Bottlehead Forum
Bottlehead Kits => Legacy Kit Products => Quickie => Topic started by: mortron on March 23, 2013, 06:31:13 PM
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Currently my Quickie feeds a rotation of power amplifiers, and a pair of Visaton B200 full range drivers in open baffles. Cheap and dirty, but I like it.... Well sort of...
I am adding four 18" woofers running off of a QSC MX1500a to my system and am going to be bi-a ping the system.
The initial plan was to use an all active setup, but am not keen on the idea due to some experiments. I will eventually build the Linkwitz MT1 and WM1 boards, but for the time being, am looking towards passive line level crossovers for the full range drivers, and then running the active crossover on the low end. But may use the PLLXO on bass as well to avoid extra components.
Can the Quickie be modified for a second output properly? I assume its more than just running wires to another pair of outputs from the other set, yes? Can I build the PLLXO into the Quickie?
Any help would be great thanks.
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I assume its more than just running wires to another pair of outputs from the other set, yes?
Yeah, it's about that simple.
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there is another post here somewhere on adding second output,there are other ways besides just paralleling with wire.paul also talks in that other post on ways to do it also. Ill try to find that post a post a link here for you, it is somewhere in the quickie folder.
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here is the other discussion on second output
http://www.bottlehead.com/smf/index.php/topic,3927.0.html
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For experimenting around I would just add a splitter to the existing output.
Like this:
http://www.crutchfield.com/S-nZI7xM8T9IB/p_703M22FRHD/AudioQuest-Hard-RCA-Splitter.html
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I have to agree with your idea about using a passive x-over compared to an electronic one. I have tried the same concept years ago and was unimpressed by comparison. The low end however, was still best served with an electronic x-over, due to the fact that there was much that could be adjusted, benefitting the bass.
As far as building in more circuitry into the Q, I see it only as a matter of additional chassis space needed, as well as consideration of bringing in separate DC voltage voltage for those circuits. At least some sort of separation should be used.
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Hi there,
I have a similar project (well, kind of) waiting on the bench. I want to try an OB design using a 15" Eminence Alpha and Wildburro Betsy or my FX120 for the mids / highs. I bought a miniDSP and a measuring mic to play with. I felt that this will give me lots of possibilities with x-over frequencies and also allows for some equalization.
I will post in the speaker forum, when I am done.
Best
Michael
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Thanks for the replies... I had seen that other thread, but am not sure what exactly Paul is saying. I see that having two amps with inputs in parallel can be a bad thing. On the second page there is mention of a 100ohm resistor in between the two outputs? Is there a schematic that would explain this? Thanks
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Thanks for the replies... I had seen that other thread, but am not sure what exactly Paul is saying. I see that having two amps with inputs in parallel can be a bad thing. On the second page there is mention of a 100ohm resistor in between the two outputs? Is there a schematic that would explain this? Thanks
I wouldn't worry about that additional resistor. What are the input impedances of the devices in question that you want the Quickie to drive?
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The bass amp is 10Kohm and the High's are running on an amp that has 25Kohm input impedance.
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Hey Morton - this set-up sounds familiar... I forgot though, are you running a vinyl or digital front end? If its digital I have some suggestions that can make things much simpler. - Eric
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A 10K load isn't super friendly for the Quickie, 25K won't be a problem though.
The 100 Ohm resistors between output jacks will not have any effect on the input impedance issue.
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So I built a unit to plug into my quickie with the required filters.
I have yet to test my low pass... The 10kohm load is doable. Was running my quickie thru that amp exclusively for a while. Iirc 7kohm was the bottom limit of the quickie.
Anyways... I have hooked up the HP and have sound. No hum. But am only testing one channel. When I really crank the channel with the input for said channel to the quickie disconnected, I get SOME crosstalk. Is this because I don't have both channels connected? Or is this the quickies crosstalk and I've just not noticed it under normal conditions?
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crosstalk humm.... I might be wrong about this but I believe the Quickie is dual mono. Crosstalk would then be due to the pot.
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Sure, with the signal really high in one channel you will hear a tiny bit of crosstalk in a lot of gear. It's not an absolute measurement, that is to say it never really goes completely to zero. The B+ and ground connections are common to both channels.
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Ok I get it!
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Want to experiment? A capacitor across the high voltage supply will reduce its impedance, reducing the crosstalk for common impedance but not that from capacitive coupling between channels. Try it and see what you learn?
:^)