snoz65

Hey Myles and all, My appologies if this has been covered elsewhere... It has been a while since I have had a working EL34 amp but I have just rebuilt an old '65 twin channel amp fitted with an old pair of National 6CA7's. These 'ol girls are well due for retirement so I'm looking at the what is currently available. Back when I had my last EL34 amp (a Marshall 2204) the Svetlana's were my favourites. I'm aware that the Svet factory no longer makes these and they are made by Reflector instead but there are still some older versions around (I hope). Firstly are these the tubes known as 'Winged C' or 'SED' Svet's? Since my amps have all been 6L6 powered for the last few years I have not been following the EL34's evolution. Secondly can anybody recommend a good supply of these old Svetlana's? Thanks...

These look exactly like the current JJ ECC83 and that tube is completely different than any of the older RCA tubes. They also sound completely different. I have no experience with a JJ copy of an RCA tube that is shown here.Thanks Miles, you are absolutely correct. I already bought two of these and when they arrived I checked them against a JJ ECC83s and they are exactly the same! I plugged them into my Marshall, replacing a Blackburn Mullard and of course there is NO comparison. These are much brighter and kinda thin sounding, not as much body about their tone. So I feel kind of ripped off by this ebayer who is apparently rubbing off the 'JJ' label and putting them int RCA 7025 boxes. At least they were fairly cheap. Thanks again, Shaun. \'RCA 7025\' auction.

Hi Myles, I am looking at some 'RCA' 12ax7/7025 tubes to try out. The ones that I'm interested in are reportedly 'the re-issue series made by TESLA' They are NOS, unmarked and in RCA boxes. http://i17.ebayimg.com/01/i/02/7e/f7/8a_1.JPG http://i18.ebayimg.com/01/i/02/7f/0d/67_1.JPG Do you know anything about these 're-issues' or are they simply re-boxed Teslas. Why would they not be marked with anything? Any experience with 'em? Thanx bud, Shauno.

Wow Your a real gentleman Myles, Thank you very much. Shaun.

Thanks Miles, I have ordered a couple of GT-6L6GE's and a SAG12ax7MPI. I'm not sure that I realy want earlier power tube break up now so I'll give the 6L6WGB's a miss, for now. Shaun. P.S. Congrats on the best forum thread on the net!

Heya Miles. I recently checked the bias in my Marshall 30th anniversary and found one tube to be drawing 10mA more than the other. I have two (50W Mode) 6L6STR Harma's in there, about 12 months old. I figure that a new set of tubes is due and probaby a 12ax7MPI. Can you see a pair of NOS 6L6WGB JAN GE's being a marked improvement over the Harmas in my amp (when they were matched)? Plate voltage is 470-480V and I don't mind some earlier break up and lower output. Besides that, do you know of a source of pre '02 Svet 6L6GC's? They were much warmer than the Harmas. Thanks, Shaun.

....If you are ever in my area, feel free to bring in any tubes from your vendor that you may or may not trust....[/QB] That's a great offer Miles. Unfortunately you're in LA and I'm in South Australia so I don't get to your area much. Thanks.

Shaun, A few things .... The 7581 is similar to a 6L6, but in many amps it will cause problems due to screen resistors not being of a correct value. They are nothing at all like a KT-66, the curves are very different. Current Svetlana's (made anytime in 2002, 2003, are low in vacuum, and are showing a very low service life, prone to premature failure, and the bias should be checked after only 10 hours of use. The GT version of this tube is the GT-6L6R2, and they are checked for low vacuum. If you buy Svet 6L6's make sure you know and trust your vendor. There is a popular internet tube vendor that has some pretty awful examples of these. NOS tubes DO need to me matched. They were closer than today's tubes, but over the years of handling, I have found that in regard to power tubes, they are even more inconsistent than new made power tubes with less travel time on them. A lot of NOS folks with a limited supply, group tubes that are far from being matched into what they term as matched sets, as single tubes do not do a lot of folks much good, unless you own something like a THD Univalve or GT Solo Single type of amp. Most any 6L6 is much better than the current production runs of the Svetlana 6L6. Hopefully this will change, as it seems to every now and then from that particular factory.[/QB] Thanks Miles, That's very dissapointing about the Svet's. They have done me well in the past to last as long as they have with a fairly hot bias. I don't think I trust this vendor that much, he is ordering in some more 6L6's in for me and hopefully they will be in today as I want to retube and use the amp tonight. I'll see what he gets in. Cheers, Shaun.

Hi Miles, I have been doing the rounds looking for a pair of 6L6's for my Marshall 30th aniversary. I like the Svetlana's that I have in there currently but after a couple of years they are sounding a bit thin. I have found some NOS Philips 7581's that are apparently equivalent to 6L6's. I have not heard of 7581's before and I understand that they are a more rugged version of the 6L6 with a higher plate dissipation of 35 Watts. Apparently similar to a KT66. The fellow in the store told me that they do not need to be matched since they are NOS and made to a high tollerance so they should all have the same rating! Does this ring true to you? My second question to you is, are these a good tube in comparison to the Svet's? Thanks in advance and for other replies in the past. Shaun.

Shaun ..... Good enough .... with the brackets on the plates and the square getter, it is 4th of 5th generation Chinese. Some folks loved these. They were either great or awful, a lot of inconsistancy, but if you got a good one, they lasted forever. Wow the difference in tone is quite amazing. Thanks for your insight Miles. I had to go back and try some other tubes incase my ears were playing tricks on me, but that one bottle is a far better sounding tube than any of the other six or seven Chinese tubes that I have spare. Looks like I'll be hanging those on the Christmas tree as decorations. Shaun.

Thanks Miles, I don't have a scanner at hand but I can describe the tube a bit from memory. It looks the same as the Marshall branded tubes that I pulled out of my early '90's 30th aniversary. The Marshall ones sound like shite. This one sounds great however. It has a square getter and has two little shinny silver brackets on the plates. Hope this helps. Shaun.

Hi Miles, I have been messing around with the preamp compliment in my 30th aniv. Marshall. I'm really happy with channel 2, it gives a great blues/rock vibe. Channel 3 (lead) has never sounded great until I tried a GT12AX7 on the weekend. These two channels share the first tube (V2), a NOS Brimar. Channel 3 is now running through the GT for the 2nd and 3rd gain stage. This tube colours the tone alot more than I thought it would which is great because I wanted a heavier sound from the 3rd channel. My question is, can you tell me what original brand the GT might be? It is probably just a few years old, since I stole it from another amp that was retubed a few years ago. It has the usual GT logo with no 'made in...' and only states 'GT12AX7', no 'A', 'C' or 'R' or whatever. Any suggestions on the original brand? Thanks, Shaun.

Hi there Miles, I am looking for a new preamp tube for the first position of channel 2 and 3 of my Marshall 30th aniversary. I currently have an old Brimar 12AX7 which has gone microphonic and I am seriously considering some Mullard CV4004's as a replacement. Do you have any comments or experience with these Mullards and why are they known as CV4004's rather than 12AX7's. Regards, Shaun.

Hi Myles and all, I have an 12AU7 that is made in Japan. There are no other markings on the tube and I was wondering what brand of tube this might be. Any ideas?