very
I will try to make a simulation to know how it work...
Can you make pdf file for this IPS?
I still do not understand clearly how your OPS work. Can you or someone compare this OPS with EF3 OPS with same IPS?
Here we go - PDFs are attached.
I can't compare with EF3 OPS right now - just got no EF3 in hand. However, comparison with Lateral FET OPS shows the difference in distortion level of more than an order, especially at the higher end of the audio bandwidth.
P.S. In a nut shell - the left bias spreader sets the bias with no signal (as usual) - 40-50mA is enough. The right spreader sets the minimal bias, when running with signal - inactive shoulder will not "switch off", collector current will be kept close to zero, but will never reach it. That's the key principle.
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Hi Jeff,
If you look at your broken devices, your will see that the smaller plate runs all the way to the top of the larger plate. The pictures I was shown indicated if a small notch was filed at the top of the transistor so that the plates were exposed, a real sanken will reveal both plates and a fake will not. If you can confirm that I would appreciate it. I suppose it wouldn't hurt anything for me to try the ones I have. I can't return them now anyway.
Hi Valery,
Thanks for the updated files. I will try to get to it this week.
Blessings, Terry
I ground the top on one. You can see two layers of metal backing. It's tough to see in the picture, but there's a parting line down the middle of the copper.
Sanken devices always come with mica thermal pads. This is another sign of real devices.
Sanken devices always come with mica thermal pads. This is another sign of real devices.
Attachments
if he/she sells you a fake or a different transistor from the marked type then that seller is committing fraud.Hi Valery,
I had it all mounted and ready to fire. While waiting for you to get a chance to set yours up I did some reading about the outputs. Newark was out of them when I got ready to order so I bought some from an ebay seller who swore they were genuine. I read you could check them by filing the top edge and exposing the double die. A single die meant they are fakes. Guess what mine had.I pulled them to send back but the shipping was half the cost so I just chalked it up to bad judgement. When I can get some real ones I 'll get it mounted again. Meanwhile, could you post the asbuilt for both vertical and the NS OPS?
Thanks, Terry
Tell Ebay about the fraud, show them his/her reply and guarantee they were genuine.
And demand a full refund including posting them back if Ebay wants you to do that.
I could have done that but I waited too long. By the time I contacted the seller, the time limit with eBay had expired. Also, because of all that, I can't even leave a bad feedback to warn others. I learned a few lessons through this experience. I would probably just install some onsemi parts but I already drilled the heatsink for the Sanken devices so I will likely just wait now until I can afford to buy known, genuine parts from Digikey or Newark.
This is the seller and item.
2 Pairs 2SA1216 2SC2922 Original Sanken Transistor | eBay
I first asked if they were sure what they were selling were genuine and they said yes. Then I ordered them and told them if they weren't genuine Sanken to please cancel the order and not send them. They replied that they were sure and if I was unhappy with them I could send them back. When I received them they looked OK and tested fine on my meter so I installed them. As I said, while waiting for Valery to test his boards, I got curious and pulled one and filed the top to look at the plate. By then ebay's return time had expired. I contacted they seller and they sent me $4 for return postage. Postage bac to them was $16 and I had installed the parts so I figured I was probably in for a battle to get a refund at that point so I just dropped it. I wanted to leave a feedback to warn others but because I had filed for a return I lost the ability to leave feedback. I guess the best I can do now is warn folks here.
Blessings, Terry
Hi Terry, that is the same seller that sold me the fake BJTs which caused a lot of grief!!!.
Quan
Because it is deliberate fraud, I think you should pursue Ebay and Paypal.
They should both blacklist the Seller once they have investigated your evidence.
You might not get anything but others should not get caught.
Not going to happen. Ebay would have done something about it if I had responded within the time limit. The seller offered to refund the money if I shipped them back. It is my choice not to spend the money on the shipping. I will settle for warning others and learning a lesson. I have a few projects I am working on right now so I'm in no hurry. I may just install some Onsemi outputs so I can test this OPS. It's not like I need one more OPS. It's more about the fun and challenge of getting it working.
Virtual Zero (distortion) amplifier
After some minor corrections in VERTICAL IPS and certain tune-up of NS-OPS, amazing results are observed. See the spectrums... I did not believe what I see initially, so I have checked everything a few times, measured with some other front-ends, then with this one again. It's what it is. Measured at 50W @ 8 ohm dummy load (20V RMS) with +/-52V rails.
Sounds delicious, at least in my environment. Jeff - you've got to try and see (hear)
Very, very cool one
Cheers,
Valery
What differences are there when assembling the output bord for the Vertical input as opposed to the TubSoMo input? I see R1 isn't populated. Is there anything else I missed?
R1 = 2.7k should be in place. No differences with either VERTICAL or TubSuMo front-ends.
Right! There is one on the schematic. But on the PCB it's ok. I will correct the schematic
Cool! Just in case - download the latest version of the building and setting up instructions PDF here:
NON-SWITCHING OPS
Also, don't forget to place 2 caps (22pF) under the board on TO-126 devices (VERTICAL) - you've got the 1-st version of the PCB, where they were missing.
