No I haven't. The Hammond 193V is rated for 3A so 5A is not feasible. The other thing to watch out for is power dissipation as the 2SK180 is a 300W device.
Thanks again for this information Ben.
https://www.diyaudio.com/forums/pas...-choke-loaded-2sk180-lamp-21.html#post6631726
I'm starting to gather parts for this build and have been checking out suitable chokes - I have found the Lundahl LL1694 filament choke, a smaller brother to the LL2733 - connected with its windings in parallel the LL1694 is rated at 0.04mH 3A so looks suitable for my project to build a bandwidth limited version for the main driver in my Pass SLOB speaker build as it will further roll-off the bottom end. Is my thinking right on that?
https://www.lundahltransformers.com/wp-content/uploads/datasheets/1694.pdf
Cheers
https://www.diyaudio.com/forums/pas...-choke-loaded-2sk180-lamp-21.html#post6631726
I'm starting to gather parts for this build and have been checking out suitable chokes - I have found the Lundahl LL1694 filament choke, a smaller brother to the LL2733 - connected with its windings in parallel the LL1694 is rated at 0.04mH 3A so looks suitable for my project to build a bandwidth limited version for the main driver in my Pass SLOB speaker build as it will further roll-off the bottom end. Is my thinking right on that?
https://www.lundahltransformers.com/wp-content/uploads/datasheets/1694.pdf
Cheers
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Your thinking is right but your numbers are wrong. Starting with the choke which is 0.04H.
40mH will move slightly the low frequency limit but it still remains below 10Hz. Remember, the source has a really low impedance so the choke even at 40mH @10Hz remains a much bigger load.
If you need some meaningful filtration choose a much lower value, a 2mH speaker inductor will get you in the region of 100Hz.
Yes, I probably didn't phrase that very well. What I was trying to say is that rolling-off the bottom end by changing the input cap, as per the simulations, lessens the demands on the choke so I can use a lower value one, at significantly lower cost, and it will have a small benefit to the roll-off. The choke isn't intended to be the primary means of rolling off the bottom end.
I also looked at the Triad C56-U choke, specified as 0.035mH, which would have a similar affect but is only rated for 2A. Though it's about four times the cost of the Triad, the Lundahl's 3A rating gives a lot more flexibility when evaluating the optimal operating point.
I also looked at the Triad C56-U choke, specified as 0.035mH, which would have a similar affect but is only rated for 2A. Though it's about four times the cost of the Triad, the Lundahl's 3A rating gives a lot more flexibility when evaluating the optimal operating point.
I think I'll buy an LL1694 and assemble, test and measure one channel with my full-range drivers mounted on a representative baffle.
Although building a bandwidth-limited buffer for a very specific use-case might seem a bit constraining, a great advantage of these designs is there simplicty and low-parts count so it will be pretty simple to revert it to full bandwidth operation, especially with a bit of forward planning.
Ray
Although building a bandwidth-limited buffer for a very specific use-case might seem a bit constraining, a great advantage of these designs is there simplicty and low-parts count so it will be pretty simple to revert it to full bandwidth operation, especially with a bit of forward planning.
Ray
what about having two 5x5 spacers , with a space beteen the two for pins (with the 2SK180/2): then there is only need for one hole per sheet to be made. Still need a ceramic drill but these are available.
Are you sure it's 0.1mH? Not 0.1H, which is 100mH?
Huge difference, check it out again.
Nice choke. Where can that be found? I am asking some Alie's shops for 100mH-150mH/2-3Amp = something like this; no response yet.
& And in my sim with 2SK182, @ 4Vpp in, with 24V/2.1 amp = -36dB 2nd /-55 dB 3rd while 39V/2.5A = -45 db / -67 dB. So higher Vb is better, then the 2SK182 becomes more lineair.
Compare to the 2SK180 at 24V -31db / -41 dB @ 4Vpp that also has many more higher harmonics. But they still have a nice degradation [on paper that is]
Only Papa knows what is better from paper.
You should perhaps pay more attention to reading and comprehension than to passing judgement
Seriously, how can the serial connection have less inductance than the parallel?
I suggest a Vds of 35V and Iq of 2.5A. Depending on the DCR of your choke, the supply voltage would be 35V + (choke DCR)x2.5A. If you have lab power supply you can play around with the voltage and current and measure the distortion.
Because it is a follower, you will need a preamp or voltage gain stage that can output a lot of voltage if you want to test the amp at high power output. The measured distortion then would be the combination of the distortions of the preamp or voltage gain stage and follower amplifier.
Because it is a follower, you will need a preamp or voltage gain stage that can output a lot of voltage if you want to test the amp at high power output. The measured distortion then would be the combination of the distortions of the preamp or voltage gain stage and follower amplifier.