DX - Owners' Club UK

The F.M. legend - a personal history

For me, it all started one day in mid'1984 when I walked into my friendly neighbourhood music-inst shop (actually, it was Soho Soundhouse, London) and there was a buzz in the air. The sales-guy says "You're here to try out the DX-7, right?". I, of course, didn't know what he was talking about and enquired about the price. It was out of my reach (obviously). Not to be deterred, the sales-guy instead plonks me in front of a Yamaha DX-9 and hands me some headphones. I started playing and... aaaahh, heaven!

It's hard to describe what I heard (bearing in mind it's my first time hearing F.M. synthesis). You have to understand that, up to this point, synths were all about strings and brass. Occasionally, you'd have a few plinky plonky xylo-sounds (heck, the MKS-10 was considered realistic) but percussives, vibes, pianos etc were elusive (ie non-existent). But right there in front of me, in the form of a DX-9, was the holy grail. And, to make matters worse, there weren't any knobs or sliders or anything in fact which gave any inkling as to how this synth worked.

I was hooked! I took the plunge and bought a DX-7 in Nov'84 and later a CX-5 in Jan'85. Unfortunately, programming these FM synths was an absolute nightmare. Nothing was fast and nothing was easy. It really wasn't intuitive at all and the manual wasn't exactly that helpful. But I was determined to master this beast. Learning to program the DX-7 was a slow and tedious process.

But one day in late 1984, humanity was saved by a fellow synth-enthusiast called Tony Wride. Fed-up and tired with struggling alone with his DX-7, he mooted the idea of a "DX-club" in a letter to the magazine "Electronics & Music Maker". This caused a huge stirring of support from the public (DX synth owners), the media (music mags) and Yamaha too. Thus was born the DX-Owners Club.

It was the DX-Owners Club which took FM programming to new heights. Via its newsletter, we began sharing patches/ sounds (one patch called "Wurlitzer" was really popular) and programming techniques (excellent articles by Ken Campbell). Part of Tony Wride's vision was also to have a network of co-ordinators who anyone could telephone for help and advice (you'll find listed under Area Co-ordinator for London W2 is "Yahaya 01-221-5314" which is me).

Beyond the popular newsletter (these typed-up/ hand-drawn photocopy newsletters were inspirational), the club also organised get-together seminars bringing programmers together to meet experts like Dave Bristow to discuss FM in depth (I remember that fixed-frequency operators was a big topic). FM ruled and the DX-7 was king... Life was good!

But as life goes on, reality takes its hold... Tony's job in the Royal Navy gave him less time to run the club. Eventually, the club was handed over to (surprise surprise) Yamaha who appointed Martin Tennant (not to be confused with Martin Russ) to run the re-named X-Series Owners Club. With Yamaha's backing (ie money), the newsletter became a regular magazine (with pictures and all) and everything was taken to a more polished level.

The X-Series Owners Club was good... but with the change of management of the club, came a change in objectivity. You see, us members may all be dx-synth enthusiasts but we didn't work for Yamaha (the old newsletter would include info on non-Yamaha products as well). I remember an interesting session where Yamaha was launching their DX-5 while Tony was happily proposing to just add a TX-7 to a DX-7 (ie half the cost). Ah, well! Nevermind.

As far as I know, the magazine continued until around mid'1987.

CX5M MUSIC COMPUTER

The CX5M is now available from the YAMAHA Hi-Tech Dealers listed below and if you haven't got one it is well worth looking at. The price is somewhat lower than predicted with the basic package (CX5M & 44 note mini keyboard) costing @ £534. If you decide on the optional full size 48 note keyboard the package will cost @ £614. The software ROMS should be @ £36 each but if You buy a complete package you may get a slight reduction.

The Club will aim to help CX5M owners as much as possible and I am already in the process of transposing DX Voices to the CX5M for release on cassette. If you buy a CXSM then please complete the enclosed enrollment form to update the Clubs' records. The cassette mentioned should be available in mid December providing the copying firm don't hang around. If any of you are real computer wizards there is room for improvement on CX5M software and it should be possible, with the right software, to have a good real-time sequencer and play the CXSM's Synth via MIDI. I am trying to get the required in/out statements so that programmes can be written but for obvious reasons Yamaha are hanging on to them for the moment. No doubt new software will be available from Yamaha in the New Year.

