markp said:You are litterally playing with fire if you don't do it right!
Please buy another and save this one for another project or sell it to buy the other one.
As far as three transformers in a series, you must get the phasing right or you might have a problem(read bang).
There is no bang problem. If you get the secondary series connection in the wrong phasing, youi just get (much) lower output. No bang at all.
However, you must have the primaries in parallel. Each xfromer has to see 120 (or 220 in Europe) mains. You would want to have the phasing right here, but if you don't, you will see less secondary and will have to reverse the secondaries until you get max output. No bang here either.
Jan Didden
Good !!!
Hi ,
I just finish winding the wire on the toroidal , with some problems from the voltmeter .
As i wind about 140 , the voltmeter tell me it droped to 38 from 42 , i go wind till 600 winding reach ( no room for more winding ) and mesure again .. 37 V .. As i thinked that was imposible , i check my multimeter and i notice that the battery was in a bad condition , i changed the battery and the toroidal droped to 18 V , i unwind some wire and i go to 30 V ( the voltage i was needing )
That stupid multimeter ....
In the photo i attach is the modified xformer , notice the blue wire ( next to keyboard ) that is my + winding's .
Thanks all for you excelent help / support .
Now .. all i have to do is to wait the KIT to arrive
a brand new 700 W RMS 8 Ohm Amplifier ) -- 350 x 2 8 Ohm --
Another Question ,
I have 30 Volt
And 500 VA ( writed on the transformer from the manufaceter )
That means i have :
30 * x = 500
x = aprox 16 Amp's ?
Thank's. Mihai.
Hi ,
I just finish winding the wire on the toroidal , with some problems from the voltmeter .
As i wind about 140 , the voltmeter tell me it droped to 38 from 42 , i go wind till 600 winding reach ( no room for more winding ) and mesure again .. 37 V .. As i thinked that was imposible , i check my multimeter and i notice that the battery was in a bad condition , i changed the battery and the toroidal droped to 18 V , i unwind some wire and i go to 30 V ( the voltage i was needing )
That stupid multimeter ....
In the photo i attach is the modified xformer , notice the blue wire ( next to keyboard ) that is my + winding's .
Thanks all for you excelent help / support .
Now .. all i have to do is to wait the KIT to arrive
a brand new 700 W RMS 8 Ohm Amplifier ) -- 350 x 2 8 Ohm --Another Question ,
I have 30 Volt
And 500 VA ( writed on the transformer from the manufaceter )
That means i have :
30 * x = 500
x = aprox 16 Amp's ?
Thank's. Mihai.
Attachments
Va
actually you have 2 * 30 * x = 500va which gives you ~8 amps. It is a center tapped unit with 30 vac on each side of center, right?
darkm4n said:Hi ,
I just finish winding the wire on the toroidal , with some problems from the voltmeter .
As i wind about 140 , the voltmeter tell me it droped to 38 from 42 , i go wind till 600 winding reach ( no room for more winding ) and mesure again .. 37 V .. As i thinked that was imposible , i check my multimeter and i notice that the battery was in a bad condition , i changed the battery and the toroidal droped to 18 V , i unwind some wire and i go to 30 V ( the voltage i was needing )
That stupid multimeter ....
In the photo i attach is the modified xformer , notice the blue wire ( next to keyboard ) that is my + winding's .
Thanks all for you excelent help / support .
Now .. all i have to do is to wait the KIT to arrive
Another Question ,
I have 30 Volt
And 500 VA ( writed on the transformer from the manufaceter )
That means i have :
30 * x = 500
x = aprox 16 Amp's ?
Thank's. Mihai.
actually you have 2 * 30 * x = 500va which gives you ~8 amps. It is a center tapped unit with 30 vac on each side of center, right?
Re: Good !!!
100watts.. it'll give 100watts into 8 ohms.... if you bridge it you may get 300watts into 8 ohms... I mean, your transformer isn't even really high enough powered for a 700 watt amp... two of them would be... not one...
I thought you said this kit was already made, and that you didn't want to change for this reason?? hmm...
darkm4n said:
Thanks all for you excelent help / support .
Now .. all i have to do is to wait the KIT to arrive
Thank's. Mihai.
100watts.. it'll give 100watts into 8 ohms.... if you bridge it you may get 300watts into 8 ohms... I mean, your transformer isn't even really high enough powered for a 700 watt amp... two of them would be... not one...
