2n3055 replacement

[tardishead]

Has anyone noticed the differences between brands of 2n3055. Some are very poor.
My tech mentioned that 2n3055 are in a lot of cases not as good as they used to be. They are a general purpose transistor and not manufactured to meet strict criteria. They are often the cast offs of other more specified transistors - ie they dont quite meet the spec.
I have a lot of Neve equipment with BA283 output stages and some of the old transistors are probably a little tired
He recommended to get more top end and clarity I should replace the 2n3055 with something with a bigger hfe and higher operating conditions.
The new replacement would operate well within itself and should be more efficient.
What do you guys think? Can anyone recommend some inspiring replacements?

 

[clintrubber]

Various previous discussions about this, with some valuable info.

 

[amorris]

not manufactured to meet strict criteria. They are often the cast offs of other more specified transistors

thats exactly what Ive been told as well.

you can get a good one that works well in a good channel and do a transistor trace of its "curve". then get several different brands of new ones and match the curves. Ive used a curve tracer (expensive) before to match output transistor in power amps, and have been told that you can set up a less expensive scope and such to do it without the curve tracer per se, but Im not an expert in that.many times a better more efficient replacement will make gear less appealing for why you chose that classic piece in the first place.


http://www.testequipmentdepot.com/usedequipment/tektronix/curvetracers/tek576&577.htm?source=google_ppc_Used_Test_Equipment_Tek_Curve_Tracers&kw=CURVE_TRACER&gclid=CLGmobuQ24kCFRgYgQodZH-s0Q

http://www.ese.upenn.edu/rca/instruments/Curvetracer/curvetracer.html

 

[JohnRoberts]

[quote author="tardishead"]Has anyone noticed the differences between brands of 2n3055. Some are very poor.
My tech mentioned that 2n3055 are in a lot of cases not as good as they used to be. They are a general purpose transistor and not manufactured to meet strict criteria. They are often the cast offs of other more specified transistors - ie they dont quite meet the spec.
I have a lot of Neve equipment with BA283 output stages and some of the old transistors are probably a little tired
He recommended to get more top end and clarity I should replace the 2n3055 with something with a bigger hfe and higher operating conditions.
The new replacement would operate well within itself and should be more efficient.
What do you guys think? Can anyone recommend some inspiring replacements?[/quote]

The 2N3055 is the grand dad of NPN power transistors. When they first came out they were slow as mold, but rugged and people loved them. Since the 3055 is lousy by today's standards it's entirely possible that some manufacturer's just rebrand dropouts parts that are still better than the original spec but performance can be variable that way, and generally poor.

Back in the '70s I used 2N3772 in a power amp as improved (quite a bit faster) over the old 3055 but still pretty rugged NPN. I suspect now some 3 decades later there are probably even better parts available. Keep in mind if you drop faster parts into an existing circuit make sure all negative feedback paths are still stable. The 2N3771,2 was not super fast but still something like 10x faster than the good ole 2N3055.

JR

 

[khstudio]

Interesting.

From others more wxperienced with the Neve stuff, I've been told that the ON SEMICONDUCTOR Parts performs very6 well & gives you that "Neve" Sound, like the old Motorola's.

Even though I used the On Semi's, I'm still confussed about the drastic prices differences & sub part #s/ suffixes.

Kevin

 

[BYacey]

I don't think the TIP41C will handle as much power dissapation as a 2n3055.
See Rod Elliots website. he has a section on Re-branded forgery transistors. I ran into this problem a couple years back with some supposedly Motorola power transistors that kept blowing, instantly. After putting them on the curve tracer, they fell short of the supposed maximum ce voltage by about 60 volts.

 

[BYacey]

2N3055 if I recall correctly was rated for 115W.

 

[ungifted]

Old thread, but not to start new topic: have anyone used BDY38 as 2N3055 substitution?
if i understood correctly it's something like "hifi" 2N3055.
https://en.wikipedia.org/wiki/2N3055
http://www.radiomuseum.org/tubes/tube_bdy38.html

 

[guy_4]

Hello All,
I have used with success 2N5885 ( or 2N5886 ) as replacements of 2N3055.
More Ic current too ( 25A )
Best,
Guy

 

[JohnRoberts]

Pretty much any modern power transistor with comparable data sheet specs will out perform the original 3055. Coming up with a replacement that behaves exactly the same as the original may be very difficult. Better is generally better, unless you want same..

