steve williams
Site Founder, Site Owner, Administrator
yes we’ve moved on from the OS1 and TFKN RGN2004 what we have now is truly end game
LampizatOr Horizon - Tube Rolling Paradise
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steve williams
Site Founder, Site Owner, Administrator
Big reveal coming soon. Having said that the TFKN RGN 2004/Klangfilm with mesh plate and special adapter and Tungsram OS1 with adapters is truly superb.
For my system this new change brought me as close to the music as I have ever been. It is spooky real and the new rectifier is a big reason
It is a 2.5A tube which means that it works with a different adapter than the 2 A RGN2004 tube.
Just bought a really cheap but effective emission type tube tester from eBay for testing rectifier tubes. My ultra suave Amplitrex tube tester sadly cannot test rectifiers. This one below can and does a great job. Particularly on Lampi DACs and SETs, rectifiers make a huge difference.
The best rectifier tubes are NOS golden oldies, the Western Electric 274b or 422a. To test these you need something like this Knight 600B, which I paid $200 for on eBay for a fully calibrated model. If you tube roll and you don’t have a tube tester, that’s like trying different tires on your car with no pressure gauge! Testers give you lots of useful data. Of course, every self respecting Lampi owner should spring for the Amplitrex, the Rolls Royce of modern PC testers. You can measure noise and generate response curves. But that’s 3 grand. But guess what? If you buy WE NOS tubes, you can pay a lot more for those!
Of course, real pros use Textronix tube tracers, but those are unobtanium now. They also weigh a ton. The Knight below is a Best Buy.
The best rectifier tubes are NOS golden oldies, the Western Electric 274b or 422a. To test these you need something like this Knight 600B, which I paid $200 for on eBay for a fully calibrated model. If you tube roll and you don’t have a tube tester, that’s like trying different tires on your car with no pressure gauge! Testers give you lots of useful data. Of course, every self respecting Lampi owner should spring for the Amplitrex, the Rolls Royce of modern PC testers. You can measure noise and generate response curves. But that’s 3 grand. But guess what? If you buy WE NOS tubes, you can pay a lot more for those!
Of course, real pros use Textronix tube tracers, but those are unobtanium now. They also weigh a ton. The Knight below is a Best Buy.
steve williams
Site Founder, Site Owner, Administrator
I feel obligated to clarify my post #921. What is paramount for everyone to understand is that a preferred tube set for the Horizon comes down to several things such as one's system. one's room , one's audio preferences etc
Bottom line is there have been countless posts where a tube is offered up as something special but this does not necessarily mean special for all users. One man's passion can be another man's poison. It all boils down to the factors mentioned above.
My system is 100% tubes and I my power is 32 wpc pure class A so my preferences are different than those who have big powerful solid state systems or their rooms are much bigger than mine.
So over the course of the past 4 months I have been playing with alternatives to my initial and much loved preferences. This lead to a complete do over and finally as most here are aware I was able to source all new tubes and for several months was mesmerized by the beauty of the Tungsram OS1, TFN RGN 2004/klangfilm and Mullard Brown base ECC32. Like a post above it really seems that these very old rectifiers are the best performers, and shortly afterwards a new rectifier was found and that lead to a change in OS1. Having said this it is most unlikely that I will part with those tubes in my system as the sound is beautiful. My search lead to a very rare rare and difficult ti find rectifier that in my system and to my ears added just a little more tonal balance as well as timbre and dynamics. These tubes also needed different adapters than used for the RGN as well as the different power tubes I found. Sourcing these tubes has been virtually impossibllle and again the uptick in SQ in my system and to my ears. For those with OS1/RGN 2004 mesh plate I would keep and cherish those. The sound Fromm those is simply superb. What I found is a change that improved my system. Had I never found them I would be eternally happy with the OS1/RGN 2004 and I have kept these as well. The other thing that I have done is based on how I run my Horizon and the scarcity of these very old tubes. I run my Horizon single ended but previously used a quad of pentodes. Finding back ups was almost impossible. So I started using only a set of OS1 as well as the new tube I use now. Took the OS1 out of the right bank pentodes and filled the right side with my TS KT 170. This allows me an extra back up for OS1 as well as the other tube I found. I normally buy a quad with a quad backup but by using only a pair in the left bank it allows me to have more back ups
Finding the rectifier has proved a daunting task and that is why I said I am not prepared to mention this tube until I find a suitable back up. I found the rectifier recently in Scandinavia but that has been the only one so far
So please take my comments as being specific to all factors mentioned above. Bottom line is I would not be rushing out to sell your OS1/RGN as the sound is simply beautiful.
