the real Duke Spinner Posted December 29, 2023 Share Posted December 29, 2023 For those that may discernn a difference What and Why?? I will refrain from comment for a bit. 🙂 Quote Link to comment Share on other sites More sharing options...
Flevoman Posted December 29, 2023 Share Posted December 29, 2023 Perhaps your question is a bit too open-ended. Are you expecting everyone to post an extensive list of tubes along with an explanation of how they sound? Or do you mean which tube sounds most pleasant in their system and why? 1 Quote Link to comment Share on other sites More sharing options...
Ceptorman Posted December 29, 2023 Share Posted December 29, 2023 I like the tubes in my new Vox amp over the Marshall amp! 1 Quote Link to comment Share on other sites More sharing options...
the real Duke Spinner Posted December 30, 2023 Author Share Posted December 30, 2023 20 hours ago, Ceptorman said: I like the tubes in my new Vox amp over the Marshall amp! I have either run JJ or EH. ,🙂 My SL 100 used to eat power tubes Quote Link to comment Share on other sites More sharing options...
the real Duke Spinner Posted December 30, 2023 Author Share Posted December 30, 2023 I have. a JMI AC 30 cepto. 🙂 Quote Link to comment Share on other sites More sharing options...
Schu Posted December 31, 2023 Share Posted December 31, 2023 This is kind of being set up like a 'trap' of some kind... but I did an extensive listening test a few years ago making an el34 comparison and I could hear a difference in the same circuit.    They had some distinct differences that I could discern... but they were more alike than different. The 66 and 88 were more potent and had a very forward mid's and the 34 were more laid back and significantly more balanced from top to bottom.  That was about it for me... like most things, none was right and none were wrong. They were different flavors  2 Quote Link to comment Share on other sites More sharing options...
the real Duke Spinner Posted December 31, 2023 Author Share Posted December 31, 2023 Circuit and Bias dependent no doubi find in my amp. The 34d are more "middy" This is a Marshall JMP Quote Link to comment Share on other sites More sharing options...
the real Duke Spinner Posted December 31, 2023 Author Share Posted December 31, 2023 btw Mine is biased hot ...I forget how many mA on the Plate. 55 ?? Quote Link to comment Share on other sites More sharing options...
henry4841 Posted December 31, 2023 Share Posted December 31, 2023 29 minutes ago, the real Duke Spinner said: btw Mine is biased hot ...I forget how many mA on the Plate. 55 ?? The more current you run in the tube the better it is going to sound that is until it self destructs. Changing the bias has the same effect as tube rolling. The figure of 55ma on an EL34 sounds about right depending on the plate voltage and the brand of tube of course. You do not want to exceed the max power rating of the tube being about 20 watts for a typical EL34 25 watt tube biased at 80% of max. V X I = P. Eighty % of max is the figure most designers aim for when biasing a tube. This rating is found in the data sheet of the specific tube. For example a JJ EL-34. https://frank.pocnet.net/sheets/163/e/EL34.pdf  If you want to play reduce the current from 55ma and listen then turn it back to 55ma and see if you can hear any difference. Do not exceed the mfg current in ma if not sure what you are doing. The sure sign you are running the tubes too hot is red spots on the plates. If see red spots back off current. 1 Quote Link to comment Share on other sites More sharing options...