CX5M DEMONSTRATIONS AND CLUB GET TOGETHER.

I have managed to arrange a couple of special demonstrations of the CX5M to DX Owners' Club members in the London, Glasgow, and Newcastle. These demo evenings willalso provide a chance for you to meet other Club members within those areas.

The first of these demonstration evenings will be held at CHROMATIX of Ealing Broadway Centre LONDON between 2000 & 2200 on Thursday 29 November. Those of you who would like to attend should ideally phone Dave Crombie or Howard Brain on 01-567-3623 so that they have some idea of numbers to cater for. I hope to attend this evening and look forward to meeting you.

The other two evenings are being arranged by ROCK CITY of Newcastle and McCORMACKS of Glasgow and are likely to take place on the same evening. Please phone either Jim Corbett at Rock City(0632-324175) or Tommy McGinley of McCormacks(041-332-6644) for details.

Apart from these two special evenings any of the Hi-Tech dealers listed should be only too willing to demonstrate the CX5M to you. However I suggest that you phone them to arrange a convenient time since walking in on a Saturday and expecting the busy staff to devote sufficient time is unrealistic.

YAMAHA HI-TECH DEALERS

ABC MUSIC: All Branches / ANDERTONS: Guildford / ARGENTS: London / AXE: Colchester/ Ipswich / BAIRD: Belfast / BROADWAY MUSIC: Worthing / PETER BONNER: Eastbourne / BRISTOL GUITAR WORKSHOP./ CARLSBORO: All Branches / CHAPPELLS: London / CHROMATIX: Ealing / CITY MUSIC: All Branches / DAWSONS: All Branches / DERBY ORGAN CENTRE / DOUGIES: Northwich / ESS: Barnet / FREEMANS: Leytonstone / FUTURE MUSIC: All Branches

GIGSOUNDS: Catford / JAMES GRANT: All Branches / HESSY: Liverpool / HONKY TONK: Hadleigh / JSG: Bingley / JONES & CROSSLAND: Birmingham / KINGFISHER: Fleet / LONDON ROCK SHOP: & BRISTOL / MILTON KEYNES MUSIC: Leighton Buzzard / E.MOORS: Bournemouth / McCOMACKS: Glasgow /.MUSICLAND: Cardiff / MUSIC VILLAGE: Romford / ONE WAY MUSIC Wolverhampton / PICTONS: Swansea / REIDY: Blackburn / ROCKBOTTOM: Croydon

ROSE MORRIS: London / SHARON MUSIC: Maidstone / SOHO SOUNDHOUSE: London / SOUND CONTROL: All Branches / SOUNDS GREAT: Heald Green / STIX: Peterborough / SYCO SYSTEMS: London / WHAM MUSIC: Cambridge / WHITE ELECTRIC: Sunderland / ROCK CITY: Newcastle

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YAMAHA D1500 MIDI COMPATIBLE DIGITAL DELAY @ £699.

The first MIDI Compatible Digital Delay is now available. This unit responds to MIDI programme change commands to allow you to select 1 of 16 programmable delay effects simply by pressing the voice selection on your DX. For live performance this is a must since being able to have just the right effect for each voice selected means a much better sound.

COMPUTER INTERFACES.

I have had several queries regarding computer interfaces and software for use with a DX. It would take rather along time to run through all of the units available so I have decided to give, my personal opinion on what an ideal set up should be. Obviously finances will be the deciding factor in the end.

The CX5M is the obvious choice if you want a dedicated music computer designed specificaly for use with a DX and containing effectively a DX9 to boot. However if you already have a computer you may consider that buying a CX5M is a bit of a waste, but if you think of the CX5 as a very powerful FM synth that just happens to have an MSX Computer attached you may not.

