2N5376 low-noise substitute

[JohnRoberts]

Thanks for the info

It's a little odd to hear those described as vintage.

I recall Hitachi being pretty well respected for semiconductors, they were the single source for the widely used lateral power MOSFETs popular in many hifi amps, a few decades ago.

I guess it is fair to ASSume that somebody will fab parts too cheap to work properly. Noisy and low beta may be evidence of semiconductor process problems. I can imagine some popular device numbers being knocked off, and showing up inside off brand SKUs.

I am still unfamiliar with a transistor aging mechanism. As I shared in my Audio Mythology column on the topic last century there is a small metal migration issue inside some ICs but not a widespread problem.

JR

 

[Disco Volante]

Thanks for the tips, I can get the 2240's at Reichelt. I've located two of the squarish ones (BC147) and there is several round little black ones (BF2745GS) and a few bigger metal-housed ones (SGS BC310 in the power section).
The RIAA only has 2N5376, 2 in each channel. The RIAA amp is my main concern, since I've previously had good results replacing old transistors specifically in RIAA stages.

No tantalums in this one.
BTW, the machine is a ScanDyna 2100, built in Denmark. I have not been able to source a schematic on it...
@JR: I am under the impression that some of the older transistors are noisier. Don't know that they age per se. I did get a better S/N ratio when I replaced the transistors in my Quad 33 preamp some years ago.

Thanks for this wealth of useful information.
Cheers,

 

[moamps]

Here's a schematic of the 2000 model. It might be useful to you.

 

[musipol]

I am still unfamiliar with a transistor aging mechanism. As I shared in my Audio Mythology column on the topic last century there is a small metal migration issue inside some ICs but not a widespread problem.

Hi JR. Are you referring to electromigration?

 

[CJ]

no, he means tin whiskers.

i checked hfe on some of those outhouse transistors that i pulled from the Marantz phono preamps, one would be at 600 and the other 350, pretty crazy.

 

[JohnRoberts]

@JR: I am under the impression that some of the older transistors are noisier. Don't know that they age per se. I did get a better S/N ratio when I replaced the transistors in my Quad 33 preamp some years ago.

Thanks for this wealth of useful information.
Cheers,

The posted schematic is not very readable.

Indeed modern low noise transistors can be quieter than devices from way back when, but its not immediately obvious (to me) that they are the limiting factor (vinyl surface noise usually dominates).

The last couple phono preamps I designed used low noise JFET input stages but a JFET will not drop in place of a bipolar transistor.

There are many modern devices to choose from... If you can, try to find something with low NF wrt 1.5K source impedance or so.

I recall that transistors "called" low noise back in the 60s-70s (like 2n5088), weren't really very quiet A GP switch like 2n4403 was better.

Have fun...

JR

 

[JohnRoberts]

Hi JR. Are you referring to electromigration?

Perhaps... IDK. When I researched it for my column back in the 80s I found a mention about faults caused inside ICs with really narrow traces on the metallization layer.

Since the 80s device geometry has gotten a lot smaller so who knows, not me?

JR

 

[JohnRoberts]

no, he means tin whiskers.

Huh.... Tin whiskers is a lead free solder problem that causes shorts, not failed metallization layer "inside" ICs.

JR