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Hydra2 (JP21 version)

Hydra2  (JP21 version)

Not yet available




Price will be the same as EURO VERSION of HYDRA2




Fully automatic SCART switch with full galvanic inputs separation. 

  • 8 scart inputs ( RGB, s-video, composite) - easily expandable to 16 or 24 inputs with HYDRA HEADS device
  • 2 scart ouput -  now, You can connect Your 2 ouput devices !!
  • "Knight rider" style active scart detection
  • full ROHS
  • AVR controller with firmware future updates
  • HQ plexi transparent ( made by me ;-) at my laser machine)
  • STEREO RCA audio output 
  • IR controlled
  • manual/automatic mode
  • MICRO USB power supply (regular mobile phone charger 5V will do the job - please, use sth decent - approx 1A)
  • Dedicted remote sold separately - soon; thus You can always use any NEC/ENEC compatible one You may already have - Please, check FAQ tab above


How doees it work ?

      Imagine, You have many retro system in use. Amiga, Atari ST, ZX spectrum, etc... And You have only one classical TV/Monitor with one SCART INPUT. Each time, You want to switch system, You have to connect Your machine to Your monitor. Everytime, You do it - You damage scart socket inside. Those days are over. Connect up to 24 computers/consoles to HYDRA, then connect HYDRA to Your TV/Monitor and power on hydra. Since now, HYDRA will detect active scart input and forward all signals to Your monitor. Simple and efficent.



(nevertheless Hydra2 has  additional ESD protection  that should save Your device)



  • left - scan left in auto mode / next scart in manual mode
  • middle - HD/SD filter 
  • right - scan right in auto mode / previous scart in manual mode
  • left + right - DISABLES/ENABLE leds
  • middle + right - automatic/manual mode
  • CS1 - ttl/75ohm synd ouput for scart 1
  • CS2 - ttl/75ohm synd ouput for scart 2


Soon - more info about remote codes learnig


Hydra2  8port scart switcher, may be “easily” expanded with 2 additional HYDRA HEADS devices to offer outstanding 24inputs scart functionality.

How does it work ?

       After establishing connection with flat cables between HYDRA (master unit) and HYDRA HEADS (slave unit), user  forces HYDRA to work with HEADS expansion and 8 additional scart inputs it offers.  BOTTOM SWITCH MUST BE SET IN 16P mode.

How about connecting another Hydra Heads to already connected one ?

Additional Hydra Heads unit may be added to previously  installed one to achieve 24 inputs. BOTTOM SWITCH MUST BE SET IN 24P mode.



Product gallery


Q.What happens if i have two active sources the same time ?

Nothing, First applied input is a master signal. You can switch to next one by pressing buttons ( previous/next) or switching  first computer off


Q: I have a PlayStation 1  have hooked up to it and it does not seem to work.I am using a very high performance scart cord from the hydra to the adapter and all of my scart cables are from retro gaming cables in the UK or retro gaming accessories from ebay.

A:  You have a sync stripper installed inside scart socket and "composite sync" signal exceeds voltage level, definied by scart signal standart. Please, have a look at table below - source: Instead of desired 0.7 Vpp (on 0.3V) You get 4Vpp.  As Your TV may not care, Hydra may not detect Your signal.

What Can You do:

  • Feed composite video (or best luma) to scart pin 20 directly, avoiding elements on the way. 
  • Use orginal cable 

"Be aware that in the context of retro gaming, there are two types of csync signals:  TTL and 75 Ohm.  Most displays and processors will require 75 Ohm csync, but some can accept TTL.  As a general rule, unless your setup specifically requires otherwise, your target goal is that the cables you use with your consoles will all be outputting a 75 Ohm signal and the target device will also be receiving a 75 Ohm signal."


Please, remeber and keep in mind, that HYDRA may

not lock on scanning on input with composite sync of TTL LEVEL (4Vpp),

as SCART STANDART ASSUMES 1Vpp including sync



Pin      Signal    Level     Impedance   
1 Audio Out Right 0.5 V rms <1k ohm
2 Audio In Right 0.5 V rms >10k ohm
3 Audio Out Left + Mono 0.5 V rms <1k ohm
4 Ground Audio    
5 RGB Ground Blue    
6 Audio In Left + Mono 0.5 V rms >10k ohm
7 RGB Blue In 0.7 V 75 ohm
8 Audio/RGB switch / 16:9 High (9.5-12V) AVmode
Low (0-2V) TVmode
9 RGB Ground Green    
10 Comms Data 2         
11 RGB Green In 0.7 V 75 ohm
12 Comms Data 1    
13 RGB Ground Red    
14 Ground Data    
15 RGB Red In / Chrominance 0.7 V (Chrom.: 0.3 V burst) 75 ohm
16 Blanking Signal High (1-3V) RGB
Low (0-0.4V) Composite
75 ohm
17 Ground Composite Video    
18 Ground Blanking Signal    
19 Composite Video Out 1V including sync 75 ohm
20 Composite Video In 1V including sync 75 ohm
21 Ground/Shield (Chassis)    




Q: Hydra1 was making  "click sounds" when scanning. Does Hydra2 the same ?

A: No, HYDRA2 mutes outputs during scan


Q: Hydra acts strange. doesn`t detect inputs, sound is disturbed, video blurry...etc

A: Two words: POWER SUPPLY. Please, use decent one.


Q: Hydra gives "jumpy" picture. I have SNES and my cable is pal one.

A:  HYDRA has built in signal termination - 75ohm resistors to gnd. If Your cable has this feature, picture will be darker and may be jumpy. Remove passive elements on RGB lines.  please, read next one answer


Q: Hydra is very problematic with my systems.

A: No. it is not. problematic are Your cables. Please, keep in mind, that hydra has built in many features, like sync stripper for signal detection on scart, signal termination, low/high pass filters. Please, use regular and simple cables to connect Your systems.  For best effects, please considering direct RGB connection, composite video connection and sound to scart socket. ONLY EXCEPTION is RGB switch - 16pin of scart input. it must be pulled high by resistor from 5V to make hydra switch into RGB MODE. How to get proper signal from You system -


FIRMWARE UPDATE PROCEDURE: (thanks to Frank Skilton for debugging)

  • download last firmware from FILES section
  • connect usbasp (or any avr programmer) to KANDA connector of HYDRA
  • run Your AVR programming software
  • load *.XEX file; do not change any fuses !
  • flash it


Q: My monitor/TV  do not switch to RGB MODE. When i connect my device to TV directly, all works ok. 

in order to switch to RGB mode, TV receiver needs 1V-3V level blanking signal at pin 16 of scart  (table above). Unfortunatelly,  some TVs will not switch when HYDRA ouptputs ~1,3V.  it is caused by scart standart signal termination with two 150R resistors at each scart input.  ( 2 parallel resistors 150R equals 75OHM) . FIX: remove one of 150R resitor at desired scart input ( they are located next to pad of scart pin 16 connected to gnd).