henry4841

Going to plug-in SS rectifier when you amplifier was designed for tube rectification is not something I would recommend without checking, changing the bias of your amplifier either yourself or using some electronic geek or shop. Chances are, if your amplifier is biased conservatively you will be OK but the only way to be sure is by doing some testing. Using a plug in SS rectifier is going to increase the voltage on your rails a considerable amount, 30 to 40v's.

I deleted more info on my previous post after you made your post with ??? being I do not believe you really want more info on this subject from me. What I posted with the video is not something that concerns an audiophile because the effect mentioned in the video is not something you will hear or should be concerned about. I think your question mark post was just something personal for some reason against me. Sorry, it is just the way I feel.

I ran across this video from a guy I respect, along with many others, on youtube who in the video declares that SS rectification is the way to go. There are some other videos with more details on what he found to be the differences in SS vs tube rectification. One thing I picked up from this video is he measured a significant voltage drop on a tube rectifier when the amplifier produces more power which in turns lowers the voltage to the power tubes reducing the power. Not something one particularly desires in a hifi amplifier. Personally I favor SS today, might change opinion later, because of the extra voltage one has to work with. This is if one considers higher voltages a plus. https://www.youtube.com/watch?v=ietxiWXVNNo

That's it.

You are to be commended for doing real world test and not just simulations on some software which is what one mostly sees on forums these days.

Not sure, I was afraid something was wrong with tubes or amp when I first noticed the pretty blue glow.

Probably has to do with SS amp and not speakers. You may want to swap the leads at the speakers and see how that sounds. Put positive on neg and neg on positive on both speakers. It's technical but give it a try and see how it projects the sound that way.

CL-90 I hope is one of them since that is what I use.

Yes I have but I had my doubts of having enough current to run tubes. Especially 4 of them. Modjeski claimed to run PP EL-84's at half dissipation creating 40 watts running 720v's on the plates. It is fascinating to me when most only expect a lot less from a PP EL-84 amplifier. Playing with over 700v's is not something I really feel confident doing. My field was always repair work and not designing. All SS until a few years ago.

I do not think I have ever worked on anything with a voltage doubler, at least I did not recognize it as such. After some reading, very little time spent, there is a question. Will there be enough current to operate all the tubes using a voltage doubler for a high voltage source. From what I have read a voltage doubler is limited on the current potential.

Voltage doubler, simple. I still would not advise using one of those SS rectifiers gadgets in place of rectifier tube without biasing your output tubes for the extra voltage which can be quite large. If your amplifier is conservatively biased it should not be a problem but if not you could damage some tubes or at least shorten their life expectancy. On my KT-88 amplifier I have been experimenting with I raised the cathode resistor value to lower the plate dissipation to a more safe value when I installed the $5 SS rectifier gadget which is as Nick said no more than two 1n4007 diodes.

They glow a pretty blue don't they. I really like the sound of those tubes too. Found googling a while back "a fluorescent glow in the blue spectrum." being the reason.

That blue glow is nice. Some tubes do that. The first time I saw a tube do that I was afraid something was not right. Found out it is just a nice touch tubes have at times.

Thanks for pointing this out. Then I should be fine without reducing the voltage, current in my g2 at 8ma. With 420V's and 8ma current if my math is correct I am running 3.36w and should be alright on Electro Harmonic KT-88's rated at 6.6w on g2. I cannot see the screen grids inside of these tubes to see if there is any glowing. Typical ma on data sheet says 7ma which was what I was looking at. I have been experimenting with higher voltages on plates but being careful of g2 which is the main problem of higher voltages. Modjeski and Anderson both like higher voltages on plates but Modjeski took it to the extreme using 720V's on EL84's, those small tubes. Most plates can take the higher voltages . It is the screen one has to be careful of burning up. Tubes are not cheap anymore. A pair of Electro-Harmonix KT-88's is over $150 now. Modjeski did not say how he reduced the V on the screen grid but adding a regulated screen could be possible the way he did it. I may at some time use 700+v's but first I would like to see how using just a resistor looks like on scope and distortion software before abandoning using just a resistor for simplicity sake. I like to keep things simple a much as possible. Dealing with designing a high voltage regulated g2 supply is not something I relish doing. We are getting away from the original OP topic of rectifier rolling so perhaps we can start another thread and continue this discussion. I would like to see what you come up with for reducing the voltage on g2 using higher voltages on the plates. With higher voltages one has more voltage swing for the signal to operate in. Modjeski's point. He got 40 watts output from a PP EL-84 amplifier where 17.5w is more common in a PP EL-84 amp.

