Furture of Octo?

[JAmBer]

Is there any chance we might see a higher-quality version in the future? The current units do suffer from a fair bit of power-supply noise, and the pops on startup (biasing?) mean that I need a cumbersome out-of-band management system to mute my amplifiers on startup.

I have two octos, one in use as a portable music system, with active crossovers, and the other in my one car, also active crossovers. I love 'em both!

Some of the local hificlub guys have been eyeing my setup in place of some MiniDSP crossovers as well, but the audio quality is not quite where it needs to be yet.

[flatmax]

Hi there,

Yes next year we plan to do a revised version of the octo addressing this noise - it will be a kickstarter.

Are you aware of the mute pin on the output header ? have you worked in an arrangement to hard solder onto that pin ?

Matt

[JAmBer]

Great to hear there's a new model coming! I'll keep an eye out for the kickstarter.

I wasn't aware of a mute pin. I'm currently using an off-board solution with timers. Is this mute asserted when the audio is off, or is it under software control? Whenever I start audio, there's a nasty pop (presumably as bias levels are reached). Could this pin keep external circuitry muted during this startup time, too?

[robiwan]

You could probably route a GPIO pin to the mute input, with appropriate startup state, then set that GPIO pin to "unmute" in /etc/rc.local ?

[flatmax]

Great to hear there's a new model coming! I'll keep an eye out for the kickstarter.

I wasn't aware of a mute pin. I'm currently using an off-board solution with timers. Is this mute asserted when the audio is off, or is it under software control? Whenever I start audio, there's a nasty pop (presumably as bias levels are reached). Could this pin keep external circuitry muted during this startup time, too?

Yes, so if you look at the data sheet :
http://www.mouser.com/ds/2/76/CS42448_F4-275685.pdf

For example the flow chart in Figure 12 ... it suggests there is a 400 ms ramp up to set the bias levels, once the bias levels are in power down mode ... this will guard your amplifiers from pops.

I am not in front of a working system now - so I can't tell you whether is goes low or high during mute. Typically however, a transistor is used to shunt voltage off any active circuits you are using ... for example, they recommend a transistor shunt to gnd (with protection/current limiting resistors) to keep output voltage low during mute.

Matt

[robiwan]

A small tip for next revision of OC, instead of 24 pin headers, use 26 pin ones, because of the large availability of premounted 26 pin cables