For guitar amps that work hard keeping them running with vintage tubes is an expensive proposition. A good compromise if you both play "live" and "record" or occasionally play more important gigs, would be to have a set of quality matched vintage tubes and just swap them in for a short time. Of course if you have a second rig then that makes life easy!

Good question! Well for a long time I've really liked the Electro-Harmonix EL34, which was the first house brand of New Sensor and made i the Reflector plant. It's a rock solid, good sounding budget EL34. The reissued Mullard look very much like the old Electro-Harmonix EL34's. The weird thing is the reissued Mullards don't sound as good as the old Electro-Harmonix. So maybe the quality control has gone down hill or I got a bad batch in (maybe 16 tubes came in and 2 were doa!).

@@tubelab194 ah doa is not cricket! Yes I've read that mullard were extremely particular with their chemical coatings etc... making it extremely difficult to clone. It would be lovely if sensor could clone them precisely. From my experience so far of the 70's reflector valves, the physical manufacturing is excellent. I have a load of 6j11pe tubes and some 6j20pe tubes (both equivalent to e180f 6688 6j9 pentode) it would seems that sensor did a good job in buying up the reflector factory as it appears to be a very capable plant in the past.. hence my asking if it still is to this day lol. I've started collecting different types of tybe from the world over and observing how they are all constructed (thanks to you sir). Been looking at how the plates are folded and jointed, how the plate is tethered to the micas, number of micas, getter type and mounting method, etc. I now have nevz, reflector, October sputnik, voskhod, mullard, valvo, ge electronic, pinnacle, zaerix and tantalum to roll through. I want some western electric but they are money! Thanks again for a wonderful channel sir xx

To check for a bad tube, shut down and move the suspect over a socket and power up with minimum volume, if a loud noise shut down immediately. If all quiet check the bias on the tubes, if the problem moved with the tube, then you know for certain it is a bad tube. My set of tubes for the R8 came in unmatched and one of the power tubes died inside of 24hrs operating time and sounded crap, I binned them at that point!

@@tubelab194 thanks for the info. I'll try when home. I didn't realise you could do that. Just to be clear. I can put V3 onto V4 port ans visa versa. If bias is zero on V4 its the tube. If its OK its the amplifier, is that it. Thanks again.

@@tubelab194 just heard back from Yong Lee in China. He suggested the same thing. Put V3 into V1 and visa versa. Turn on and bias. I'll let you know to outcome.

@@tubelab194 A1 Bias Current is now zero and A3 fine.

@@seanoreilly8603 in my experience many Chinese power tubes are poor quality and short lived, I'm sure there are exceptions, I've just never found any! Quality vintage tubes in general have very long life spans. I'm regularly listening to power tubes built in the 1960's and they still sound great!

Tube Lab is the KZfaq channel of www.valvesnmore.com and we specialize in Mullard EL34 xf2 series. And yes a high value tube like the xf2 have some of the most fakes in the market place - so buyer beware! We don't charge anything extra to properly test and match our tubes - that's what we do 7 days a week.

Will I think you are going to like what I'm going to tell you! Philips owned Mullard (and many other quality tube manufacturers). A common rebrand of a Mullard XF2 was Dynaco (as in the famous Dynaco Kit Amps) another common rebrand was Philips themselves. Some of the EL34 line was made in Belgium I think, but just as desirable. From what you're telling me the tubes are probably genuine Mullards, but I'd need pictures to confirm. Note the Matsushita EL34 is a nice tube, but in no way is it anything like the Mullard. Good luck!

@@tubelab194 Except they're made, according to seller, by Matsushita. There's a lot of talk about Matsushita being akin to NOS Mullard due to the fact that they were, presumably, manufactured on Mullard/Phillips tools. Well anyway, I bought them and they are coming tomorrow. They were the same price as the pair of re-issue Mullards I was originally considering. Your info on spotting the real ones ruined those for me. Thankfully.

I just scored a real 60's Blackburn Mullard 12ax7! This will pretty much complete the compliment of tubes needed for my amp build. Next to the Mullard (V2 and PI) will be 2 red label Holland Ampirex 12ax7's made for Hammond organ company that I also scored. Now I am considering getting a Matsushita rectifier for the amp, but my tech is saying that because that tube is not in the signal path, it will not effect overall tone so NOS would be a waste.

For pricing and availability, just drop in on the store. www.valvesnmore.com

Thanks for the clarifications, I specialize only in the Mullard Blackburn xf2's. The D getter tube you identified didn't have it's etched factory code intact, so I'm glad you were able to identify it. And I didn't know the xf3 & xf4 were made in Brussels! That explains the very different plate assembly (rivets instead of welds like all xf2's - which I much prefer). Thanks for all your help!

@@tubelab194 I must correct myself - the "D"-getter EL34 with Xf3 code would have been made in the Sittard Philips factory. "D"-getter with Xf4 or Xf5 would be made in the Brussels Philips factory. But to be clear, not all Xf4 were made in Brussels - just the "D"-getter ones. If you have an Xf4 with a circular getter wire, that is most certainly a Mullard/Blackburn tube. Same with circular getter Xf3.

@@thomkopal1740 thanks for the further clarification! I would add that IF the etched factory code is visible, anyone can download the Philips factory code information and it is easy enough to figure out the factory, year and month of manufacture.

Interesting, can you provide your reference source to support a manufacturing date of 1973? That would be most helpful!

@@tubelab194 An Xf2 with code B2XX B3XX has double getters when it is 1962-1963. Single getters came around 68. The Xf2 single getter has production codes up to B3FX, meaning it was produced until at least June 1973. Then it was replaced for the Xf3. In 75 it was replaced by Xf4 until end of production in 1980.

Please go to the store and read the reviews (in order to post a review, you must have purchased that tube type). I work 7 days a week at this and even though I enjoy every minute, it is still work and financial risk. It is true that vintage tubes have been going up in price at a startling price. I believe that a large number of music lovers have gotten seriously into tubes and want great sound, which most of the time means vintage, the more demand for a tube the more scarce it becomes. And not surprisingly the price goes up. Remember the inventory of vintage tubes is finite and gets lower every day!

Sad to see a comment such as this my guess is he didn’t watch any of your informative videos , to educate himself , as I needed to do . Best I bought quite a few recommendations and what a voyage of discovery . Mr. Negative should by the very reasonable Electro-harmonic 6500’s I quite liked them . Then I upgraded to Svetlana’s 6500 which are rich and never fatiguing . Just saying before being critical one should watch the video’s or buy then speak .

@@tubelab194 trying to find your online store, please post info for contact

Valvesandmore

@@richardnadelman9609 www.valvesnmore.com