ECE4448 L33: Bass Response of Cathode Bypass Capacitors (Guitar Amplification and Effects)

Подписаться 28 тыс.

Просмотров 3,5 тыс.

50% 1

CORRECTION: At 12:53, to be consistent with my earlier notation, there shouldn't be a negative sign in front of A_0 because A_0 already has a negative sign in it.
Support this channel via a special purpose donation to the Georgia Tech Foundation (GTF210000920), earmarked for my work: • Support This Channel v...
Here is the class playlist: • Guitar Amplification &...
0:00 -- Introduction
1:27 -- Cathode bypass capacitor
1:59 -- Cathode impedance
3:11 -- Sanity checks
4:01 -- Thevenin equivalent
5:21 -- Transfer function
7:02 -- Staring into the abyss
10:58 -- Time constants
12:32 -- Fully bypassed case
13:40 -- Mesa Boogie Dual Rectifier
14:20 -- Zero corner frequencies
15:32 -- Shelf amplitudes
17:32 -- Pole corner frequencies (code)
19:53 -- Realizing my mistake
20:21 -- Pole corner frequencies (results)

Опубликовано:

8 июл 2024

Ссылка:

Скачать:

Готовим ссылку...

Добавить в:

Мой плейлист

Посмотреть позже

Комментарии : 11

@georgegkountouras4311 2 года назад

17:16 Interesting to see the Gain-Bandwidth tradeoff of the fully bypassed cathode.

@Lantertronics 2 года назад

That seems to be a theme in electronics in general. There is no free lunch. :)

@locojose13 2 года назад

Around @12:30 on the final form slide, we suck the - sign into the A_0 term as it's included in our definition of A_0 from earlier in the lecture, but @13:05 the - sign shows up outside of it. I think it's a minor clerical error, but just in case anyone else was confused, I believe that's what happened!

@Lantertronics 2 года назад

Whoops, thanks for catching that!

@possible-realities 2 года назад

17:32 Since this is a first order shelf filter, the ratio of the asymptotic gains should be equal to the ratio of the corner frequencies. So if you have the zero frequency and the asymptotic gains, you should be able to calculate the pole frequency from those. That also means that at 20:22, the pole should indeed be very close to the zero (as you calculate it to), since the asymptotic gains are so similar.

@Kimodokun 2 года назад

13:17 KIND of looks like the parallel combo of R_ACL + r_p and R_k, but then with some weird reflection of u +1?... a bit of a stretch at that point.

@Lantertronics 2 года назад

Yeah, I saw something looking like a kind of parallel combination but couldn't quite make it work.

@brettclark8020 2 года назад

Wouldn't this derivation be a lot simpler if you did it in terms of gm instead of mu and rp? For practical calculation, I would estimate that pole's time constant at C/gm.

@Lantertronics 2 года назад

Maybe? I'd need to try it. Maybe something pops out clearly if you approximate mu+1 as mu.