All works great. I think i've spotted a fake 1943 & 5200 . Sample 2sc2987 & 2sa1227
http://www.which.co.uk/consumer-rig...ted-a-fake-or-counterfeit-good-how-can-i-tell
http://www.which.co.uk/consumer-rig...ted-a-fake-or-counterfeit-good-how-can-i-tell
All works great. I think i've spotted a fake 1943 & 5200 . Sample 2sc2987 & 2sa1227
Hello Blantozaur,
Good to hear it works!! also with some pictures would be great....
Regards,
What i did:
- removed damaged amplifier section oryginal magnat 480
- mounted ba1000
- rewinded trafo up to +/- 40v at 14,4v 2x1x1.5
What i will do:
- sample output tranzistors to MJL in ba1000
- add subwoofer filters 20hz hpf and virable 30-100 lpf
- use amplifier protection circuit build in power supply
- add amplifier mute synchronizetd width power supply
- rewind trafo up to +/- 70v at 14,4v
- removed damaged amplifier section oryginal magnat 480
- mounted ba1000
- rewinded trafo up to +/- 40v at 14,4v 2x1x1.5
What i will do:
- sample output tranzistors to MJL in ba1000
- add subwoofer filters 20hz hpf and virable 30-100 lpf
- use amplifier protection circuit build in power supply
- add amplifier mute synchronizetd width power supply
- rewind trafo up to +/- 70v at 14,4v
Attachments
What i did:
- removed damaged amplifier section oryginal magnat 480
- mounted ba1000
- rewinded trafo up to +/- 40v at 14,4v 2x1x1.5
What i will do:
- sample output tranzistors to MJL in ba1000
- add subwoofer filters 20hz hpf and virable 30-100 lpf
- use amplifier protection circuit build in power supply
- add amplifier mute synchronizetd width power supply
- rewind trafo up to +/- 70v at 14,4v
Nice work.
Regards
Assess the SOA capability of the output stage by using the relationship:
Maximum Output power is ~ Total output device power rating divided by 4.
This applies to normal ClassAB amplifiers.
The switched rail type are quite different.
I don't have a rule for them.
eg.
for classAB
using a 4pair output stage of 250W devices equates to total device power rating of 2000W.
Maximum power is ~ 500W.
Maximum Output power is ~ Total output device power rating divided by 4.
This applies to normal ClassAB amplifiers.
The switched rail type are quite different.
I don't have a rule for them.
eg.
for classAB
using a 4pair output stage of 250W devices equates to total device power rating of 2000W.
Maximum power is ~ 500W.
different duty requires different device parameters.
D3 & D4 should be small signal diodes, try 1n4148.
D2, D5 & D6 may be OK to leave as power diodes, 1n4002 or above.
D7 & D8 must be power diodes.
But the back emf and the resulting current coming from the speaker and it's crossover components cannot be that high, that 1n540x devices must be used.
I use 1n4003 or above here. But I don't drive 1kW speakers. Maybe the peak transient currents from really big speakers can exceed the short term peak capabilities of the 1n400x series.
D3 & D4 should be small signal diodes, try 1n4148.
D2, D5 & D6 may be OK to leave as power diodes, 1n4002 or above.
D7 & D8 must be power diodes.
But the back emf and the resulting current coming from the speaker and it's crossover components cannot be that high, that 1n540x devices must be used.
I use 1n4003 or above here. But I don't drive 1kW speakers. Maybe the peak transient currents from really big speakers can exceed the short term peak capabilities of the 1n400x series.
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