New transistors with driver board

[Almost1]

The release notes for the Rev. E driver board say to change all your transistors (for quasi) to MJ21196. After looking those up, I see they are obsoleted. Mouser has the MJ21196G and I'm curious if these will be sufficient.

Here is the data:
http://www.mouser.com/Search/m_ProductDetail.aspx?ON-Semiconductor%2FMJ21196G%2F&qs=HVbQlW5zcXW9Hdwg53oKog%3D%3D

 

[MarkWComer]

They're the same, or maybe a typo in the release notes omitted the "G."

 

[laatsch55]

I think "G" was the ROHS compliant model....

 

[Gepetto]

I think "G" was the ROHS compliant model....

G means Green for RoHS...

 

[Almost1]

Ok great! Thanks for the info. Now about the drivers, the notes say to use the RCA410 or SJ2741 which are both obsolete. I currently have the 410's in there now which I believe are original. I have read people say that you can use the same device as the upper rows, but the fact that the notes specifically list the drivers only for the quasi builds has me wary. If not, is there a suitable substitution available? I figure I might as well replace them all while I'm ordering parts n such

 

[laatsch55]

The RCA410 were the best drivers for the quasi configuration....

 

[Almost1]

Well, that's good to know. Does anybody have some stock they'd be willing to part with?

And does anybody know what you call the rubber pads you put under the transistors?

 

[laatsch55]

Berquist sil-pads, And if the RCA 410's are good, use em, NOS is probably rare....

 

[NavLinear]

Well, that's good to know. Does anybody have some stock they'd be willing to part with?

And does anybody know what you call the rubber pads you put under the transistors?

The pads are manufactured by Bergquist - Sil-Pad 400. The part number is SP400-0.009-00-04.



Looks like you beat me to it Lee.

 

[laatsch55]

I guess we should link the mouser part number from the archives, or is that the Mouser number???

 

[NavLinear]

That's from Digikey. Edit - the part number above is a Bergquist number.

Here's an eBay vendor selling NOS RCA 410 transistors. I just happened on them now - I don't know if they're the real deal.

http://www.ebay.com/itm/RCA410-RCA-TRANSISTOR-/351493578831

 

[Almost1]

That seemed like it was the Mouser number. Those are the pre-cut ones right?

 

[laatsch55]

That's from Digikey.

Here's an eBay vendor selling NOS RCA 410 transistors. I just happened on them now - I don't know if they're the real deal.

http://www.ebay.com/itm/RCA410-RCA-TRANSISTOR-/351493578831

21st week of 1979, did you check out the hold down holes?? Looks like they've been torqued up..



Almost1, If the 410's test good, use em, not much load on the drivers, they last long time....

 

[NavLinear]

That seemed like it was the Mouser number. Those are the pre-cut ones right?

I misspoke - the part number listed above is a Bergquist part number not Digi-Key. Yes these pads are pre-cut.

 

[NavLinear]

21st week of 1979, did you check out the hold down holes?? Looks like they've been torqued up..



Almost1, If the 410's test good, use em, not much load on the drivers, they last long time....

I did see the markings on the close up shot. Would that make them ANOS?

 

[laatsch55]

They look pretty good otherwise, I've pulled some used ones that look that good too. Bought a bunch of heatsinks that had 8 of those on each one, gave most of em away, to folks here....

 

[Almost1]

So I bought 4 of those 410's linked earlier just to take advantage of the opportunity and the price wasn't going to break the bank. From what I can tell, they are new, and they are legit unless someone more experienced can prove otherwise...

 

[laatsch55]

Look good to me, correct paint and style....

 

[Gepetto]

So I bought 4 of those 410's linked earlier just to take advantage of the opportunity and the price wasn't going to break the bank. From what I can tell, they are new, and they are legit unless someone more experienced can prove otherwise...

View attachment 26949

No one would knock off an old, obsolete transistor like the RCA410. You are good.

 

[Almost1]

Well, everything is installed. By everything I mean WO Cap kit, driver board, and output transistors. My emitter resistors were already .33ohm, so no worries there. I'm trying to adjust the bias and on both channels, I only have a range from 3.5mV to 18mV on both channels. I made sure to turn the input sensitivity knobs all the way down as per instructions. What are your thoughts on this? I also checked DC offset and -0.1mV Left and -0.6mV Right.