Hey gang, I am curious about amps for ESL's and specifically Janszen 1-30.
There is a high pass filter before the 1:50 audio transformer. I was toying around with the idea of removing it and putting one before the power amp that is driving those panels. Being a reactive load the voltage and current aren't in phase and I was curious how much power is actually really needed, especially without the crossover before the audio transformer.
I vaguely remember being told the panels are something like 20pF each, and there is four of them.
I wonder if one could get away with using a high quality low power amp capable of delivering the voltage needed?
There is a high pass filter before the 1:50 audio transformer. I was toying around with the idea of removing it and putting one before the power amp that is driving those panels. Being a reactive load the voltage and current aren't in phase and I was curious how much power is actually really needed, especially without the crossover before the audio transformer.
I vaguely remember being told the panels are something like 20pF each, and there is four of them.
I wonder if one could get away with using a high quality low power amp capable of delivering the voltage needed?
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May I ask why ? The high pass is only a cap & inductor. Just use a good quality cap, upgrade the inductor & you’ll still get great sound. Been mucking around with the XO of my ML Odyssey & have made vast improvements. If you like to test it out pls pm me. Will share some experiences with you
Cheers
May I ask why ? The high pass is only a cap & inductor. Just use a good quality cap, upgrade the inductor & you’ll still get great sound. Been mucking around with the XO of my ML Odyssey & have made vast improvements. If you like to test it out pls pm me. Will share some experiences with you
Cheers
I have had about 30 of the Janzen panels in the past....vary ezey to do what you wont with a small output...30 watt... tube amp....b+ of about 4-450v...well drive the panes right off the plats of the output tubes...best sound I got was with a hhscott 299c EL84 tube...
but in the end ...thay just never gave SPL.. output I wonted..sweet sound
good luck
but in the end ...thay just never gave SPL.. output I wonted..sweet sound
good luck
I don't see much point in moving the crossover to before the amp, unless you are using an active crossover and you desire a particular slope and frequency that isn't offered by the post-amplifier passive filter.
In any case, I heartily recommend leaving the 1-ohm resistor is series with the transformer. It's purpose is to keep the impedance above a safe level, since the transformer can dip to a very low impedance at low frequencies.
In any case, I heartily recommend leaving the 1-ohm resistor is series with the transformer. It's purpose is to keep the impedance above a safe level, since the transformer can dip to a very low impedance at low frequencies.
Yes. You could drive the panels to lower freq if you had a sharp DSP crossover before the amp. That would get more bandwidth from the panels while still protecting them from being over-driven at too low freq.
Not to mention the other DSP EQ and other benefits.
I'll never forget the day I first heard 'em at the NY audio society demo, 1964(?).
Ben
Yes it would be fun to play around with options of the crossover point, and possibly have a steeper slope.
Quick calculations showed me that the load impedance of the panels is set by the passive filter. So why not ditch the passive filter and set a higher resistive load and drive it directly from a tube plate?
Quick calculations showed me that the load impedance of the panels is set by the passive filter. So why not ditch the passive filter and set a higher resistive load and drive it directly from a tube plate?
First the math has to work; you are substituting voltage swing that a 1:100 transformer (or thereabouts) provided. Probably will fall short for any B+ less than 2000vdc.
Second, the perils of death (suicide?) are considerable if you touch rivets, loose wires....
But direct drive is wonderful sound.
B.
Unrealizable if you mean the existing step-up transformer. But around 1968, that is just what Mike Wright promoted. The sound was fantastic, not that his sound ever was any less.
BTW, maybe that is a concept that tube-adherents might consider today, if they can find the transformers, issuming they'd rather not go to Sanders' B+ voltages.
B.
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Why not? I was thinking a CCS on the plate of a power triode or better a gyrator load with a cap output. The 1.5mH has a reactance of 7.5 ohms at 800Hz.........substitute that with a 10k resistor.
famousmockingbyrd
Look likes were off track...or I am...hehe.....
you can setup a tube amps output tubes plats to drive the panels!.......
as long as the tube amps B+ is 400-450v...forget any transformer......this should give the best sound...that what I got years ago.
Or .. you can put a 1ohm 25-30watt res on the + primary input of the stock transformer...an drive it with any amps normal outputs!...the panels well not play full rang...so you have to feed the amp a crossover point like above 1500-2k...right?
Good luck
Look likes were off track...or I am...hehe.....
you can setup a tube amps output tubes plats to drive the panels!.......
as long as the tube amps B+ is 400-450v...forget any transformer......this should give the best sound...that what I got years ago.
Or .. you can put a 1ohm 25-30watt res on the + primary input of the stock transformer...an drive it with any amps normal outputs!...the panels well not play full rang...so you have to feed the amp a crossover point like above 1500-2k...right?
Good luck
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