Sound Amplifiers and Synthesizers
The beeper originally installed inside the ZX Spectrum is actually just a buzzer which explains why the sound which comes from it is of low volume and poor quality, however it is sound none the less. The lack of quality sound from the Sinclair machine inspired a good many add-on peripherals which at the very least would improve the volume and at best would match the quality of microcomputers four or five times as expensive as the ZX Spectrum.
The simplest way to improve the sound coming from the Spectrum is to take the signal from the MIC socket and pass it through an amplifier. Another way is to use a modulator to mix a sound signal with that of the RF signal so that the sound came be heard through the TV set speaker.
For better quality sound there were Sound Synthesizers which would use a special IC such as the AY-3-8910. This IC would, with the appropriate software, reproduce sounds using its own internal circuitry independent of the Spectrum's beeper. More than that, it could also produce three channels of sound as well as a variety of effects which could be applied to any of those channels.
The ZX Spectrum+ 128K models all had an AY chip inside them to produce 3-channel sound as well as the ability to output that sound through the TV speaker or SOUND socket.
The add-ons which appear below have been seperated into two lists: Sound Amplifiers which merely amplify the ZX Spectrum's own BEEP; and Sound Synthsizers which recreate complex sounds across multiple channels.
The simplest way to improve the sound coming from the Spectrum is to take the signal from the MIC socket and pass it through an amplifier. Another way is to use a modulator to mix a sound signal with that of the RF signal so that the sound came be heard through the TV set speaker.
For better quality sound there were Sound Synthesizers which would use a special IC such as the AY-3-8910. This IC would, with the appropriate software, reproduce sounds using its own internal circuitry independent of the Spectrum's beeper. More than that, it could also produce three channels of sound as well as a variety of effects which could be applied to any of those channels.
The ZX Spectrum+ 128K models all had an AY chip inside them to produce 3-channel sound as well as the ability to output that sound through the TV speaker or SOUND socket.
The add-ons which appear below have been seperated into two lists: Sound Amplifiers which merely amplify the ZX Spectrum's own BEEP; and Sound Synthsizers which recreate complex sounds across multiple channels.
Sound Amplifiers
Features
Original Price
Saga Soundboost
Allows sounds to be played through the TV speaker. 3 long wires with crocodile clips connect to the internal circuitry of the ZX Spectrum.
Circuit board looks like, and could be the same as, the Compusound Telesound board.
Circuit board looks like, and could be the same as, the Compusound Telesound board.
£9.49*3
*p&p free
*p&p free
BEEPER AMPLIFIER
from CP Software
Plugs into EAR or MIC socket. Battery powered.
£5.95*9
* +35p p&p
* +35p p&p
Compusound Telesound
Allows sounds to be played through the TV speaker. 3 wires connect to the internal circuitry of the ZX Spectrum.
£9.95*2
*Retail price
*Retail price
Andrew Pennel Sound Amplifier
Uses ZX Spectrum power supply and does not block expansion port. Has volume control and socket which can drive an external speaker.
Measures: 118mm x 78mm x 34mm.
Came complete with leads and instructions.
Measures: 118mm x 78mm x 34mm.
Came complete with leads and instructions.
£9.95*4
*inclusive
*inclusive
8 watt BEEP amp
from Hypnotech
10 watt woofer and tweeter. Plugs into MIC input. Mains operated.
Measures: 14 inches x 8 inches x 4 inches.
Measures: 14 inches x 8 inches x 4 inches.
£23.95*10
kit version £18.55
*inclusive
kit version £18.55
*inclusive
Games Ace
from Datel
Includes controllable sound through TV.
Kempston compatible joystick interface accepts 9 pin joysticks including rapid fire.
Primarily the Games Ace is actually a joystick interface with a built-in sound booster and is listed here for completeness. A duplicate of this entry is listed under Joystick Interfaces.
Kempston compatible joystick interface accepts 9 pin joysticks including rapid fire.