For a low priced, especially if you buy the computer secondhand, yet effective set up, the 48K Sinclair Spectrum & an XRI MICON interface (Total @ -220) is a personal favourite and a set up that I have been using a great deal until I got the CX5M. Other interfaces are available for the Spectrum but I'm afraid I don't rate them that highly mainly due to their poor value for money. The other thing in favour of the MICON is the software which consists of a very good step-time and real-time sequencers plus a DX voice editor and a tape dump. This leads nicely onto what do you realy want the computer to do for you. Some people go wild about real-time sequencers, others about step-time. Personally I prefer a step time sequencer with full edit capability and the music displayed on staves as opposed to a list of numbers and values in tabular form. Several of the software options available at present,(EMR MIDITRACK for the BBC, RMS and SIEL for the Commodore 64) present the user with a tabular display. Try and look at a chord on this and you will blow your mind!! It should be emphasized that the software is the limiting factor and no doubt improvements will be made by EMR, RMS & SIEL.

For the BBC more and more interfaces and software options are becoming available with the London Rock Shops' UMI-1B System and Channel 8 Softwares' MIDISOFT 1 both looking quite promising. The Channel 8 system is also available for the CB64, IBM PC, and QL computers.

There are few real-time sequencers available that allow you to edit easily although Rossetti (RMS) have recently introduced a new piece of software for the Commodore CB64 that looks quite good, but once again presents the notes in a tabular form. For more details on the products mentioned the addresses are listed below,but I recommend the reviews contained in Electronics and Music Maker. If you own one of the odd computers, Tandy etc, few if any interfaces are available since it is not commercially viable.

If You have any other queries then please give me a call.

XRI MICON: XRI Systems, 18 Sunnybank Rd, Sutton Coldfield, W.Midlands.(021- 382-6048)

UMI-1B: London Rock Shop. 26 Chalk Farm Rd.London NW1 (01-267-5381)

MIDISOFT 1: Channel 8 Software, 51 Fishergate. Preston, Lancs.(0772-53057)

SIEL & RIMS systems are available from several dealers but contact Computer Music Studios, 62 Bleinheim Crescent, London W11 1NZ (01-221-0192). It will be to your advantage. Please mention, that you are in the Club and you just might get a discount. Certainly. XRI have offered a 10% reduction to club members.

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DX9 CASSETTES. - The cassette containing over 80 voices for loading into a DX9 is still available, price £3.00. The FREE 'Winning Voices' cassette is also still available. Please include a 24p SAE.

MEMORY EXPANSION FOR THE DX7. - The Dutch Company DIGITAL MUSIC have produced some memory expansion units for the DX7 at very competitive prices, nearly. £100 less than the SYCO equivalent. 3 units are available with different amounts of memory expansion to increase the internal memory to 64, 96, or 128 voices. The prices are £100, £125, and £150 respectively. The units apparently are very easy to fit, taking about 5 minutes at the most, and a comprehensive instruction booklet is included. A memory expansion is a much cheaper way than a RAM Pack of increasing the number of voices instantly available to you. If you would like more details on these units then please send an SAE. Hopefully they will be available either from the club or a Dealer in the next few weeks.

FOR SALE. - KORG CX3 Organ + Flight Case. £400 ono. Tel. LEEDS (0532) 784352.

IAN BODDY’S New Album 'SPIRITS'. - This album, which makes extensive use of a DX7, is now available from:- 32 HUGAR ROAD, HIGH SPEN, ROWLANDS GILL, TYNE & WEAR. Price £4.00 plus 50p P+P. Well worth a listen to.

MEMBERS QUESTIONS.

Q) TOM McLAUGHLIN from London asks:- How do the Algorithms on the DX9 relate to those of the DX7?

A) Algorithms 1-8 on the DX9 equate to Algorithms 1,14,8,7,5,22,31,32 on the DX7 less operators 1+2, ie Op1 on the DX9 = 0p3 on the DX7.

Q)CHRIS PICKFORD from London asks:- Can YOU operate the KORG EX800 Expander correctly when being driven by the CX5M.

A) As far as I know, yes. There should be no problems.

Q) J.M.MARTEN from Reading asks about info on an interface for syncing the Roland TR808 to the CX5M.

