Forums https://www.decware.com/cgi-bin/yabb22/YaBB.pl EQUIPMENT FORUMS >> SE84UFO >> rectifier,274B https://www.decware.com/cgi-bin/yabb22/YaBB.pl?num=1372938564 Message started by jameskk on 07/04/13 at 12:49:24

Title: rectifier,274B Post by jameskk on 07/04/13 at 12:49:24 Hi Steve been working up on the marcellas shale (natural gas ) fields . have not had time to send my torii to you. however I want to talk about the 274 rectifier in my superzen which is truly super. the current valve art 274 in the amp is arcing at turn on ,then its fine . I had one(the OEM) do the same in January which I changed to this one. I know you wanted to have feedback on the rectifier tube . there's no sound degradation . and if played everyday,it seems not to do it . just when the amp sits for a couple days . Well only have this day off . So happy 4th of July . Thanks

Title: Re: rectifier,274B Post by jameskk on 12/02/13 at 10:49:33 As nuts as it may seem I am answering myself and finding that  there are some 274B's that are pretty stable even at turn on  with the Superzen. Still the Valve Art 274B tube . So I guess you just have to keep on using (buying) the same 274 until you find one that doesn't arc ,spit and hum ......... So far so good

Title: Re: rectifier,274B Post by will on 12/03/13 at 02:13:32 Jameskk, I can't really answer your question, but I recall Steve's talking about folks trying various 274Bs and having arcing issues, but using them anyway because they like them. He went on further to wonder why his testing of the Valve Art 274B did not present arcing issues, the opinion being...based on the construction similarity to Shuguang/Ruby 5U4Gs, the Valve Art may in fact be a 5U4G for the most part. I don't know where Steve is on this at this point, but since my CSP3 shipped pretty recently with the Valve Art, I am guessing he still likes it. Hopefully he will see this thread and let us know. I also recall a few cases in the forum where others have had Valve Arts that arced....So far I have not had this problem with mine in my Torii MkIII or CSP3 though I tend to roll the rectifiers so they probably don't have loads of hours, but certainly several hundred.

Title: Re: rectifier,274B Post by jameskk on 12/03/13 at 12:04:16 Thanks Will as you can see by my first post around the 4th of July I didn't get any response. Yes these Valve Art 274B do look exactly like the 5u4G with the big bottle on them. the 274 I have in my superzen right now seems to be working without incident and sounds wonderful . Thanks again!

Title: Re: rectifier,274B Post by Lon on 12/03/13 at 13:18:48 Hey James, the Valve Art 274B arced in my CSP2 (first of my Zen preamps) when I was using it. Just as yours it settled down and music wasn't impaired. I just didn't really care for the sound, too big and dry and bold for me. Didn't seem realistic on my reference recordings (made myself, I've played them on everything for over twenty years). When I got Ron Sheldon of cryoset to carry these I tried a cryo'd pair in my preamps and amps, I liked it a bit more, but I still don't like the sound enough to use them. I think they're safe to use. . . . And I understand why people like them. Maybe if I invested a lot of time and money into building a tube set around them. . . but life's too short for that for me when I have great RCA rectifiers that work well with my tube sets and give me the type of sound I like.

Title: Re: rectifier,274B Post by jameskk on 12/05/13 at 10:57:28 Is there a more stable 274B out there  that will work perfectly and last forever. I have been turning on my superzen everyday this last three weeks( construction on the ceiling) with no arching or spitting. so We'll see. Might have to go to a 5u4 which I have a ton of . Thanks for all the comments. Lon ,had a great 5u4 coke bottle RCA come to think of it that worked good!

Title: Re: rectifier,274B Post by will on 12/05/13 at 19:50:52 james, check these out. The first page has comments from Steve, one a quote about mid page and an actual post toward the bottom (at least on my browser settings). https://www.decware.com/cgi-bin/yabb22/YaBB.pl?num=1348719820/0 More here: https://www.decware.com/cgi-bin/yabb22/YaBB.pl?num=1375381799/1#1 and there are segues into the Valve Art 274B in this vast thread, https://www.decware.com/cgi-bin/yabb22/YaBB.pl?num=1316486514/0 I really like them. I also like 50's RCA 5U4STs, some more than others.

Title: Re: rectifier,274B Post by jameskk on 12/06/13 at 11:25:17 Ok , I know where you guys are coming from . I'm finding it very hard to take my only RCA straight bottle 5u4 out of the Superzen . Not because its more extended in the highs ,its not, not because its open and airy, its not. I think ill just get more of these tubes and leave it at that.

