Tips and Tricks for Dream based Sound Cards

There exist various sound cards using a chipset by Dream S.A.. These sound cards usually feature a SAM9407 chip which includes the effect processor or the Crystal CS9233 chip in combination with the CS8905 effect processor. The cards usually have a combination of ROM + RAM for sound fonts. The main chip uses a loadable firmware from RAM or ROM as well.

Weak effect processing for MIDI playback in DOS on EWS64

The EWS64 features the SAM9407 that allows to adjust the parameters for effects. By default effects are set to a weak level when the DOS init tool is run with the default settings. However the startup setting for the SAM9407 are loaded from a TTM file that holds also the mixer settings. There is no tool in DOS to generate such a TTM file. It has to be saved from the Win9x mixer application. However it can be edited manually as it is basically a text file.
There has been done some tuning by comparing to the effect strength of a Roland Sound Canvas by 'CptKlotz' at Vogons. There exists now a custom TTM file with adjusted values for effects: Custom TTM file for EWS64XL that I also added to VogonsWiki. Details can be found in this Vogons Thread. There is also a Custom TTM file for EWS64S

On EWS64XL when using digital sound in Soundblaster Pro mode the Wavetable Daughterboard gets muted.

This seems to be an issue with the initialisation using Terratecs utility. This has been resolved by running the mixer tool from the default tool package from Crystal Semi. for the codec chip.
C:\EWS64\CS32MIX /M=15,15 /W=13,13 /L=0,0 /X=1 /F=7,7 /C=11,11 /I=L
Just add a line like this after the EWS64XL was initialised and the Daughterboard won't get muted next time digital sound is used in DOS.

With a Maxi Sound 64 there is no dedicated tool to set effects in DOS (as with Maxi Sound 64 Utilities in Windows).

That is right, however if the Dream DSP on the card uses default firmware all the special features are configured by sending SYSEX MIDI messages. (Might even be the case for EWS64 with it's custom firmware) For the default firmware this is covered in detail in the documentation with the default MIDI implementation on page 57 incl. all the Roland compatible SYSEX messages for effect parameters, on page 61 Dream specific NRPN MIDI messages are covered. It is also possible to configure the firmware directly by switching the MIDI port into control mode. This is covered starting at page 23.

The Dream chip offers me only 34 voices, shouldn't it have 64 voices as the common naming like EWS64 or Maxi Sound 64 suggests? How can I get the all 64 voices?

It actually can render 64 voices, but when features like equalizer are enabled the number gets reduced. With the default firmware setting are 34 usable voices left. However with the Win9x driver of the Maxi Sound 64 series a tool called dspconf.exe is included. It allows to switch on/off each feature of the firmware separately. This allows to switch off features and gain voices.
In principle this can be done as well from DOS by issuing control messages as described above.

The Maxi Sound 64 Utilities in Win9x give me an error 'Can not load soundfont.94b'.

This seems to be a bug in the Win9x Dream driver that surfaces with some 94B sound fonts. Usually the same sound fonts load without any problem from DOS or NT4. I don't know a workaround for this yet.

Is it possible to easily convert soundfonts to 94B format?

In a way yes. The Maxi Sound 64 Utilities allow to load DLS sound fonts directly. Internally the Utilities convert the DLS sound font on the fly to a 94B file. The program asks if you want to save the generated 94B elsewhere. It loads the 94B and deletes the temporary generated file. In combination with the previously described bug in the Win9x driver the 94B is already deleted when the Utilties ask to save it when the load fails. The only way is to copy the generated 94B manually from the TEMP folder while the error message is displayed. In NT4 however everything works fine.
There are tools to convert the common SBK, SF2 fonts to DLS first. It is unclear if specific information gets lost on conversion. It appears however that the resulting 94B sound fonts are good.
To convert SF2 to DLS the Extreme Sample Converter 3.6.0 Demo can be used. Choose as Source Format SF2 and as Destination Format DLS/Bank, press convert.

With my Terratec Maestro 32/96 my computer hangs on warm boot when the card should be detected or the cards resource detection sometimes detects the Codec/Midi, sometimes it doesn't.

Known hardware flaw, replace original capacitor C58 (should be 16 V, 10 microF) with 16 V, 1 microF (35 V, 1 microF works as well). C58 is in the top right region above the Codec Crystal CS4232.

Can I load the better featured Terratec EWS64XL firmware with the Maxi Sound 64?

No.

The documentation states that the default firmware of the SAM9407 has MOD playback support in hardware. Which player supports it?

The version of MOD4WIN 2.30 that has hardware support for GUS and also SAM9407. You have to set in DOS the environment variable to the port of the Dream DSP: SET SAM9407=330
If you run MOD4WIN from NT4 or Win2K you have to make the ports accessible first with e.g. GiveIO. (Same applies for native GUS playback btw).
The Terratec EWS64XL firmware makes Module playback available direct through terratecs driver and their player tool.

What is the difference between the Crystal CS4236 on the Maxi Sound 64 Home Studio and the Crystal CS4236B on the Terratec EWS64XL?

After PnP-init the CS4236B switches the connected Dream-DSP to MIDI-UART mode automatically while the CS4236 leaves it in control mode.


Dream SAM9407 documentation
Dream sound DSPs documentation