A) The KORG KMS30 at £155 should quite happily perform the task since it converts MIDI Clock into Sync Clock for use with the Roland.

WANTED. - 1) CHRISTOPHER HOPTON from Glos. needs some natural sounds on the DX7, namely SEA-SHORE, THUNDER, RAINFALL. GALES, etc.

2) JERRY VAHRMAN from Copenhagen needs some good split Keyboard sounds.

If anyone has any of these sounds then please send them to me at the address given.

3)KEYBOARD PLAYER WANTED to team up with guitarist/ bassist (CX5M owner) to form a small Combo to play for enjoyment and perhaps the occasional Gig Contact Kerry Watson, 7 BRAMBLE CLOSE, HARPENDEN, HERTS. Tel. Harpenden 63355.

ELECTRONICS & MUSIC MAKER. - You can now claim a £1.00 discount on the annual subscription to this excellent magazine. Either complete the form in the latest issue of E&MM or write to: Mail Order Dept, ELECTRONICS & MUSIC MAKER, Alexander House, 1 Milton Road, Cambridge CB4 lUY. The rates are,(including the Discount): £14.50(UK & EIRE), £15.20 (Europe & Overseas,SURFACE), £22.50 (Europe,AIRMAIL), £36.50(AIRMAIL outside Europe). Cheque/Postal Order (Bankers Draft from Overseas members) should be made payable to MUSIC MAKER PUBLICATIONS. Please include this section of the newsletter and your membership number to claim this discount price.

ACCESSORIES

Unfortunately due to complaints from certain Dealers I can no longer offer to supply the Yamaha accessories previously listed direct from the club. When dealers start complaining about losing £5 of profit, on something that they don't even keep in stock in the first place, having just sold several thousand pounds worth of Keyboards it makes you, wander!! Warrington and Chadwell Heath have same very major road works in progress at present and an alternative route should be sought!!!! A lot of Dealers are actualy very supportive of the club and have taken the trouble to contact me offering to help Club members.(Rock City, London & Bristol Rock Shops, Chromatix, Argents, Hessays, Future Music, ABC, JSG, Grants, to name but a few.) You should be able to obtain the Yamaha accessories that you require from any of the Yamaha Hi-Tech Dealers at a fair price. Certainly ROCK CITY will be keeping a stock of all of the main accessories, (Breath Controllers, Volume Pedals, RAM Packs, etc).

DUAL SUSTAIN/PORTAMENTO PEDAL FOR DX7 & DX9. £24.00 (includes P+P) - This Dual switch pedal for the sustain and Portamento functions on the DX is still available from the Club. The unit is styled in a similar form to a double piano pedal, is very robust, and saves having two individual Yamaha pedals each costing £20. Please make cheque/POs payable to the DX OWNER'S CLUB.

DX SWEATSHIRTS (£7.50) & T-SHIRTS (£4,50): Still in stock are these excellent quality goods, They come in Navy Blue with a Red Logo, and are available in SMALL, MEDIUM, LARGE, or EX.LARGE.(Machine Washable) Cheoue/PO payabe to the Club.

AMERICAN DX7 & DX9 OWNERS MANUALS. £2.25 (includes P+P) - I now have a stock of these somewhat more comprehensive (70 pages worth) manuals. Cheque/ PO to the Club.

DX7 VOICE BANK. - I would still like to receive more of your own creations for addition to the Voice Bank. In particular one of the voices that has been requested is a good Sax. If you have one then please send it for inclusion in tne next newsletter. In the meantime the 2 voices included with this newsletter, FM PIANO & VOICES, are just a couple of examples of what is available. I have produced two batches of voice data for programming into a DX7. The first batch of 50 voices contains a selection of the best sounds received by the club, while the second batch contains 30 computer print outs (including Envelope graphs) of a wide varlety of sounds to act as a reference for programming. Each batch costs £4.00. (Please include a large SAE). If you have a RAM pack then simply send it plus a padded SAE and will load it with a selection of new voices free of charge. If you are fortunate enough to have a CX5M and the DX7 Voicing ROM then a tape containing over 192 voices is available for £4.00.(Please include the usual SAE.)

