I thought it was funny.....answer drumsticks....once!
I was a firm believer that the rectifier didn't matter, within reason, except in a guitar amp. Of course you might hear a difference with tubes that affect the B+ voltage, or supply stiffness. This might be the case with mesh VS non mesh versions of the same tube due to higher dynamic resistance of the mesh version.
About 10 years ago I built a custom headphone amp for a customer with strong opinions about what sounded right. He drove 250 miles each way twice to hear the amp in the design stages so he could pick out components. He wanted everything tested with his tubes. He had a few NOS Mullard 5AR4's and claimed that they made a big difference in the sound. The headphone amp was based on a TSE design with #30 output tubes and about 180 volts of B+.
I set up a test with the listener and in the next room with the headphone cable run under the door. All tube swapping was blind, the listener didn't know which tube was being used. First up the customer was the listener and I was the tube roller. The customer did not know what tubes I added to the mix including two of his Mullards. They were Sovtek, Shuguang, RCA and Sylvania. The first test was all done with his music choices, some vinyl and some CD's, mostly vocal and Jazz. He reliably picked out his Mullards EVERY time, about 10 tries of about 1 minute each. The second test was the same except I picked the music, vocal, jazz, rock, and techno. He missed once out of about 10 tries and it was the bass heavy techno music. He also repeatedly picked out the same "garbage" tube, a new Shuguang, yet another Westinghouse branded Shuguang was "OK". A well used RCA branded Sylvania was described ad "good". It was pulled from my own TSE.
The second test I was the listener. After failing to hear much difference, he coached me as to exactly what to listen for, and when. Again I couldn't tell a Mullard from the other "OK" tubes, but could pick the "garbage." Same results with my music.
After the testing was done, I measured the B+ voltage and found it to be about the same in all cases except for the "garbage" tube. It was about 5 volts low. A scope revealed unequal ripple, so one cathode was a bit weak.
In conclusion, some people can hear rectifiers, I can not unless they are obvious. The customer was very happy with his custom amp. He gave me one of his used Mullard 5AR4's since my own TSE sounded "much better" to him with it installed. After about a week, I stuck my trusty Sylvania back in since I am running a 100uF input cap (320 volts B+) and I didn't want to toast an expensive tube. The amp still has the Sylvania in it. I have taken the Mullard with me when I show the amp off to audiophiles. Most people can't identify the Mullard when they don't know which one I install, but they can if they see me swap tubes!
Do some really think that mesh plate rectifiers will give the more transparent sound? Cause they can see the filaments through the transparent plates? Do they think that they're able to separate both mesh and solid plated rectfiers validly only by the sonic qualities of a specific amp? Do they really claim they're able to hear the grass grow?
I think the best rectifier is the one you don't hear at all. And this one, most probably, is silicon based.
Best regards!
I think the best rectifier is the one you don't hear at all. And this one, most probably, is silicon based.
Best regards!
It´s funny with those saying different components sounds different, but in a real blind test they never can pick the favorite out of, opposed to as they say inferior parts. This is true in evaluating all sorts of discrete components, such as capacitors, cables, be it interconnects, signal or power cables and even output transformers. Only when the signal level is influenced, as with rectifiers then almost everybody says that the test with an (very) small elevation of the volume always sounds better. All this when they don´t know which component that they are listening to. That´s why audiophiles don´t like blind tests, the tests always shows that theire opinion of what sound best is pure BS 
Hello Andy
Some very nice Pictures for you. First the R... Series:
Die RGN - Typen
And the A... Series:
Die AZ-Typenreihe
Even when the sound of the Mesh-types is not better, they are so beautyful on top of any amplifier.
Best regards
Michael
Well, I took the plunge and bought an Emission Labs 274B mesh plate for my 26 preamp/DAC. I have rolled many different rectifier types over the last few years: 5AR4, GZ33, 5R4GY, 5R4 potato masher, 5U4G, 5U4GB, 6106, 5Y3GT, 5Y3G, Valve Art 274B are the ones I can remember off-hand. My favorite has been the Sylvania 5Y3G for the last year or so; clean, clear, detailed, perhaps slightly lean but not too much.
