New high end Vogons Tuning Edition available now.
Parallel port soundcard with high quality tuning options, compatible with Covox Speech Thing
Line out connection, intended to connect to amplified speakers
Optional Dual Color high quality enclosure.
No compromises, we wanted to make the best possible covox clone, and did not spare effort or expenses :
after building 3 prototype generations (CVX1, CVX2, CVX3), this is now the final version :
CVX4 uses very high precision 0.1% all same value resistors, and a reverse engineered schematic (based on a real original covox) for excellent 8 bit sound. Other DIY clones use 1% or 5% resistors, different schematic, ...you can compare... CVX4 sounds way better...
Added low pass tuning options to simulate speaker effect to your own taste.
Dip switch legend :
dips 1-5 : low pass filter
1: 1nF : significant low pass filter
2: 4.7nF : heavier low pass filter
3: 10 nF : very heavy low pass filter
4 : 0.1nF : very subtle low pass filter
5 : 0.47nF : subtle low pass filter
dip 6-7 : extra volume divider :
6 : 56k (1/2R) :
7 : 27k (1/4R)
dip 8
8 : bypass coupling capacitor
Dip settings for authentic Covox' sound : dip 7 on, other dips off.
Example DIP switch settings :
DIP SWITCH Position :
(1-2-3-4-5-6-7-8) |
Result : |
| E-D-D-D-D-X-X-X |
low pass filter set medium |
| D-E-D-D-D-X-X-X |
low pass filter set heavy |
| D-D-E-D-D-X-X-X |
low pass filter set very heavy |
| D-D-D-E-D-X-X-X |
low pass filter set very low |
| D-D-D-D-E-X-X-X |
low pass filter set low |
| X-X-X-X-X-E-D-X |
extra volume divider set half |
| X-X-X-X-X-D-E-X |
extra volume divider set a quarter |
| X-X-X-X-X-X-X-E |
bypass decoupling capacitor |
Legend: E = (e)nabled or on; D = (d)isabled or off; X = doesn't matter
Review and detailed development history by Scali here :
https://scalibq.wordpress.com/2017/11/28/the-covox-years/
CVX4 soundcloud demos here :
https://soundcloud.com/user-919839499/sets/cvx4-mod-playback-with
Enclosure assembly tip : The top and bottom are printed to tight tolerances, for a good fit. When assembling, don't use excessive force.
Assembly is easy, following these steps :
- put the top lid in front of you, so that you can read the 'CVX4' text
- tilt the lid, and fit the right side notch first.
- after this first, you can gently move the lid downwards, while pulling it to the right, and fit the other notches.
CVX4 playing a song using CVXPlay in DOS :
Fasttracker II through CVX4
CVX4 in games : Electro Man
Review/Demo by Phil's computerlab:
Featured in this 8 bit guy demo :
CVX4 Modmaster Demo by FreddyV Retro Zone
Combining 2 x CVX4 for Stereo support - Retro Erik:
LPT devices comparison by Retro Erik: