push pull transistor pairs

[alpibucky]

Hello,

Is there anywhere a list of generic transistor/darlington for AF push
pull output stages from eg 10 W to 100 W in the different
configurations.
I have to repair some amplifier but do not find the old
powertransistor.
Idem for the drivers.

On Internet I can find some information (Eliot, Sams, wiki...) but no
global ones.

With kind regard

alpibucky

 

[pfjw@aol.com]

On Sunday, February 14, 2016 at 6:36:26 AM UTC-5, alpibucky wrote:

YIKES!

It would depend on the vintage, design, general ruggedness and much more. Ideally, you will find a schematic for the item you intend to repair, and replace accordingly. There are more than a few options.

A very common power transistor is the 2N3055. Which in most devices may be replaced with the more rugged 2N3772, possibly requiring some attention to the bias settings. I have five devices from three different manufacturers, Euro and US that use the 3055, most of which have been replaced with the 3772, one of which needed bias adjustment (could have been left alone with a small increase in measurable distortion).

That is ONE, and only ONE example. And all of these amps used NPN outputs in PP. Many use NPN/PNP configurations.

My advice would be to look at the OEM transistor(s), and then look up *that* part and find out what options may be available. If you are going to make a habit of this, invest in a tester that will allow you to match parts. It is often not entirely necessary, but I have found it makes for better results as transistors do not drift as much as tubes as they age.

Peter Wieck
Melrose Park, PA

 

[pfjw@aol.com]

On Sunday, February 14, 2016 at 8:32:46 AM UTC-5, pf...@aol.com wrote:

On Sunday, February 14, 2016 at 6:36:26 AM UTC-5, alpibucky wrote:

YIKES!

It would depend on the vintage, design, general ruggedness and much more. Ideally, you will find a schematic for the item you intend to repair, and replace accordingly. There are more than a few options.

A very common power transistor is the 2N3055. Which in most devices may be replaced with the more rugged 2N3772, possibly requiring some attention to the bias settings. I have five devices from three different manufacturers, Euro and US that use the 3055, most of which have been replaced with the 3772, one of which needed bias adjustment (could have been left alone with a small increase in measurable distortion).

That is ONE, and only ONE example. And all of these amps used NPN outputs in PP. Many use NPN/PNP configurations.

My advice would be to look at the OEM transistor(s), and then look up *that* part and find out what options may be available. If you are going to make a habit of this, invest in a tester that will allow you to match parts. It is often not entirely necessary, but I have found it makes for better results as transistors do not drift as much as tubes as they age.

Peter Wieck
Melrose Park, PA

p.s.: If a gun were put to my head and I were forced to make some *generic* suggestions, they would be:

a) A small stock of 2N3055
b) A small stock of 2N3772
c) A small stock of TIP31 (NPN driver)
d) A small stock of TIP32 (PNP driver)
e) A small stock of 2N3054 (NPN driver)

That pretty much covers a range of 70s/80s equipment from Revox to Dynaco to AR and even a very few B&O units. But it is a tiny range in a vast field.

 

[John-Del]

On Sunday, February 14, 2016 at 3:55:34 PM UTC-5, Trevor Wilson wrote:
.......For my part, I am presently servicing a Sansui amp from the

1980s. It is proving extremely difficult locating suitable output
devices, without installing flat pack devices in place of the original
TO3s. The client wants the amp to perform as original....

Trevor Wilson
www.rageaudio.com.au

So he wants it to sound like a bucket of shit. Good for him. What are the output numbers? I may have pair or two left. I used to do a lot of Sansewer back then. Loved the ones (G series?) that would short the outputs and burn everything all the way back to the speaker selector switch and burn that too. Fixed a lot of those dumpster fires.

 

[Trevor Wilson]

On 14/02/2016 10:36 PM, alpibucky wrote:

Hello,

Is there anywhere a list of generic transistor/darlington for AF push
pull output stages from eg 10 W to 100 W in the different configurations.
I have to repair some amplifier but do not find the old powertransistor.
Idem for the drivers.

