MBM135 Posted August 3, 2003 Share Posted August 3, 2003 Kind of want to have an extra set of 7189s for my Scott on hand. Hard to find a matched quad of 7189s--can I use EL84s? I though the Scott's were picky about using the exact tube. Thanks, Mike 1 Quote Link to comment Share on other sites More sharing options...
Deang Posted August 3, 2003 Share Posted August 3, 2003 Think of a 7189 as an EL-84 that can take the heat. You could use NOS EL-84's -- but they wouldn't last long. The best tube right now is the Russian Military 6P14P-EB -- they are sold here as EL-84M's. Whatever. I think Craig is sitting on about 1000 or so, or you can get a "matched" quad from www.triodeelectronics.com for $40. Quote Link to comment Share on other sites More sharing options...
Deang Posted August 3, 2003 Share Posted August 3, 2003 Ryan, I think this is like saying you can plug a 6DJ8 into a circuit designed for the 6922 or 7308. You should know this doesn't always work. If what you are saying is true, then the 7189s were the cream of the EL-84 crops. They would have been hand selected and individually tested to see if they could take the required voltage. I don't think scooping up NOS EL-84s left and right is the way to go here. I realize the 299A & B don't run as hot as some of the later Scott amps, but still -- in Class AB1, the EL-84 is only rated for 300 volts. Quote Link to comment Share on other sites More sharing options...
Deang Posted August 3, 2003 Share Posted August 3, 2003 You must have copied my post to insert into your response before I edited and made the fix. Yes, it's 300 volts. Doesn't it make sense though that "EL-84's" would only have been tested to 300, not 400 -- and those designated to be "7189s" would have been taken higher? I mean, there is nothing anywhere that says all EL-84's can take 400+. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted August 3, 2003 Share Posted August 3, 2003 Bunch of conspiracy theories from HH Scott once again 99% bunk. RCA pulled the wool over the entire worlds eye's and Fischer, HH Scott, GE, Sylvania, Mullard, Amperex, Telefunken and pretty much the entire tube audio world went along to rip everyone off ! The 7199 is not a repined 6U8 The 7189 is not the same as a EL84/6BQ5 Craig Quote Link to comment Share on other sites More sharing options...
NOSValves Posted August 3, 2003 Share Posted August 3, 2003 Are you sure you weren't the CEO of RCA ?? Quote Link to comment Share on other sites More sharing options...
arfz28 Posted August 3, 2003 Share Posted August 3, 2003 I was wondering about how important it is to run matched output tubes in my scott 299a. It seams to me if I bought 4 brand new sovtek el84m or some of those russian 6n14n-eb wouldnt they be matched enough for my amp since they are brand new?Just how important is it to run matched output tubes in a scott 299a amp? I guess all new tubes must test a little different from each other or else nobody would wory about getting matched quads.It just seems to me that the tubes comming out of these tube factories should all test almost exactly the same, if they had good quality controll.Must be a lot to this tube making process. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted August 3, 2003 Share Posted August 3, 2003 arfz28, You actually don't need to run matched quads in your amp at all it has full bias control. But I myself would still want to have reasonably closely matched tubes myself. I buy 7189's in pretty large lots and can tell you first hand that test scores do vary by at least 25% on some of them. Its really not that much more for matched quads from anyone including me ! $32 is pretty cheap and I really match them like 1% ! I have found this is not always the case from most tube dealers. Craig Quote Link to comment Share on other sites More sharing options...
arfz28 Posted August 3, 2003 Share Posted August 3, 2003 Thanks Craig for your reply. New tubes that test 25% differnt from each other, wow that is a lot, I had no idea they could be that far off from each other. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted August 3, 2003 Share Posted August 3, 2003 Used are even worse ! Quote Link to comment Share on other sites More sharing options...
NOSValves Posted August 4, 2003 Share Posted August 4, 2003 I have two 222D's. My family owned one is still using the Westinghouse 7189's. The other I've owned since 1984, and installed a quad of Valvo EL84's. The tubes have been running non stop, for 19 years and still test like new! My line voltage is 132 VAC (I live next to a distribution tranny). This jacks the B+ up to 430VDC. These four Valvo tubes took 19 years of abuse and they are still in excellent condition. This pretty much proves that the 7189 and EL84 are one in the same. This post is really interesting ! I was just surfing the HH Scott forum and came across this post from Ryan. Its been exactly one year since I installed a matched quad of Sovtek EL-84M's in my 222-D. My amplifier runs for an average of 4 hours per day, and has been run every day this past year. The tubes still test new, and the sound has not degraded in any way over this past year. Sovtek really built a great version of the 7189 tube. The cathode current has only drifted 1mA per channel below the 46mA per channel current rating that the amplifier was set at one year ago, not bad at all! I expect to get at least another year out of these tubes. The amplifier was not played at low volume, but it wasn't abused either. Has anyone on the forum been using these tubes for a year or longer? If so, what are your comments on the Sovtek EL-84M tube? I would definately recommend these tubes to others. Regards, Ryan 19 years none stop huh ?? Just found another post on the Scott Forum where he used RCA's 6BQ5's for 14 years this just doesn't add up LOL !! Hi David, Sovtek makes a regular EL-84/6BQ5 that works great in a 222-B. They are avaliable from MCM Electronics for $16.50 per matched quad! I wouldn't recommend using these in Scott amplifiers that require 7189 tubes though. The Sovtek EL-84M is a direct replacement for the out of production 7189 tube. Scott 7189 based amplifiers operate at a plate voltage of 420VDC, which is the exact rating of the new Sovtek EL-84M. I've been using a matched quad of Sovtek EL-84M's in my 222-D for over a year now, and they are excellent tubes. NOS 6BQ5's that were manufactured before 1970 are in every way identical to a 7189, and can be substituted without any problems. Both tubes have a dissipation rating of 12.5 watts, so power output from your amplifier will be identical using either tube. RCA 6BQ5's are a fine choice, and were the tubes that I used for 14 years before upgrading to the current production Sovtek EL-84M. Don't use currently manufactured 6BQ5/EL84's in place of a 7189, or they will fry. The only new production tube that is suitable for use as a 7189 is the Sovtek EL-84M. Regards, Ryan Craig Quote Link to comment Share on other sites More sharing options...
NOSValves Posted August 5, 2003 Share Posted August 5, 2003 I have two 222D's. My family owned one is still using the Westinghouse 7189's. This covers one amp !! Now this only leaves your amp and the story keeps changing on it !! Just like about everything you say . Quote Link to comment Share on other sites More sharing options...
Deang Posted August 5, 2003 Share Posted August 5, 2003 "RCA 6BQ5's are a fine choice, and were the tubes that I used for 14 years before upgrading to the current production Sovtek EL-84M." Why would you use the Sovtek EL-84M in an amp slated to use the ordinary EL-84 (instead of the 7189)? Quote Link to comment Share on other sites More sharing options...
avman Posted August 5, 2003 Share Posted August 5, 2003 2 shy shy hush hush i to i Quote Link to comment Share on other sites More sharing options...
MBM135 Posted August 6, 2003 Author Share Posted August 6, 2003 Whoa boys...didn't mean to start a pissing contest... I think I will just order myself a matched quad of 7189s from Craig for $32. $8 bucks cheaper than Sovtek EL84Ms and the HH Scott website says 7189s are specified so I guess I'll defer to the original manual for guidance in lieu of consensus. Respectfully, 1 Quote Link to comment Share on other sites More sharing options...
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