'GETTING STARTED' - If you have recently acquired your DX, this FREE Information booklet, produced by Dave Bristow, is available from the Club. Please send a 9”x6” 24p SAE if you would like a copy.

A NEW DX7 BOOK. £7,95 - Music Sales have just released a new book on the DX7 the owners might find useful. Entitled 'YAMAHA DX7 DIGITAL SYNTHESIZER' and written by YASUHIKO FUKUDA, it gives a guide to the controls, the basic mechanism and a useful section on programming. It does not cover everything but at least it provides a foundation on which to build confidence in using your DX. It should be availabe from any good Music Store or can be obtained direct from the Club (P+P FREE).

PRACTICAL FM SYNTHESIS AND FM SPECTROGRAMS.

Those of you who attended the Hi-Tech Convention will remember Dave Bristow showing some examples of Spectrograms and talking about Modulation Index. Included below is one of the spectrograms that he showed and following on from that a section on Practical FM Synthesis by Ken Campbell.

COMPARISON OF REAL SOPRANO WITH DX SIMULATION.

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PRACTICAL F.M. SYNTHESIS. - By Ken Campbell.

The principal behind F.M. synthesis is essentially a simple one, with only two controlling factors - Frequency and Amplitude of the components.

Frequency Modulation is the production of a complex waveform by modulating two or more sine waves together, one of these sine waves must act as a carrier providing a source for the second sine wave to work on. The alteration of the parameters of these components will cause wide tonal variations.

When F.M. takes place, the frequency of the carrier will oscillate. The difference between the basic frequency of this carrier and the highest or lowest instantaneous frequency it achieves is known as the deviation. The amount of this deviation is controlled by the AMPLITUDE of the modulating wave. The ratio of the deviation (d) to the modulator's frequency (m) is expressed as the Modulation Index (I) :-

I = d / m

The ratio of the modulator's frequency to the carrier frequency determines the spacing of the sidebands. These sidebands are sine waves of frequency outside the deviation of the centre frequency. Think of it as one sine wave providing the basic frequency with the harmonics (sidebands) superimposed on this.

EXAMPLE.

CARRIER / FREQUENCY

The above is an imaginary spectrum for the modulation with a carrier frequency of 1kHz and a modulator of 200 Hz.

The series of sidebands is theoretically infinite, but there comes a point at which these are inaudible. The modulation index dictates the relative amplitudes of each order of sidebands and these can be calculated using Bessel functions, provided that the deviation is known.

As every action has an equal and opposite reaction, each order of sideband has an upper and a lower constituent, the lower being a reflection of the upper, with the carrier as its axis. There is a second axis for the lower sidebands, which is 0Hz; it being impossible for a frequency to attain a negative value. Where sideband spacings are uneven these reflections will add new harmonics providing an asymmetric waveform. In the example (above) you will see that the fifth and sixth order sidebands are reflected. In this case the spacing is even, so they are reflected back to stengthen existing harmonics.

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The fundamental of a modulation can be calculated by finding the highest common factor of the carrier and the modulator frequencies. Thus if the carrier frequency was 1 kHz and the modulator 2 kHz, then the fundamental of the modulation would be the carrier frequency. If, however, the modulator's frequency was reduced to 1.5 kHz then the fundamental would be 500 Hz as this is the highest number that will divide both frequencies evenly.

From these principles it is possible, given that all component values are known, to calculate exactly how a modulation will act.

Frequencies and amplitudes present in a sine wave of carrier frequency 'C' frequency modulated by a sine wave of frequency 'M' with modulation index I. Jn(I) indicates the bessel function of the 'n'th order.

FREQUENCIES / AMPLITUDES

This formula takes reflections into account.

(To be continued)

DX7 VOICES.

The voice data contained with this newsletter are as follows;

SLAP BASS - As used at the recent Convention by Ken Campbell and Dave Bristow.

VANGELIS - A very analogue, Prophet 5 sound as used extensively by Vangelis. Dave Berkley from Newcastle provided this one. Well done Dave.