On Internet I can find some information (Eliot, Sams, wiki...) but no
global ones.

With kind regard

alpibucky

**Use the originals where possible. Sourcing approximate replacements
can be very time-consuming.

--
Trevor Wilson
www.rageaudio.com.au

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[legg]

On Sun, 14 Feb 2016 12:36:50 +0100, alpibucky <alpibucky@mail.be>
wrote:

Hello,

Is there anywhere a list of generic transistor/darlington for AF push
pull output stages from eg 10 W to 100 W in the different
configurations.
I have to repair some amplifier but do not find the old
powertransistor.
Idem for the drivers.

On Internet I can find some information (Eliot, Sams, wiki...) but no
global ones.

What's the original transistor part number, or brand model being
repaired?

It's a long time since 'generic' meant TO3 body sizes...

RL

 

[Trevor Wilson]

On 15/02/2016 12:32 AM, pfjw@aol.com wrote:

On Sunday, February 14, 2016 at 6:36:26 AM UTC-5, alpibucky wrote:

YIKES!

It would depend on the vintage, design, general ruggedness and much
more. Ideally, you will find a schematic for the item you intend to
repair, and replace accordingly. There are more than a few options.

A very common power transistor is the 2N3055. Which in most devices
may be replaced with the more rugged 2N3772, possibly requiring some
attention to the bias settings. I have five devices from three
different manufacturers, Euro and US that use the 3055, most of which
have been replaced with the 3772, one of which needed bias adjustment
(could have been left alone with a small increase in measurable
distortion).

**The 2N3055 and 2N3772 are both EXTREMELY low performance power
transistors. They should really only be used for DC and very low
frequency applications and NEVER for (high quality) audio. In fact,
single diffused silicon devices don't have much place in any audio product.

Best to either use the original devices, or select replacements VERY
carefully. For my part, I am presently servicing a Sansui amp from the
1980s. It is proving extremely difficult locating suitable output
devices, without installing flat pack devices in place of the original
TO3s. The client wants the amp to perform as original and he wants it to
LOOK original. The devices are rated to >40MHz. Finding TO3 devices at
that speed is proving difficult.

That is ONE, and only ONE example. And all of these amps used NPN
outputs in PP. Many use NPN/PNP configurations.

My advice would be to look at the OEM transistor(s), and then look up
*that* part and find out what options may be available. If you are
going to make a habit of this, invest in a tester that will allow you
to match parts. It is often not entirely necessary, but I have found
it makes for better results as transistors do not drift as much as
tubes as they age.

**Correct. Original part numbers are always best.


--
Trevor Wilson
www.rageaudio.com.au

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[Phil Allison]

Trevor Wilson wrote:

Is there anywhere a list of generic transistor/darlington for AF push
pull output stages from eg 10 W to 100 W in the different configurations.
I have to repair some amplifier but do not find the old powertransistor.
Idem for the drivers.

On Internet I can find some information (Eliot, Sams, wiki...) but no
global ones.



**Use the originals where possible. Sourcing approximate replacements
can be very time-consuming.

** What drivel.

There is normally no need to use original part numbers for output and driver transistors or darlingtons. By using more modern devices, you upgrade the equipment as you repair it.

Types like MJ15003/4 and MJ15024/25 replace can nearly any TO3 power transistor.

TO220 outputs can usually be replaced by 2N3055Ts and MJ2955Ts with advantages in power dissipation and current ratings.

Nearly all TO220 drivers can be relaced by MJE15030/31 or MJE15032/33.

MJE34s and MJE350s cover the TO126 pack size for drivers.

2SC5200s and 2SA1943s cover a huge range of large flat pack types, with advantages.

Try sourcing obsolete types to match what was used in the 70s or 80s and you will get sold substitutes or fakes.