Primarily the Games Ace is actually a joystick interface with a built-in sound booster and is listed here for completeness. A duplicate of this entry is listed under Joystick Interfaces.
£10.99*18
£17.99* - with Quickshot II joystick18
*Post free
£17.99* - with Quickshot II joystick18
*Post free
Kayde Spectrum Sound Module
Fits inside Spectrum. Sound comes through TV. No soldering required.
£9.95*7
* +£2 p&p
* +£2 p&p
Super Sound Spec-Amp
from Kelwood
Plugs into MIC socket. Fully adjustable (whatever that means) Spectrum Sound Amplifier. Runs on a 9V PP3 battery (which was included).
£7*12
* VAT and p&p inclusive
* VAT and p&p inclusive
The Sound Expander
from AFDEC Electronics Ltd
Came with leads, volume control and built-in loudspeaker. Plugs into MIC input.
£7.50*8
*inclusive
*inclusive
Echo
Stonechip Electronics
Control volume and tone. LOAD and SAVE without switching leads. Audible cue facility. DIN compatibile.
£23.50*6
*inclusive of p&p and VAT.
*inclusive of p&p and VAT.
Zeal Sound Booster
Output control (looks like a volume control). LOAD and SAVE facility. No batteries needed.
£14.99*13
*inclusive of p&p and VAT.
*inclusive of p&p and VAT.
ZX-BOX
from Interservice Electronics Ltd
The line drawing appears to show a Volume control dial, a Spectrum compatible power lead, and a 3.5mm jack plug, presumably for the MIC socket.
£9.95*16
*Was sold from larger branches of W.H. SMITH & SON. Didn't appear to be available by mail order, although a supplier's address was published with the advert.
*Was sold from larger branches of W.H. SMITH & SON. Didn't appear to be available by mail order, although a supplier's address was published with the advert.
Sound Synthesizers
Features
Original Price
dk'tronics 3 Channel Sound Synthesizer
Uses AY-3-8912 sound chip17. With through connector, jack plug socket for a speaker. Came with a speaker and a 1 metre cable17, and in later versions a Music Designer cassette.
Works with ZX Spectrum and ZX Spectrum+
Works with ZX Spectrum and ZX Spectrum+
Sound synthesizer - £29.95*†14
*+£1.25 p&p
†Music Designer Cassette price normally £9.95 (Later versions only)
*+£1.25 p&p
†Music Designer Cassette price normally £9.95 (Later versions only)
The Fuller Box
Built-in audio amplifier allows programming of music, explosions, zaps chimes, whistles and an infinite range of other sounds. Based around the popular Gl-AY-3-8912 sound chip giving complete control over 3 channels of tone and/or white noise, plus an overall envelope control. Also provided with a joystick port, compatible with all the commercially available joysticks e.g. Atari/Commodore.
Came complete with full documentation and demo tape. Microdrive compatible.
Worked with certain Artic and A&F games to give speech and sound effects.
Master Unit was available which combined The Fuller Box with the Fuller Orator.
Came complete with full documentation and demo tape. Microdrive compatible.
Worked with certain Artic and A&F games to give speech and sound effects.
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Master Unit was available which combined The Fuller Box with the Fuller Orator.
Fuller Box - £29.95*15
Master Unit - £54.95*15
*+£80p p&p
Master Unit - £54.95*15
*+£80p p&p
The Spectrum Add-on
from Micro Power
Utilises the AY-3-8910 chip from General Instruments. 2 Watt speaker. BEEP can be amplified by plugging the lead from the Spectrum Add-on into the MIC socket.
Optional joystick kits can be connected to the Spectrum Add-on.
Has a ZX81 through port.
Optional joystick kits can be connected to the Spectrum Add-on.
Has a ZX81 through port.
Spectrum Add-on - £19.50*19
Joystick kit - £3.95*19
*exclusive of VAT.
Joystick kit - £3.95*19
*exclusive of VAT.
