Best tubes for the Rocket

[Mark]

Cool let me know what you think.

[rooster]

[5-7-18: I'm going to edit this a bit because I have two more quads I want to demo. They are similar to 2 of the quads I have listed. One is another quad of dimpled getter Sovteks like Set 3 but without the '6n14n' label, and the other is the quad I picked up from redshark a few years back which are like Set 2, marked 6n14n with the halo getter supported by 3 connecting wires. I will call the added dimpled quad 'Set 3B' and the added redshark 6n14n quad Set 2B.]

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OK, I finally received the Saratov 6P14P/6n14n tubes from Russia. It took forever but they look great, have the proper gold label, and are dated 1975 (although I may be reading these dates incorrectly). I have installed them and will burn them in for a few hours. before any play testing or recording.

So let me describe the 3 quads of EL84s I have on hand and their mA current draw. My plate voltage is 335VDC, my bias resistor is 65 ohms.

Set 1) Stock current issue Sovtek New Sensor (comparing physical features), halo getter (with single wire mount) version from 2012 and NOT the Saratov 6n14n tube. mA values are: 44.1 - 44 - 43.7 - 43.5. [These tubes cost $23 from Ness Tubes in California. Nice ppl, not trying to present the current Sovtek tube as the 6n14n tube although they did say 'NOS' and originally posted a picture of a 2004 Sovtek tube (which got me excited) that they changed to a 2012 dated tube picture after I sent an email.]

Set 2) Not a current issue Sovtek (comparing physical features), but with a halo getter (not the dimple getter) with 3 metal attachment mounts with Russian date codes I can't identify, labeled '6n14n EB' (apparently the EB is translated as 'EV'). mA values are: 47.7 - 45.7 - 46.8 - 43.2. [These tubes cost $73 from an eBay seller in Massachusetts, VIVA tubes. This seller DID describe his tubes as the NOS Saratov 6P14P tube and posted a picture of the tubes I purchased.]

Set 2B) 39.4 - 46.6 - 43.1 - 44.7

Set 3) Apparently Saratov 6n14n tubes dated 1975 (again, not clear on the dating of these tubes), gold labels. These have the dimpled getter (with single wire mount) and look legit, purchased from a Russian seller. mA values are: 46.1 - 35.5 - 41.1 - 41.5. [These tubes cost $37 and took a month to arrive but they were well packaged and are the real deal as far as I can tell.]

Set 3B) 43.7 - 39.6 - 41.6 - 42.2

Also I should point out that my method of madness when installing tubes in a P/P amp that are not matched perfectly to each other, is to treat the two pairs of tubes as an overall ma current draw, left pair vs. right pair, and also place the hotter of the two pairs in the two sockets furthest away from the PT. This last decision deals with the LTP PI and how it tends to run hotter on the pair closest to the PT, all dealing with the 82K vs.100K resistors and 10K tail found in the PI of the Express or similar PI'd amps. [Note: the AC30 and Rocket use 100K resistors to the plates of V3 and a 47K tail so this off balance may not exist like it does in the Express but I still set my tubes up this way.] This is me, do what you like. Doing the math, adding the pairs and dividing by 2, my three quads look like this to the OT:

Set 1) 44.05 - 43.6
Set 2) 46.7 - 45
Set 2B) 43 - 43.9
Set 3) 40.8 - 41.3 (This tends to break my own rule about tube placement, but the compromise is based on the 46.1mA tube. I don't want it sitting on that side of the PI.)
Set 3B) 41.7 - 41.9

I'll come back and post pictures later today and then get on with the recording. Obviously the last 6n14n quad is colder than the new issue Sovteks and what might be the other legit 6n14n quad, so it'll be interesting to know what, if any, difference we can hear.

