Yes Nelson, I understand. I'm sorry, I am not helping you helping me...
I cleaned the board before that post. To much in a hurry.
Ok. I have the board in front of me. Nutubes are up, (in the head). Trimmers are down, (in the feet). I can read the inscriptions on the board.
There are 4 groups for fets. I used those the holes that are "UP".
For example, in the group at the left side of the Nutubes I used the holes that are closer to the 10μf cap. Hope this is clear.
In the groups near the trimmers I used the holes that are closer to the 1000μf caps.
I cleaned the board before that post. To much in a hurry.
Ok. I have the board in front of me. Nutubes are up, (in the head). Trimmers are down, (in the feet). I can read the inscriptions on the board.
There are 4 groups for fets. I used those the holes that are "UP".
For example, in the group at the left side of the Nutubes I used the holes that are closer to the 10μf cap. Hope this is clear.
In the groups near the trimmers I used the holes that are closer to the 1000μf caps.
That's clear. You used the right holes.
I guess we proceed with replacing Fets.
Ok, I'm ready.
Hi, sorry for butting in earlier. Could my T8 voltage instability be a consequence of a defective Nutube? Seek advice as to seeking a replacement Nutube or could this be caused by something else?
Attachments
Now I wanted to ask something that seams to be out of topic, but it is related, anyway.
I am building a Aleph3 amp. I don't know if that's the best Aleph amp to my speakers, wich are Eikona drivers in a VTL transmission line. I wanted to build a F5, but I choosed the 3 because I have already a very nice case with two good psu's inside, generating 24 "symetric" volts. Is the F5 better? I don't know, but I ting that I Will like the 3. Is it well matched to my speakers? These 86 or 87db drivers are easy to drive, nevertheless. I had a 210 - 8w Verdier with them with wonderful results.
My fear is that there is no cap in this system. Is it dangerous?
I bought the kits with the boards in ebay, (they are not available in the diyforum!!), but I think they are good, I think I can trust the seller. The layout is exactly the same as originals, anyway.
The kits come with nice parts, but I bought better resistors, (rn55), one of my favourites, and Elna Silmics. I love these caps and I read that Mr Nelson Pass loves them too, so I must have done a good choice.
My question is if this amp (electrically) matches the Nutube buffer.
I idealised a system with the Soekris dam1921 dac, Nutube preamp with 10k resistor vol control, Aleph3 and Eikonas. I think this will be coherent, but I would like to have a litle comment if some of you feel like it. Later, I may replace the vol control by a LDR preamp.
Thanks!
I am building a Aleph3 amp. I don't know if that's the best Aleph amp to my speakers, wich are Eikona drivers in a VTL transmission line. I wanted to build a F5, but I choosed the 3 because I have already a very nice case with two good psu's inside, generating 24 "symetric" volts. Is the F5 better? I don't know, but I ting that I Will like the 3. Is it well matched to my speakers? These 86 or 87db drivers are easy to drive, nevertheless. I had a 210 - 8w Verdier with them with wonderful results.
My fear is that there is no cap in this system. Is it dangerous?
I bought the kits with the boards in ebay, (they are not available in the diyforum!!), but I think they are good, I think I can trust the seller. The layout is exactly the same as originals, anyway.
The kits come with nice parts, but I bought better resistors, (rn55), one of my favourites, and Elna Silmics. I love these caps and I read that Mr Nelson Pass loves them too, so I must have done a good choice.
My question is if this amp (electrically) matches the Nutube buffer.
I idealised a system with the Soekris dam1921 dac, Nutube preamp with 10k resistor vol control, Aleph3 and Eikonas. I think this will be coherent, but I would like to have a litle comment if some of you feel like it. Later, I may replace the vol control by a LDR preamp.
Thanks!
if you done everything as prescribed and you have stable voltage at T4, point B, same as across R1 , then tube is in question
Aleph is simple to set just few things and that's it
F5 is trickier (last and most versatile iteration with P3) to set, and you need to have THD spectra measuring setup
generally , Aleph is more romantically sounding than F5
both will drive your speakers well , if they're easy , as you said
Aleph is simple to set just few things and that's it
F5 is trickier (last and most versatile iteration with P3) to set, and you need to have THD spectra measuring setup
generally , Aleph is more romantically sounding than F5
both will drive your speakers well , if they're easy , as you said[/QUOTE]
Hi Zen Mod
What do I need to measure THD?
It's time to make an upgrade in my diy arsenal and take a step up in my autonomy.
Oscilloscope? Can you suggest one not very expensive?
Accurate. Not to complex. Thanks.
F5 is trickier (last and most versatile iteration with P3) to set, and you need to have THD spectra measuring setup
generally , Aleph is more romantically sounding than F5
both will drive your speakers well , if they're easy , as you said[/QUOTE]
Hi Zen Mod
What do I need to measure THD?
It's time to make an upgrade in my diy arsenal and take a step up in my autonomy.
Oscilloscope? Can you suggest one not very expensive?
Accurate. Not to complex. Thanks.
For THD spectra most use a PC with external sound card and some free software that can interface to the soundcard.
The BA3-pre thread is good to look at as BA3-pre also has a "P3".
Oscilloscope is a good thing but not for THD spectra. The cheap digital oscilloscopes can do spectrum analyzing but resolution is to poor for any real use.
The BA3-pre thread is good to look at as BA3-pre also has a "P3".
Oscilloscope is a good thing but not for THD spectra. The cheap digital oscilloscopes can do spectrum analyzing but resolution is to poor for any real use.
If you can find a fine (calibrated) used Tektronix 2225 for let us say 150 USD (incl. two original Tektronix probes) it is very nice for audio. It is one of the old analog scopes so it is bigger than modern digital scopes. I think you get more for the money than one of the cheaper digital scopes. But others may have another opinion. Tek 2225 has a x10 on vertical resolution so it goes to 0.5 mV/div which is quite good for a cheap scope.
There's an active thread on this now: Howto - Distortion Measurements with REW
You didn't mention your price range, but I believe the Rigol DS1054Z is well regarding by many as a good entry level oscilloscope if you're looking to buy new. Amazon has it for $375