Bottom line is there have been countless posts where a tube is offered up as something special but this does not necessarily mean special for all users. One man's passion can be another man's poison. It all boils down to the factors mentioned above.
My system is 100% tubes and I my power is 32 wpc pure class A so my preferences are different than those who have big powerful solid state systems or their rooms are much bigger than mine.
So over the course of the past 4 months I have been playing with alternatives to my initial and much loved preferences. This lead to a complete do over and finally as most here are aware I was able to source all new tubes and for several months was mesmerized by the beauty of the Tungsram OS1, TFN RGN 2004/klangfilm and Mullard Brown base ECC32. Like a post above it really seems that these very old rectifiers are the best performers, and shortly afterwards a new rectifier was found and that lead to a change in OS1. Having said this it is most unlikely that I will part with those tubes in my system as the sound is beautiful. My search lead to a very rare rare and difficult ti find rectifier that in my system and to my ears added just a little more tonal balance as well as timbre and dynamics. These tubes also needed different adapters than used for the RGN as well as the different power tubes I found. Sourcing these tubes has been virtually impossibllle and again the uptick in SQ in my system and to my ears. For those with OS1/RGN 2004 mesh plate I would keep and cherish those. The sound Fromm those is simply superb. What I found is a change that improved my system. Had I never found them I would be eternally happy with the OS1/RGN 2004 and I have kept these as well. The other thing that I have done is based on how I run my Horizon and the scarcity of these very old tubes. I run my Horizon single ended but previously used a quad of pentodes. Finding back ups was almost impossible. So I started using only a set of OS1 as well as the new tube I use now. Took the OS1 out of the right bank pentodes and filled the right side with my TS KT 170. This allows me an extra back up for OS1 as well as the other tube I found. I normally buy a quad with a quad backup but by using only a pair in the left bank it allows me to have more back ups
Finding the rectifier has proved a daunting task and that is why I said I am not prepared to mention this tube until I find a suitable back up. I found the rectifier recently in Scandinavia but that has been the only one so far
So please take my comments as being specific to all factors mentioned above. Bottom line is I would not be rushing out to sell your OS1/RGN as the sound is simply beautiful.
Pentode Update; EL50 (Tesla 4654, Tungram OS1/18/600, and SFP P17c) and EL51
When I learned about the 4654 from Goran in post #776 in this thread, I started to explore these pentodes in earnest. The first question I sought to answer was whether the Tesla 4654 and the Tungram OS 1 (which also goes by the variant name OS18/600) were indeed the same tube. It turns out that there was quite an incestuous relationship between the Philips tooling which was used both by Tesla (Czech) and Tungram (Hungary) for this 6.3V pentode. If appears that for all practical purposes they were indeed a highly similar if not identical tube. This was discussed in my post #860. Having learned to pay attention to Goran’s thoughts on tubes, I decided to try the 4654 to begin, but couldn’t do so because my shelving height could not accommodate their height, which is considerably taller than my Mullard xf2 EL34’s. I was also interested in trying the even taller EL-51’s (kindly loaned to me by @dminches) and in order to try either, it turned out that a “shelfectomy” had to be performed, which finally occurred last month.
Although I was more than pleased with my xf2’s, it was only after Goran’s encouragement last fall that I tried the famed Bendix 6384 which described in post #619. To summarize,, it was the first pentode that made me aware than there was room for improvement in the bass compared to the Mullard xf2, but unfortunately, it did not have that magic midrange of the xf2, which I continued to use to the present. Now, along comes the 4684, a tube that surprised me in that it had the bass tautness and extension of the 6384 while providing the musical midrange that I love in the xf2. Overall the bass from the 4654 is more in the “same time zone” on low bass transients and a tiny bit fuller than on the EL34 but with excellent definition. Left hand piano never sounded so damned good. That was my assessment on the Bendix as well but the midrange just didn't have the same suppleness as the EL34. The 4654 does. I can't find a weak spot. It just seems to get out of the way more so the ECC32 can do its thing even slightly better than it does with an xf2, if that makes any sense. It wasn’t easy to find as tube that made me retire the xf2, which has vanquished all challengers for well over a year, but listening over the past month seems to have supported that decision.
It might be useful to mention that I found that the EL-51 was also a tube that had superb bass performance. As I told David about a month ago “I've been listening to the EL-51s for a few days. No question these are formidable tubes. To begin, they are a lower distortion tube at high output than the EL-34 so their sense of "control" is exceptional. They are also quite linear, especially in the lower bass through mid bass. That is an obvious strength of this tube. With the limited listening I've done, my sense is that its worth doing a more prolonged evaluation. At this point, I would say that if I listened mainly to rock, these might be my pentode of choice. However, the issue for me is whether they can deliver the sound I seem to enjoy from the Xf2 on the piano and orchestral material”. Since then, I’ve favored the 4654’s overall because of its ability to reproduce piano and symphonic music a bit more to my liking, but I can easily see why its David’s preferred pentode.