Bananas and Blow Posted December 31, 2023 Share Posted December 31, 2023 I've owned 2 integrated tube amps so my experience is limited. I had a Raven Osprey MK3.1 with 7581a tubes and those were incredibly dynamic. Terrific with rolled off sounding speakers like my Dynaudios. It was too Dynamic with Fortes and Heresy and I didn't like the combination at all. It sounded harsh and too forward.  My main experience with power tube rolling comes via my Cary Audio SLi-80 signature (ca 2005, tube rectified). Started with the KT88's and I liked the sound with the Forte IV. Tried the Tung-sol KT120 and liked the sound less. Just sounded less interesting and more solid state sounding. I don't think my amp really takes advantage of the extra power of the KT120 as there is no adjustment when changing from 88s to 120s. Next I tried the Gold Lion KT77s and they are truly excellent modern tubes. Had a little more harmonics and more "in the room" presence to the sound. For an EL34 family tube it did a great job of still producing a full frequency range. It had less bass than the 88's. Next up I tried some NOS 1960's RFT power tubes siemens. These are probably the best I've had in the amp. Terrific detail, magic midrange. That 2nd harmonic distortion that places the artist in between your speakers is just incredible. Draws me in. Ironically these tubes are not my daily drivers and that's because when I purchased these used RFTs, they threw in a set of barely used modern Tung-Sol EL34's. I plugged in the TS EL34s and liked the sound so much I didn't even bother trying the RFT's for a couple of weeks. They are a bit rolled off on the highs and the bass. But I think a big of tube softening of the sound does well with Klipsch Heritage speakers. And with the Forte you can tube the bass wonderfully with speaker placement. So moving the Forte back an inch filled in the bass nicely. I get wonderful detail. Incredible dynamics. Great clarity from the EL34. It softens some of the edges of the music without losing the dynamics, which is the perfect combination with the Fortes.  I've had many amps and even more speakers and nothing has approached the quality of sound of this combination. The SLI80 was used to demo the Heritage line for a reason. I could happily live with any of the 3 EL34 family of power tubes I've found. I found an even bigger improvement in sound from using NOS 60's small signal tubes in the preamp. But you didn't ask about preamp tubes.  Due to a temporary move I've been powering my Fortes with a Yamaha A-s1200 and it's a nice amp. Does some things well. It does not have the same magic of the Cary. 1 Quote Link to comment Share on other sites More sharing options...
the real Duke Spinner Posted January 1 Author Share Posted January 1 I had a Yamaha integrated I found it a bit cold Quote Link to comment Share on other sites More sharing options...
KT88 Posted January 1 Share Posted January 1 20 hours ago, Bananas and Blow said: I've owned 2 integrated tube amps so my experience is limited. I had a Raven Osprey MK3.1 with 7581a tubes and those were incredibly dynamic. Terrific with rolled off sounding speakers like my Dynaudios. It was too Dynamic with Fortes and Heresy and I didn't like the combination at all. It sounded harsh and too forward.  My main experience with power tube rolling comes via my Cary Audio SLi-80 signature (ca 2005, tube rectified). Started with the KT88's and I liked the sound with the Forte IV. Tried the Tung-sol KT120 and liked the sound less. Just sounded less interesting and more solid state sounding. I don't think my amp really takes advantage of the extra power of the KT120 as there is no adjustment when changing from 88s to 120s. Next I tried the Gold Lion KT77s and they are truly excellent modern tubes. Had a little more harmonics and more "in the room" presence to the sound. For an EL34 family tube it did a great job of still producing a full frequency range. It had less bass than the 88's. Next up I tried some NOS 1960's RFT power tubes siemens. These are probably the best I've had in the amp. Terrific detail, magic midrange. That 2nd harmonic distortion that places the artist in between your speakers is just incredible. Draws me in. Ironically these tubes are not my daily drivers and that's because when I purchased these used RFTs, they threw in a set of barely used modern Tung-Sol EL34's. I plugged in the TS EL34s and liked the sound so much I didn't even bother trying the RFT's for a couple of weeks. They are a bit rolled off on the highs and the bass. But I think a big of tube softening of the sound does well with Klipsch Heritage speakers. And with the Forte you can tube the bass wonderfully with speaker placement. So moving the Forte back an inch filled in the bass nicely. I get wonderful detail. Incredible dynamics. Great clarity from the EL34. It softens some of the edges of the music without losing the dynamics, which is the perfect combination with the Fortes.  I've had many amps and even more speakers and nothing has approached the quality of sound of this combination. The SLI80 was used to demo the Heritage line for a reason. I could happily live with any of the 3 EL34 family of power tubes I've found. I found an even bigger improvement in sound from using NOS 60's small signal tubes in the preamp. But you didn't ask about preamp tubes.  Due to a temporary move I've been powering my Fortes with a Yamaha A-s1200 and it's a nice amp. Does some things well. It does not have the same magic of the Cary.  Thanks for your insightful post, Bananas and Blow. I first stumbled over your designation "RFT Siemens" for your NOS EL34. But you are absolutely right. When Telefunken, Siemens and other companies in West Germany stopped making tubes, they were supplied by the communist DDR (GDR in English for "German Democratic Republic") by RFT which means "Radio Funk Technik" ("Radio Wireless Technology"). Foreign, even US tubes were also labelled and came from RFT in East Germany. Here is a small article about the RFT EL 34 in German with pictures, which you can easily read in English with the google translator.  https://www.jogis-roehrenbude.de/EL34-Story/EL34-Story-Seite4.htm 1 Quote Link to comment Share on other sites More sharing options...