Well, the EML274B mesh is a cut above the 5Y3G. I'm surprised there is such a difference! The EML is at once more detailed, yet fuller sounding, with more 3-D soundstage, airier highs and deeper punchier bass. It baffles me, being more of an objectivist, but the difference is there.
Even more amazingly, the 26 has a CCS/VR tube shunt regulator in front of it, and a CCS-loaded plate (although I use the mu output of the CCS from lower Z, so less isolation)! That ought to isolate it from the PS, but I still hear the change...PS is critical choke input, BTW.
Now, the 274B gives about 5V higher B+ than the 5Y3G (simulated in PSUD) so perhaps that has something to do with it, but the regulator drops that from about 280V to 225V before the 26 plate CCS. Or perhaps the mesh plate is damping PS ultrasonic resonances, resulting in a smoother-sounding B+. Or maybe it's the higher dynamic resistance of the mesh. I'm not sure why it makes a difference, but I like it! It's staying.
Well, the EML274B mesh is a cut above the 5Y3G. I'm surprised there is such a difference! The EML is at once more detailed, yet fuller sounding, with more 3-D soundstage, airier highs and deeper punchier bass. It baffles me, being more of an objectivist, but the difference is there.
Even more amazingly, the 26 has a CCS/VR tube shunt regulator in front of it, and a CCS-loaded plate (although I use the mu output of the CCS from lower Z, so less isolation)! That ought to isolate it from the PS, but I still hear the change...PS is critical choke input, BTW.
Now, the 274B gives about 5V higher B+ than the 5Y3G (simulated in PSUD) so perhaps that has something to do with it, but the regulator drops that from about 280V to 225V before the 26 plate CCS. Or perhaps the mesh plate is damping PS ultrasonic resonances, resulting in a smoother-sounding B+. Or maybe it's the higher dynamic resistance of the mesh. I'm not sure why it makes a difference, but I like it! It's staying.
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Telefuken RGN 1064!
I loves those Tele RGN 1064 balloon shaped, mesh plate + inverted 'V' filament. Use in my #26 preamp and sounding smooth and sweet. Whatever one choose to comment, there's no denial that it looks good sitting on the top deck, just like the control tower for a top class airport in Dublai.
I loves those Tele RGN 1064 balloon shaped, mesh plate + inverted 'V' filament. Use in my #26 preamp and sounding smooth and sweet. Whatever one choose to comment, there's no denial that it looks good sitting on the top deck, just like the control tower for a top class airport in Dublai.
The plate voltage of the 26 is regulated with CCS-fed VR tubes (0D3 + 0A3 for 225V), and then the plate current is fixed with another CCS, so the operating point of the 26 should stay the same regardless of the changes in voltage further upstream. That's why I'm leaning toward some sort of noise reduction as being at work here. Interestingly, I once tried swapping in 0C3 and 0B3 VR tubes for the 0A3s, and it had zero effect on the sound, so changes in voltage didn't change the sound then...
The differences between rectifiers isn't huge, and most of them sound pretty much the same. The EML mesh plate does sound a bit better than the others, though. Confirmation bias? Perhaps, but it sure seems real.
The differences between rectifiers isn't huge, and most of them sound pretty much the same. The EML mesh plate does sound a bit better than the others, though. Confirmation bias? Perhaps, but it sure seems real.
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Hello all,
I saw some colleagues were talking about a spark that occur when the system is powered on. I want to share my humble thoughts about this.
1. Never exceed the max. capacitor value in the first position. If on the rectifier's datasheet is written 4uF, use maximum 4 uF, not 6.8 or 10 uF.
2. Every rectifier need a minimum transformer copper resistance in DC per winding (measured from plate to plate).
I learned these from a current tube producer webpage and I don't know if I can put the links here, but I can cite them:
"Note 2) To prevent large charge current peaks, the first capacitor (C1) should NOT be larger than 40uF (My note: they are talking about 5U4, but this rule is generally applicable to all rectifiers, depending on the value of C1 mentioned in the datasheet). If the input capacitor is too large, this will result in heavy AC charge current through this capacitor. This is not good for the rectifier tube, and also not for the capacitor lifetime. The AC capacitor current peaks may cause hum radiation into the preamplifier. With the given C-L-C values in table, the rectifier circuit will work best. For filtering, with oversized components, you will have best results by increasing the choke. Do not oversize capacitor C1, this may increase hum. You can choose the choke large as you want. This will have better results with high voltage rectification.
