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Rod I guess first time you don't sold me the regs for filament bias and accordingly you don't give me the right PSU for filament bias.
As far as I know the regulator PCBs are all the same - you change one resistor to match the input voltage. Rod will tell you all this, but it's probably in the instructions anyway.
You have to be able to rely on your own calculations to do a lot of this DIY stuff. There are numerous posts telling you how to do the calculations.
You have to be able to rely on your own calculations to do a lot of this DIY stuff. There are numerous posts telling you how to do the calculations.
Is possible the pcb is the same (Rod told me 1st reg was for cathode bias, capacitor 1st reg was 16V in place of 35V also some components changed) the PSU Rod told me for filament bias doesn't works to reach the necessary voltage..
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Try some 15v transformers. Or some 18v transformers with a choke, or dropper resistor - whatever. This is only a basic power supply which needs to output around 17v. You'll find about a million tutorials on the internet showing you how to construct a power supply. I like to use choke input with a Hammond choke 159ZC - chokes are excellent even for low voltage power supplies. That requires a higher voltage transformer again - it's all in standard power supply theory.
Or if you want to use your existing power supply, use a different operating point on the 26 so the voltage on the cathode is less than 10v. Several ways to do this. The 26 works fine at lower operating points. You can also use a 105v voltage reg like 0C3. You have choices.
Or if you want to use your existing power supply, use a different operating point on the 26 so the voltage on the cathode is less than 10v. Several ways to do this. The 26 works fine at lower operating points. You can also use a 105v voltage reg like 0C3. You have choices.
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Felipe, I am not exactly sure what you mean, but it looks like an unfriendly accusation that I have mislead you.
Yes, the first kits you bought were for normal bias. They are easily configured for filament bias - but, as Andy says, you have to check that you have done the work, and/or ask me. Applying 17V to a regulator configured to accept 8V is never going to end happily.
In fact, the instructions for converting any Regulator to filament bias were sent to you in email of Jan 13, 2013.
Felipe, you ask me an endless number of questions about your preamp, both in posts on the forums, and in over 200 private emails to me. These have taken me a great deal of time and trouble to answer. Many of these were so basic, you should have answered by looking them up yourself. And you now appear to return this courtesy by claiming to have been mislead.
My advice: Find an experienced engineer located near enough to you, that can help you learn some of the basic work, like Ohm's Law, making a rectified dc supply, and how to debug an amplifier. This is very hard to learn properly, without seeing a experienced person at work. If you can't do that, please study the Sticky Thread "Online Learning for Newbies", so that you don't have to ask so many basic queries - which have now completely hijacked this "26 preamp" thread, and turned it into a private debug thread.
(Maybe the Debug questions can be removed and put in a new thread, to keep everyone from being interrupted by posts of no interest to most 26 preamp builders)??
http://www.diyaudio.com/forums/tubes-valves/38278-line-tube-learning-newbies.html
Yes, the first kits you bought were for normal bias. They are easily configured for filament bias - but, as Andy says, you have to check that you have done the work, and/or ask me. Applying 17V to a regulator configured to accept 8V is never going to end happily.
In fact, the instructions for converting any Regulator to filament bias were sent to you in email of Jan 13, 2013.
Felipe, you ask me an endless number of questions about your preamp, both in posts on the forums, and in over 200 private emails to me. These have taken me a great deal of time and trouble to answer. Many of these were so basic, you should have answered by looking them up yourself. And you now appear to return this courtesy by claiming to have been mislead.
My advice: Find an experienced engineer located near enough to you, that can help you learn some of the basic work, like Ohm's Law, making a rectified dc supply, and how to debug an amplifier. This is very hard to learn properly, without seeing a experienced person at work. If you can't do that, please study the Sticky Thread "Online Learning for Newbies", so that you don't have to ask so many basic queries - which have now completely hijacked this "26 preamp" thread, and turned it into a private debug thread.
(Maybe the Debug questions can be removed and put in a new thread, to keep everyone from being interrupted by posts of no interest to most 26 preamp builders)??
http://www.diyaudio.com/forums/tubes-valves/38278-line-tube-learning-newbies.html
I can only echo what Rod says.
Filipe - you MUST learn basic electronic theory. This thread is not here to teach you electronics. If you need a PSU that outputs 17v then post on a thread about power supplies. Get a book like Morgan Jones Valve Amplifiers. Follow online tutorials. Buy a book in Spanish about basic theory - there must be loads of them. There's probably loads of Spanish tutorials online.