Motorola brand ( or ON) MJ802s, MJ4502s and 2N3773s sold today are not - they are just relabelled MJ15003/4s and MJ15024s.


..... Phil

 

[Trevor Wilson]

On 15/02/2016 10:27 AM, John-Del wrote:

On Sunday, February 14, 2016 at 3:55:34 PM UTC-5, Trevor Wilson
wrote: .......For my part, I am presently servicing a Sansui amp from
the
1980s. It is proving extremely difficult locating suitable output
devices, without installing flat pack devices in place of the
original TO3s. The client wants the amp to perform as original....

Trevor Wilson www.rageaudio.com.au


So he wants it to sound like a bucket of shit. Good for him. What
are the output numbers?

**A "bucket of shit"? No. In fact, in going condition I'd put his amp up
against a slew of modern amps. Sansui built some excellent products in
the old days (along with some absolute shit). The model on the bench is
AU-X1. The output devices are: 2SC2493 & 2SA1068. 100W, 150V, 10A,
35MHz. I require 6 of each. If I can't locate some in the next few
weeks, I'll persuade the client into allowing me to use flat packs.


I may have pair or two left. I used to do a

lot of Sansewer back then. Loved the ones (G series?) that would
short the outputs and burn everything all the way back to the speaker
selector switch and burn that too. Fixed a lot of those dumpster
fires.

**No doubt about it, the G series, along with others were crap. The
AU-X1, however, is a completely different animal. Expensively built,
using lots of expensive components, with decent sound quality and a high
secondary market value. IOW: It is worth restoring.



--
Trevor Wilson
www.rageaudio.com.au

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[Phil Allison]

alpibucky wrote:

I have 2 amplifier to be repaired : the first one a scott a416 (i have
the schematics but in bad quality and with drawing errors).

** The full manuals is on the web.

http://elektrotanya.com/scott_a416_a426_a436.pdf/download.html

The outputs are both Toshiba 2SC789, NPN 70V, 4A, 30W in TO220 pack.

MJE3055Ts will replace these with many advantages.

https://www.fairchildsemi.com/datasheets/MJ/MJE3055T.pdf

The second one is a Marantz superscope MS-30 (without schematic)


** Probably uses TO220s as well, so MJE3055Ts and MJE2955Ts are also you best options. Watch out for blown driver transistors.

I generally use BC639/640 for this kind of amp, be careful with the pin outs.


..... Phil

 

[Phil Allison]

Phil Allison wrote:

TO220 outputs can usually be replaced by 2N3055Ts and MJ2955Ts
with advantages in power dissipation and current ratings.

** Should be MJE3055T and MJE2955T.

70V, 10A, 75W, Hfe=100 typ and Ft well over 2MHz.

Not too shabby for a low cost, garden variety part.



..... Phil

 

[alpibucky]

Il se trouve que legg a formulé :

On Sun, 14 Feb 2016 12:36:50 +0100, alpibucky <alpibucky@mail.be
wrote:

Hello,

Is there anywhere a list of generic transistor/darlington for AF push
pull output stages from eg 10 W to 100 W in the different
configurations.
I have to repair some amplifier but do not find the old
powertransistor.
Idem for the drivers.

On Internet I can find some information (Eliot, Sams, wiki...) but no
global ones.

What's the original transistor part number, or brand model being
repaired?

It's a long time since 'generic' meant TO3 body sizes...

RL

Hi,

I have 2 amplifier to be repaired : the first one a scott a416 (i have
the schematics but in bad quality and with drawing errors).
The second one is a Marantz superscope MS-30 (without schematic)

With kind regards

 

[pfjw@aol.com]

On Monday, February 15, 2016 at 2:16:36 AM UTC-5, Phil Allison wrote:

Trevor Wilson wrote:



Is there anywhere a list of generic transistor/darlington for AF push
pull output stages from eg 10 W to 100 W in the different configurations.
I have to repair some amplifier but do not find the old powertransistor.
Idem for the drivers.

