Orange Terror Bass 500 Power amp FET question

[Arbutt]

Hello
I have had 2 Terror bass amps in with Blown power fets. I looked at the part No IRFB5615 and all of the UK suppliers were out of stock with 330 days lead time. I'm guessing its down this pandemic

I went to orange and they agreed to sell me some, Only providing 4 for the amp on my bench. I got the impression that they really didn't want to sell them to me
Since then ive had another one in with the same fault
I have found what is said to be an equivalent and is in stock

IRFB5615 https://alltransistors.com/adv/pdfvi...onal_rectifier

IFB42228 https://www.farnell.com/datasheets/370568.pdf

I think these would work looking at the spec.. Any of you guys see any reason why they wouldn't or have had the same problem and fitted another fet with good results
many thanks
Mr A

[alexradium]

i found them recently from a german ebay seller, darisusgmbh ,good stuff,genuine.

[J M Fahey]

Ahem!!! Post he amp schematic , MosFets or any other parts don´t live in a vacuum but inside an amp, we have no clue as of voltage or current requirements, or how are they driven.
Hint: "supposed equivalent" might match or exceed those parameters, yet have too high gate capacitance so impossible to drive.

And in any case, if 2 or more are parallel , all must be replaced with same type, brand, and if possible same batch for consistency.

FWIW we don´t even know whether it´s Class AB or D.

[Arbutt]

i found them recently from a german ebay seller, darisusgmbh ,good stuff,genuine.

Thanks Alex. I looked through eBay but avoided them but now I've got a decent seller. I might use them. As the UK is not in Europe any more will have check the customs charges

[DrGonz78]

Schematic...
orange_tb500_bass_terror_sch.pdf

[Jazz P Bass]

So which mosfet is in the amp from the factory?
The schematic shows a FQA28N50 TO3 PN device.
The part number that you supplied, IRFB5615, is a TO220 device.

[Arbutt]

So which mosfet is in the amp from the factory?
The schematic shows a FQA28N50 TO3 PN device.
The part number that you supplied, IRFB5615, is a TO220 device.

You are looking at psu. It's the power amp fets have gone

Stock amp with irfb5615. And it's what orange supplied me. I have ordered some from ebay Germany where Alex said he got good ones from

[Gingertube]

Element14 (Farnell) list these as ex stock.
IRFP4568PbF.pmd (farnell.com)

They would work (same pinout, compatible TO-247 pysicals, superior ratings)

Cheers,
Ian

[Jazz P Bass]

If the smps mosfets are blown I would recommend that you also change the driver ic (IR2153).

[Mars Amp Repair]

If the smps mosfets are blown I would recommend that you also change the driver ic (IR2153).

Be careful when ordering the IC you use for the IR2153 was testing. I entered IR2153 into the Mouser search and didn't realize what I actually ordered was a IR21531.
Fortunately. it didn't damage anything as I was testing the SMPS stand-alone and monitoring the output. The effect was that there was no regulation of the output voltage. It would slowly increase possibly because that particular IC required some feedback. Strange that this configuration does not have FB.
Anyway, I put the original IC back in and all was well with the Orange world.
I still would agree with Jazz P that I would also have replace the osc IC.