I was talking about when designing a new amplifier I am only going to use SS rectification from now on. I do not know what you problem is but carry on. It appears you do much the same as you do here on other threads as well. One way to avoid this is to just ignore all my postings. Make things much more pleasant on this forum. I just have a hard time understanding what your point is after saying above you have both SS and tube rectified amplifiers. Are you trying to say you prefer one over the other or is it just wanting someone to attack is what you are after.

On another tube thread I mentioned one of those SS replacements for a rectifier tube wanting to know what members thought of them. I decided to do some test and see just how much the voltage is increased when installing one of those SS tube gadgets in place of a rectifier tube. I would not recommended it because there is a considerable voltage increase. At least in my SE KT-88 amplifier. The K to P voltage in this amplifier increased from 388V to 421V which means the current is going to increase as well raising the wattage of the tube. Chances are the tube can handle this increase if you do not see any red platting but it will decrease the life of the tube. The part that concerned me though was the screen grid current. The max screen grid current of my tubes ,Electro Harmonix KT-88's increased to a little over 8ma when the tube is rated at 7ma max. I lowered this to 6.5ma on my amplifier before I listened to my amplifier to see what if any the improvement of using SS rectification in place of a tube. Chances are one would not have a tube failure installing one of these replacement SS rectifier gadgets but tubes are too expensive these days for me to take a chance. What all this amounts to is in my opinion I would use what the amplifier is designed for and not replace a tube rectifier with one of the SS gadgets without making some adjustments in the bias and screen grid circuits. Just to be safe without having someone doing some adjustments for the increase in voltages. Stick with what the designer intended your amplifier to rectify with.

Just heard about his passing. He sure could bring a crowd alive.

...

Love this one! A woman decided to give herself a big treat for her 70th birthday by staying overnight in a really nice hotel.. When she checked out the next morning, the desk clerk handed her a bill for $250.00.  She demanded to know why the charge was so high "I agree it's a nice hotel, but the rooms aren't worth $250..00 for just an overnight stay - I didn't even have breakfast!"  The clerk told her that $250.00 is the 'standard rate,' and breakfast had been included had she wanted it.  She insisted on speaking to the Manager. The Manager appeared and, forewarned by the desk clerk, announced: "This hotel has an Olympic-sized pool and a huge conference center which are available for use."  "But I didn't use them."  'Well, they are here, and you could have." He went on to explain that she could also have seen one of the in-hotel shows for which they were so famous."We have the best entertainers from the world over performing here."  "But I didn't go to any of those shows.."  "Well, we have them, and you could have."  No matter what amenity the Manager mentioned, she replied, "But I didn't use it!" and the Manager countered with his standard response.  After several minutes discussion, and with the Manager still unmoved, she decided to pay, wrote a check and gave it to him. The Manager was surprised when he looked at the check.  "But Madam, this check is for only $50.00"  "That's correct I charged you $200.00 for sleeping with me."  "But I didn't!"  "Well, too bad, I was here, and you could have."

Inflation, price increase of new Heritage speakers, and limited supply for sale is a big part of the reason for rising prices of Heritage speakers. For decades old LaScala's sold in the neighborhood of $500 a pair. Price has steadily risen the last decade or so. Having bought my LS's in 86 the price increase only makes me smile even though I have no intention of parting with them.

Friend this is not my thread. I just posted what little I know about rectification when it comes to tube circuits. You seem to be the one who has nothing to contribute to the thread other than negative comments. This is what you said that you have since deleted. It is obvious that you are not a tube guy but just wanted to express your opinions of tubes in general which is fine. Let's just get over it and move one. Regulars 1.7k Posted 1 hour ago