Have checked the MAT02 with Diode setting on a Multimeter? Ages ago, I bought a bunch of these devices at a premium, only to discover later that MAT03 were also NPN types, just reprinted.
Looks correct. Maybe Sam is right and something is wrong with MAT02 itself?
I don't really see any reason why MAT02 in working condition would not work well here 🙄
Here what i got.
The first picture is as all other test with floating heatsink when second is with a grounded heatsink.
I wonder,is it something to do with the bandwidth difference?
The first picture is as all other test with floating heatsink when second is with a grounded heatsink.
I wonder,is it something to do with the bandwidth difference?
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But... 50 / 100 Hz components at the other spectrums are looking more like the ones on the right picture, aren't they?
I don't think fT difference of this kind would influence the noise performance that way.
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Valery,all other spectrums looking like the ones on the right picture BUT all previous spectrums was taken with a floating heatsink.
Using MAT02 as input device spectrums are as in left picture regardless of the testing level.The problem solved when heatsink connected to GND.
I have triple checked this.
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I'm wondering if this can be somehow related to this note in the datasheet, placed right under the pinout picture:
NOTE
Substrate is connected to case on TO-78 package. Sub-
strate is normally connected to the most negative circuit
potential, but can be floated.
NOTE
Substrate is connected to case on TO-78 package. Sub-
strate is normally connected to the most negative circuit
potential, but can be floated.
Valery, i had seen this too.
What is the most negative circuit potential in our case?
Is the negative pole of power supply?
Grounding the metal case of the MAT02 not resolve the issue.
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Yes, the most negative potential is the negative rail.
Circuit behavior with MAT02 is kind of ... strange ))
Circuit behavior with MAT02 is kind of ... strange ))
AX-Deluxe adventures
Just for the curiosity.
Testing this AX-Deluxe IPS using a FAKE MAT02 this time.
No issue found!
I came to believe that the issue have to do with the internal R&D in the authentic MAT02.
Transistor tester not recognized R&D in the FAKE MAT02.
Just for the curiosity.
Testing this AX-Deluxe IPS using a FAKE MAT02 this time.
No issue found!
I came to believe that the issue have to do with the internal R&D in the authentic MAT02.
Transistor tester not recognized R&D in the FAKE MAT02.
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TubSuMo is alive and working beautifully! I only built one channel but it sounds great even in mono. Solid bass! Excellent detail. No hint of hum. My build of the original version wasn't overly inspiring due to some hum issues I never was able to find the cause of. I'm very happy with the results here so for.
Initial tests were with +/- 56V rails and an 8R dummy load. my bench supply sags quite a bit so it's clipping around 125W. Runs great at full power well past 100kHz but the zobel network was stinking up my office so I didn't get any pictures.
Initial tests were with +/- 56V rails and an 8R dummy load. my bench supply sags quite a bit so it's clipping around 125W. Runs great at full power well past 100kHz but the zobel network was stinking up my office so I didn't get any pictures.
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Great News!
Another alive boy to the family.
What is the power board?
Aha,i see ver.2 NS.integrating protection
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I'm almost done with the amplifier PCBs, last will be the controller and rectifier PCBs.
I bought the Tubsumo and Vertical CFA so it will be fun to compare them, especially that it is quite easy to swap them!
Do
I bought the Tubsumo and Vertical CFA so it will be fun to compare them, especially that it is quite easy to swap them!
Do
The past couple weeks have been very busy. I haven't had a chance to pull parts for you yet. I hope to be able to do this in the next couple days though.