+2A doesn't play sound

Sparky · Post by **Sparky** » Fri Dec 25, 2020 9:59 pm

I tried PLAY "ga" as an example and nothing comes out of the TV. It's connected via RF until I get my SCART cable. Is there anything else I can try to see If there is something wrong with my AY chip?

Guesser · Post by **Guesser** » Fri Dec 25, 2020 10:39 pm

Plug a pair of speakers or headphones into the 3.5mm sound socket.

Sparky · Post by **Sparky** » Fri Dec 25, 2020 10:48 pm

I can hear the sound through the speaker, but I guess it's not making it out to the CRT TV. Maybe the cable is not the right one, although the picture is surprisingly good for RF.
Thanks.

Guesser · Post by **Guesser** » Fri Dec 25, 2020 10:59 pm

It may just be a matter of fine tuning to get the TV to lock on to the sound subcarrier. There could be a fault inside (cracked ceramic oscillator would be one possibility) but if so it's probably not worth the effort tracking it down and fixing it if you have a SCART cable on the way anyway!

TMD2003 · Post by **TMD2003** » Fri Dec 25, 2020 11:48 pm

I have a +2B which I've been using with a CRT TV recently, and I find can it either be tuned to a sharp picture for the +2B or produce sound (with a slightly snowy picture and washed-out colours), but not both.

Then I discovered that the TV I was using actually had an RGB-capable SCART socket...

Ast A. Moore · Post by **Ast A. Moore** » Fri Dec 25, 2020 11:59 pm

TMD2003 wrote: ↑Fri Dec 25, 2020 11:48 pm I have a +2B which I've been using with a CRT TV recently, and I find can it either be tuned to a sharp picture for the +2B or produce sound (with a slightly snowy picture and washed-out colours), but not both.

There are different PAL subsystems. Some differ only in the frequency of the sound subcarrier. That’s why you can either tune your TV into the video frequency or the sound frequency. Your Spectrum was probably manufactured for a different region. The sound carrier frequency in a +2A/B cannot be adjusted; the X200 crystal oscillator needs to be replaced instead.

1024MAK · Post by **1024MAK** » Sat Dec 26, 2020 2:34 pm

Also some TVs are more forgiving over the signals from the ZX Spectrum not being, err, fully to the broadcast specification.
Remember, it was only designed to work with 1980s analogue CRT technology.

When tuning in via RF/UHF it’s often a compromise between nice sharp clear picture, one with colours (not just monochrome) and sound...

Definitely go for RGB SCART if you can

Mark

1024MAK · Post by **1024MAK** » Sat Dec 26, 2020 2:37 pm

Sparky wrote: ↑Fri Dec 25, 2020 9:59 pm I tried PLAY "ga" as an example and nothing comes out of the TV. It's connected via RF until I get my SCART cable. Is there anything else I can try to see If there is something wrong with my AY chip?

Can you hear the beeper?

Try BEEP 1,1

See also here for what the manual says on BEEP.

Mark

Sparky · Post by **Sparky** » Sat Dec 26, 2020 4:53 pm

I can't hear anything from the TV speaker.
I made a simple program in +3 BASIC
10 PLAY "ga"
20 GO TO 10

When I run it, nothing comes out of the TV, but I can hear the sound If I plug in speakers to the SOUND port.

P.S. With fine tuning I can hear the sound through the TV but the picture is very distorted, and this is a UK edition +2A
I'll have my SCART cable soon so I'll wear speakers in the meantime.

Spectrum Computing

+2A doesn't play sound

+2A doesn't play sound

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