...Also watching with rapt attention since I will be building one soon.. Just got my chasis and digikey order.. Sorry to hear about your setback, flamethrower, but thank you for documenting it! It could help many people (myself included) someday..
There is stupid and then there is a moment of inattention, a brief distraction or the ever lurking "one more thing and then I call it good".
I've banged my head against the wall going "stupid, stupid, stupid" plenty of times. Just last week I fired up my ESP P3A amp for the first time and after a bit decided that I should really try swapping the SMPS power supply for a linear one to see if the noise dropped and so I tapped into the power supply of another amp I'd built. Except I reversed the white and black wire "wait, which one was negative and which was ground?" The magic smoke escaped.
And this was after swearing up and down that I was going to do things right this time. I'd been patient and made sure and got all the components solidly mounted in the case and all the wires run correctly and secured.
I'd assembled the case so nothing could get moved and pull on a wire; all before powering it up. It was all working perfectly; then my brain faded and I quickly dragged wires over from another case over and.....
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Flamethrower1,
As you can see, many of us have made mistakes in our diy builds. My early
mini Aleph actually had flame bursting out of a CRC resistor in the power supply. 🙂
Things happen...and it's part of the learning process.
And there are many members here who will cheer you on as you fix your amp.
As 6L6 said earlier, it's absolutely fixable.
One of the great things about the F5 is that there are so few parts, and all,
aside from the jfets, are readily available. My guess is the jfets are fine; we
can do a basic test in circuit later.
The hardest part of the repair will likely be desoldering some parts... 🙂
Cheers,
Dennis
As you can see, many of us have made mistakes in our diy builds. My early
mini Aleph actually had flame bursting out of a CRC resistor in the power supply. 🙂
Things happen...and it's part of the learning process.
And there are many members here who will cheer you on as you fix your amp.
As 6L6 said earlier, it's absolutely fixable.
One of the great things about the F5 is that there are so few parts, and all,
aside from the jfets, are readily available. My guess is the jfets are fine; we
can do a basic test in circuit later.
The hardest part of the repair will likely be desoldering some parts... 🙂
Cheers,
Dennis
I fried a channel on my F5 which was also my first major build. I had to rebuild the boards from scratch and since I had to order two boards, the parts kits, etc I just rebuilt both channels. The great thing was that it took me only 20% of the time to do it the second time around so it was rather quick and pain free.
Kevin
Kevin
Seeing the difficulties some encounter, I am glad to have done what I did.
This means, I followed the building guide and the bom scrupulously. I tested every part before soldering and just after. My F5 has been then very wise and didn't gave me any trouble, except one condenser which leaked after few hours run.
This means, I followed the building guide and the bom scrupulously. I tested every part before soldering and just after. My F5 has been then very wise and didn't gave me any trouble, except one condenser which leaked after few hours run.
Was surprised to see so many people responding to my "initiation".
All I can say is wow and thank you.
Why cant the whole world work like this.
What happened was my doing I am sure.
Going to address training issues in a meeting tomorrow ( of coarse baggles will be served).
So the above post is where I leaning toward after thinking about things today.
Thanks for your support
Greg
We are fearless amplifier builders. A little heat doesn't scare us at all.
- NP 2002
Should read:
We are fearless amplifier builders. A little heat doesn't scare us at all.
Disclaimer,if you see smoke, you balled something up or you took it to far
- NP 2002
Hope that isn't a copy right infringement or something
- NP 2002
Should read:
We are fearless amplifier builders. A little heat doesn't scare us at all.
Disclaimer,if you see smoke, you balled something up or you took it to far
- NP 2002
Hope that isn't a copy right infringement or something
So looking into building boards again.
I see punkydawgs does not have anymore of the Toshibas available anymore.
Any body have a good verified source?
I see punkydawgs does not have anymore of the Toshibas available anymore.
Any body have a good verified source?
I think punkydawgs is still well stocked. Maybe you have an old link.
Just search `punkydawgs`in google and the first hit will be the ebay store.
100% listen to 6L6, but....
Seeing stock:
Toshiba 2SJ74 + 2SK170 LAB MATCHED QUAD to 0.03mA AND 4mV (10mA range "BL") | eBay
This vendor has also been reported to have the goods...
Genuine Toshiba 2SK170BL/2SJ74BL high transconductance JFET complimentary pair | eBay
I had some smoke and drama—I'm better for it—learned a ton—you WILL have a great amp! And then you will build another. And another. And....
Monoblocks ;-)
Seeing stock:
Toshiba 2SJ74 + 2SK170 LAB MATCHED QUAD to 0.03mA AND 4mV (10mA range "BL") | eBay
This vendor has also been reported to have the goods...
Genuine Toshiba 2SK170BL/2SJ74BL high transconductance JFET complimentary pair | eBay
I had some smoke and drama—I'm better for it—learned a ton—you WILL have a great amp! And then you will build another. And another. And....
Monoblocks ;-)
Also if it makes you feel any better, I once accidentally powered an F5 on with one of the boards not attached to the heat sink. Poof. At least it only cooked the MOSFETs.
Ok Mark you are right, I see where you are going with that, cant change anything now though.
Anyway, yes I managed to power it up with the pots turned the wrong way, but, wait for it,
this was already after I had it set up and moved onto the second board.
Based on the numbers from the second board and now getting used to how the pots react, I thought zero the first board and start over.
I was talking to my son about deer hunting (there was also a couple of homebrews involved) I turned them the wrong way.
So, I do have some resistors and I am going to replace them and see if that works.
Thanks for the links guys
Anyway, yes I managed to power it up with the pots turned the wrong way, but, wait for it,
this was already after I had it set up and moved onto the second board.
Based on the numbers from the second board and now getting used to how the pots react, I thought zero the first board and start over.
I was talking to my son about deer hunting (there was also a couple of homebrews involved) I turned them the wrong way.
So, I do have some resistors and I am going to replace them and see if that works.
Thanks for the links guys
Well, to zero the bias in preparation for initial startup,
just adjust P1 and P2 so that the measure resistances across R5 and
R6 are low (at most a few ohms)
I find trying to remember directions to be tricky.
Good luck with your repair.
just adjust P1 and P2 so that the measure resistances across R5 and
R6 are low (at most a few ohms)
I find trying to remember directions to be tricky.
Good luck with your repair.
Yeah, the worst part of my situation is, I knew that and didn't verify it.
BIG lessons learned that will not be repeated.
Thanks, Greg
BIG lessons learned that will not be repeated.
Thanks, Greg