On Internet I can find some information (Eliot, Sams, wiki...) but no
global ones.



**Use the originals where possible. Sourcing approximate replacements
can be very time-consuming.


** What drivel.

There is normally no need to use original part numbers for output and driver transistors or darlingtons. By using more modern devices, you upgrade the equipment as you repair it.

Types like MJ15003/4 and MJ15024/25 replace can nearly any TO3 power transistor.

TO220 outputs can usually be replaced by 2N3055Ts and MJ2955Ts with advantages in power dissipation and current ratings.

Nearly all TO220 drivers can be relaced by MJE15030/31 or MJE15032/33.

MJE34s and MJE350s cover the TO126 pack size for drivers.

2SC5200s and 2SA1943s cover a huge range of large flat pack types, with advantages.

Try sourcing obsolete types to match what was used in the 70s or 80s and you will get sold substitutes or fakes.

Motorola brand ( or ON) MJ802s, MJ4502s and 2N3773s sold today are not - they are just relabelled MJ15003/4s and MJ15024s.


.... Phil

Phil:

Perhaps down-under that last statement is true. But here in the US, adjacent to Mexico, ON is still a viable brand. Whether they re-label or not in actuality, they *say* not. In any case, those I have purchased through Mouser have been very, very good.

http://www.mouser.com/ProductDetail/ON-Semiconductor/2N3772G/?qs=sGAEpiMZZMtqO%252bWUGLBzeBPp6OfDaMjI

Peter Wieck
Melrose Park, PA

 

[Phil Allison]

pf...@aol.com wrote:

Try sourcing obsolete types to match what was used in the 70s or 80s
and you will get sold substitutes or fakes.

Motorola brand ( or ON) MJ802s, MJ4502s and 2N3773s sold today are
not - they are just relabelled MJ15003/4s and MJ15024s.



Perhaps down-under that last statement is true. But here in the US,
adjacent to Mexico, ON is still a viable brand.

** Never suggested otherwise.

Whether they re-label or not in actuality, they *say* not.

** Really - where ?

In any case, those I have purchased through Mouser have been very, very good.

** Of course, MJ15003/4 devices are class leaders as are MJ15024/5s.

Take a look at the disclaimer at the end of this datasheet:

http://pdf1.alldatasheet.com/datasheet-pdf/view/4813/MOTOROLA/MJ802.html

" Motorola reserves the right to make changes without further notice to any products herin." This is to be taken quite literally !!

What they have been doing for decades is to upgrade and update the chip design of certain products at regular intervals - but keep using the same, very popular part number. The data sheets are not updated to indicate such changes.

Manufacture of the legacy chip is then dropped in favour of the new one.

When a part is obsolete ( ie sales fall to a low level) they continue to offer the part by number but supply a modern equivalent that has superior specs. This is the case with MJ802, MJ4502 and 2N3773 to my certain knowledge.

For proof, you need to slice open a few examples of different vintages and see how the chips inside are quite different.

No doubt this makes good business sense for Motorola/ON but confuses the hell out of folk who believe what they read on packages tells you what is inside.

Prices charged for legacy type numbers are significantly higher than for modern parts too - so it is both pointless and expensive to buy them.

I have not noticed other semiconductor makers doing likewise - improved chip designs are given new numbers or a suffix so the buyer knows they have something with differences.


.... Phil

 

[Uffe BĂŚrentsen]

Den 15-02-2016 kl. 02:42 skrev Trevor Wilson:

**A "bucket of shit"? No. In fact, in going condition I'd put his amp up
against a slew of modern amps. Sansui built some excellent products in
the old days (along with some absolute shit). The model on the bench is
AU-X1. The output devices are: 2SC2493 & 2SA1068. 100W, 150V, 10A,
35MHz. I require 6 of each. If I can't locate some in the next few
weeks, I'll persuade the client into allowing me to use flat packs.