Before moving on, I’ll say that I have not had the opportunity to hear an OS1 (OS18/600). If anyone is a generous as David and would consider loaning me a pair, I’d certainly be most appreciative.
Finally, I went on to buy a tube that you had to read between the lines of Goran’s post #776 to figure out was worth exploring as it hasn’t really talked about it very much although he did indeed show some beautiful pics of this exceptionally well-made tube which is the French SRF P17c's . Some ads have called it a "4654 killer" although that was simply hard to believe as the 4654 and (I presume) the other EL50 Philips counterparts described above, are damned impressive tubes! But as we say in the lab, that’s why you do the experiment. Fortunately, we all know how to do listening experiments!
Let me cut to the chase. The SFR P17c is currently my preferred pentode, if only by a tiny bit over the Tesla 4654. Yes, YMMV and all that stuff but for me, it proves just a smidge more palpability which better translates to “realism” for me in my system. 4654 ‘killer’? Hardly, but a damn fine tube in any case, for me. Both its musicality and its “palpability” were Goran’s initial descriptive attributes (in fact, pretty much his only comments!) and I concur completely. If I had to score the Tesla 4654 on an overall satisfaction scale as “95” I would give the SFR a 96+. I thought it had excellent bass, a gorgeous midrange and it makes music sound very compelling and believable. It passed my “does a Steinway sound like a Steinway?” test with flying colors. Gorgeous timbre and that elusive palpability is a hard combination to beat. A recent ad described the tube this way:
"The P17C is a power/output pentode tube that delivers rich and powerful sound quality. It's designed specifically for audiophiles who prioritize musicality in their equipment. With a robust construction and high-quality materials, this tube provides excellent performance and reliability, making it an ideal choice for demanding applications. Its technical specifications are equally impressive, with high output power, low distortion, and extended frequency response. If you're looking for a premium quality power/output pentode tube, the P17C is an excellent choice."
I intend to live with it for quite some time to come to confirm the long-term satisfaction I think it is eminently capable of providing.
I should add that one of the most attractive things about the 4654 and the P17c is that these are very affordable tubes, with prices in the range of $100 each or less! While not plentiful, they are readily found and available at prices well below the unobtanium level we see for far less substantial and over-hyped candidates. With both the 4654 and the P17c, we can rejoice as we may finally be seeing some pricing sanity in the world of high end audio! You just have to know where to look. And nobody seems to know how to do that better than Goran, who just might be the Benjamin Graham (Warren Buffet’s “teacher”) of value investing when it comes to audio tubes for the Horizon.
When I learned about the 4654 from Goran in post #776 in this thread, I started to explore these pentodes in earnest. The first question I sought to answer was whether the Tesla 4654 and the Tungram OS 1 (which also goes by the variant name OS18/600) were indeed the same tube. It turns out that there was quite an incestuous relationship between the Philips tooling which was used both by Tesla (Czech) and Tungram (Hungary) for this 6.3V pentode. If appears that for all practical purposes they were indeed a highly similar if not identical tube. This was discussed in my post #860. Having learned to pay attention to Goran’s thoughts on tubes, I decided to try the 4654 to begin, but couldn’t do so because my shelving height could not accommodate their height, which is considerably taller than my Mullard xf2 EL34’s. I was also interested in trying the even taller EL-51’s (kindly loaned to me by @dminches) and in order to try either, it turned out that a “shelfectomy” had to be performed, which finally occurred last month.
Although I was more than pleased with my xf2’s, it was only after Goran’s encouragement last fall that I tried the famed Bendix 6384 which described in post #619. To summarize,, it was the first pentode that made me aware than there was room for improvement in the bass compared to the Mullard xf2, but unfortunately, it did not have that magic midrange of the xf2, which I continued to use to the present. Now, along comes the 4684, a tube that surprised me in that it had the bass tautness and extension of the 6384 while providing the musical midrange that I love in the xf2. Overall the bass from the 4654 is more in the “same time zone” on low bass transients and a tiny bit fuller than on the EL34 but with excellent definition. Left hand piano never sounded so damned good. That was my assessment on the Bendix as well but the midrange just didn't have the same suppleness as the EL34. The 4654 does. I can't find a weak spot. It just seems to get out of the way more so the ECC32 can do its thing even slightly better than it does with an xf2, if that makes any sense. It wasn’t easy to find as tube that made me retire the xf2, which has vanquished all challengers for well over a year, but listening over the past month seems to have supported that decision.