Note 3) Rectifier tubes may under no circumstance carry larger current peaks as what they are designed for. The current peaks are mainly a function of: power supply DC load, first capacitor and transformer copper resistance. The copper resistance for 5U4G and 5Z3 may not be smaller than 170 Ohms. This is very important to check, and too low copper resistance may damage the rectifier, no matter what brand or construction. Use a small series resistor if the copper resistance of the used transformer is too low. If you scroll further down this data sheet., there is a link to a table with historical information about this, for several rectifier types, not only 5U4G."
Also, please see the attachment to learn which is (for some rectifiers) the minimum copper resistance of the HV secondary measured from plate to plate. Generally this information can be found on the rectifiers datasheets.
Regarding sonic differences between rectifiers, there are a lot of opinions and for sure there are "audiophiles" who appreciate the components and designs which imply the most amount of $$. But, as an amusement, blind test the Russian 5Ц3С grey plate vs 5Ц3С black plate. Please let me know if you hear any difference. We are talking about the same tube with the same characteristics.
Thank you!
I saw some colleagues were talking about a spark that occur when the system is powered on. I want to share my humble thoughts about this.
1. Never exceed the max. capacitor value in the first position. If on the rectifier's datasheet is written 4uF, use maximum 4 uF, not 6.8 or 10 uF.
2. Every rectifier need a minimum transformer copper resistance in DC per winding (measured from plate to plate).
I learned these from a current tube producer webpage and I don't know if I can put the links here, but I can cite them:
"Note 2) To prevent large charge current peaks, the first capacitor (C1) should NOT be larger than 40uF (My note: they are talking about 5U4, but this rule is generally applicable to all rectifiers, depending on the value of C1 mentioned in the datasheet). If the input capacitor is too large, this will result in heavy AC charge current through this capacitor. This is not good for the rectifier tube, and also not for the capacitor lifetime. The AC capacitor current peaks may cause hum radiation into the preamplifier. With the given C-L-C values in table, the rectifier circuit will work best. For filtering, with oversized components, you will have best results by increasing the choke. Do not oversize capacitor C1, this may increase hum. You can choose the choke large as you want. This will have better results with high voltage rectification.
Note 3) Rectifier tubes may under no circumstance carry larger current peaks as what they are designed for. The current peaks are mainly a function of: power supply DC load, first capacitor and transformer copper resistance. The copper resistance for 5U4G and 5Z3 may not be smaller than 170 Ohms. This is very important to check, and too low copper resistance may damage the rectifier, no matter what brand or construction. Use a small series resistor if the copper resistance of the used transformer is too low. If you scroll further down this data sheet., there is a link to a table with historical information about this, for several rectifier types, not only 5U4G."
Also, please see the attachment to learn which is (for some rectifiers) the minimum copper resistance of the HV secondary measured from plate to plate. Generally this information can be found on the rectifiers datasheets.
Regarding sonic differences between rectifiers, there are a lot of opinions and for sure there are "audiophiles" who appreciate the components and designs which imply the most amount of $$. But, as an amusement, blind test the Russian 5Ц3С grey plate vs 5Ц3С black plate. Please let me know if you hear any difference. We are talking about the same tube with the same characteristics.
Thank you!
Attachments
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There are some mesh plate rectifiers with unusual (30V) heaters that can be found for cheap. I have one, but I'm too lazy to dig into my tube stash at the moment. I'm saving this tube for my final build of SE headphone amp. If you insist, I'll search for it.
As for the rectifier's sound signature, overpricing sellers inhibit my wish to give my money away, while I could use it to upgrade much more important parts in the amplifier, such as capacitors, chokes and the output transformer.
So my current "compromised" decision is to use AZ1 or AZ11 solid plate for lower voltage applications and MV rectifiers for higher voltage applications. Both can be found at flea markets for really cheap.
In Sofia, there is an usual Saturday flea market, sometimes there is a lot of TV tubes to be found there, but there is also a lot of competition. You have to go there really early in the morning and constantly walk around like a fly, in case something "octal" drops around.
