Needing schema for class AB Amp with 220v Single or double rail

Jump to Latest
M

marconi118

Member
Joined 2008
#1
Any good advice on a good sounding class AB Amp with a single or symmetric - + 220v rails?

By chance I could get 2 toroids from noratel
7kw with one 220v ac secondary each

Single rail with one toroid. cap coupled output
Or symmetric with 2 toroids and 4 times more power...
 
#2
I would try a class d in a 220v single supply. Rememder after retification and smoothing your dc voltage will be over 300v a split rail with +- 300v would be risking life and limb. The closest class ab amp with that type of supply would be the Crown VZ5000 that had a single supply of 180v.
 
#5
marconi118 said:
Any good advice on a good sounding class AB Amp with a single or symmetric - + 220v rails?

By chance I could get 2 toroids from noratel
7kw with one 220v ac secondary each

Single rail with one toroid. cap coupled output
Or symmetric with 2 toroids and 4 times more power...
Click to expand...
Brillant idea, starting with a ton of metall to build an extreme high power amp without any suitable speakers. Is this your very first amp project? I could provide you with my original design from the eighties that delivered 5kW continous 10kW peak using 72 hitachi power MOSFETs. Sadly most of the components are obsolete for decades now. 😀
 
#8
So I scanned my manual from 1987. Attached is the driver circuitry and one of 6 power modules. The hole amp was supplied by three 2kVA toroids (Cekon16A) in a 19"-inch rack 6 units high. Above this 19" by 4 units the fan, a 12 inch ebm. This was on custom order by German Navy and worked on the former "Forschungsplattform Nordsee" for several years. A journey back into the electronics "moyen age". 😀
 

Attachments

Last edited:
#10
Input differential might have been BC560, the other bjts were hi-voltage video types like BF469,BF471 or similar, not the fastest at their time so I went for the cascode. The predrivers were hitachi 200V LatFETS TO-220 2SK214/2SJ79 if memory serves, emitter-followers were too slow as well. All these are obsolete now for a long time. Power supply was +-85V unregulated. This unit drove some submarine transducers - being piezo-drivers with ~2m diameter in a sealed "bomb", driven by a 100 Ohms sea cable via huge matching transformers. A requirement was stable operation over a wide range of reactive load from capacitiv - real - inductive. So I added a "phase monitor" instrument that showed actual phase shift of load. And yes, during measurement this varied between -90 and +90 degrees giving loads of heat to be dissipated. With a helicopter I flew several times to the platform for inspection and setting up the lab fixture. This was a real adventurous enterprise at that time!
 
Last edited:
#12
The purpose was submarine sonic measurements, with automated protocol running without an operator in the lab. Although being about 30 sm west of the island Sylt the sea was only 30m deep there. They had installed a submarine microphone at a distance of 500m and 10km from the platform measuring the sound waves sent from the platform. It was quite surprising to listen to a toneburst on the 10km monitor: It took 10sec to hit the mic and there was a great submarine reverb on the signal due to ground reflections! Another day we send from a tape recorder the triumphal march from "Aida" into the sea and it was reported that a marine vessel anchoring that time in a distance of 500 could hear it inside the hole ship. Outside the lab you could here the sound coming from the sea 30m below your feet...😛 Concerning the transistors I choosed: At this time these were off-the shelf-types, nothing special at all. I always avoided exotics as far as possible.
 
Last edited:
You must log in or register to reply here.
Top Bottom