Vintage hifi amp - what's this battery for?

[stevehertz]

Whilst addressing another problem in a c1989 Pioneer A-91D amp I noticed a PCB mounted Sanyo R2430 battery, 3V. I'm thinking being as I'm 'in there' and this is a very awkward board to access, I may as well change it being as it's 30 years old. But what does this battery do in this amp?

I can't seem to find an exact style replacement that will drop in (middle and side pins), there are other PCB mount ones so I'll have to adapt the pcb pins to suit - assuming I need to change it.

[paulsherwin]

Presumably it's for memory retention. You should be able to replace it with a 2032 in a holder.

[stevehertz]

Originally Posted by paulsherwin

Presumably it's for memory retention. You should be able to replace it with a 2032 in a holder.

Paul, I kinda guessed that, but memory retention of what? It's not a receiver. For sure, it has to be doing something, but I'm curious as to what.

[Herald1360]

Is it modern enough to have "soft" level controls?

[paulsherwin]

It seems to be quite a complex amp with lots of built in digital processing facilities. It may well contain one or more microprocessors. Very high tech for 1989.

[stevehertz]

Originally Posted by Herald1360

Is it modern enough to have "soft" level controls?

I don't know (1989), and what if it did?! You got me there!

[Electronpusher0]

The service manual is available at
https://www.hifiengine.com/manual_li...er/a-91d.shtml

It does have a micro processor, IC801, the schematic has a note about the battery, see attached.

Peter

[Paul JD]

Plenty of CR2430 batteries available cheaply on eBay.

[GrimJosef]

So I guess it's just there so that the amp 'remembers' through power-downs whatever complicated state it had previously been set up in.

Cheers,

GJ

[Keith956]

It's some sort of backup for the main controller chip, heavens knows what for. The circuit diagram is available online - see https://elektrotanya.com/pioneer_a-9.../download.html

[McMurdo]

I assume it's to remember what input it's set to, that sort of thing. My integrated amp at work is set to radio when I power-up in the morning and if it reverted to 'phono' every time I unplugged it, that would be very annoying.

That sort of thing.

[Joe_Lorenz]

Gentlemen,

please can anyone tell me the why a modern amp with processors, transistors, LEDs and such may be called "vintage"? Yes, my point of view is surely old-fashioned, but my vintage amps like Telefunken V311 and Jensen A-21 have got valves in their signal paths only.

After all, I am not really convinced if it would be ok to declare a Telefunken Opus 2650 Hybrid "vintage". Your opinions?

Thanks, Joe

[GrimJosef]

In the past loose references have been made to age. This thing is 30 years old now. Young people wouldn't be able to identify it for what it is (mostly because it isn't a phone).

Cheers,

GJ

[Outrun_uk]

If it's a receiver then the battery could be for storing radio presets??

Kev

[stevehertz]

Originally Posted by McMurdo

I assume it's to remember what input it's set to, that sort of thing. My integrated amp at work is set to radio when I power-up in the morning and if it reverted to 'phono' every time I unplugged it, that would be very annoying.

That sort of thing.

I think you're right there Kevin. Because while some of the controls; volume, tones etc are true analogue pots and switches, the input ones and some others are momentary, so their settings need to be stored for the next power up.

BTW everyone, I have the service and user manuals but I couldn't see a reference to the battery, so thanks Peter for spotting that.

Having previously looked (always first port of call) I am aware of the batteries on Ebay but like I say above, there's not a drop in one that's physically configured like the existing one. But no problem, I can 'adjust' the positions of the terminals with wire, or as Paul suggested, try to fit a holder - that's if there's enough room.

Thanks everyone, I will change it for a new one.

[Paul JD]

Originally Posted by stevehertz

I am aware of the batteries on Ebay but like I say above, there's not a drop in one that's physically configured like the existing one.

Not sure what you mean? The battery looks to be a standard coin cell, 2430 refers to the physical size (24mm dia x 3.0mm thick) and CR cells are lithium 3v cells. Your photo clearly shows the +ve side and the other side facing the circuit board will be the -ve terminal?

[paulsherwin]

The battery in the photo appears to be fitted with tags for semi-permanent connection to a PCB. The easiest modern replacement would be to use a holder, which can be bought from eBay sellers for pennies, or scavenged from scrap equipment.

Originally Posted by Joe_Lorenz

Please can anyone tell me the why a modern amp with processors, transistors, LEDs and such may be called "vintage"? Yes, my point of view is surely old-fashioned, but my vintage amps like Telefunken V311 and Jensen A-21 have got valves in their signal paths only.

After all, I am not really convinced if it would be ok to declare a Telefunken Opus 2650 Hybrid "vintage". Your opinions?

The forum convention is that anything more than 25 years old is vintage, and newer equipment should be discussed in the Modern Technology section.

[ahankinson]

If you were calling valve amplifiers from the 1960s “vintage” in the 1990s, then it’s justifiable to call amps from the 1980s vintage today. Strangely, they’re the same distance, historically speaking, from each other.

[Diabolical Artificer]

I've got about 100 of this type of battery if you need one. It's possible to solder leads on them using a very hot iron quickly applied.

By modern standards anything over a year old is vintage : )

Andy.

[stevehertz]

I've just removed the battery, it measured just a few millivolts. As you can see, it has 'centre and side' PCB mounting pins whereas all the other PCB types that I've seen for sale are 'tripod' style. Anyway I can bend the connections and add wires to them to adapt for my application.