SIMMON - This is very representative of a Simmons Drum kit with a snare at the top end of the Keyboard and the Drums at the bottom. You need to turn the volume up to achieve the best results! Try a simple change of Algorithm to change the sound.

ORCH VLN - A classy string sound from Dave Bristow which uses Fixed Frequency to achieve a very realistic sound.

Those of you who do not own a CX5M may find the computer print outs a bit confusing so I have included some information below to help you fathom out what is what. If when programming in voices you start with button 7 (Algorithm) and work up through the buttons you should not have any problems.

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AREA CO-ORDINATORS.

Listed below are the Christian names and telephone numbers of members who have volunteered to help co-ordinate the club in the areas shown. if you are within one of these areas then give this a call. For security reasons, I an trying to keep the number of people with access to names and addresses to a minimum, quote only your Membership Number, Christian Name, and a contact telephone number.

Each of the Co-ordinators will be provided with just about every voice and piece of information that I have and should try and arrange a meeting of club members on a regular basis. A pub or indeed the local Yamaha dealer may be a good place to have such meetings. The aim of these meetings, or get togethers, is quite simple, by meeting other users of the equipment you have the opportunity to make new friends, expand musical ideas, pool equipment, and most important of all LEARN. The end result should be that you will get the best possible results from your Yamaha Hi-Tech equipment, and a few new bands may be formed!!

CHRISTIAN NAME - TEL.NO. - AREA.

PHILIP - 0272-73870 - BRISTOL

TONY - 02205-3662 - CAMBRIDGE

YAHAYA - 01-221-5314 - LONDON W2

RICHARD - STAINES 53979 - SURREY

MIKE - 061-440-0118 - STOCKPORT

BERNARD - 0227-60825 - EAST KENT

KEITH - 061-881-0570 - MANCHESTER

MARK - 0632 576901 - NEWCASTLE

CAMERON - BIDEFORD 75778 - N. DEVON

ANDREW - 0782-639180 - STAFFS.

BARRIE - 084-94-53692 - N. IRELAND

ROGER - 01-653-0211 - SOUTH NORWOOD

WAYNE - 626-0780 - OLDHAM

MIKE - 0642 471120 - CLEVLAND

BILL - 0742-739569 - SHEFFIELD

STUART - 01-806-2091 - LONDON E5

MARTIN - 0473-625290 - IPSWICH

CHRIS - 01-422-5587 - HARROW, MIDDX.

BILL - 041-637-4737 - GLASGOW

TIM - 0242-35114 - CHELTENHAM

TERRY - 241792 - LEIXLIP, EIRE.

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PRACTICAL F.M. SYNTHESIS. Part 2. - By Ken Campbell.

F.M. AND THE DX7

This section will deal solely with the various controls which in different ways, are involved with F.M. synthesis. In order to avoid confusion I have omitted all function and performance controls. The majority of the principles discussed here are also relevent to any of the Yamaha FM synths.

1.0PERATORS. - The basic building block of the DX7 is the operator. The sole product of each individual operator (of which there are six) is a sine wave of variable frequency and amplitude.

[Diagram : Pitch data / Mod data]

The input buffer processes information supplied from two sources and sends this to the oscillator which produces the relevent waveform. The first input supplies pitch data which determines the frequency, and the second, modulation information, output from any operators higher up the chain.

This information is then passed on to the amplitude section which is controlled by information from an envelope generator.

It must be stressed that terms such as oscillator and amplifier are merely convenient labels and do not actualy describe the internal operation of an operator. At this stage all the information is still in digital form and it is only after all the necessary calculations have been performed that the final 'waveform' is passed through a digital to analogue converter (D/A) to become a voltage which can then be amplified.

2.FREQUENCY

The scale used for frequency on the DX7 is very convenient (and thus probably intentional) when relating it to the previous discussion of F.M. theory. This is because the frequency course adjustment is numbered from 0.50, 1.00 etc to 31.00, and relates exactly to the harmonic series. It is therefore possible to relate the frequency displayed to a set of partials without having to resort to Hertz, and leave the interger set.

The frequency fine control allows you to multiply the course frequency by between 1 and 1.99.

