From James Grenert Sent Wed, Jan 17th 2018, 21:35
From James Grenert Sent Wed, Jan 17th 2018, 21:35
Thank you for your thoughtful analysis. Just a couple of comments/questions: On 1/17/18, Oakley Sound <xxxxxxxxxxx@xxxxxxxxxx.xxx> wrote: > However, I would argue that > replacing the cap with a 4.7uF electrolytic like in Don's modification > isn't going to improve things. > Agree, but it's possible to get reasonably-sized polyester caps in this value: https://www.mouser.com/productdetail/wima/mks2b044701k00jssd?qs=sGAEpiMZZMv1cc3ydrPrF7l45uRd9dVhWlrbRYtfjMU%3D > I'd be tempted to pad the input before even the first > op-amp. The CE-300 has only a +15V supply and a virtual 7.5V for > reference. Thus all the op-amps can only swing by about 10V peak to > peak, which is quite small for a pro-audio unit. > Doesn't the combination of R1 (10k) and R2 (10k after the mod) actually create a -6dB pad as it is? What do you think about swapping to audio opamps that swing closer to the rails such as LM4562 or OPA2134? > Ignoring that bit all I can see they do is to have > the same effect as simply turning the input level down a bit and > increasing the gain required on the output. > In the end, that looks to be true!