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Transistor Substitutions

Update: The amp stage is a pair of emitter followers, which have low output impedance. In this case the Cob matters less.

This amp suffered a "heat and light event" (a term used by the account team serving a major US ISP, which had a fire in a very big IP router designed by my former employer). As a start, I am assuming these parts are blown. My cheap transistor tester arrives later this week.

Thanks!!!
Tim
 
The only vendor, AFAIK, selling decent through hole VAS and driver transistors anymore is Profusion UK. No affiliation.

Medium Power Driver Transistors

us.profusion.uk us.profusion.uk

ETA: sometimes on DIY Audio you can pick up some pretty nice parts in their swap meet area. Every now and then, some pop in BT here.
 
Thanks for that link!

eBay seller voice-28 has been helpful and has quite a few bipolar transistors and audio caps available. He's in PA, USA and claims to have been on both AK and diyAudio. I ordered 2SC6145 and 2SA2223A from him.

Consolidated Electronics was recommended here and have the 2SA1930 available. I've attached the data sheet for that part and the original 2SA1383 / 2SC3514.

Looks like the KTA1700 from Profusion would also work.

Thanks, Tim
 

Attachments

tarior said:
KTC3503 from Profusion.
Click to expand...
Is this source reliable and KTC3503 a quality product to replace 2SC1451 in the power amp driver? Asking for an Accuphase E202, uses a 2SC1451 as Q3 in the power amp driver and as Q9, 10 in the phono preamp. Both use cases with low CoB requirement. Thanks.
 
wondoka said:
Is this source reliable and KTC3503 a quality product to replace 2SC1451 in the power amp driver? Asking for an Accuphase E202, uses a 2SC1451 as Q3 in the power amp driver and as Q9, 10 in the phono preamp. Both use cases with low CoB requirement. Thanks.
Click to expand...
Jose beat me to it. I just recently used some in an Accuphase E-202.
 
Hi Audiokarma Friends

A few years ago, I had an online source where I could compare the Japan and US produced transistors with the European type numbers, like BDxx, BCxx, TIPxx, etc.
I have seen El-Component, but can’t find a “search mask”
Unfortunately, that website is no longer available and I’m looking for something similar source.
This thread is very helpful, but sometimes one need even more options or choices with the European types .

Can anybody help me with that?
 
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pa_200 said:
Hi Audiokarma Friends

A few years ago, I had an online source where I could compare the Japan and US produced transistors with the European type numbers, like BDxx, BCxx, TIPxx, etc.
I have seen El-Component, but can’t find a “search mask”
Unfortunately, that website is no longer available and I’m looking for something similar source.
This thread is very helpful, but sometimes one need even more options or choices with the European types .

Can anybody help me with that?
Click to expand...
Agreed, we have not tracked the EU parts here.
I am unaware of a similar thread for EU parts so maybe one needs to be started or merged with one of these.
 
pa_200 said:
Hi Audiokarma Friends

A few years ago, I had an online source where I could compare the Japan and US produced transistors with the European type numbers, like BDxx, BCxx, TIPxx, etc.
I have seen El-Component, but can’t find a “search mask”
Unfortunately, that website is no longer available and I’m looking for something similar source.
This thread is very helpful, but sometimes one need even more options or choices with the European types .

Can anybody help me with that?
Click to expand...
This isn't what you're looking for? Bipolar Transistors
 
 
rwwear said:

You can replace the 2SC3421 with the 2SC1565, 2SC1565A, 2SC2481, 2SC2690, 2SC2690A, 2SC2824, 2SD600K, 2SD669, KSC2690, KSC2690A or KTC2800.

Click to expand...
I just browsed this site out of interest, and looked on a few pages, and as on all "crossreferences" I already found one having some totally unsuitable replacements in the very first few minutes.

2SA1402 pnp transistor complementary npn, replacement, pinout, pin configuration, substitute, marking A1402, equivalent, datasheet

Therefore, I always regard transistors crossreferences as "it has three pins, it looks like a transistor, so maybe it is a transistor"

Apparently, they compare a fast 700MHZ ft transistor with a slow power driver.

Below this transistor and one of its totally usuless substitutes for the places where it would be used, in the real.


Characteristics of 2SA1402 Transistor​

  • Type: PNP
  • Collector-Emitter Voltage, max: -60 V
  • Collector-Base Voltage, max: -80 V
  • Emitter-Base Voltage, max: -4 V
  • Collector Current − Continuous, max: -0.3 A
  • Collector Dissipation: 8 W
  • DC Current Gain (hfe): 40 to 320
  • Transition Frequency, min: 700 MHz
  • Operating and Storage Junction Temperature Range: -55 to +150 °C
  • Package: TO-126


Characteristics of BD236 Transistor​

  • Type: PNP
  • Collector-Emitter Voltage, max: -60 V
  • Collector-Base Voltage, max: -60 V
  • Emitter-Base Voltage, max: -5 V
  • Collector Current − Continuous, max: -2 A
  • Collector Dissipation: 25 W
  • DC Current Gain (hfe): 40
  • Transition Frequency, min: 3 MHz
  • Operating and Storage Junction Temperature Range: -65 to +150 °C
  • Package: TO-126
 
pa_200 said:
@gslikker Is there an easy way to find a special transistor without having to search through every single one of all 345 pages?
Click to expand...
It is funny how we react when not getting instant gratification.

What about the folks that take the time to help and contribute to this type of thread?

Now, and generally speaking, you can use the search feature of the site. It works quite well. If not, use the google search or get used to AI searches. AI would state the source and in most cases it would fetch information from threads like this, here or from DIY audio.
AI can, and will hallucinate so you need to actually read the source info yourself, after AI finds it for you.
 
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Thanks to all

After a bit playing around in the WWW and with some luck, I found this website, listing a whole bunch of transistors in this Component Cross Reference List.
Component Cross Reference List

But it lists only the type numbers and no detailed comparison possible.
 
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