RS232 ports on AV amps



Over the years i've been reading reviews on selected "high end" A/V Amps & Receivers there is usually a small comment which usually says:
"an RS 232 or serial port for future upgrades"

My question is,
what future upgrades? :confused: I thought most manufacturers incorporated upgrades into the next model! I've not seen many firmware updates for "high end" A/V Amps & Receivers.

I know that any firmware updates would have to be done by a authorised dealer/service agent. I would rather wait for a newer model to be launched with those updates included!

Wouldn't a better use for this port to connect to other A/V or Hi-fi components or a computer as part of a central HC/Hi-fi/home automation system? or, in this day & age a DIY firmware upgrade could be done by anyone with internet access, a serial lead & the knowledge on how to do the upgrade?


Active Member
Some RS232 ports also support remote control protocols, some only those, i.e. no upgrades (e.g. Yamaha DSP-AX1) while others are strictly for upgrading only.

There have been very few SW only upgrades, currently only the first update for the Onkyo TX-DS989 comes to mind which added DTS Es Discrete and DPLII. The 2nd update requires HW modifications like with the Denon AVC-A1SE.

Some AV processors however allow SW upgrades to add/enable certain features.

Usually new features are added to the replacement model or newer version of the same model and are sometimes even passed down to lower budget equipment.

I would rather wait for a newer model to be launched with those updates included!

An expensive choice. Why buy a new model just because of a new feature when you loose so much value of the current one?
Take the above mentioned Onkyo for example - would you actually like to throw away your 989 for a 989 MkII just because of DTS Es Discrete and DPLII? Something which happended only a few months after is was released!

Nothing wrong if someone upgrades for that reason (after all it's your money) but I personally would appreciate the possibility of a SW only upgrade - especially if it's for free. :D


Cheers for the reply, Reiner,

Contrary to what I said, I don't buy a new a/v amp/receiver every year just because it has a new feature on it - funds don't permit it!
In fact, the A/V receiver I currently own is the 4th model I've owned in the last 10 years.

1st one was a pioneer VSA 730 pro-logic amp - owned that for 6 years very happy with it until…….
2nd one was a Sherwood 925, reason - upgraded to 5.1 (I bought my 1st dvd player at the same time, owned that model for 2 1/2 years but used it for 18 months b4 storing it for just over a year) happy with it until…….
3rd one was a Sony 930, reason - upgraded to dts sound, happy with it until it went wrong twice in the space of 3 weeks (just as well I extended the guarantee) so I sold that to a workmate when it was repaired. I'd still have it now if the blessed thing had never gone wrong!

The 4th one (the one I have now) is a Sony 940, which I got in part-ex for the Sherwood.
Happy with it, but I feel there is something lacking in the sound at times & I would like to upgrade (again!) to 6.1 & PLII.
I would tend to go with the forum flow & buy a Denon or Yamaha next time.
Funds at the moment are lacking due to just spending 5K on having my house double-glazed & fascias & soffits fitted.

Also, it would simply be too much hassle for me to wire an extra speaker or two via the loft because it now has floorboards fitted, as well as hunting around for a pair of 2nd hand Tannoy M1s (which are my rear speakers). I couldn't justify spending out on a completely new 6.1 speaker system at the moment!

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