Not cheap - but they do exist

http://www.ebay.com/itm/2SC2493-Original-Pulled-Sanken-Transistor-C2493-/400368094263?hash=item5d37cc4c37:m:m0uz_bIdDAfg-MYg3Ff-6aQ

http://www.ebay.com/itm/2SA1068-Original-Pulled-Sanken-Silicon-PNP-Power-Transistor-A1068-/120965623553?hash=item1c2a1cef01:m:mYI_8fFbjVtJpzzcvk__LEA



--
Uffe

 

[Trevor Wilson]

On 16/02/2016 8:55 AM, Uffe Bćrentsen wrote:

Den 15-02-2016 kl. 02:42 skrev Trevor Wilson:

**A "bucket of shit"? No. In fact, in going condition I'd put his amp up
against a slew of modern amps. Sansui built some excellent products in
the old days (along with some absolute shit). The model on the bench is
AU-X1. The output devices are: 2SC2493 & 2SA1068. 100W, 150V, 10A,
35MHz. I require 6 of each. If I can't locate some in the next few
weeks, I'll persuade the client into allowing me to use flat packs.

Not cheap - but they do exist

http://www.ebay.com/itm/2SC2493-Original-Pulled-Sanken-Transistor-C2493-/400368094263?hash=item5d37cc4c37:m:m0uz_bIdDAfg-MYg3Ff-6aQ


http://www.ebay.com/itm/2SA1068-Original-Pulled-Sanken-Silicon-PNP-Power-Transistor-A1068-/120965623553?hash=item1c2a1cef01:m:mYI_8fFbjVtJpzzcvk__LEA

**Thanks for that. I'm hoping to locate new parts, that John-Del may
have in his stocks.


--
Trevor Wilson
www.rageaudio.com.au

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[legg]

On Mon, 15 Feb 2016 09:01:57 +0100, alpibucky <alpibucky@mail.be>
wrote:

>Marantz superscope MS-30

I'd be surprised if the MS-30 had output transistors. These
multichannel all-in-one one units often just used a power IC for each
channel.

Sounds like you don't know if the output circuit is the actual
problem, here, or you'd be able to quote the part number from its
physical markings, on the assembly.

RL

 

[John-Del]

On Monday, February 15, 2016 at 5:22:53 PM UTC-5, Trevor Wilson wrote:

**Thanks for that. I'm hoping to locate new parts, that John-Del may
have in his stocks.

Sorry Trevor, I have some audio TO-3s somewhere in storage but couldn't put my hand on them. In any case, I don't think I'd have six of each. I have one more place to look and if there's any there, you can have them. I know I have an older Sansui receiver in storage that I fixed years ago that used TO-3s, I'll pull that out and see what it has for outputs.

 

[pfjw@aol.com]

On Monday, February 15, 2016 at 7:16:14 PM UTC-5, Phil Allison wrote:

Whether they re-label or not in actuality, they *say* not.

** Really - where ?

Being in the US, I may pick up the phone and give Mouser (or the ON factory in Mexico, if I wish) a call at no cost. I have spoken to Mouser on just this issue on the 3772, and their statement is that the higher the suffix letter (they are up to G, now), the more upgraded the unit. But they stated that the 2N3772 is not a re-label, but a series of upgrades. Why? Because it is a HUGELY popular transistor justifying its own line with ON. Again, this is their statement, not proof.

Peter Wieck
Melrose Park, PA

 

[Look165]

NTE130 and NTE219 are still available at Farnell.

Around 2$ each.


alpibucky a écrit :

Hello,

Is there anywhere a list of generic transistor/darlington for AF push
pull output stages from eg 10 W to 100 W in the different configurations.
I have to repair some amplifier but do not find the old powertransistor.
Idem for the drivers.

On Internet I can find some information (Eliot, Sams, wiki...) but no
global ones.

With kind regard

alpibucky