Petron Trichord
6134 X 3 note chords (48K ZX Spectrum), pre-programmed PROM has a range of sound effects accessed with 2 BASIC instructions, ordinary music notation used (A to G), range of more than 8 octaves, key signature applied throughout.
Originally presented as a project in Electronics Today International (ETI) (April/May 1983)
Also produced for the ZX81.
Originally presented as a project in Electronics Today International (ETI) (April/May 1983)
Also produced for the ZX81.
with internal amp and speaker £28.951
with BEEP amplifier £29.951
without amp or speaker £26.951
Demo cassette £1.25 extra1
with BEEP amplifier £29.951
without amp or speaker £26.951
Demo cassette £1.25 extra1
The Spectrum Sound Synthesizer
from Signpoint Ltd
3 channels of sound with envelope control, with integral amplifier and speaker. I/0 port, Plugs into the back of the Spectrum. Came with documentation and demonstration and utility programs on tape.
£28.00*20
*+80p p&p
*+80p p&p
ZON-X 81
from BI-PAK Semiconductors
Uses the 8912 sound chip and has an internal amplifier, loudspeaker and volume control.
Originally produced for the ZX81, the ZON-X 81 requires an addition 2 inch long board containing a 3.5MHz oscillator, which fits between the ZON-X and the Spectrum.
Not compatible with the ZX Interface 1 or ZX Microdrives (later versions were fully compatible11).
Measures: 6 inches x 3 inches x 2 inches.
Originally produced for the ZX81, the ZON-X 81 requires an addition 2 inch long board containing a 3.5MHz oscillator, which fits between the ZON-X and the Spectrum.
Not compatible with the ZX Interface 1 or ZX Microdrives (later versions were fully compatible11).
Measures: 6 inches x 3 inches x 2 inches.
£25.955
Spectrum adaptor board (required) £6.805
Spectrum adaptor board (required) £6.805
References
1. "SPECTRUM IN HARMONY" / Petron advert, Your Spectrum, No.1, January 1984, p.15/792. "BETTER BEEPING", Your Spectrum, No.7, September 1984, p.5
3. Saga Systems Ltd advert, Sinclair User, No.32, November 1984, p.88
4. "Plug-in Sound amplifier", Sinclair Projects, No.1, December 1982/January 1983, p.6
5. "Sound box for Spectrum", Sinclair Projects, No.3, April/May 1983, p.10
6. "More sound from your Spectrum" - advert, Sinclair User, No.14, May 1983, p.15
7. Kayde advert, Sinclair User, No.14, May 1983, p.42
8. AFDEC Electronics advert, Sinclair User, No.14, May 1983, p.71
9. CP Software advert, Sinclair User, No.15, June 1983, p.70
10. "AT LAST YOU CAN BEEP A SIGH OF RELIEF!" - advert, Sinclair User, No.15, June 1983, p.112
11. "ZON-X is now fully-decoded", Sinclair User, No.16, July 1983, p.24
12. Kelwood advert, Sinclair User, No.23, February 1984, p.136
13. Zeal Sound Booster - advert, Sinclair User, No.25, April 1984, p.146
14. "EXPLORING THE SENSE OF SOUND!" - advert, Your Spectrum, No.11, February 1985, p.55
15. Fuller advert, ZX Computing, February/March 1984, p.79
16. "ZX-BOX - A Sound Investment for your SPECTRUM!" - advert, Sinclair User, No.19, October 1983, p.122
17. dk'tronics - advert, Sinclair User, No.33, December 1984, p.75
18. "SPECIAL OFFERS For Your SPECTRUM/PLUS/128K - advert", Sinclair User, No.55, October 1986, p.74
19. "Adding on your Spectrum" - article, ZX Computing, April/May 1983, p.28
20. "The Spectrum SOUND SYNTHESIZER" - advert, Sinclair User, No.25, April 1984, p.99
External Links
Testing a BI-PAK ZON X-81 on a ZX81. Programmable sound unit.Last revision : 28/09/2024