Your welcome! It's funny, I had gotten better about things like that. Then I started shooting video, and the distraction had me making the same old mistakes again. Hence the tape. 😁
Great that you did not find anything in the driver section blown! Usually, those direct coupled designs mostly blow the whole chain of transistors! Great clip. Thanks.
Nice repair! It's always good to see an old Eico 443 out in the wild and being used in a shop. I do hope you make a short video on the speaker terminal replacement, just to share possibilities of what can be installed to replace the stock spring ones.
Nice, got lucky the white rabbit was stopped by a fuse. What curve tracer is that? I wish I had one for the 3000a I had. Bad enough finding replacement transistors but matching was fun. Thankfully there were individual bias adjustments. Still would have made the job better to match them.
Best of luck to you. Remember, there are only two reasons for a unit to be stuck in protection mode: Excess DC on an output or a defect in the protection stage.
Another great video thank you Ray. I appreciate how thorough you are even on the basics you may have covered in previous videos. Invaluable to a newb like me. Also looks like the bench is getting a little cluttered man ;p
Another great video as usual. Keep them coming. I love watching them. You're a great source to learn audio amplifiers. Now I have other stuff to play with
Incredibly interesting & well explained tutorial as usual Ray, thanks again for the invaluable service you continuously provide. Just 1 question here: @ 10:33 you said the driver transistors are only the 2 right-most transistors, those on the heatsinks. But since that entire schematic is of the driver board, would the rest of the transistors on it not also be considered driver transistors ?
No, because there are many other components on the board that perform different tasks, such as the bias transistor or the input differential pair. Think of it as akin to an output stage; every transistor on it is not an output transistor. The 2 transistors on the board are actually driving the output transistors. The output transistors provide current gain, and the drivers provide voltage gain. The product of voltage and current is power (watts).
@@raygianelli3612 got it , thank you so much Ray , you really have a brilliant skill of breaking this stuff down in a very thorough & easy to understand way !!
Thankyou for the tape tidbit.
Your welcome!
It's funny, I had gotten better about things like that. Then I started shooting video, and the distraction had me making the same old mistakes again. Hence the tape. 😁
Great that you did not find anything in the driver section blown! Usually, those direct coupled designs mostly blow the whole chain of transistors!
Great clip. Thanks.
Nice repair! It's always good to see an old Eico 443 out in the wild and being used in a shop. I do hope you make a short video on the speaker terminal replacement, just to share possibilities of what can be installed to replace the stock spring ones.
Thank you!
Funny thing, I was just getting out of bed this morning and thinking about doing a short video on the terminal replacement.
Was this 9090 post Service Bulletin?
It’s post service bulletin, can see the fuses on the driver board.
Thanks Ray for the video and the fix, like always awesome job.
Thanks Luiz!
Got an idea to mount the banana jacks that will be completely reversible should you or someone else want that.
@@raygianelli3612 Thanks Ray, appreciate
Great Job Ray!
Nice ! Another one saved :- ) Always picking up bit of knowledge that help. Really great stuff.
Glad to hear this! Just trying to share what I've learned before I shuffle off this mortal coil. 😁
Nice, got lucky the white rabbit was stopped by a fuse. What curve tracer is that? I wish I had one for the 3000a I had. Bad enough finding replacement transistors but matching was fun. Thankfully there were individual bias adjustments. Still would have made the job better to match them.
That curve tracer is an old Eico 443. I used to have an old boat anchor Tek 574. Took up a lot of bench real estate but it was a great bit of gear!
Thank You Sir. I will now repair mine following you guidance.
Best of luck to you. Remember, there are only two reasons for a unit to be stuck in protection mode: Excess DC on an output or a defect in the protection stage.
Good advices and nice job as always ! Did you change the output terminals ?
Hi Roro. I'm actually going to do a video on that soon.
Another great video thank you Ray. I appreciate how thorough you are even on the basics you may have covered in previous videos. Invaluable to a newb like me. Also looks like the bench is getting a little cluttered man ;p
Thanks! I remember what it was like when I started out, so I try to cover everything, the who, what, when, where and how.
Another great video as usual. Keep them coming. I love watching them. You're a great source to learn audio amplifiers. Now I have other stuff to play with
Thanks Adam, that's the whole point of this channel, to share what others so generously shared with me.
Always look forward to a new video from you!
Thanks! Got to get cracking on the next one.
Great work Ray much fun for an easy fix...cheers,
Thanks Andy. Good to see you!
Incredibly interesting & well explained tutorial as usual Ray, thanks again for the invaluable service you continuously provide.
Just 1 question here: @ 10:33 you said the driver transistors are only the 2 right-most transistors, those on the heatsinks. But since that entire schematic is of the driver board, would the rest of the transistors on it not also be considered driver transistors ?
No, because there are many other components on the board that perform different tasks, such as the bias transistor or the input differential pair.
Think of it as akin to an output stage; every transistor on it is not an output transistor.
The 2 transistors on the board are actually driving the output transistors.
The output transistors provide current gain, and the drivers provide voltage gain. The product of voltage and current is power (watts).
@@raygianelli3612 got it , thank you so much Ray , you really have a brilliant skill of breaking this stuff down in a very thorough & easy to understand way !!
@@bigmedge Thanks so much, that's a wonderful thing for you to say and for me to hear!