Topic: Active Bi-Amp recommendations

[Lil Kim Jong-Il]

Anyone have recommendations on reasonably priced crossovers for an active bi-amping arrangement?  Any other advice related to active bi-amping?

[nickgregory]

nothing but get it done before I come up in January so I can hear it

[Lil Kim Jong-Il]

I made a deal on an amp last night, so I should have the passive bi-wire rig running before Thanksgiving.

I had a change of heart about getting another Premier 11a.  I really want more authority in the bass region and I don't think that the tubes are going to give me that unless I jump up to the next power level.  I found a good deal on an MF2250 which CJ has recommended as a good match for the Premier 11A in a bi-amped system.   It should be able to drive the bass cabinets a bit deeper than the 11A.  I traded emails with another guy doing the same thing, and he was pretty happy with these two mated in a passive configuration.

The other benefit of going with the MF2250 is it is cheaper than the 11A I was going to buy, so I have enough change to look into getting the active crossovers.

[nickgregory]

very cool...cant wait to hear it...you have the playback that I want...need to convince the wife though, and that is no easy task

[Lil Kim Jong-Il]

Since no one had a recommendation, maybe I can ask a different question toward the same end.

Has anyone built a tube based project?  I've built tons of SS and passive suff in the past, but never tubes.  I'm not scared of the voltages.   What does concern me is that I don't know how much a tube design will be impacted by construction technique.  I'm thinking about trying this active crossover design:  http://members.aol.com/sbench101/#Electronic  There is a lot of discussion on AA about it and some people think it's a very good crossover.  There is a PCB available from a third party that would make it a simpler project but I have a tendency to favor point to point wiring.  Any comment on construction or the design of the tube crossover?

There is also a different/SS design for which a PCB is available.  That circuit seems to be well regarded too.  info here:  http://sound.westhost.com/project09.htm

I've looked at a lot of postings regarding active crossovers and from what I've read, it seems that I'm either going to spend $1k to buy a decent used one (should one ever come available) or I'm going to build one.   Can any of you guys with analog circuit backgrounds give me some insight into which of those two might be a better project? 

[cheshirecat]

I've built a bunch of tube based projects before.  The design you pointed out looks extremely simple to build, a few caps and just over a dozen resistors, 1 tube, and looks like it can be done on the cheap.  With that few components i'd just get a few terminal strips and forget the PCB. You can probably do it in the $50 range.

[Lil Kim Jong-Il]

I'm guessing the $50 range is one channel and no power supply?  I'm doing a parts search today.  I know I can build an inexpensive prototype.  Maybe I should build both and see what I like best before I blow the money on black-gates and auricaps.

The thing holding me back right now is that I've been reading about how some people have had hum problems and also issues diving certain loads.    I shouldn't have a problem with 100K input impedence of the power amps, but I am still hesitant about the hum issues.   Several people on AA give advice about adding followers to the circuit and input buffers.  That increases the complexity and I don't know jack about tube designs so I hesitate to just start cascading design blocks.  OTOH, I know I can bang out that SS design in few hours, including the supply.

BTW, I got the second amp installed and I'm running a passive splitter from the PV14.  It sounds great!  It's incremental for sure, but there is noticably more power throughout.  There is more authority in the bass region and more depth.  I was hoping that the upper part would sound a little more clear.  It seems that it does but not as much as I hoped.  I think this is where going active will help.  Now I need a few days alone with the stereo but the GF decided delay her visit to the parents so I won't be able push any limits while she's in the house.  ;-)