Issue 2 Spectrum not loading software

For experts to discuss very technical stuff and newbies to ask why the Spectrum they bought off ebay doesn't work.
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StephenM
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Issue 2 Spectrum not loading software

Post by StephenM »

Hi can anyone give me some ideas of what may be wrong with my Spectrum.

It's an issue 2 board and I'm using the PlayZX app on Android to try and load software. I have a mono cable and have tried various different volume levels to no avail.
The loading bars appear and I can get it to recognise the program, which it then continues to start displaying the title screen (sometimes this is corrupted other not) At this stage I get the tape loading error either 1:13 or 1:14.

The beeper works but I cannot hear the sound of the audio file loading. Is there something in the audio input circuit playing up and what can that be.

Any help will gratefully received
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Ast A. Moore
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Re: Issue 2 Spectrum not loading software

Post by Ast A. Moore »

Provided you’re plugging the mono cable into the EAR socket (and not MIC), it’s likely that your audio source level is too low. If you are using a modern device for playback (such as a PC or a smartphone), then their output is usually not sufficient to drive a Spectrum’s audio input circuitry, especially that of the earlier models (Issue 1 and 2).

Try obtaining a small headphone amplifier and feed its output into the Spectrum.
Every man should plant a tree, build a house, and write a ZX Spectrum game.

Author of A Yankee in Iraq, a 50 fps shoot-’em-up—the first game to utilize the floating bus on the +2A/+3,
and zasm Z80 Assembler syntax highlighter.
StephenM
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Re: Issue 2 Spectrum not loading software

Post by StephenM »

Ast A. Moore wrote: Wed Oct 09, 2019 2:14 pm Try obtaining a small headphone amplifier and feed its output into the Spectrum.
Ok I'll try that thanks.
What is the minimum and maximum decibel limit that this issue 2 spectrum accept?
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Ast A. Moore
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Re: Issue 2 Spectrum not loading software

Post by Ast A. Moore »

The Speccy is looking for something like 2–5V of the input signal’s amplitude. Most PCs and smartphones don’t produce a signal of more than 1V. Apple gear (both computers and iPhones/iPads, etc.) can put out up to 1.5V, and most Spectrums are okay with it (mine certainly are), but I’d say that’s the bare minimum.
Every man should plant a tree, build a house, and write a ZX Spectrum game.

Author of A Yankee in Iraq, a 50 fps shoot-’em-up—the first game to utilize the floating bus on the +2A/+3,
and zasm Z80 Assembler syntax highlighter.
StephenM
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Re: Issue 2 Spectrum not loading software

Post by StephenM »

Hi,what do you think of these. Am I looking at the right thing? I don't want you to put your neck on the line but these are 3 different types of inline amps. Which vart would you think would more likely get the results I'm after?

https://www.amazon.co.uk/dp/B07MHH14M5/ ... NDbCFEMMFX

https://www.amazon.co.uk/dp/B07GH3K9Y4/ ... NDbWMQNBET

https://www.amazon.co.uk/dp/B07JKHSM6Z/ ... NDb058BGGD
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Ast A. Moore
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Re: Issue 2 Spectrum not loading software

Post by Ast A. Moore »

It’s hard to say with modern headphone amps, since most of them are designed to drive low-impedance loads (typically 16–32 Ohms). When the Spectrum was designed, it was meant to be used with tape recorders that expected loads in the hundred-ohm range. That said, the LIAM and DAAN looks like it will be capable of doing the job. I’m just guessing here, though. Don’t take my word as gospel.
Every man should plant a tree, build a house, and write a ZX Spectrum game.

Author of A Yankee in Iraq, a 50 fps shoot-’em-up—the first game to utilize the floating bus on the +2A/+3,
and zasm Z80 Assembler syntax highlighter.
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1024MAK
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Re: Issue 2 Spectrum not loading software

Post by 1024MAK »

I normally suggest some PC amplifier speakers like these.

Note the above is an example, I cannot vouch for that particular model. You will also have to buy suitable adapters / cables, as the speakers will be wired for stereo, but the ear socket on the ZX Spectrum will only work with a 3.5mm mono plug.

Mark
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StephenM
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Re: Issue 2 Spectrum not loading software

Post by StephenM »

Success!

I bought the £30 inline amp from Amazon last night and it was delivered today , and it worked.

Thanks for the help.
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Ast A. Moore
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Re: Issue 2 Spectrum not loading software

Post by Ast A. Moore »

Glad it all worked out for you.
Every man should plant a tree, build a house, and write a ZX Spectrum game.

Author of A Yankee in Iraq, a 50 fps shoot-’em-up—the first game to utilize the floating bus on the +2A/+3,
and zasm Z80 Assembler syntax highlighter.
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