Micke,
Balanced crossovers are rare creatures, no matter what kind of load you're talking about. However...
You can 'roll your own.' I'd recommend 6DJ8s, as they are capable of much more output current than, say, a 12AX7. Start with a differential, followed by the filter network, and finish with cathode followers. The cathode followers are important because, like an emitter or source follower, they have lower output impedance and more drive capability. You'll need to go into this having a clear idea of what crossover slopes and frequencies you will need.
There are some tube crossovers (none balanced, mind you) at http://www.tubecad.com. There are other tube crossovers out there, but again, none balanced that I can recall. Hit the links section here in DIY and fan out from there.
It is also possible, if you are building from scratch, to work the crossover slope into the amplifier itself. There are several ways to do this, but it's best to keep it flexible in case you decide to change speakers (or amps) later.
Grey
Balanced crossovers are rare creatures, no matter what kind of load you're talking about. However...
You can 'roll your own.' I'd recommend 6DJ8s, as they are capable of much more output current than, say, a 12AX7. Start with a differential, followed by the filter network, and finish with cathode followers. The cathode followers are important because, like an emitter or source follower, they have lower output impedance and more drive capability. You'll need to go into this having a clear idea of what crossover slopes and frequencies you will need.
There are some tube crossovers (none balanced, mind you) at http://www.tubecad.com. There are other tube crossovers out there, but again, none balanced that I can recall. Hit the links section here in DIY and fan out from there.
It is also possible, if you are building from scratch, to work the crossover slope into the amplifier itself. There are several ways to do this, but it's best to keep it flexible in case you decide to change speakers (or amps) later.
Grey
if your looking for all types of active crossovers that work, have a look at this site. www.marchandelec.com
v-man.
v-man.
No reason to use balanced (though you can use a balanced in, convert to single-ended, do the filtration, then back to balanced). I'd heartily second GR's suggestion of 6DJ8s or similar.
I've got a couple of the Marchand boards. They look very nice, but they don't take standard 9 pin PC sockets.
I've got a couple of the Marchand boards. They look very nice, but they don't take standard 9 pin PC sockets.
Konnichiwa,
The Marchand Tube crossover schematics are in their downloadable manuals. They can be made balanced I/O by using suitable Transformers. By using a 4:1 Line Input transformer and changing the first buffer stage to one that combines a gain of 16 and a buffer stage you can get the whole X-over to work at a higher level.
Then add suitable output transformers with stepdown (S&B, Jensen and Sowter have nice ones in their pro ranges) and use a follower valve with more current (eg ECC82 instead of ECC83 and reduce th cathode resistor in the marchand design by a factor 5 - 6).
That way you have an output that will tolerate 10K load easily and is balanced. Using a 4:1 stepdown you will have a 10K load translated into 160KOhm in the transformers primary.
Sayonara
hifi said:
The Marchand Tube crossover schematics are in their downloadable manuals. They can be made balanced I/O by using suitable Transformers. By using a 4:1 Line Input transformer and changing the first buffer stage to one that combines a gain of 16 and a buffer stage you can get the whole X-over to work at a higher level.
Then add suitable output transformers with stepdown (S&B, Jensen and Sowter have nice ones in their pro ranges) and use a follower valve with more current (eg ECC82 instead of ECC83 and reduce th cathode resistor in the marchand design by a factor 5 - 6).
That way you have an output that will tolerate 10K load easily and is balanced. Using a 4:1 stepdown you will have a 10K load translated into 160KOhm in the transformers primary.
Sayonara
You mean like my active preamp?
http://webpages.charter.net/dawill/Images/Active Preamp.gif
Cathode follower output will easily cope with 500 ohm loads, although gain will be a bit lower. You can fudge around with the tone stack and add as many stages as you want... a Spice simulator might help ease analysis though...
Tim
http://webpages.charter.net/dawill/Images/Active Preamp.gif
Cathode follower output will easily cope with 500 ohm loads, although gain will be a bit lower. You can fudge around with the tone stack and add as many stages as you want... a Spice simulator might help ease analysis though...
Tim
There was an article how to design tube crossovers in the german magazine ELEKTOR 2/03 with free crossover design
software:
http://www.elektor.de/dl/dl.htm
To download the software, choose:
Frequenz-Weichen mit Röhren 020297-11 Design-Software
I think, the software comes from www.glass-ware.com
Franz
software:
http://www.elektor.de/dl/dl.htm
To download the software, choose:
Frequenz-Weichen mit Röhren 020297-11 Design-Software
I think, the software comes from www.glass-ware.com
Franz
Hi Thorsten, I have Oris 150 with AER bd3 and ripoles 4 x bd15. I have pset 2a3 for horns and ss 200w for bass. I use a March and xm26 heavily Duelund modified.
The question. Can I use ecc81 tubes without modifying resistors? Only v4 or all tubes, input buffer, dividers and output bigger. Is better ecc81 than ecc83 for cathode follower. Second question. In order to get xlr inputs I only need a lindahl 1.1 transformer? My player is Dcs and has same voltage in rca and xlr.
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