Title: Re: rectifier,274B Post by will on 12/06/13 at 17:56:02 James, If you like the 5U4GB (straight bottle), have you tried Raytheons. When I was exploring that tube type, the short bottle RCA was my least favorite...a little slow, thick and dark in my system. A very tall bottle 50's RCA (with inner construction like the ST/coke bottles...no bottom mica) was one of my favorites, balanced, big and open, but depending on what it was with, sometimes "too good." They look like this: http://www.ebay.com/itm/2-x-5u4gb-RCA-Rectifier-Tubes-Tall-Bottle-Black-Plates-3-Pair-Available-/281206339131?pt=Vintage_Electronics_R2&hash=item417934363b And there is something interesting about the Raytheons I tried too...warm and textured but not veiled in my room. Like these: http://www.ebay.com/itm/2-Raytheon-5U4GB-Rectifier-Tubes-5U4-Dual-D-Getters-Black-Plates-Tested-/370859861139?pt=Vintage_Electronics_R2&hash=item5658f86493 The thing I found a little difficult with the GBs was their tendency to bigger/deeper bass than the STs, but I could work with it with other tubes. This is also a tendency of the MkIII though...big bass unless your room is very controlled or sucks it out. All in all these days though, I tend come back to a particular bottom getter 50's RCA 5U4G-ST in my Torii MkIII, and in my CSP3, a GE labeled RCA ST.

Title: Re: rectifier,274B Post by jameskk on 12/07/13 at 11:39:07 Thanks Will looked at all them and purchased a Raytheon to try . The Rca that you find dark and slow is a great thing for single driver speaker that have some SHOUT in their characteristic. I like the tone this tube produces also as compared to the 274B, which I have to thank Lon for. I will also persue the RCA's without the bottom mica. Thanks again

Title: Re: rectifier,274B Post by will on 12/07/13 at 16:31:02 James, I was not clear if your RCA was a short bottle or not, and really, there are bound to be a number of variations of the short RCA 5U4GB. So who knows how close ours are. But assuming they are close, you may not like the tall-tall bottle RCA without bottom mica. This is a very clear and open tube. It does that very well in my system, solid and extended, and open without edginess or hardness, but you may need warmer tubes. The Raytheons will vary also...the one I showed you is constructed like my favorite, with two top/side rectangle getters. I hope it works in your setting. My HR-1s definitely do not have shout, rather, I would guess they are a little on the warm side. Something I like about the GBs is they are generally inexpensive so exploring is easier.

Title: Re: rectifier,274B Post by jameskk on 12/08/13 at 11:15:37 Will, regardless if my system needs warmth I will get one of the RCA's without the bottom mica just to try it. Just have to know the difference. Thanks

Title: Re: rectifier,274B Post by Lonely Raven on 12/08/13 at 17:37:47 Well this is odd - When Steve modified my SE84-A he put a 5U4 in it because he didn't think the 274B would fit. On a whim, I picked up a 274B from Amazon, and it just, barely fits (I had to loosen up the transformer bolts and shift it 1mm). So I've been reading this thread, not really relating to it since I don't have the arcing issue...till this morning. I fired up the amp first thing this morning before making coffee and breakfast, and I was startled by a bright arc at the top of the tube. Everything seems fine after that though.

Title: Re: rectifier,274B Post by jameskk on 12/09/13 at 22:42:20 So your saying the 274 arced at start up then it was fine. this is what most people experience . and are frightened by, a little scary but seems not to hurt anything . Have not heard of any deteriorating either!?!?!???

Title: Re: rectifier,274B Post by Lonely Raven on 12/10/13 at 04:02:25 No bad side effects at all. In fact, the amp has really bloomed lately and sounds the best I've ever heard it in 15 years! I've had the tube in for maybe a month now, it was a cold start since it was early in the morning and I was getting it warmed up so it would be ready by the time I had coffee and breakfast in front of me. Just the opposite of the warm start arc mentioned above.

Title: Re: rectifier,274B Post by jameskk on 12/10/13 at 11:52:47 In an earlier post I said if you don't turn the amp on every day and leave the amp totally off for a few days the 274 tends to arc, having something to do with seeing a higher value cap in the power supply. Makes sense since the capacitors do charge down after a couple of days.

Title: Re: rectifier,274B Post by jameskk on 12/15/13 at 20:40:06 Will and Lon Thanks for the RCA 5u4 recommendations, and the GE  6BQ7 in another post by Riveiraranch. try these together.

Title: Re: rectifier,274B Post by jameskk on 04/19/14 at 19:48:43 I have gone back to the MIC made in china 5u4 with no acring. so back to the SE84c+ tubes in my superzen and all Decware amps I have. Safe common sense choice, even in the Racheal, El34's of my own choice. seems the best compromise...

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