While I strictly buy parts from either Mouser and DigiKey, I took the risk and just bough a 10 pairs for ~$22 of the beloved AF drivers 2SA1837 / 2SC4793 based on the seller positive feedback regarding this items, after receiving them the package cases looked very weird/different and non matching for being complementary parts, so I instantly got disappointed and even without testing them I've ordered for the first time at Profusion 15 pairs of the still in-production UTC-2SA1837 / UTC-2SC4793 and this is what I find out.
My Profusion order was as follow:
After 24 days(International Customs) I've received the the following parts:
A tube with 15x 2SA1837G
A tube with 15x 2SC4793L --> I thought it should be 2SC4793G
I used a budget TFT transistor/semiconductor tester that just gives average results/readings but they're useful to find out transistors hFE and for parts quick testing, so I've tested each parts and write down the results to pick closest match for my old amplifiers mod/repairs, surprisingly this UTC complementary drivers specs where pretty close and easily to pick matches:
The average hFE for the UTC-2SA1837 was ~194, and the average hFE for the UTC-2SC4793L was ~232, however my cheap DMM reads the Vbe as the typical ~6XXmV.
Now this is what I got from an eBay US seller(seller name protected), "10 Pairs 2SA1837 + 2SC4793 Toshiba" and the seller specified them as "Brand Toshiba" rather than Generic/Unbranded like most foreign sellers at least specify, plus a blurry image which makes the items package cosmetics hard to identify/recognize, regardless this is what I find out:
The average hFE for the above 2SA183 was varying between 160~180, and the average hFE for the above 2SC4793 was varying between 148~165.
So the 2SC4793 appears to be relabeled unknown unit while the 2SA1837 appears to be either generic production or relabeled but not a genuine Fairchild, so rather than sending them back I will keep them just for low voltage linear regulation/switch repair applications but definitely not for audio.
So finally I have all the parts for my next amplifier modification and repair fun, the Samson S700 and the S500.
EDIT: This UTC transistors will replace the pair KA1659(2SA1659) / KC4370(2SC4370), the hFE measurements where as follow for this parts:
2SA1659 hFE = ~201
2SC4370 hFE = ~115
Regards
My Profusion order was as follow:
| Part Number | Cust. ref | Prof. ref | Status | Quantity | Each | Line total |
|---|---|---|---|---|---|---|
| 2SA1837G-TF3-T | 230316XXXX | 65XXX | 15 | $0.629 | $09.44 | |
| 2SC4793G-TF3T | 230316XXXX | 65XXX | 15 | $0.629 | $09.44 | |
| Carriage | $18.00 | |||||
| Total | $36.87 |
After 24 days(International Customs) I've received the the following parts:
A tube with 15x 2SA1837G
A tube with 15x 2SC4793L --> I thought it should be 2SC4793G
I used a budget TFT transistor/semiconductor tester that just gives average results/readings but they're useful to find out transistors hFE and for parts quick testing, so I've tested each parts and write down the results to pick closest match for my old amplifiers mod/repairs, surprisingly this UTC complementary drivers specs where pretty close and easily to pick matches:
The average hFE for the UTC-2SA1837 was ~194, and the average hFE for the UTC-2SC4793L was ~232, however my cheap DMM reads the Vbe as the typical ~6XXmV.
Now this is what I got from an eBay US seller(seller name protected), "10 Pairs 2SA1837 + 2SC4793 Toshiba" and the seller specified them as "Brand Toshiba" rather than Generic/Unbranded like most foreign sellers at least specify, plus a blurry image which makes the items package cosmetics hard to identify/recognize, regardless this is what I find out:
The average hFE for the above 2SA183 was varying between 160~180, and the average hFE for the above 2SC4793 was varying between 148~165.
So the 2SC4793 appears to be relabeled unknown unit while the 2SA1837 appears to be either generic production or relabeled but not a genuine Fairchild, so rather than sending them back I will keep them just for low voltage linear regulation/switch repair applications but definitely not for audio.
So finally I have all the parts for my next amplifier modification and repair fun, the Samson S700 and the S500.
EDIT: This UTC transistors will replace the pair KA1659(2SA1659) / KC4370(2SC4370), the hFE measurements where as follow for this parts:
2SA1659 hFE = ~201
2SC4370 hFE = ~115
Regards
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