A little detail on what the Schottky diodes and chokes do:
The Schottkies are simply a higher quality diode than what the kit comes with. Theoretically (and I assume measurably) they should be better at rectifying (turning AC into DC) the AC voltage.
The chokes serve the same purpose as the resistors that come with the kit. However, the difference is that #1 they don’t limit current as much as the resistors and #2 they are basically a highpass filter (a crossover) helping to eliminate any 120HZ on the power line. It’s 120HZ (double the 60HZ that comes out of the wall) because the rectifier has flipped the negative phase of the AC signal to positive.
I was very impressed with your answers, so I figured I’d toss a fairly obscure BHOC question at you. The E80CC is a tall tube with more output than expected but the right pin count/placement. You have to change out a pair of resistors on the speedball board to make proper use of it. It’s worth the trouble because the E80CC testing in new condition has almost everything right except its a hair bright and the low bass losses some definition, outside of that its very good.
Yeah I looked up the E80CC on Bottlehead and saw that there needs to be some change done but I didn’t research exactly what that is. And I’m not well versed on the SB so I can’t comment without educating myself first. For me it also doesn’t make sense to change SB just for a single tube because then I’m married to it . I suppose I could use a switch to swap between between the 2 sets of resistors but I’m not currently fired up to go through the trouble. Maybe down the line when I get bored.
Again good thoughts but this is a 10k hour tube and I’m nearing 64, don’t think I’ll fussing with the tube again because I like hybrid or very clear tube sound, the Dyna Mk VI - sure, Mk III - meh.
Now, I’d like to know where to get one of 2-3 best power tubes, I was quite unsuccessful this summer looking for that.
Yeah you can use a switch but the plan seemed rinky dink. My next mod is to install a SE input next to my XLR input.
Keep looking lol. I used to scour the interwebs looking for tubes. To the point where I got annoyed at the hunt and decided to just stick with what I have. My current setup makes me happy (aside from a noisy 12AU7 that’s getting replaced) so I’m like “meh…whatevs”.
So my parts finally arrived. I replaced the two 22k ohm resistors which eliminated the crackling issue.
I have replaced the two silver Audyn caps (1,5uf) with some 100uf ones that meet the specs of bottleheads stock caps and this brought back the lowend which was completely missing before. Its silent now and i have a first listen since an hour. What i hear is really awesome now! Just going through my music and enjoying it so much!
Listening with the T1.2 since they are my favourite headphones at the moment. Had a few minutes with my 6XX but i had to grab my T1
Running my RCA black plates and a Toshiba 12au7 HI-S
For the most part, they just have a lower voltage drop compared to normal diodes. (0.4V vs 0.7)
Or in case of SiC-Schottky Diodes, they have faster recovery times making them better for switch mode power supplies.
Depends.
Inductors resist a change in current (causing a rise in voltage).
I would be very carefull replacing a resistor with an inductor.
That is the job of a capacitor though.
Build a low-pass filter with R = 10 and C = 470uF and you got yourself a ~34Hz cut off low pass filter.
Okay, grabbed my 6XX and whoaaa seems to reignite my love for this headphone.
I often read that this amp just sounds super “musical” and i really start to get that now. My music sounds so sweet - i hate that i have to go to sleep soon
T1.2 is awesome
6XX is awesome
880 600Ohm is awesome
They resist a change in current yes. But resistors reduce current.
For a capacitor to completely eliminate ripple it has to be #1 massive and #2 able to discharge at crazy fast rates. This is why resistors (or chokes) are also used - they basically chop off the top (ripples).
The problem though is that you can’t realistically get a cap big enough to fill the entire drop between the peaks. Hence the use of resistors or chokes.
Check out the video I posted above on power supply filter. What I did is simply replace the first resistor right after the rectifier bridge and first cap with a coil. It’s a pretty standard mod for Crack. Caps are not the only thing that’s needed for filtering. Maybe you know something no else does.
I should add - I’m no electronics expert. I may be wrong on certain points but I can’t find a single example of power supply filtering that uses only caps.
On the workings of the BHC-PSU (take with grain of salt, have not moddled this in a simulator and my understanding of tubes is a bit basic, so guessing to an extent):
The 3 capacitors stabilize the “choppy” DC from the rectifier. The resistors connecting them limit the rate at wich the last capacitor “refills” after a heavy current draw.
The 270k Ohm resistor paralel to the capacitors discharges them on shutdown (so you don’t get a nasty zing of them when not in use).
What the mod as I understood would do, is provide a short to ground (can’t be right).
The inductor leading towards the other caps would limit the rate at wich the caps recharge in a filter-ish manner.
Current would be steady (inductors do not resist DC), on a heavy current draw, they would make the caps recharge slower and then overshoot voltage a bit when the capacitors are back to normal.
What I could reasonably see is having an inductor before all the filtering caps to reject high frequencies which may pass straight though the transformer.
Definetly. Are essential for stabilizing DC though.
. I suppose I could use a switch to swap between between the 2 sets of resistors but I’m not currently fired up to go through the trouble. Maybe down the line when I get bored.
seems to reignite my love for this headphone.
