Hello,
I saw that digikey has the 2SA1837 and 2SC4793 in stock again.
https://www.digikey.de/de/products/detail/evvo/2SA1837/22674746
https://www.digikey.de/de/products/detail/evvo/2SC4793/22674681
It looks like there are made from another company (Toshiba was the orginal one)
Does anyone has some experience about them or does someone know a reliable source for Toshiba parts?
Have a nice day!
I saw that digikey has the 2SA1837 and 2SC4793 in stock again.
https://www.digikey.de/de/products/detail/evvo/2SA1837/22674746
https://www.digikey.de/de/products/detail/evvo/2SC4793/22674681
It looks like there are made from another company (Toshiba was the orginal one)
Does anyone has some experience about them or does someone know a reliable source for Toshiba parts?
Have a nice day!
Those TTA/C are A1837/C4793 stuck in a TO-126. The original pair was always rather fragile as TO-220 drivers go (older A1306 /C3298 or A968/ C2238 were better in every way, except Vceo). Those Evvo parts claim 50w dissipation for a TO-220 full pack, and only 40 MHz fT. That doesn’t sound like A1837/C4793 at all - seems more like MJF15032/3.
Replacement... One more option is ''Unisonic'' / UTC. Profusion Ltd /UK/:
''European Union Customers:
Orders to European Union countries are delivered by a tracked courier at a rate of €19.50 (5-7 working days).
Deliveries to the EU will be dispatched from the UK via our distribution hub in the Netherlands. You will receive tracking information direct from our courier company when the goods leave the distribution hub.
Using this method means there is no need for you to clear your goods through customs, and VAT will be charged on your invoice in accordance with EU VAT regulations – If you are VAT registered, VAT is 0% using the Reverse Charge rules. If you are not a VAT registered business, VAT is charged at your country’s standard rate.''
Ian Finch - #16, #18, #20:
https://www.diyaudio.com/community/threads/replacement-for-2sc4793-and-2sa1837.193899/
''European Union Customers:
Orders to European Union countries are delivered by a tracked courier at a rate of €19.50 (5-7 working days).
Deliveries to the EU will be dispatched from the UK via our distribution hub in the Netherlands. You will receive tracking information direct from our courier company when the goods leave the distribution hub.
Using this method means there is no need for you to clear your goods through customs, and VAT will be charged on your invoice in accordance with EU VAT regulations – If you are VAT registered, VAT is 0% using the Reverse Charge rules. If you are not a VAT registered business, VAT is charged at your country’s standard rate.''
Ian Finch - #16, #18, #20:
https://www.diyaudio.com/community/threads/replacement-for-2sc4793-and-2sa1837.193899/
Last edited:
Thank you for your help! I appreciate it!
There are nice options I can choose, thats nice.
Just for somebody who is taking the advise of Bate Vanko:
TTA006B
TTC011B
This devices hav the opposite order of Pin position, so you have to turn them around, but it´s a great tip because the case has almost the same face then the backside.
There are nice options I can choose, thats nice.
Just for somebody who is taking the advise of Bate Vanko:
TTA006B
TTC011B
This devices hav the opposite order of Pin position, so you have to turn them around, but it´s a great tip because the case has almost the same face then the backside.
Sometimes second sources are pretty close to the original. Others they are only rough equivalents which can generally be used as replacements. (And some just blow up, like ISC’s clones of Sanken LAPTs - which are no better than outright fakes.) One can often just sub the MJE15032 for any unobtainium driver, with the understanding that higher capacitance may or may not afford full performance. My guess is Evvo traded off some speed for ruggedness so they could make something that could generally be used in place of C4793 without earning them a bad reputation. It’s not really a bad way to go. Someone really concerned about top end performance may try them, put their test mule on a distortion analyzer, and decide whether they are good or go back to whatever they were using before.
Nobody has managed to fully clone the original D669/B649. UTC’s are very close to the Toshiba TO-126’s - a bit higher capacitance than the old Hitachi parts, but almost always work well. It’s just when you’re looking for the very last mile (or ten inches) you could be out of luck.
The reversed position Toshiba’s are fine, but remember they dont heat sink quite as well from the front side. The lead frame is physically closer to the back side. When you are dissipating one watt it does not matter. When you are dissipating five it does. If it has a small stand alone heat sink, you swap it around too along with the transistor. For new DIY design, one might have two sets of holes, along with an SMD land pattern with 10 square inches of copper. Doesn’t exactly make a space efficient layout, but at least you know there will be something that can be used next month/year.
Nobody has managed to fully clone the original D669/B649. UTC’s are very close to the Toshiba TO-126’s - a bit higher capacitance than the old Hitachi parts, but almost always work well. It’s just when you’re looking for the very last mile (or ten inches) you could be out of luck.
The reversed position Toshiba’s are fine, but remember they dont heat sink quite as well from the front side. The lead frame is physically closer to the back side. When you are dissipating one watt it does not matter. When you are dissipating five it does. If it has a small stand alone heat sink, you swap it around too along with the transistor. For new DIY design, one might have two sets of holes, along with an SMD land pattern with 10 square inches of copper. Doesn’t exactly make a space efficient layout, but at least you know there will be something that can be used next month/year.