Freeing these Waveblaster Cards

[Great Hierophant]

Waveblaster cards, like the Roland SCB-55, Yamaha DB-50XG output the same sound as the much more expensive Roland SC-55mkII and Yamaha MU-50, but are not as versatile.  They are tied to the waveblaster connector, which is found in ISA and PCI cards.  However, unlike the card versions of these devices, these cards are not tied down to an obselete bus or one that will be in the future (and if not, slots-in-short supply).  I have heard of adapters that can make these devices work without a card, homemade devices that supply the necessary signals to the card.  Anyone know if someone is still building these adapters?  Anyone have an interest in building adapters for a fair price?

[Juho Sippola]

A friend of mine built me an adapter several years ago based on the instructions of the file http://koti.mbnet.fi/tuhos/db50ext.zip. The package includes original documentation and a cleaned-up sheet for PCB printing. I've never acquainted myself sufficiently with the secrets of PCB printing but the files included did the job.

I've used the adapter with Roland SCD-15 and some kind of Terratec/DREAM daughterboard without any notable issues. However, I can't supply the adapters since the board has a line-voltage transformer which practically makes selling such things illegal here without proper permission&etc. stuff. Besides, I believe that you can find somebody who can manufacture the PCB locally and who is able to find a supply for the parts. Soldering that thing together yourself shouldn't be impossible, though.

[shad0wfax]

I remember having read some years ago an article in CU Amiga magazine (an Amiga review from UK) which explained a detailed process to build up an external sound module from a Yamaha DB50XG. However, as far as I remember, this device connected directly to the Amiga's serial port, istead of using standard midi connectors and a midi interface. And no, Amiga's serial port is not like PC's serial port (the Amiga can transmit at the standard MIDI rate of 32kbps, unlike PCs).

[Cloudschatze]

Juho,

Would you mind taking a few photographs of your adapter that clearly show the components?

[Laust]

There's also this one from the German c't magazine, for which you can (or could) order a preetched PCB. You'd still have to do the soldering however.

Both designs seem kinda old, though, with the reliance on a mains power supply to generate the necessary voltages. USB powered makes more sense to me nowadays.

[Great Hierophant]

I saw that site, but the site isn't English friendly and what little German I ever knew I have lost.  Also, I have to consider whether their design needs to be adjusted in any way for a 120 VAC power supply, as opposed to the 240 VAC they use in Europe.  Do they even include the parts? 

USB might make more sense, but it would not work on its own because it can supply only +5 volts and the waveblasters require +12V and -12V. 

[Cloudschatze]

I ran into the c't design a few days ago while looking into the Elektor board.

I went the Elektor route, and have two PCBs on order. I wish the design had a MIDI OUT, in addition to a couple of other things. Guess I'll need to design my own at some point...

At present, I am trying to find a transformer that might work (the Monacor one doesn't seem to exist). I *think* that the Tamura SB3516-3018 fits the bill.

Should be a fun project!

[Cloudschatze]

Should be a fun project!

 

I am having a terrible time trying to locate a suitable transformer, and the Tamura model isn't pin-compatible with the circuit board (and I'd prefer not to modify anything, if possible).

Can anyone help? (Laust, please help me.) 

The project calls for a 2x 9v/3A3 transformer, and suggests the Monacor VTR-3209. I can't find one of these anywhere, nor is it listed on the Monacor website.

Here is the hole spacing (not to scale):


     -  O               O -
     |                    | 5mm
     |               -  O -
     |               |   
20mm |          10mm |   
     |               |     
     |               -  O -
     |                    | 5mm
     -  O               O -
        |_______________|
               25mm

[Juho Sippola]

The transformer on my unit has following markings on it:

Type:
P-CG35-090118-2

Prim: 1-5
230V AC/50-60Hz

Sec 1: 6-7
9VAC/178mA/1.6VA

Sec 2: 9-10
9VAC/178mA/1.6VA

ta = 40degC / F
(Fuse symbol) 250mA T

There are "aspro" markings in the case but I couldn't identify whether that is the manufacturing company of the unit. The electricity in Finland is 230V (previously 220V) AC 50Hz

[Cloudschatze]

Thanks, Juho. I looked into Aspro, and they were apparently bought out by Salcomp in 2002. I couldn't find any stock of the transformer either, but if you happen to run across any, please let me know.


I did happen to find the exact transformer I need: Zettler (Myrra) 44212. It's even 115VAC. Boy, was I excited to find this.

I tried to order a couple from the Zettler shop... Out of Stock.

So I called them up, and they're apparently out of stock because they've never been sold in this country, and there is a 1000 piece minimum to get them to produce them.

Such fun!

At this point, I might just sell the unused PCBs. You guys over in Europe might have better luck with obtaining the necessary parts.

[Cloudschatze]

Hmm. I may have found another possible transformer...

[Cloudschatze]

Here they are, 115VAC transformers.

You guys have no idea how difficult it was to get these...

Technically, they're not even produced...

These were engineering samples...

Free ones, at that.

[Great Hierophant]

Good score, but aren't they just a bit big for the PCB? While you could mount the waveblasters on the non-component side of the PCB, does the size of the transformer block any of the silkscreen for the other components?

Btw, this is no longer a real concern for me.  I have modules for all my daughtercards now. 

[Cloudschatze]

Good score, but aren't they just a bit big for the PCB? While you could mount the waveblasters on the non-component side of the PCB, does the size of the transformer block any of the silkscreen for the other components?

No, they're the correct size. When complete, the daughterboard will mount on the underside.

[kreatorb]

just wondering where you got the PCB manufactured and how much it cost you?

Oh yeah and where you got the samples from too

[Cloudschatze]

just wondering where you got the PCB manufactured and how much it cost you?

Oh yeah and where you got the samples from too

Eh, I really don't recommend this particular project. The design could use a lot of tweaking/updating.

But hey, with that in mind...

Elektor pointed me in the direction of Eurocircuits for the PCBs, though I'm sure I could (and probably should) have found somebody local to do it.

23,95EUR per board
25,00EUR for shipping (Flat rate. Kind-of a rip-off when you're only buying two boards...)

Oh, and if the transformer woe wasn't enough, there's the (unnecessary, IMO) amplifier chip that isn't produced as a DIP any longer. I had to order these from the Netherlands.

The transformers came from the manufacturer's production plant in China, by no small miracle I imagine.

[Juho Sippola]

I didn't include that amplifier and respectable connectors at all in my device. Only the line outputs.

[Laust]

Futurelec claims to still have the DIP version of the TDA7050 in stock.

Personally, I'm waiting for a suitable (read cheap) USB to MIDI solution to emerge before putting something together.  I think USB power is the way to go, but then it would be silly not to also use that as the MIDI interface...

[Cloudschatze]

I didn't include that amplifier and respectable connectors at all in my device. Only the line outputs.

I was tempted not to include them either, since I'll never use them. Same as with the gameport connector.

Futurelec claims to still have the DIP version of the TDA7050 in stock.

Hey, thank-you for the link. I only paid three cents more, per chip, but it's nice to know of a somewhat local source.

Personally, I'm waiting for a suitable (read cheap) USB to MIDI solution to emerge before putting something together.  I think USB power is the way to go, but then it would be silly not to also use that as the MIDI interface...

Can a standard USB port provide +12, -12, +5v though? Something like this might work:
http://www.everythingusb.com/powered_usb.html

[Laust]

Well, I was going for the Maxim MAX743.