Search found 140 matches
- Fri Feb 05, 2021 3:42 pm
- Forum: Circuits
- Topic: Klipsch woofer - tweeter crossover network.
- Replies: 29
- Views: 46903
i am in agreement with this... we are saying mainly the same thing with different terms. differential = common mode. the primary turns of the output transformer can be less than optimum because the chokes boost the load for the 2A3s. an economical tranny for bass. and a small economical one for the ...
- Fri Feb 05, 2021 11:17 am
- Forum: Circuits
- Topic: Klipsch woofer - tweeter crossover network.
- Replies: 29
- Views: 46903
- Fri Feb 05, 2021 10:47 am
- Forum: Circuits
- Topic: Klipsch woofer - tweeter crossover network.
- Replies: 29
- Views: 46903
- Fri Feb 05, 2021 10:27 am
- Forum: Circuits
- Topic: Klipsch woofer - tweeter crossover network.
- Replies: 29
- Views: 46903
- Fri Feb 05, 2021 10:24 am
- Forum: Circuits
- Topic: Klipsch woofer - tweeter crossover network.
- Replies: 29
- Views: 46903
- Fri Feb 05, 2021 10:20 am
- Forum: Circuits
- Topic: Klipsch woofer - tweeter crossover network.
- Replies: 29
- Views: 46903
- Fri Feb 05, 2021 10:17 am
- Forum: Circuits
- Topic: Klipsch woofer - tweeter crossover network.
- Replies: 29
- Views: 46903
here are the sweeps. the top is obviously pi filter. the middle is conventional choke input. and the bottom is AC choke. each is 1H each winding, common mode (coupled). so there is almost double the drop of a conventional choke input, but more regulation. this action takes cost away from the output ...
- Fri Feb 05, 2021 10:11 am
- Forum: Circuits
- Topic: Klipsch woofer - tweeter crossover network.
- Replies: 29
- Views: 46903
- Fri Feb 05, 2021 9:17 am
- Forum: Circuits
- Topic: Klipsch woofer - tweeter crossover network.
- Replies: 29
- Views: 46903
i think it is important to pay attention to Klipsch's initial statements about low cost. large value caps cost more than transformers at that time, and perform poorly. a low turns ratio transformer together with a 1:1 common mode choke gives a higher performance per dollar... at that time. the commo...
- Fri Feb 05, 2021 2:27 am
- Forum: Circuits
- Topic: Klipsch woofer - tweeter crossover network.
- Replies: 29
- Views: 46903
because its low frequencies! and the windings are coupled... bifilar on the same core is a common mode choke. a 1:1 transformer functions exactly the same. you will not get much high frequency left on the other side but that is the point! the clever part isn't that. i don't think...? it's the simple...
- Fri Feb 05, 2021 1:52 am
- Forum: Circuits
- Topic: Klipsch woofer - tweeter crossover network.
- Replies: 29
- Views: 46903
- Fri Feb 05, 2021 1:49 am
- Forum: Circuits
- Topic: Klipsch woofer - tweeter crossover network.
- Replies: 29
- Views: 46903
- Fri Feb 05, 2021 1:45 am
- Forum: Circuits
- Topic: Klipsch woofer - tweeter crossover network.
- Replies: 29
- Views: 46903
it's clear that L1 - L2 is a common mode choke. as soon as you hear that it simply means a balanced network, and not common ground. that makes the crossover much simpler. the bass is a balanced 2nd order filter and i love the idea of incorporating it on the high Z side to avoid large value caps... u...
- Fri Jan 22, 2021 9:40 pm
- Forum: Circuits
- Topic: Mac Unity coupled
- Replies: 88
- Views: 27836
- Fri Jan 22, 2021 9:33 pm
- Forum: Circuits
- Topic: Mac Unity coupled
- Replies: 88
- Views: 27836
output Z is inversely proportional to transconductance in tetrodes/pentodes, and a ratio in triodes. high gm is low Z. in the transition from A to B, it's going to be Z/2, to a bit more than Z, as only one tube is on at a time... so you already know the answer to your question. but there's a wrinkle...
