Maybe the ones in the EBAY listing are Good Chinese?
1 Pair | 2SK2013 + 2SJ313 | New Original TOSHIBA | eBay
Regarding the driver, remember that you can build version 5.1 with darlington Sanken BJT drivers. These BJT are still in production and do not require matching and are not costly.😉
These BJT are also very good.
Fab
These BJT are also very good.
Fab
Please be careful. I got a whole bunch of counterfeits of the precious Toshiba drivers from. UTSOURCE. They didn't respond to my mail.
I checked NicMac spreadsheet and he still got one matched quad for sale, however it is for 120EUR.
Has anyone purchased the MOSFET pair from this source? Are they reliable with authentic parts?
TOSHIBA MOSFET 2SK2013 2SJ313 Pair 2-10R1B_Transistor_Analog Metric - DIY Audio Kit Developer
TOSHIBA MOSFET 2SK2013 2SJ313 Pair 2-10R1B_Transistor_Analog Metric - DIY Audio Kit Developer
When you say "good Chinese" do you mean that the devices pictured in the second picture are acceptable Chinese knock off parts?
The second picture look to be the same as the ones in the following link
from Analog Metric.
TOSHIBA MOSFET 2SK2013 2SJ313 Pair 2-10R1B_Transistor_Analog Metric - DIY Audio Kit Developer
This may not be the right thread, but since the question came up... If someone finds a source that is sort-of trustworthy, we could maybe work out a money-back guarantee for authenticity with them. I could offer to curve trace (some) of those parts in order to validate them. If the parts are bad, we return the parts and tell everyone not to buy from them. If they're good, we are all happy and may work out a small group buy. Let me know if anyone is interested to take the lead.
That is a great idea. These parts are getting very difficult to source, especially for a reasonable price.
I am in the US. Would it be best from me to order the parts and have the vendor ship them to you directly? Or would you be willing to place the order and I could reimburse you for the purchase?
I guess the first method is easier. How many parts would you want to buy? I'd suggest you to get as many as you can, plus some more.
They are offering pairs with Beta matching for $10.90 USD/matched pair. I would be willing to risk the price of 4 pair to Check them out.
I did e-mail the supplier asking if they guarantee devices to be authentic NOS Toshiba devices? Before the order is placed let's see if I get a response from them?
I did e-mail the supplier asking if they guarantee devices to be authentic NOS Toshiba devices? Before the order is placed let's see if I get a response from them?
Hi,
I finished first channel. When working on second channel, I messed up polarity, I accidentally connected VCC+ from PSU to VCC- AMP PCB and VCC- from PSU to VCC+ AMP PCB. C2, C4, C5 and C6 are gone. From C5 there was also some smoke going outside. It took about 10 seconds until I disconnected PSU. Is there any chances that I could destroy all transistors? J112, 557,547 and also TOSHIBA drivers were installed 🙁
I finished first channel. When working on second channel, I messed up polarity, I accidentally connected VCC+ from PSU to VCC- AMP PCB and VCC- from PSU to VCC+ AMP PCB. C2, C4, C5 and C6 are gone. From C5 there was also some smoke going outside. It took about 10 seconds until I disconnected PSU. Is there any chances that I could destroy all transistors? J112, 557,547 and also TOSHIBA drivers were installed 🙁
Hi Tmas
I have not performed an A to B comparison but after break-in of my USSA5.1 in my main system I have not felt the need to switch back to USSA5.0 so it is a good sign. I easily noticed differences between different USSA versions but really input stage and output stage are the main contributors to sound and the driver stage just need to be appropriate. If you follow the manual section related to 5.1 it shows how to get the same THD profile as the USSA5.0 by using P1 and P2 adjustment.
Fab
If you do not have a curve tracer, the build manual section 8.11 shows a test circuit and measurement steps to determine if your mosfet drivers are genuine.
Fab
Fab