The technique of “ping-ponging,” which permits overdubbing of audio so

Kushchokhani I beg to differ. As much is different from As much as. And there's no ellipsis at play here.
Look at the following usage of "as much as"

1. Help yourself to as much of the noodles as you want. (to indicate whatever amount you wish)
2. These exercises can lead to as much as a 20% drop in body fat percentage. (to indicate this or almost this amount)
3. As much as I hate to, I must finish this book report tonight. (to indicate no matter how)

In the sentence quoted, however, "as much" is used to indicate the number of times the technique of ping-ponging has been used. It is not used to indicate comparison. "As much" is a phrase for "much" meaning "the same".
Eg:
1. I like her just as much.
2. I am sure she would do as much for me.
3. Go on, lend me the money - you know I'd do as much for you.
4. My fare was £10, and it was almost as much for the children.

We use "since" when we refer to the time when the action started. Thus (B) clearly conveys that the technique of ping-ponging has not been used as much (enough/as many times) since the advent of computer-based recording.

Hope that helps.

PyjamaScientist
IMO To indicate "enough/as many times", merely "much" can be used rather than "as much". Per this ques, I thought we are comparing how frequently ping-ponging was used before vs after the advent of CBR, and hence related to ellipsis.

Yes, you can use "much" to indicate "enough/as many times", and so can you use "as much". Just because you can use one structure does not mean you can't use another "grammatically correct" structure. I agree that the usage of "as much" phrase is not a common occurrence in official quesitons. But, the phrase "as much" is not wrong.

If you require a deeper look into it, click here, here, and here.

Hope it helps.

All the links that you shared indicate that "as much" means something we already believed to be true i.e. we are comparing actuals with expected. Nowhere does "as much" indicate "enough/as many times" in these links.