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3.ALGORITHMS

An algorithm is mainly a description of the way in which the operators are combined. These combinations relate to the final sound in much the same way as an architect's drawing relates to a building. They affect the overall 'shape' of the sound. The DX7 has a fixed set of algorithm's numbering thirty-two.

[Diagram : Algorithms 1, 17, 22]

The above examples show various different combinations of operators.

A modulation will always move downwards from the top modifier out through the carrier(s). In cases where a carrier has more than one modulator in series (algorithm 1 and 17) the top modifier will modulate the one below which will in its turn modify the one below that. The final product is still only one waveform, but this will be more complex than a simple carrier modulator relationship which will provide an even spread of harmonics. To illustrate this point:-

[Diagram : M->-M->-C]

Let us take an example whereby we have a frequency ratio of 4:3:1. Taking the first modulation, this is the arrangement of the first four order sidebands.

[Diagram : Separate USB & LSB]

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8.

Therefore the overall product is:-

[Diagram : Combined USB & LSB

Some of the partials are duplicated in different sidebands and are thus stengthened according to the amplitude of that sideband. This is controlled by the amplitude of the modulators.

It is also possible for more than one modifier to modulate one carrier in parallel (as in algorithm 17). Take the previous example and re-arrange the configuration of the operators so we now have:-

[Diagram : 2M->-C]

Instead of a 4:3:1 relationship, we now have a relationship of 4:1 and 3:1. Taking the first of these, the product for the first four order sidebands is:-

[Diagram : 1st USB / LSB]

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For the second:-

[Diagram : 2nd USB / LSB and Combined

Compare this with the first example.

One night at first glance think that it would be possible to do the same with four operators in series, but this would add an extra ratio between the middle two operators, changing the character entirely.

Taking the last example and reversing it so that we have one operator modulating two carriers, produces a further variation.

[Diagram : M->-2C]

This will produce the same components as previously stated, but instead of one final product there will be two separate waveforms.

The final example (algorithm 32) involves no frequency modulation and is an example of simple additive synthesis.

Whenever there are two or more carriers present in a sound, the result is the sum of the waveforms. Depending on the frequencies of the sounds involved, amplitude modulation, beating, and combination tones will also occur.

All the algorithms on the DX7 are combinations of the above principles.

[Diagram : Algorithm #32]

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PROGRAMMING 'ANALOG' SOUNDS ON A DX7'. - By Peter Rochon, Yamaha Canada.

Many DX7 owners have expressed an interest in being able to program 'analog" sounding patches. Here is a programming 'formula' which will do just that! Start with STRING 1 (ROM 1A 4). Go into the 'Edit' mode. The first step is to indentify which Algorithm is being used and which operators are acting as 'Carriers'. In this case it is Algorithm 2 and operators 1 & 3.

The next step is to change operators 1 & 3 from Frequency (Ratio) mode to Fixed Frequency mode using button 17. Having done this go back to operator 1 then press the 'Frequency Course' button 18. Your LCD should read 'F Course = 10.00 Hz', press the 'NO' button to change this to read 'F Course = 1.000 Hz". Repeat this procedure for operator 3. Once you've completed this phase of the edit, you will notice a difference in the sound. Press the 'Edit/Compare' button and listen for yourself. Now press the 'Frequency Fine' button 19, select operator 1, then move the 'Data Entry' slider to bring the Frequency to a range of 1.950 Hz. As you change the frequency, listen to the effect by playing the Keyboard after you change the value. Repeat the process for operator 3.

You have just successfully completed the modification of STRING 1 to an 'Analog' sounding string sound. Congratulations! You can now apply this same formula to any other sound by changing one or more carriers in the given Algorithm to a fixed frequency. Try it with other sounds such as Brass, Synths, etc.

Thank you Peter and Yamaha Canada Music Ltd. for this article taken from their “X-PRESS” newsletter. Interesting to note that both the X-CLUB in Canada and the DX CLUB in Japan are run by Yamaha!!

TX7 TIPS.