I think maybe the only way to encourage you to learn basic electronics properly is to not answer your many, many questions. You can't keep emailing Rod - he's a busy technician not a basic electronics tutor. It's just not fair, and one day he will simply not answer your questions.
Get some confidence in your own ability. Learn to answer your own questions. We all went through this ourselves. I am completely self taught. I read Morgan Jones book so often it fell apart. Try and do the same.
Filipe - you MUST learn basic electronic theory. This thread is not here to teach you electronics. If you need a PSU that outputs 17v then post on a thread about power supplies. Get a book like Morgan Jones Valve Amplifiers. Follow online tutorials. Buy a book in Spanish about basic theory - there must be loads of them. There's probably loads of Spanish tutorials online.
I think maybe the only way to encourage you to learn basic electronics properly is to not answer your many, many questions. You can't keep emailing Rod - he's a busy technician not a basic electronics tutor. It's just not fair, and one day he will simply not answer your questions.
Get some confidence in your own ability. Learn to answer your own questions. We all went through this ourselves. I am completely self taught. I read Morgan Jones book so often it fell apart. Try and do the same.
Filipe - please read what we are saying here. Can you find a Spanish electronics tutorial? Tell us what is available.
Or otherwise, work it out with Ohms law and a tutorial on power supplies. Tell us your own calculations and we can check them. But you have to show us you know how to do the calculation first.
OK?
Or otherwise, work it out with Ohms law and a tutorial on power supplies. Tell us your own calculations and we can check them. But you have to show us you know how to do the calculation first.
OK?
Seems fine Felipe.
Connect this power supply to the regulator.
Place the #26.
THEN measure the voltage at the input connector of the regulator.
It must be 17 volts or a little higher.
If you have reached this point you are almost finished.
Now rotate the trimmer so there's 10 volts between filament and ground.
Check back when you have done so and no new questions anymore!
Connect this power supply to the regulator.
Place the #26.
THEN measure the voltage at the input connector of the regulator.
It must be 17 volts or a little higher.
If you have reached this point you are almost finished.
Now rotate the trimmer so there's 10 volts between filament and ground.
Check back when you have done so and no new questions anymore!
I do agree.....yes.....merlin please tell him straight what you feel as a purchaser of the board.. .....cheers.....
Actually, Felipe wrote email to apologise for suggesting, in the posts above, that I had given bad advice.
I think that he, and many other users of my Regulator would agree that I have provided very thorough and useful support.
This isn't right at all. Rod is a huge support to the audio community - we all know this. His regs have launched hundreds (probably thousands by now) of DHT builds to levels they could only dream of a few years ago.
As someone who has used a few of his regs I can only say what any other user would - the documentation is extremely detailed, the parts are as good as you can get and the email support is as good as it gets.
I've never seen Rod's work criticised anywhere in the audio community and I can't think of any reason why it ever should be.
Rod thanks to accept my apologizes, he is still helping me by email so I don't have enough words to appreciate his help.
Well installed new txs Hammond 229D40 20V 2,4A, measurements with all tubes Cunningham globe:
Right channel
B+ 150,7V
Anode 130,7V
OPT current 15mA
Filament gnd 10V
Filament to heater+ 11,6V
Voltage input heater reg 16,3V
Left channel
B+ 150,7V
Anode 131,4V
OPT current 15mA
Filament gnd 10V
Filament to heater+ 11,6V
Voltage input heater reg 16,5V
Are the tubes OK or I have to change to the news ST type bought to Andy?
TIA
Felipe
Right channel
B+ 150,7V
Anode 130,7V
OPT current 15mA
Filament gnd 10V
Filament to heater+ 11,6V
Voltage input heater reg 16,3V
Left channel
B+ 150,7V
Anode 131,4V
OPT current 15mA
Filament gnd 10V
Filament to heater+ 11,6V
Voltage input heater reg 16,5V
Are the tubes OK or I have to change to the news ST type bought to Andy?
TIA
Felipe
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Something oscillating again?
Could shorten/shield the grid wiring.
Try a temporary high value of grid stopper, like 10K.
Could shorten/shield the grid wiring.
Try a temporary high value of grid stopper, like 10K.