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24.137.243.96
Hi to all. Do these rectifiers give warnings or symptoms they need to be replaced or is it sudden death? Thanks.
Follow Ups:
If tube is defective or there are issues with the PSU or output section.
Otherwise, loss of bass transient response or dropping B+ could be signs the rectifier is getting old & weak.
IME, good US made vintage 5Y3GT types last the longest. US made 5U4GB. Then Mullard-Philips GZ34. For some reason, the small 9-pin EZ80 and EZ81 seem to have shortest life (maybe too much demand by the unit).
I have used the Mullard GZ34 extensively and after a few thousand hours they still measure and work as new. Even more so with the metal base, that never seem to wear out. On those, I have 2 that have many 1000's of hours of use and still measure and work as new.
iBasso DX100,DX50 DX90. Chord Hugo. HiFiman 901s balanced. RSA Intruder, The Lightning. Fostex TH900 balanced, HE1000, HE-6, 560, 500, JH13 Pro balanced. Lyr2, Audeze. Balanced mostly with Whiplash cables. Photo gallery: www.pbase.com/jamato8
With the 9-pin EZ80 and EZ81, the same 6.3v heater supply is often used for other tubes and grounded. The resulting heater to cathode differential in these rectifiers stresses out the tube and causes shorts.
Thanks! Is this true with the 6VDC octal rectifiers? Like the 6X5?
Guess the best thing to do is lift both legs of the heater lines off ground --- run twin heater leads.
The 6X5s that I mentioned in another thread are powered in that manner. They have a filament winding that's separate from the other tubes.
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Buy Chinese. Bury freedom.
Vidal
It can cause an oscillation if there are issues with the tube.In your preamp you emailed me about,the biggest issue I had on the Suprateks are broken wire connections on the function switch..Look closely and you may see a solder connection that came loose on the switch..I meant to email you back but I just got back.
You need to do this as well.Go up to the 5881 regulator tubes and see if you have 305vdc in pin 3..If you don't,readjust the pots in the regulator until you get 305vdc.
"For every complex problem there is an answer that is clear, simple, and wrong" H. L. Mencken
Edits: 07/19/16 07/26/16
"the biggest issue I had on the Suprateks are broken wire connections on the function switch..Look closely and you may see a solder connection that came loose on the switch"
Do those issues appear to be factory defects? That's unforgivable for a unit in the Supratek price range.
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Buy Chinese. Bury freedom.
Jack
The problem with them in a sense is a factory weakness out of a very fine preamp..I do a lot Supratek upgrades and repairs..I actually have all the schematics to the units but the function switch is turned and works itself loose and if you don't retighten it,it tweaks on the solid stranded wire which connects to the switch.I put a special washer in to lock the switch down and change some of the wires that could potentially become brittle..It is a first rate preamp tho.
The other issue I have,if any of them use battery bias in the phono stage cathodes,I remove it and put a resistor in its place because it causes oscillation as well.The 1.5v battery used for the negative voltage on some tubes,you leave that alone.
"For every complex problem there is an answer that is clear, simple, and wrong" H. L. Mencken
Edits: 07/20/16
Michael Samra, may I have your contact info for future reference in case I ever need work on my Supratek, that is if you are still accepting work.
Don't all rotary switches now have a mechanism to prevent rotation if the nut isn't properly torqued down? Either a D shaft or a pin that protrudes through the panel? In any event, this is an indicator that they weren't paying attention to details when designing the gear. That's the problem sometimes with small companies. You're at the mercy of the often limited experience of one or two engineers. Things look good, but they fail later.
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Buy Chinese. Bury freedom.
You are right they do,but this was only on a couple early models of the Chenin and the cortese
"For every complex problem there is an answer that is clear, simple, and wrong" H. L. Mencken
maybe some low voltage on the B+ and MAYBE some difficulty biasing. Otherwise they just blow. But if never hurts to put in a new fresh rectifier tube every few years.
My experience with rectifiers in general is that they tend to work fine, right up until they don't.
Edits: 07/19/16
As long as the vacuum is maintained, the filament/heater is intact, and sufficient thermionic electrons are produced, little (if anything) can go wrong in a rectifier.
When emission falls too far, the tube needs replacement. Many a 5AR4 has worked well for 20+ years.
Eli D.
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