Orion 250 amp

[mike49504]

Im working on an orion 250 amp. Someone did a eal hack job on the unit. SO im wondering what are the value of the gate resistors for the amp?? And what power supply fets do i need since the resistors and fets are missing off the board. Hers a pic of the amp so you know what series it is

 

[Perry Babin]

Can you post a photo of the inside of the amp (the power supply end)?

 

[mike49504]

like i said someone did a real hack job on this unit. they took out the reisitors and used wire in there place, also put 2n6488's in the power supply section . so wondering if u can help? im wondering what power supply fets i need and what value resistors and what% they are? thanks for the help

 

[Perry Babin]

In that amp, they used 6488s in the supply. In most of their amps that used 6488s in the supply, they used wires or had the bases connected directly to the drive circuit (no resistor, no jumper wire).

There was another thread where someone was repairing one of these but I can't find it. Maybe someone else can find it for you.

 

[ben04srt]

http://www.diyaudio.com/forums/showthread.php?s=&threadid=129125&highlight=


this is from a 225 hcca don"t know if the same , but you can see the board real well

 

[mike49504]

Thanks Perry ill replace the 6488'sin the supply. I have antoher question on 1 side of the supply there are + and - marks on the board 2 of the locations are for the 317's and the 337t's what are the other 2 locations for? Im thinking diodes go there but what diodes do i need any help would greatly be appericared

 

[Perry Babin]

Are you sure that the regulators are supposed to be the 317/337?

If the center leg of the positive regulator and the first leg of the negative regulator are connected together and also connected to the shield ground, the regs are the L7815 and L7915.

There are lots of options for the rectifiers. If you're using the Motorola parts, the MUR1620CT is the positive rectifier. The MUR1620CTR is the negative rectifier.

 

[mike49504]

ok they are connected together like i said someone hacked the amp and put differnt parts in. so they are all suppose to be 620 and 1620r 2 of each?

 

[Perry Babin]

2 are rectifiers. The other two (with the legs connected as I described) are the regulators.

 

[mike49504]

the 317 and 337's are not connected together so im thinking thats what they are suppose to be.. wondering if anyone knows for sure if thats what belongs there? doesnt look like the solder has been messed with on the pads. thats why im thinking thats what belongs there

 

[Perry Babin]

If there is no connection between the regulators, they are not 7815/7915s. If the solder looks is original, they have probably never been replaced and are the correct part.

 

[Clipped]

if you have problems finding the 6488, you can use the BD 909 or BD 911

the pairs are 909/910
and 911/912