diyAudio

diyAudio (https://www.diyaudio.com/forums/index.php)
-   Analog Line Level (https://www.diyaudio.com/forums/analog-line-level/)
-   -   The Kuartlotron - keantoken's simple error-correction superbuffer (https://www.diyaudio.com/forums/analog-line-level/251413-kuartlotron-keantokens-simple-error-correction-superbuffer.html)

qq33006498 3rd January 2020 02:28 AM

Hello @ keantoken, I have adjusted the TP terminal to half of the positive voltage, R1 and R2 are 56R, when using Onsemibc550c/560c, the output voltage can not be adjusted to 0, there are tens of MV, and the output voltage will jump around. And the TP terminal voltage will change from time to time 5.8-5.3v. When I add R9 to 4M, the output can be adjusted to 0, but it is also unstable and will change. But when using PHILIPSbc550c/560c transistors, the TP terminal voltage and output voltage are very stable and will not change, but R9 also needs to be added to 4M to adjust to 0v.

qq33006498 3rd January 2020 05:16 AM

R1R2 = 56R, power supply 10vTP = 5V, working points are normal, play some high level CD, high frequency will break, how is it?

Dave S 16th January 2020 09:56 PM

Now that On-Semi BC560C is obsolete are there any suggestions for alternative devices to the BC550/560C?

Which parameters are important when selecting parts for this circuit?

keantoken 17th January 2020 03:33 AM

Mouser has OnSemi BC5x0C and they are actually the same Fairchild parts I original recommended, now that OnSemi has acquired Fairchild.

keantoken 17th January 2020 03:40 AM

Quote:

Originally Posted by qq33006498 (https://www.diyaudio.com/forums/analog-line-level/251413-kuartlotron-keantokens-simple-error-correction-superbuffer-post6030252.html#post6030252)
Hello @ keantoken, I have adjusted the TP terminal to half of the positive voltage, R1 and R2 are 56R, when using Onsemibc550c/560c, the output voltage can not be adjusted to 0, there are tens of MV, and the output voltage will jump around. And the TP terminal voltage will change from time to time 5.8-5.3v. When I add R9 to 4M, the output can be adjusted to 0, but it is also unstable and will change. But when using PHILIPSbc550c/560c transistors, the TP terminal voltage and output voltage are very stable and will not change, but R9 also needs to be added to 4M to adjust to 0v.

It sounds like oscillation, or perhaps a bad connection somewhere. It could be you have an unusual layout that is causing a problem. You can use the Phillips transistors if they work better, but they have higher noise and I designed the Kuartlotron for the Fairchild (now OnSemi) parts.

Destroyer OS 17th January 2020 08:50 AM

Quote:

Originally Posted by keantoken (https://www.diyaudio.com/forums/analog-line-level/251413-kuartlotron-keantokens-simple-error-correction-superbuffer-post6047548.html#post6047548)
Mouser has OnSemi BC5x0C and they are actually the same Fairchild parts I original recommended, now that OnSemi has acquired Fairchild.

I don't see anything available

silasmellor 17th January 2020 09:11 AM

BC550CTA ON Semiconductor / Fairchild | Mouser Denmark

No more bc560 it seems, Mark Johnson bought them all :o)

keantoken 17th January 2020 09:12 AM

I was looking at the NPN, looks like the PNP is now obsolete. Hmm.

Destroyer OS 17th January 2020 05:51 PM

Temp source

BC560C FAIRCHILD PNP LOW NOISE TRANSISTOR x10PCS | eBay

qq33006498 20th January 2020 04:59 AM

I use the DIY dartZeel nhb108 Amplifiers, then your Superbuffer Amplifiers midpoint voltage will rise from tens of MV to 700-800mv, what is the reason for this? Do I add 4.7 UF capacitors to the input or output? Superbuffer output midpoint is already within 10mv

I have used the same Fairchild BC550CTABC560CTA (HFE/800) as you listed, when R9 = 2.7M, the lowest midpoint voltage is still tens of MV, when R9 = 4M, the midpoint voltage is still 10mv, TP = 5V, sometimes 4.8v and sometimes 5.2v. With PHILIPSbc550c/560c won't such, what reason is this?


All times are GMT. The time now is 11:37 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 17.65%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Copyright ©1999-2020 diyAudio

Wiki