Retro Mac audio project?

[aujawindar]

Good sirs and madams,

Here's a possibly fun project that you are welcome to chime in on, if you like. I happen to have revived a 2007 20" Imac (or iMac, if you want) by installing Linux Mint on it. This is a Core 2 Duo Mac with its original hard disk replaced by an SSD, and the RAM is upgraded to 3GB. We might say that this isn't retro, but perhaps that's exactly what it is now. I remember recording a few singles with Ardour on a single-core 1GHz Acer laptop, so the iMac's dual-core 2GHz CPU is in fact rather mighty by comparison. Of course, these days, the CPU power is close to nothing compared to current PCs. Time flies.

Anyway: For many years, I have found it to be a hassle recording with USB sound cards - which is what I have been using for a long time now. I never seem to get rid of the xruns, even with rather recent computers. I remember having fewer issues when I used a firewire soundcard back in the day, so maybe this is the time to revisit that obsolete protocol? Rather nice firewire soundcards can be had for very little money, so maybe I'd actually enjoy recording with this (semi-)retro gear? In itself, the iMac is a fine machine, with a screen that's still enjoyable. (I'm typing this post on the machine.) But can it really be used for reliable audio recording and mixing? I have used Ardour and Mixbus for quite some time now, and would like to continue using them.

I don't really have questions for you, except maybe: What do you think? Caveats, thoughts, setup tips or any input welcome, be it positive or negative. And a happy new year to you all!

[bluebell]

I'd first check out if I can tune the machine by using a realtime kernel, performance governor and rtirq.

[asbak]

Typical problems with USB are that soundcards are on a shared bus with other device which interrupt it, or the USB chipset is less than stellar for that particular soundcard, or the OS has not been tuned, or the usual Linux Audio prepwork was not done, or the kernel isn't at least in preempt, or jack or pipewire settings are misconfigured or not configured, or rogue processes are running on the PC, or rtirq is not being used to prioritise the audio device, or hyperthreading is on, or CPU is not in performance mode, a combination of these and many many more potential factors.

Firewire may help a little in the sense that there aren't going to be many processes competing for resources with a firewire soundcard but it seems kinda unlikely to me that firewire is going to be the be-all and end-all solution.

Some firewire cards are relatively cheap now but a TB2 to Firewire dongle will probably cost the same if not more than the soundcard today since Apple stopped selling them.

The TL;DR - the box probably has tuning and configuration issues and firewire may not be a magic fix.

[aujawindar]

Thanks to both of you for replying. I can see that part of my post may come across as complaining - that wasn't my intention. My aim is to find out if a 17 year old Mac can be fun to use for audio work. Heck, I looked at Sound on sound review of a firewire sound card that's still highly relevant sound quality-wise, and they were testing it using a G3 Mac running at 600MHz. It follows that it should be possible to do audio work on a slightly newer computer with an SSD. I did so yesterday, installing AVLinux on the iMac. Initial results are promising, I will report back when I have tried Mixbus on it

[aujawindar]

Well, I must say: Ouf of old hardware one can get a perfectly working studio. Using Mixbus 8 on AVLinux, I recorded 9 tracks in 48kHz, used some EQ, compression and reverb, and had a DSP load of about 30-40% on the Core 2 duo iMac in question. 3 xruns in 3 hours (and all of them with the computer idling) using a sizable buffer of 1024 over 3 periods. The latency doesn't really matter, because I always monitor through the soundcard anyway. Here's a picture of the current "old mac" setup. What you see here is a usable studio for very little money. I am impressed by what this old machine can do.

macstudio.jpg (121.69 KiB) Viewed 222 times

[LesPaul]

Looks cute but I got you beat for low cost by a mile. I recently found a 30" ASUS monitor on the curb because the woman couldn't find the power supply. It was a standard 19v. I took it home and it fired right up. Audio and kdenlive is completely different on a 30" monitor. On my laptop I can't even see all the instruments in hydrogen but on this it looks like I can load another 10. My PC is a finder too, a Quad core DDR2 based system, I have since found better stuff like i5 and i7 but have been too lazy to build another PC.

[aujawindar]

but have been too lazy to build another PC.

And that is a very good point indeed, which has taken me and likely many others among us a long time to understand: This kind of laziness is good. If an old system works and does what you want it to do, don't change it.