It's digital "square" wave, can't be perfect, check 2 traces, one directly source and second from Amp with load
Hi Zen mod,
Thanks, I agree with you.
Except main transformer I would only like to change T1 for something more linear. Which Toshiba's did you have in mind? I can get 4pcs 2sk2013, do you know anything about them?
yeah for Donut - if buzzing, that's part of TLC
2SK2013, yup - I meant those - they're all the rage, used with cousin in, say, BA3 here and few more, besides being used in PL products
but, you are old enough, so you know that nothing is really worth leg and kidney
if not available for sane price, there are always other sane priced parts
2SK2013, yup - I meant those - they're all the rage, used with cousin in, say, BA3 here and few more, besides being used in PL products
but, you are old enough, so you know that nothing is really worth leg and kidney
if not available for sane price, there are always other sane priced parts
in that case there is no point in carrying out the test, it defeats the whole objective.
that being said, i appreciate that people are reluctant to obtain suitable test equipment for one off measurements.
Thanks Zen,
It'll be then. Local shop has 4 pcs at 6euro per piece. 24 eur is about 1% of total Amp cost, so I will spend it gladly for the most important component in the whole thing, if they are not fake 🤭
seriously, think about introducing small JFet buffers in front of input mosfets
even if you use fancy ones
luckily, we have current production JFets on disposal, even if smd... in case you don't have TO92 already in drawer
even if you use fancy ones
luckily, we have current production JFets on disposal, even if smd... in case you don't have TO92 already in drawer
seriously, think about introducing small JFet buffers in front of input mosfets
I have 2sj109 dual matched P jfet to use, just then this becomes 3 stage amplifier, even that doesn't matter really.
Do you have suggestion how to connect it? that's new circuit (with also new voltage supply for jfets) and some hanky panky will be needed with PCB to accomodate them
I have 2sj109 dual matched P jfet to use, just then this becomes 3 stage amplifier, even that doesn't matter really.
Do you have suggestion how to connect it? that's new circuit (with also new voltage supply for jfets) and some hanky panky will be needed with PCB to accomodate them
Toshibas are in the house
They even look like genuine, not fake. But I'll test those before insatlling
Unfortunately couldnt find 2sk109, than remembered they went into phono preamp for friend some years ago, dementia 🥴.
Other rebuilt material is gathering, so soon I'll start with it.
They even look like genuine, not fake. But I'll test those before insatlling
Unfortunately couldnt find 2sk109, than remembered they went into phono preamp for friend some years ago, dementia 🥴.
Other rebuilt material is gathering, so soon I'll start with it.
Well, not good, seems I bought fakes!!!
I just measured Vgs and it shows approx 3.7V, that's more than 1Volt higher than Toshiba spec for Y grade.
This thread shows almost exactly the same transistors as mine :
Before I go to shop (which is real psychical shop with Name, address and VAT number, so possible to report to consumer protection inspection) and raise the hell;
Is there possibility that Toshiba had 2 versions of this transistor? I know there is just remote possibility but better check before accusing someone.
Thanks!
I just measured Vgs and it shows approx 3.7V, that's more than 1Volt higher than Toshiba spec for Y grade.
This thread shows almost exactly the same transistors as mine :
Fake or real 2SK2013?
They look so real and genuine!!!!Before I go to shop (which is real psychical shop with Name, address and VAT number, so possible to report to consumer protection inspection) and raise the hell;
Is there possibility that Toshiba had 2 versions of this transistor? I know there is just remote possibility but better check before accusing someone.
Thanks!
It is the highest time the europian union and amerika go look into these chinese fakes, the zagreb fakes are
for shure buyed from chinese sellers, maybe not even know by seller that is fake, most because sellers are not all electronic
educated people. Also be aware that parts who are alfready stopping to produce years ago, you buy proberly fakes.
for shure buyed from chinese sellers, maybe not even know by seller that is fake, most because sellers are not all electronic
educated people. Also be aware that parts who are alfready stopping to produce years ago, you buy proberly fakes.
Last edited:
Cant agree more! I made similar post here in fake transistors forum just to show example
https://www.diyaudio.com/community/threads/my-transistors-original-or-copy.82638/post-7681126
Why to hell do we need to play semiconductor production experts, policeman and customs officers? The declaration on the product must be enough to buy with confidence in organized world, might be better described as "organized"
I will go to this shop and see what they have to say about it, if I don't like it, and I probably will not, I am going to report the issue as example to customer protection inspector, with note that this is for EU commission. Probably it will change nothing , but it also costs me 20 min of effort and I think its worth it. If more people and companies scream of this horrific theft, might be something will happen.
And this is just us, buying few chips here and there, but the damage done to the industry (that apparently pays out taxes for our benefits) is enormous. I think I heard lately on news that counterfeiting in general makes something like trillion Euro damage to EU industry annually...
Hi,
So I returned fake transistors to the shop, they just paid the money back without asking. When I asked why do they do that (selling counterfeits) as it was obvious guy knew it was fake, they told me that now I know so my problem is solved. You can buy connectors and cables, but nothing sophisticated... Nice...
Ill still report the whole story to customer protection service, but to make story shorter, Ill put epilogue on this thread where its more appropriate:
https://www.diyaudio.com/community/threads/my-transistors-original-or-copy.82638/post-7681126
Second, big toroid buzz seems to be coming from my house mains that are close to 240V, this toroid was built long time ago and I'm not sure if it was 220 or 230V specified. Nevertheless when I applied bucking trafo and reduced mains , buzz is almost not hear able (like in the past), more here:
https://www.diyaudio.com/community/threads/toroidal-power-transformers-questions.409995/post-7680906
And finally, I'm lucky that I did not take this apart more than 2 chassis plates.
Unless someone has to offer 2 pairs of original 2SK2013, 2sk213, 4, 5, 6 or 2SK2162 (I,m not sure if list of right transistors is exhausted by this? please propose others if you know) , first I will spend couple of hours testing chokes in main PS (results will come soon) and than I am closing the chassis and putting amplifier back in use where it belongs.
Cheers,
Drazen
So I returned fake transistors to the shop, they just paid the money back without asking. When I asked why do they do that (selling counterfeits) as it was obvious guy knew it was fake, they told me that now I know so my problem is solved. You can buy connectors and cables, but nothing sophisticated... Nice...
Ill still report the whole story to customer protection service, but to make story shorter, Ill put epilogue on this thread where its more appropriate:
https://www.diyaudio.com/community/threads/my-transistors-original-or-copy.82638/post-7681126
Second, big toroid buzz seems to be coming from my house mains that are close to 240V, this toroid was built long time ago and I'm not sure if it was 220 or 230V specified. Nevertheless when I applied bucking trafo and reduced mains , buzz is almost not hear able (like in the past), more here:
https://www.diyaudio.com/community/threads/toroidal-power-transformers-questions.409995/post-7680906
And finally, I'm lucky that I did not take this apart more than 2 chassis plates.
Unless someone has to offer 2 pairs of original 2SK2013, 2sk213, 4, 5, 6 or 2SK2162 (I,m not sure if list of right transistors is exhausted by this? please propose others if you know) , first I will spend couple of hours testing chokes in main PS (results will come soon) and than I am closing the chassis and putting amplifier back in use where it belongs.
Cheers,
Drazen