- Fri Jan 22, 2021 3:36 pm
- Forum: Circuits
- Topic: Mac Unity coupled
- Replies: 88
- Views: 27836
- Fri Jan 22, 2021 3:35 pm
- Forum: Circuits
- Topic: Mac Unity coupled
- Replies: 88
- Views: 27836
the mu in tetrode operation is much higher, so there is more internal feedback. it isn't the same! transconductance does matter for a follower, but most important for insertion loss is mu. this is why 5687's are such lousy cathode followers all by themselves, and 6922s or 6C45Ps are such excellent c...
- Thu Jan 21, 2021 10:42 pm
- Forum: Circuits
- Topic: Mac Unity coupled
- Replies: 88
- Views: 27836
just to summarize a few important things, the bifilar unity coupled circuit is definitely based on the split load inverter. in push pull, 2 inverters can work well in class B... the coupling between the windings is also a feedback system, besides the degenerative fb inherent in the split load. the s...
- Thu Jan 21, 2021 10:33 pm
- Forum: Circuits
- Topic: Mac Unity coupled
- Replies: 88
- Views: 27836
- Thu Jan 21, 2021 10:32 pm
- Forum: Circuits
- Topic: Mac Unity coupled
- Replies: 88
- Views: 27836
- Thu Jan 21, 2021 10:30 pm
- Forum: Circuits
- Topic: Mac Unity coupled
- Replies: 88
- Views: 27836
here is the circuit with 350V supply and 60mA per tube. class A - AB old school. with 240 pp input and into 8 ohms, about 12 watts, no additional error correction... you can see the onset of clipping just coming in the current waveforms of the windings... it looks horrible! output distortion just ov...
- Thu Jan 21, 2021 9:48 pm
- Forum: Circuits
- Topic: Mac Unity coupled
- Replies: 88
- Views: 27836
the green is the plate winding, you can see the clipping caused by the peaking screen on the opposing side. and yet in the cathode (the blue trace), the subtracted third from the sine... (tall and narrow). this is the power of feedback. the sum of these is a near perfect sine of current in the 2.5K ...
- Thu Jan 21, 2021 9:46 pm
- Forum: Circuits
- Topic: Mac Unity coupled
- Replies: 88
- Views: 27836
- Thu Jan 21, 2021 9:45 pm
- Forum: Circuits
- Topic: Mac Unity coupled
- Replies: 88
- Views: 27836
here is another money shot... from your circuit! i increased the voltage to 400 volts because this 6L6 model just doesn't have enough cajones at 350... i reduced the inductance to 10 H each winding. i increased the screen current limiting resistors to 500 ohms. 2.5K gives the same current in the loa...
- Thu Jan 21, 2021 9:29 pm
- Forum: Circuits
- Topic: Mac Unity coupled
- Replies: 88
- Views: 27836
in any case, i think the mystery is solved. the unity coupled output stage is very good. and very interesting! and i see NO reason to use it only in class B. wtf! other than economy? it's an inefficient circuit because of the 100% feedback. it is applied just like a cathode follower. it takes a lot ...
- Thu Jan 21, 2021 9:19 pm
- Forum: Circuits
- Topic: Mac Unity coupled
- Replies: 88
- Views: 27836
- Thu Jan 21, 2021 4:07 pm
- Forum: Circuits
- Topic: Mac Unity coupled
- Replies: 88
- Views: 27836
- Thu Jan 21, 2021 4:04 pm
- Forum: Circuits
- Topic: Mac Unity coupled
- Replies: 88
- Views: 27836
- Thu Jan 21, 2021 3:59 pm
- Forum: Circuits
- Topic: Mac Unity coupled
- Replies: 88
- Views: 27836
- Thu Jan 21, 2021 8:32 am
- Forum: Circuits
- Topic: Mac Unity coupled
- Replies: 88
- Views: 27836
in terms of output impedance, the next test will be voltage changes with load changes at high frequencies... but the magnitude isn't going to be large. one can already see that in the 8 ohm load. the peak current is the same, although the duty cycle is changed by some percent. a modest rise. but i w...