Those of you fortunate enough to own a TX7 may have noticed a few obvious omissions from the owners' manual, like details of single voice transfer and storage. It is possible to transfer and store a single voice from a DX7 to a TX7 provided you have 'SYSTEMS INFO AVAIL' on the DX and the 'MEMORY PROTECT OFF' on the TX. When you select a voice on the DX7 it is then transfered to the TX7 Edit Buffer. Using the 'STR TX PERF' procedure you can store this voice in one of the memory slots of the TX. Note however that you may need to adjust the function parameters to suit your needs. A single voice can be sent from the TX7 to either a DX7 or CX5M using the 'EDIT VOICE OUT' procedure. Of interest voices an only be sent individualy from the TX7 to a CX5M when using the DX7 Voice Editor software due to differing formats. However, a complete bank of 32, or an individual voice, can be transfered the other way.

The other point to note is that some of the preset voices on the TX7 have one of the EG BIAS sections turned on therefore requiring a Breath Controller, Modulation Pedal, Modulation Wheel, or After Touch to allow the sound to be heard. 'Hi Strings' is an example of this. If you do not possess either a Modulation Pedal or a Breath Controller then you may need to edit the Function data in both the TX7 & DX7 Function memory of the TX7.

If you want some more voices for your TX and DX see DX7 Voice Tape.

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CX5M VOICE & TUNE TAPE.

Provided you sent in a record card stating that you own a CX5M then included with this newsletter you should find a cassette containing a selection of Voices and Tunes. I intend producing another similar cassette in about six months time and would appreciate any pieces of music or new voices that you have. If you own a CX5M and have not got a tape then did you return the record card or have you just bought one and not told us?

DX7 VOICE TAPE FOR USE WITH TX7 OR CX5M.

I am working on a cassette containing at least 20 banks,(hopefully more like 30), of 32 voices (640) to be loaded into a DX7 via a CX5M or TX7. I intend getting the tape comercially copied if the demand is sufficient. If you would like a copy then please send a cheque/PO for £10 (made payable to the DX OWNERS' CLUB). Please allow at least 28 days delivery since I do not intend placing the order for copies of the tape until mid July so that I do not order too many, or too few. Please note that some of the voices on this tape are already on the 192 voice cassette that some of you may already have.

DX7 VOICE TAPE FOR SINCLAIR SPECTRUM & MIDI INTERFACE.

I am also working on a similar tape to the above for use with a Sinclair Spectrum, MIDI interface, and the SOS DX7 VOICE EDITOR software. This will be available mid August price £7.50. Once again I would like some idea of how many copies to make up so please send your order before the end of July. (Cheque/PO made payable to the DX OWNERS' CLUB)

DX7 VOICE DATA SHEETS & RAM LOADING.

For those of you that do not possess a computer, or a TX7, new voices for your DX7 can be obtained in printed form. There are two batches of voice data available. The first batch of 58 voices contains a selection of the best sounds received by the club, while the second batch contains 38 computer print outs of voices (including Envelope graphs) of a wide variety of sounds to act as a reference for programing. Each batch costs £4.00. (PLEASE include a LARGE SAE). If you have a RAM pack then simply send it plus a padded SAE (50p postage to cover Recorded delivery) and I will load it with a selection of voices FREE of charge. Please send the RAM Recorded Delivery and include sufficient return postage for Recorded Delivery ie 58p. The Club accepts no responsibility for RAMs lost in the post.

DX7 VOICE DISC FOR USE VIA BBC 'B' AND E&MM "BEEBMIDI".

Thanks, yet again, to Martin Russ a disc containing a bulk (32 voices) dump programme and approximately 800 DX7 voices is being prepared at this moment and should be available from AUGUST. If you own a BBC'B', E&MM BEEBMIDI, and a 5&1/4” disc drive then you may be intersted in this disc. Send a cheque/PO for £10 (made payable to DX Owners' Club).

DX DISC & FM DISC FOR BBC 'B'.

Martin has also produced a couple of programmes that plot FM waveforms and spectrums which are both well worth looking at if you would like to study some of the theory of FM. Each disc comes complete with a comprehensive instruction manual. The two discs cost £7.50 each or if you buy both £10. Cheque/PO made payable to the club.

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