It might be useful to mention that I found that the EL-51 was also a tube that had superb bass performance. As I told David about a month ago “I've been listening to the EL-51s for a few days. No question these are formidable tubes. To begin, they are a lower distortion tube at high output than the EL-34 so their sense of "control" is exceptional. They are also quite linear, especially in the lower bass through mid bass. That is an obvious strength of this tube. With the limited listening I've done, my sense is that its worth doing a more prolonged evaluation. At this point, I would say that if I listened mainly to rock, these might be my pentode of choice. However, the issue for me is whether they can deliver the sound I seem to enjoy from the Xf2 on the piano and orchestral material”. Since then, I’ve favored the 4654’s overall because of its ability to reproduce piano and symphonic music a bit more to my liking, but I can easily see why its David’s preferred pentode.
Before moving on, I’ll say that I have not had the opportunity to hear an OS1 (OS18/600). If anyone is a generous as David and would consider loaning me a pair, I’d certainly be most appreciative.
Finally, I went on to buy a tube that you had to read between the lines of Goran’s post #776 to figure out was worth exploring as it hasn’t really talked about it very much although he did indeed show some beautiful pics of this exceptionally well-made tube which is the French SRF P17c's . Some ads have called it a "4654 killer" although that was simply hard to believe as the 4654 and (I presume) the other EL50 Philips counterparts described above, are damned impressive tubes! But as we say in the lab, that’s why you do the experiment. Fortunately, we all know how to do listening experiments!
Let me cut to the chase. The SFR P17c is currently my preferred pentode, if only by a tiny bit over the Tesla 4654. Yes, YMMV and all that stuff but for me, it proves just a smidge more palpability which better translates to “realism” for me in my system. 4654 ‘killer’? Hardly, but a damn fine tube in any case, for me. Both its musicality and its “palpability” were Goran’s initial descriptive attributes (in fact, pretty much his only comments!) and I concur completely. If I had to score the Tesla 4654 on an overall satisfaction scale as “95” I would give the SFR a 96+. I thought it had excellent bass, a gorgeous midrange and it makes music sound very compelling and believable. It passed my “does a Steinway sound like a Steinway?” test with flying colors. Gorgeous timbre and that elusive palpability is a hard combination to beat. A recent ad described the tube this way:
"The P17C is a power/output pentode tube that delivers rich and powerful sound quality. It's designed specifically for audiophiles who prioritize musicality in their equipment. With a robust construction and high-quality materials, this tube provides excellent performance and reliability, making it an ideal choice for demanding applications. Its technical specifications are equally impressive, with high output power, low distortion, and extended frequency response. If you're looking for a premium quality power/output pentode tube, the P17C is an excellent choice."
I intend to live with it for quite some time to come to confirm the long-term satisfaction I think it is eminently capable of providing.
I should add that one of the most attractive things about the 4654 and the P17c is that these are very affordable tubes, with prices in the range of $100 each or less! While not plentiful, they are readily found and available at prices well below the unobtanium level we see for far less substantial and over-hyped candidates. With both the 4654 and the P17c, we can rejoice as we may finally be seeing some pricing sanity in the world of high end audio! You just have to know where to look. And nobody seems to know how to do that better than Goran, who just might be the Benjamin Graham (Warren Buffet’s “teacher”) of value investing when it comes to audio tubes for the Horizon.
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steve williams
Site Founder, Site Owner, Administrator
If you like the p17c you’ll love the OS1. The P17c surfaced from our source in France when the OS1 dried up. They are very similar but OS1 apparently is preferred. I stuck with the OS1
There’s no point to talk about it. There is no adapter for the SRS on the market. I’ve asked the guy on ebay who makes all the adapters. He said he can’t make it. There are no new production parts to built it. The only way is to make one is to find old adapters and use the sockets. They are very rare and expensive. The other problem is finding a matched quad.
steve williams
Site Founder, Site Owner, Administrator
steve williams
Site Founder, Site Owner, Administrator
The tubes I replaced the OS1 and RGN2004 with have plenty of meat on the bone. I do agree with the post that the very oldest rectifiers are the best sounding
steve williams
Site Founder, Site Owner, Administrator
I've also read about the RGN that people are using. To my ears the very best is the 1934 Telefunken RGN 2004 mesh plate with Klangfilm 75301some are using solid plate RGN 2004 and some using other than RGN2004
I remain completely mesmerized by the glow caused by this tube when it is powered on
I remain completely mesmerized by the glow caused by this tube when it is powered on
steve williams
Site Founder, Site Owner, Administrator
There are many different shapes of the RGN 2004 as well . All make a difference IMO
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