The greatest flea market that drops gold for the DIY audiophile is the radio hobbyist's one that occurs once per year at the rose city of Kazanlak in June. Exotic stuff drops sometimes, such as mesh plate AZ, lots of TV and transmitter tubes and MV rectifiers in the hundred ampere range and more.
The greatest flea market that drops gold for the DIY audiophile is the radio hobbyist's one that occurs once per year at the rose city of Kazanlak in June. Exotic stuff drops sometimes, such as mesh plate AZ, lots of TV and transmitter tubes and MV rectifiers in the hundred ampere range and more.
Kudo's for pointing out that rectifiers need to be used according to the data-sheet! lots of people don't follow these clear absolute maximums, whit short tube life as a result.
About the prices of tubes, here is my rant.
People dont realize that there are people that hoard this stuff, and they almost never sell anything. The market for tubes has been ruined by this.
Case and point, there was a guy in Holland, when he passed away, the family found out he had a few warehouses full of tubes and tube amps. they spend the better part of two years just sorting out all the stuff he collected.
Furthermore a lot of these collectors are getting old, i suspect that in a few years a lot of this stuff will come to martket. As interest in this old stuff will disappear slowly.
Personally i have a handful of rare rectifiers, I had a crate of used normal AZ1, i sold those for 50-75c each, because i wasn't using them. Philips literally made them for a decade in the millions of units per year.
At the end of the day, it is all obsolete glass and the prices for this are well, fuelled by a-technical lemmings that read wildly subjective texts about the virtues of part X.
About the prices of tubes, here is my rant.
People dont realize that there are people that hoard this stuff, and they almost never sell anything. The market for tubes has been ruined by this.
Case and point, there was a guy in Holland, when he passed away, the family found out he had a few warehouses full of tubes and tube amps. they spend the better part of two years just sorting out all the stuff he collected.
Furthermore a lot of these collectors are getting old, i suspect that in a few years a lot of this stuff will come to martket. As interest in this old stuff will disappear slowly.
Personally i have a handful of rare rectifiers, I had a crate of used normal AZ1, i sold those for 50-75c each, because i wasn't using them.
Philips literally made them for a decade in the millions of units per year. At the end of the day, it is all obsolete glass and the prices for this are well, fuelled by a-technical lemmings that read wildly subjective texts about the virtues of part X.
What annoys me is I suspect korean and chinese companies are buying up a lot of rare tubes speculating. I see rare tubes listed by them on ebay nos trans too for about 5times the going rate no offers. I think they're doing this so greedy sellers see those listings and start pricing theirs higher.
Ten years ago a similar thing happened with aussie muscle cars. Speculators got in on the classic car market and with in ten years they all ended up in garages of filtly elites never to
be owned driven or even seen by the hardworking men and woman thät grew up around these cars. It is how everything nice is going up to the 1% to put in warehouses .Everthing land included.
My advice if you discover a nice tube don't talk about it outside of messaging because the dealers and speculators have google and use it. When I just found this thread my heart sank because I have yet to afford to buy any mesh plates yet.
Ten years ago a similar thing happened with aussie muscle cars. Speculators got in on the classic car market and with in ten years they all ended up in garages of filtly elites never to
be owned driven or even seen by the hardworking men and woman thät grew up around these cars. It is how everything nice is going up to the 1% to put in warehouses .Everthing land included.
My advice if you discover a nice tube don't talk about it outside of messaging because the dealers and speculators have google and use it. When I just found this thread my heart sank because I have yet to afford to buy any mesh plates yet.
I am using the rgn1064 in my dac-outputstage and for the driver stage of my power amp in Mesh-Version.
They play with 100ohm at each anode into 22H choke-input with again 80ohm followed by a 50uF followed by LC again...(40H, 800ohm, and 100uF)...DC is just like 16mA needed...
So no heavy condidtions and perfectly with the specs of the data sheet...and it gives me the very nasty white sparks in the first second of switching on.
The Amplifier tubes (e182cc) are preheated to save their lifes a bit.
Someone in a different forum wrote that the Mesh-Types, especially the rgn1064 etc are far, far lower in specs than what the data sheet says. So, any experience on that ?
The only solution I found so far is: Take a large 5k resistor before the first choke, switch the PSU on, after a few secs, bypass the 5k resistor with a switch.
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