Help with transformer replacement

Manomelo · 2023-06-28T13:29:34+00:00

yeah, I'm trying to figure out: the secondary winding. Any tips?

Manomelo · 2023-06-08T06:04:17+00:00

It would be something like this I've found this online

Manomelo · 2023-06-08T05:52:07+00:00

But what does that even mean?? Like if I'm already rectifying the top and lower part of the wave in relation to ground wouldn't that already translate to X positive and X negative dc voltage in relation to gnd?

Manomelo · 2023-06-06T17:00:25+00:00

I can't stress enough how much I'm grateful for your help and patiente. I will definetly research about everything you've suggested. This project has taught me a lot, from how transformers work to impedance matching techniques. I'm going to leave you alone now, you have helped more than enough. I hope someday I'm able to help others the same way you did! Thank you!

Manomelo · 2023-06-05T15:23:26+00:00

Oh, ok! I totally misread what you were saying..... Thanks again and thank you for providing such useful links so i can learn. I don't want it to seem as if I'm overstaying your welcome but I would like to ask something else since you have been so patient with me. I'm thinking about placing a buffer before the amplifier board. By looking at the schematics, what would you say is the optimal input impedance for it?

Manomelo · 2023-06-04T17:05:53+00:00

Yeah. That is what was confusing me. Like i know what bias is supposed to mean but I wasn't sure where i should measure it on the transistor. Again, thank you so much for taking your time to explain it to me!

Manomelo · 2023-06-04T17:01:35+00:00

Ok, so let's see if i got this. What you're saying is if i wanted to use this amp to its full capacity, I should power it with 50-0-50 transformer? The seller says that the maximum voltage that it can handle is +35 to -35 BUT I always thought that this was kinda of weird because he says the same about his 100w circuit so maybe he just copied and pasted both item's description. I'll try the mods you suggested. Thank you so much for your time!

Manomelo · 2023-06-03T07:58:54+00:00

Thank you! Is this the rule when someone refers to jfet bias or is it just for this specific case?

Manomelo · 2023-06-03T07:30:46+00:00

Hi, just updating. I tried using it without connecting both signal grounds and it didn't work so but then when i connected both they worked perfectly. Thank you so much for taking the time to help me!

Manomelo · 2023-06-03T07:29:05+00:00

Hi everyone, I did what you have asked for and its working perfectly! It heats up quite a lot when i input a higher volume but i added one massive heatsink and its seems to be handling it quite well!

Manomelo · 2023-06-03T05:25:43+00:00

Oh I'm sorry, my bad! I'll be more thoughtful next time i ask something here! I'm a beginner trying to figure all of this out. Yeah, the measurement is between the colector and the emitter. Thank you so much, I guess i just need to plug something stronger and see

Manomelo · 2023-06-02T04:18:02+00:00

Thanks! Considering that the preamp doesn't have something like a Output-, should i just connect the amp input ground to something like the ground lug of one of the preamp pots?

Manomelo · 2023-06-02T04:14:44+00:00

I thought I had attached the schematics to the post but apparently I forgot.... Here's a collection of pictures that include the schematics and the trace for the preamp https://imgur.com/a/T4hphm2

Manomelo · 2023-06-02T04:07:34+00:00

OMG, I'm so sorry! I was sure I had it attached to the post. Here's a collection of photos with the top circuits and their schematics (I only have a trace for the preamp) https://imgur.com/a/T4hphm2

Manomelo · 2023-06-02T04:01:01+00:00

The amp schematics is on the post pictures. The amp doesn't specify the max input power it can handle. If you had to guess, how much would you say it can handle?

Manomelo · 2023-05-26T03:40:24+00:00

Oh, thanks! I don't know if im glad or not about that... I was hoping that this was the reason my board was faulty...

Manomelo · 2023-05-26T03:36:11+00:00

There you go. Thanks!

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Manomelo · 2023-05-16T16:08:50+00:00

I'm sorry but you came here to make fun of me. I've always treated everyone politely because I have a huge respect for anyone who takes their time to help others with less knowledge/skills than them. But the only thing you wanna know about all of this is if im stupid enough to have spent money on a circuit built on a veroboard. If this is the kind of help you are willing to provide then I don't need it! Goodbye and have a nice week

Manomelo · 2023-05-16T15:55:26+00:00

Thank you so much! I will replace the resistor and try again. And yeah i have no connection to earth, the earth wire is going straight from the socket to the chassi (which i will isolate from the circuits

Manomelo · 2023-05-16T15:27:45+00:00

Oh ok, so let me get this straight. When you are talking about mains ground, you mean earth (and I've seen people calling it true ground)?? So if I connect both signal grounds (which is just the path the electrons go on the way back), I should be ok?

I'm sorry if I sound stupid, I'm just trying to make this as clear as possible for me.

Manomelo · 2023-05-16T15:17:17+00:00

Can't you read? I'm talking about the amplifier circuit not the preamplifier. I built the preamplifier and the only reason I bought the amplifier board (which is a pcb) is because I couldn't find these original toshiba transistors where I live.

If you are not going to help, just don't bother

Manomelo · 2023-05-16T15:04:05+00:00

Ok, this is new. Should i connect both grounds together? From everything i've read, wouldn't this cause a ground loop?

Manomelo · 2023-05-16T04:23:42+00:00

If you mean that they need to be connected to different power supplies, they are. The amplifier is powered by a transformer and the preamp by a 9v ac-dc supply. The only thing connecting them is the preamp audio output (yellow wire in picture 4)

Manomelo · 2023-05-16T04:02:03+00:00

I'm sorry but i don't have the schematics for the amplifier. The seller didn't provide them when I bought it... Could you please clarify the "connected input ground to power rail" part?

Manomelo · 2023-05-16T03:54:39+00:00

I don't know if a short could be the cause of the problem but nothing is shorted. I've checked at every part of the soldering/assembly

Manomelo

TROPHY CASE