Studer A800 audio noise from PSU

[Pat Maki]

Future Electronics and Rochester Electronics are not "primary" suppliers, but they often have NOS for obsolete parts. I've bought some odds and ends from them over the years and they seemed OK. Can't 100% say they don't sell counterfeits. Rochester seems to specialize in NOS.

https://www.futureelectronics.com/p...s--bipolar-transistors/2n5884g-onsemi-1429786

https://www.rocelec.com/part/01t4w00000NZ6jyAAD-2N5884G

The picture at Rochester is wonky but the specs seem correct. I also don't know what MOQ both companies currently have.

Bri

Thanks Bri, I hadn't found these guys before. Interesting Rochester is a hotbed for electronic components. Looks like they have a $250 min spend. Will give them a call tomorrow to see if there's any flex on this.

 

[Pat Maki]

BTW, Jameco is another source I use for NOS. In the past few years I've bought a "smallish" inventory of 74xx TTL logic chips from them for maintaining some Ampex ATR-100 and MCI JH-110 recorders. Alas, Jameco didn't have the 2N5884.

Bri

Ooooh...those are both beautiful machines! Thanks for checking Jameco, found them when repairing a Lexicon Primetime this year. They seem legit.

 

[Brian Roth]

As I mentioned, I don't know current MOQ for those vendors. I suspect Future may have a lower threshold.

Bri

 

[Brian Roth]

I just checked Onsemi's website and they state the MJ4502G as the replacement.

https://www.onsemi.com/PowerSolutions/pcnPub.do?pn=2N5884G

Click on the link at the left side of the top entry and that new part number pops up. It's actually somewhat beefier if you look up the specs.

Bri

 

[Walrus]

Would a MJ15004G also be a suitable substitute?

 

[zamproject]

Maybe little short ?
The original one is rated for 25A max
Studer designers probably over size it, still it's preferable to not downsize, especially as junction have failed over the time.

Don't know how this power transistor is mounted on this card, I suppose on some radiator, make sure for clean surfaces, eventually with past or mica sheet, and tight mount for max dissipation.

 

[Walrus]

Just checked and farnell UK have 13 2N5884G in stock still, also have the MJ4502G too.
I know we here can buy stuff from Farnell USA stock (at a premium postage charge!), is there a reciprocal system?

 

[Brian Roth]

Mouser shows MJ4592G stock.

https://www.mouser.com/ProductDetail/onsemi/MJ4502G?qs=HVbQlW5zcXXll1Oe0dMDgg==

Bri