So much for R4’s superiority!
There must be something that eludes me here. I had my CBM (r3) MIDIBox sid for a while,
then decided to look at what other SID i had in this c64c i found in a recylcing facility for 2$..
It had an R4 in it, Yay i says, lets swap it…
These shots were taken right after a program change in both cases.
Is there a solid link/comparison thats been made across chip revs/dates etc?
Not that I know of…
With some basic side-by-side testing, I’ve noticed a difference between 6581R4AR, 8580R5, CSG6582A (d/c 89) and CSG6582A (d/c 92)
The 8580R5 and both kinds of 6582A have a MUCH lower volume click, everyone with them in a MB-SID would notice the difference on program changes. I’ve even modulated the volume register and if you’re modulating between 50% and 100% volume (i.e. tremolo effect) you can’t hear any clicks.
What was interesting to observe is that the 8580R5s and d/c 89 6582As have identical output amplitudes, but the d/c 92 6582As peak a tiny bit lower. It’s not an audible difference, but it is fairly consistent across the frequencies. I’m using the Spectroman in FL Studio, so I don’t have any fancy graphs or figures ;D I just see two overlaid graphs with peak on the y axis, freq. on the x axis, and one line is just a little bit higher.
Thanks for the interresting bits about recent chips
Maybe i should collect them and do graphs and post them on the wiki.
i woke up at night and remembered that my particular MBox SID hums when ask too much current,
say i boost the LCD’s brightness (it even reboots the pic) so maybe this hum was just caused by the
R4 sucking more juice?
i woke up at night and remembered that my particular MBox SID hums when ask too much current,
say i boost the LCD’s brightness (it even reboots the pic) so maybe this hum was just caused by the
R4 sucking more juice?
You need a better power supply. It’s coming out of regulation, or tripping the current limiter in the regulator.
Mike
You need a better power supply. It’s coming out of regulation, or tripping the current limiter in the regulator.
Mike
Im using the smashtv’s kits with included parts. Could it be the transfos?
iirc they are 500 or 600ma (will check tonight)
There’s your answer…
