That ship has sailed. That would be more changes than I want to make at this point.
But I do wish I knew how to roll my own transformers, there is great magic in that.
I prefer the silicon diode hack right now. There is enough heat being generated in that amp already. 🔥
Would HFA08TB60 have any advantage over UF4007 to stand in front of the 5AR4 plates?
@vinylkid58 @6A3sUMMER
@vinylkid58 @6A3sUMMER
I don't see any advantage, but maybe I'm missing something.
jeff
jeff
And then you find this:
https://www.diyaudio.com/community/threads/sparking-rectifier-tubes.202180/#post-2813878
https://www.diyaudio.com/community/threads/sparking-rectifier-tubes.202180/#post-2813878
you bet....i am never constrained to use off the self types, although you can ask Edcor to make one for you...
To implement 2), 3) and 4) together is trivial, and I thought it was part of the standard build (i.e. CL90 + CL140 + serial diodes).
Using a choke with insufficient resistance has compounded your issue. Replacing that gets you all the serial resistance you need, and gets you back to 'spec'.
Using a choke with insufficient resistance has compounded your issue. Replacing that gets you all the serial resistance you need, and gets you back to 'spec'.
I think it’s part of the standard SSE build.
Plus the post by @Tubelab_com I linked to above (https://www.diyaudio.com/community/threads/sparking-rectifier-tubes.202180/#post-2813878) has this last paragraph:
(referring to silicon diodes in series with the plates)
So, that certainly needs more consideration.
Now, that was the most seamless and elegant solution, but I could not find a 10H choke with more than 100 ohm of DCR. (at 200 mA of current rating)
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And I think this comment eliminates the possibility of a CL-140 on the HV CT:
https://www.diyaudio.com/community/threads/after-a-14-year-run-the-tse-must-die.331038/post-6058265
https://www.diyaudio.com/community/threads/after-a-14-year-run-the-tse-must-die.331038/post-6058265
I think I’ll bite the bullet and add power resistors after all. All other “solutions” have potential side effects.
Yeah, better safe than sorry. I wasn't aware that adding diodes to the rectifier tube was a no-no with the TSE.
jeff
That amp sound amazing, it’s why I am going to such great length to make it work reliably.
George carefully dialed in the design over many years and the only reasons my build is having difficulties are:
- My lack of knowledge.
- The fact that modern parts have different characteristics.
- The very unique design of the power supply.
Looking at the old schem., you can see he used the same transformer winding for both the 5AR4 and the -ve. bias supply for the 2SK2700 transistor.
jeff
And finally, this exchange with Merlin goes to the core of the issue:
https://www.diyaudio.com/community/threads/tubelab-simple-se-rectifier-problem.123790/post-1523489
(from this post on in the thread)
After reflection, my recommendation for anyone wanting to build a TSE-II is: Make sure you pick a PT with enough DCR in the secondary handling the 5AR4. My Edcor is not good for this project.
https://www.diyaudio.com/community/threads/tubelab-simple-se-rectifier-problem.123790/post-1523489
(from this post on in the thread)
After reflection, my recommendation for anyone wanting to build a TSE-II is: Make sure you pick a PT with enough DCR in the secondary handling the 5AR4. My Edcor is not good for this project.
X Ohms DCR of the secondary, and X Ohms of an external resistor work exactly the same way.
The integral of the rectifier current is the same, and the I-Squared x R heating is the same.
All the head that is generated is in the transformer secondary, or all is in the external resistor, or most often it is in Both the secondary DCR and the external resistor.
Why is having an external resistor a problem?
Would you rather have your power transformer take all the heat?
An external resistor is less convienient, it takes space, and is two extra connections.
Having all the resistance in the power transformer is more convienient, but it might make for less reliability.
The integral of the rectifier current is the same, and the I-Squared x R heating is the same.
All the head that is generated is in the transformer secondary, or all is in the external resistor, or most often it is in Both the secondary DCR and the external resistor.
Why is having an external resistor a problem?
Would you rather have your power transformer take all the heat?
An external resistor is less convienient, it takes space, and is two extra connections.
Having all the resistance in the power transformer is more convienient, but it might make for less reliability.
@6A3sUMMER You are right that it’s probably easier to dissipate the heat if it comes from 2 separate locations. And chassis-mounted resistors make that practical.
At this point, I just want to implement the fix and get back to listening to music.
I’ll find a place for the power resistors.
At this point, I just want to implement the fix and get back to listening to music.
I’ll find a place for the power resistors.
A single resistor from the cathode that is rated for 2 x the watts, is the same as 2 individual plate resistors at 1 x the watts for each resistor.
Less connections, and only one big space required.
"You should make things as simple as possible, but no simpler" - Albert Einstein
Less connections, and only one big space required.
"You should make things as simple as possible, but no simpler" - Albert Einstein
how can you say that? all you need is add external resistors and i have given the table and the formula to determine the value of those resistors...my calculations is that, without external resistors, your 5AR4 plates is already looking at around 600 ohms at the plate already, for added safety and peace of mind you can add external resistors of say 33 ohms to each plates..,, why worry so much? Edcors are such fine transformers looking at how they build those...
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