with resistors.
What parts d you have lying around that might be useful.
Peter, where in Sydney are you?
I have some L pads you can have, but as Allen says, it's better to replace them with fixed resistors.
there's a couple of hundred dollars worth of parts in that crossover, even using cheap ones for the high resistance inductors. Good parts can be sourced from Speakerbug
I have some L pads you can have, but as Allen says, it's better to replace them with fixed resistors.
there's a couple of hundred dollars worth of parts in that crossover, even using cheap ones for the high resistance inductors. Good parts can be sourced from Speakerbug
Hi PeteMcK,
I live at Ropes Crossing near St Marys, I would love to try and get them as close to the original as much as I can, but maybe the cost would be too high.
its the L-pads and inductors that start to add up.
I live at Ropes Crossing near St Marys, I would love to try and get them as close to the original as much as I can, but maybe the cost would be too high.
its the L-pads and inductors that start to add up.
Sound quality is about the numbers, low price doesn't mean low quality if the part is appropriate. Caps and coils 120 new, unless OP has some spares.
Have you checked with Marantz? Is it possible that the company may have some NOS spare parts? There is a part number for the XO in the PDF after all.
Remote possibility but maybe worth an email.
Remote possibility but maybe worth an email.
Peter, I'm in St Marys! send me a PM, I'm happy to help.
But you need a plan, something like: A: Acquire the parts, B; Assemble the crossovers, C: install & tweak them
But you need a plan, something like: A: Acquire the parts, B; Assemble the crossovers, C: install & tweak them
^Sounds like a good plan! Go!
Adjustable L-pads might be worth making, tone adjust most likely will be needed to get best sound. Or then prepare for lots of extra diy with acoustic measurements and listening tests - and collapse of museum/resale value.
Adjustable L-pads might be worth making, tone adjust most likely will be needed to get best sound. Or then prepare for lots of extra diy with acoustic measurements and listening tests - and collapse of museum/resale value.
Wind your own coils?
Perhaps we can assist in doing your own coils. I am positive that with help of a coil calculator, we can predict diameter and inductance within a couple of percent from the original value. If there were any issues finding right magnet wire for the higher dcr inductors, adding a resistor in series would solve it.
How much does awg 18 and awg 27 magnet wire cost in Australia?
Perhaps we can assist in doing your own coils. I am positive that with help of a coil calculator, we can predict diameter and inductance within a couple of percent from the original value. If there were any issues finding right magnet wire for the higher dcr inductors, adding a resistor in series would solve it.
How much does awg 18 and awg 27 magnet wire cost in Australia?
There is also the option of purchasing ready made cheap Chinese crossovers employing iron core inductors. Modifying these to meet the original marantz values would not be hard, some caps might fit also. The excess wire from one could be used to increase the inductance of another.
Peterma,
it could work assuming the necessary changes to the inductance/capacitance values were done. Before that, you need to get a hold of an LCR meter, either a dedicated one or a sound card based one. You could even rewire the board to suit the original schematic.
it could work assuming the necessary changes to the inductance/capacitance values were done. Before that, you need to get a hold of an LCR meter, either a dedicated one or a sound card based one. You could even rewire the board to suit the original schematic.