JR

 

[ungifted]

Wiki says:  In the sixties and early seventies, Philips produced similar devices encapsulated in TO-3 packages under the reference BDY20 (described as being for "hifi" purposes) and BDY38 (although the BDY38 has lower voltage ratings than the 2N3055).
So it was curious if it can be used in Neve preamps as a part produced in the same era. I can get some NOS BDY38. Please let me know if it's interesting.

 

[DE]

I have four Neve B283AM boards, all removed from the same  broadcast router rack. Three boards have Motorola 2N3055s on them, the fourth has a BDY62 (also marked 703 2 DG, if that means anything).  As far as I can tell from the soldering, the BDY62 is factory fitted and not a replacement, so not even Neve always used the 3055 (but it is possible that the card was swapped from another unit at some time).

 

[ruffrecords]

Pretty much any modern power transistor with comparable data sheet specs will out perform the original 3055. Coming up with a replacement that behaves exactly the same as the original may be very difficult. Better is generally better, unless you want same..

JR

Rupert was a great believer in negative feedback and this design like most of his others should be relatively independent of component parameters. Unless the original 2N3055s significantly worsened the open loop response then the closed loop response should be identical. Most of the Neve sound is in the Class A stages and the transformers, not in the transistor or other passive components used.

Cheers

Ian

 

[abbey road d enfer]

I have a lot of Neve equipment with BA283 output stages and some of the old transistors are probably a little tired

Transistors don't "tire" as vacuum tubes do. They may suffer from thermal fatigue, which would result in more or less sudden death, but not in significant loss of performance.

He recommended to get more top end and clarity I should replace the 2n3055 with something with a bigger hfe

I would take that with a pinch of salt; the transistor here operates under strict NFB, which makes variations of individual parameters negligible. I would think the top end is limited by copper and iron, not silicon.

and higher operating conditions.

  Huh? Higher current, perhaps? I think the output xfmr would not like that much...

The new replacement would operate well within itself and should be more efficient.

In what way is it supposed to be more "efficient"? Tell him to look at the definition of efficiency.

  Can anyone recommend some inspiring replacements?

Farnell lists the ON Semi 2N3055G at $2.2 a piece.

 

[noulou]

This is authentic neve

 

[Rob Flinn]

I notice that some of the JLH classA amp boards for sale on the bay use the MJ21194  (https://www.onsemi.com/pub/Collateral/MJ21193-D.PDF)  instead of the 2n3055.  This device seeems to be 16A capable.    I was thinking of using them in my MCI console PSU's since the 2n3055 seem to blow ocassionally, but only because they have more of a current capability whch leads me to believe they may be more robust in this function.   

 

[CJ]

there is a thread that talks about  increased freq response leading to unstable operation from the newer transistors because of the way they are made,

forget where that thread is, 

 

[abbey road d enfer]

there is a thread that talks about  increased freq response leading to unstable operation from the newer transistors because of the way they are made,

forget where that thread is, 

Indeed, if the ft of the replacement is much higher than expected, that can lead to increased frequency response, but also to instability and/or oscillation.
The ON Semi 3055 is in conformity with the original specs in that respect.

 

[ungifted]

The ON Semi 3055 is in conformity with the original specs in that respect.

BDY38 has 1MHz and 2n3055 - 2.5, is it ok?

PS: There's always "a smell of mojo" when we speak about cloning old equippment: carbon comp resistors, PIO capacitors. Even if transistor gives nothing to the final result, I'm sure all theese Motorola 2n3055 purchased at ebay - all gone for Neve clones.  ;D

 

[abbey road d enfer]

BDY38 has 1MHz and 2n3055 - 2.5, is it ok?

Correct. Do you suggest using BDY38 as a replacement for 2N3055? I would think most aspects of performance are inferior, and BDY38 belongs to museum...

PS: There's always "a smell of mojo" when we speak about cloning old equippment: carbon comp resistors, PIO capacitors.

Mojo is what makes objectively inferior parts sell at a premium.


[/quote] Even if transistor gives nothing to the final result, I'm sure all theese Motorola 2n3055 purchased at ebay - all gone for Neve clones.  ;D
[/quote] And most of them are in fact different parts, but re-badged. Some may even be "better" than an original 3055.