I thought you said this kit was already made, and that you didn't want to change for this reason?? hmm...
wait a minute... lol
with this amplifier... at 80watts it has 0.5% distortion... (I asume that after 80watts output, the figure goes ^UP^
at 300watt output.. the amplifier uses 6.5 amps... so.. with 45 volt rails.. that mean it uses 292.5 watts input... to give 300 watts output... which means the amplifier is 102.6% efficient... hey... ya don't need a heatsink.. it doesn't generate any heat... I'm sorry... but please listen when people tell you something...
anyway... I've had my moneys worth.. back to you whoever says something next...
with this amplifier... at 80watts it has 0.5% distortion... (I asume that after 80watts output, the figure goes ^UP^
at 300watt output.. the amplifier uses 6.5 amps... so.. with 45 volt rails.. that mean it uses 292.5 watts input... to give 300 watts output... which means the amplifier is 102.6% efficient... hey... ya don't need a heatsink.. it doesn't generate any heat...
I'm sorry... but please listen when people tell you something...anyway... I've had my moneys worth.. back to you whoever says something next...
Hi
I meen , the trafo run initialy at 42 V per side VAC and i reduce it to 30 V AC per side , after regulation i'll get about 40 V
DC witch is OK for my amp ..
Sorry that was my mistake i didn't tell that vere v AC no v DC
I contact the Adelaida ( the producer of my amps ) and sayed that it's 300 W per module , and it use 4 final transistors rated at 150 W eatch and they are bridger ( pair of 2 ) Or something like that ...
Thanks
I meen , the trafo run initialy at 42 V per side VAC and i reduce it to 30 V AC per side , after regulation i'll get about 40 V
DC witch is OK for my amp ..
Sorry that was my mistake i didn't tell that vere v AC no v DC
I contact the Adelaida ( the producer of my amps ) and sayed that it's 300 W per module , and it use 4 final transistors rated at 150 W eatch and they are bridger ( pair of 2 ) Or something like that ...
Thanks
darkm4n said:
yeah... ok
just that the information sheet thing reccomends +-45 volt rails.... even if this thing could give 300watts.... you are running TWO (I think) off a transformer that can really only give enough power for one.. so, you'll only get about 160watts per module...Adelaida is lying either way... there is no way you can get 300watts from +-45 volt rails.... if you use the reccomended powersupply, you will only be using 290VA of power input... and teh amplifier isn't 100% efficient... and there is no way to get 300watts from it from the suggested powersupply or such low voltage rails.... lets just say it was a bridged amplifier.. (one pair of transistors per side, 2 amplifiers on the one board, and they are bridged) you'd still be lucky to get 200watts from it.. and there is no way you could run a 4 ohm speaker....
I have infront of me, a circuit diagram for an amplifier that also uses +-40 volt rails... it has 2 pairs of power transistors and gives 50watts into 8ohms... or 70watts into 4 ohms....
OK
OK .. That was suspicios for me too , that's way i asked about the 350 W , it's really imposible to get that amout of power with such a low voltage supply ...
I saw today a 300 W Amplifier .. i really can't compare the real thing with the modul thing ... there is a big dieference on the output .. that thing got 32 Output ... and 4 Trafs , I guess it was a JBL amplfier or something like this , or FBT , i'am not really shure ...
I call them again and now sayd that the output is bridge to the TDA7250 to get a big power .. i can't really belive that ...
About the trafo .. i don't have other option than winding a new toroidal ... I have done this in the past , but the number of winding's was provided by a friend and the positon of them ...
Or to use this one ..
On the spesc of that amp says :
Recomanded Trafo : 220VacL2x38V/8A max
And i have exacty the same specs on my trafo ...
Thank's Mihai
OK .. That was suspicios for me too , that's way i asked about the 350 W , it's really imposible to get that amout of power with such a low voltage supply ...
I saw today a 300 W Amplifier .. i really can't compare the real thing with the modul thing ... there is a big dieference on the output .. that thing got 32 Output ... and 4 Trafs , I guess it was a JBL amplfier or something like this , or FBT , i'am not really shure ...
I call them again and now sayd that the output is bridge to the TDA7250 to get a big power .. i can't really belive that ...
About the trafo .. i don't have other option than winding a new toroidal ... I have done this in the past , but the number of winding's was provided by a friend and the positon of them ...
Or to use this one ..
On the spesc of that amp says :
Recomanded Trafo : 220VacL2x38V/8A max
And i have exacty the same specs on my trafo ...
Thank's Mihai
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