hanksjim1 Posted January 1 Share Posted January 1 These are pretty highly regarded (at least there is a "best offer" option...lol):  https://www.ebay.com/itm/304760675395?chn=ps&norover=1&mkevt=1&mkrid=711-213727-13078-0&mkcid=2&itemid=304760675395&targetid=4580428016871206&device=c&mktype=&googleloc=&poi=&campaignid=603247657&mkgroupid=1229254994528356&rlsatarget=pla-4580428016871206&abcId=9316139&merchantid=51291&msclkid=464e725aabb414cad18817c9ac1a292e  Quote Link to comment Share on other sites More sharing options...
JohnA Posted January 2 Share Posted January 2 On 12/29/2023 at 1:36 AM, Flevoman said: Perhaps your question is a bit too open-ended. Are you expecting everyone to post an extensive list of tubes along with an explanation of how they sound? Or do you mean which tube sounds most pleasant in their system and why? Â Not single-ended? 2 1 Quote Link to comment Share on other sites More sharing options...
SWL Posted January 2 Share Posted January 2 I've only rolled tubes in an HH Scott 222c of which I have three fully restored units. I like it that much.  I've found that NOS 7189's are the ticket and while the Russian 6P14P-EV tubes do very good, they don't quite measure up to the 7189's.  The 6P14P-EV can add a hard/glare to the sound when in my amp. The "Gold Grid" versions sound much better to me. They don't have that hard sound and have a lot of fullness to them.  The NOS 7189's are more articulate and refined in comparison. They better be because that's what the amp was originally designed to use but for a backup....the Russian tubes will get me by and they were dirt cheap at the time (4-5 years ago). I loaded up on them and with RCA 7189's so I'm set for the rest of my life.  Never tried any new production 7189's. I haven't read anything particularly good about them unfortunately. Quote Link to comment Share on other sites More sharing options...
KT88 Posted January 2 Share Posted January 2 Interesting what guitar guys talk about those tubes. Just the conversation I find interesting, not that there is final advise. Â https://www.18watt.com/viewtopic.php?t=4291 Quote Link to comment Share on other sites More sharing options...
DirtyErnie Posted January 2 Share Posted January 2 More limited than SWL, but Scott 222C. Original Telefunkens are magic. RCA 7189 are almost as good. JJ EL84 were busy and edgy in that circuit. I backed the screen grid voltage down to ~315v and they sounded much better. Not magic like the Telefunkens or RCA, but I could certainly live with them as daily drivers. I really want to build something ~30-50w with JJ 6L6. Quote Link to comment Share on other sites More sharing options...
pnort Posted January 3 Share Posted January 3 Relevant discussion at https://www.audiosciencereview.com/forum/index.php?threads/record-breaker-raphaelite-cs30-mkii-tube-amplifier-review-and-measurements.44020/  discussions of the 300b Venus tube. Comment the Western Electric product has low distortion. I think probably because of high cathode efficiency analogue to Klipsch speakers.  Quote Link to comment Share on other sites More sharing options...
the real Duke Spinner Posted January 3 Author Share Posted January 3 I remember when they sold tubes at the drug store. 😀😀😀 1 Quote Link to comment Share on other sites More sharing options...
Invidiosulus Posted January 3 Share Posted January 3 My old Mesa Boogie had whatever the contemporary Mesa branded 6L6 and EL34 were that Mike Bendinelli put in it during its last service. I never got around to swapping them out for anything else. Â the preamp tubes were a different story. I ended up with a box full of vintage RCA black plate 12AX7 that I pulled out of a bunch of lab equipment they were tossing at work. The RCA tubes sounded a million times(subjectively) better than the mesa branded (Sovtek?)12ax7. Â Quote Link to comment Share on other sites More sharing options...
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