Sreten,
Sorry, I'm one of those guys that has to see big pictures before I understand details. But I understand your frustration. Working in computers for 20 years, I can't understand how people can't get the concept of Drive letters, but they don't and I continually have to explain it to them.
My confusion was in why we had 2 2.7 caps going to the lpad. Rereading Tim's post I now see the purpose of this segment. By turning the middle switch off I will cut off ALL signal to the LPAD and thus to the tweeter, by turning off the TOP switch I halve the cap from 5.4 to 2.7 which will change the rolloff. NOW AM I ON THE RIGHT TRACK?
Okay, onward to the bottom switch. I've got my prong 1 (+) going to Middle switch (tweeter) prong 2. And now I have to hook up my 5.1R - 2.7 mh (air inductor) and my 1.0 uf (not in schematic) Reading the posts, I'm to understand this switch sets either a 5k or 10k filter. Correct?
Regards,
A hopefully less confused Giacomo
Sorry, I'm one of those guys that has to see big pictures before I understand details. But I understand your frustration. Working in computers for 20 years, I can't understand how people can't get the concept of Drive letters, but they don't and I continually have to explain it to them.
My confusion was in why we had 2 2.7 caps going to the lpad. Rereading Tim's post I now see the purpose of this segment. By turning the middle switch off I will cut off ALL signal to the LPAD and thus to the tweeter, by turning off the TOP switch I halve the cap from 5.4 to 2.7 which will change the rolloff. NOW AM I ON THE RIGHT TRACK?
Okay, onward to the bottom switch. I've got my prong 1 (+) going to Middle switch (tweeter) prong 2. And now I have to hook up my 5.1R - 2.7 mh (air inductor) and my 1.0 uf (not in schematic) Reading the posts, I'm to understand this switch sets either a 5k or 10k filter. Correct?
Regards,
A hopefully less confused Giacomo
Do not use the 1.0uF capacitor, its for tweaking of the tweeter
crossover, you are correct one switch is tweeter ON/OFF, the
other switch changes the crossover frequency, tweeter roll-off,
this is the 5K/10K switch.
The filter switch is connected in parallel with the 2.7mh inductor
and the 5.1R resistor. This is placed in series with the speaker.
The switch turns the midrange filter ON / OFF by being
open circuit in one position and short circuit in another.
If you don't have a cheap multimeter I suggest you get one.
It will be easy to check all functions with one.
sreten.
crossover, you are correct one switch is tweeter ON/OFF, the
other switch changes the crossover frequency, tweeter roll-off,
this is the 5K/10K switch.
The filter switch is connected in parallel with the 2.7mh inductor
and the 5.1R resistor. This is placed in series with the speaker.
The switch turns the midrange filter ON / OFF by being
open circuit in one position and short circuit in another.
If you don't have a cheap multimeter I suggest you get one.
It will be easy to check all functions with one.
sreten.
I just read this whole thread with interest. Wish I'd found it early on to add my two cents worth.
I've had numerous old consoles and have played with a lot of OB speakers. For any interested in replacing origional 12" speakers in open backed consoles, the cheap but good way is to purchase a couple of Electro-Voice Wolverine or Michigan drivers, like the LS-12's or MC-12's. These have very high Qts (over 1) and are tailor made for OB use. They will handle the range from around 90-10,000 Hz in a console like the one being discussed here. A pair of these EV speakers just sold on epay for $75, which is pretty typical. Run them fullrange with any decent efficient tweeter crossed with a 1 or 1.5 uF cap. EV efficiency is around 94 dB.
Next, add any decent powered sub for 80 Hz down. You end up with wonderful vintage sound, the speakers will handle anything a little tube amp can dish out, and the OB sound with these type of drivers is incredible.
I've been listening to a pair of LS-12's in an OB for months now, and am completely sold on this sound. The balance is good, very flat (small peak in the 6-8 kHz range, nothing serious), and will play very loud with an old 20 watt tube amp.
Anyone considering fixing up an old console should check into the EV fullrange drivers. The build quality is the equal of almost anything made today, they are common and affordable.
There, spoke my piece. I'll go peacefully now.
Dave
I've had numerous old consoles and have played with a lot of OB speakers. For any interested in replacing origional 12" speakers in open backed consoles, the cheap but good way is to purchase a couple of Electro-Voice Wolverine or Michigan drivers, like the LS-12's or MC-12's. These have very high Qts (over 1) and are tailor made for OB use. They will handle the range from around 90-10,000 Hz in a console like the one being discussed here. A pair of these EV speakers just sold on epay for $75, which is pretty typical. Run them fullrange with any decent efficient tweeter crossed with a 1 or 1.5 uF cap. EV efficiency is around 94 dB.
Next, add any decent powered sub for 80 Hz down. You end up with wonderful vintage sound, the speakers will handle anything a little tube amp can dish out, and the OB sound with these type of drivers is incredible.
I've been listening to a pair of LS-12's in an OB for months now, and am completely sold on this sound. The balance is good, very flat (small peak in the 6-8 kHz range, nothing serious), and will play very loud with an old 20 watt tube amp.
Anyone considering fixing up an old console should check into the EV fullrange drivers. The build quality is the equal of almost anything made today, they are common and affordable.
There, spoke my piece. I'll go peacefully now.
Dave
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