NOTE: When I post the pics, if anybody (redshark?), can explain the Russian date codes or the different halo getters it would be much appreciated. To redshark, the quad I got from you years ago looks identical to the Number 2 quad form Viva Tubes (see my next post), with the halo getter being attached with three connecting wire mounts (one tube actually has two wire mounts), lableled '6n14n EB' (translated ,'EV'), but the tubes I got from you have the Russian 'Diamond' etching on them - something the #2 quad does not have. Also, regarding the getters, the #3 quad has the dimple getter attached with a single wire mount and the 'CCCP' logo. Which is to say that regarding the two tubes branded '6n14n' and '6n14n E8', there are two very different getters.

Also, I see another difference with the plates. The #2 Set and the tubes I received from redshark years ago have a narrower middle section of the plate metal than the other tubes, and also the top and bottom rectangles (two of three rectangles cut into the plate metal) are 3 sided, and not fully enclosed. Actually the mica spacers, top and bottom, complete these two rectangles. The other tubes have 3 distinct rectangles cut out of the metal and also a broader middle section in the plate.

[Mark]

Good stuff keep us in the picture.

[rooster]

Lastly a two pictures of the same tube, a Saratov 6n14n tube that I got in trade from redshark years ago. It has the halo getter (not a dimple getter) that is attached with 3 wire mounting supports, just like the #2 quad I describe above. It also has the 'Diamond' logo on one side that doesn't exist on any of the other quads, #1, #2, and #3 but was pretty common in the early days of Russian tubes. Does it have any significant meaning today? Does it mean Saratov and a tube without it means it is not a Saratov? I have no idea. ...But wait, I did read that the 'Diamond' indicates Russian military tube stock. So, a tube with the Diamond and a tube without it can both be a Saratov manufactured tube.

[Perryr]

I partnered with 2Tone on a few hundred 6n14n from a guy in Lithuania (or somewhere) back in the 90's, the internet was still kinda young so i'm not even sure how we found the guy (rec.amps or something), and we probably mailed him a check. I used them in My Dr Z MAZ 38 & MAZ 18 (I have serial #0001 MAZ 18), shortly thereafter started using the Dr Z Route 66, and forgot about my stash of 6n14n. Fast forward a decade, I call Dr Z cause I'm interested in a Zwreck, he tells me it sounds great but Ken insisted on NOS 6n14n and they are difficult to source (70's & 80's production). I told Z I had a stash, so we worked a cash/tube deal on a Zwreck. I love My Zwrecks!!

Through a friend of a friend of a friend I was able to connect with a few Tube Guys in Russia and they have been keeping Z and I supplied in NOS 6n14n. When Dr Z has a customer needing 6n14n for their Zwreck or MAZ 18, they refer em, I always have burned in and tight matched pairs and quads ready to ship.

I have been hunting 6n14n now for about 5 years and have tried to figure out when the 6n14n recipe changed, cause it did. Here's what I know, Dec 1991 the Soviet Union collapsed, and along with it the Soviet Military Industrial Complex. Before this, New Sensor already had their foot in the door, had relationships and were reselling Russian Tubes. The downturn in Military Production forced these factories to target retail consumer product and New Sensor further strengthened their relationships... and I believe now outright own a Russian tube factory.

During that transition starting Dec 1991, Reflector continued to produce the good 6n14n, but I haven't seen many date coded beyond April 1992. I suspect the standard grade 6n14n production after April 92 (maybe 93' who knows) were entirely rebranded and those are the ones Ken & 2Tone were buying from New Sensor in the early to mid 90's. Ken mentions in his 'Care and Feeding of AC30' VG piece that dealers can get them from New Sensor or consumers could buy them from Groove Tubes. A bit later you could also get them from MojoTone (continued)

[Perryr]

Here are pictures of the 'good' 6n14n rebranded

[Perryr]

Here’s a later recipe version

[Perryr]

I have 6n14n date coded back to the early 60's, through the 70's, 80's and into early 90's. The 'Soviet Era' all look and sound the same. The 200ct bulk pack boxes I get are of incredible quality, I loose maybe 1 every 100 to breakage or electrical fault. They drift right out of the gate, but seem to settle nicely after 6hrs run time. Every box I get measures the same, very consistent. I sent samples to a friend with a MAZ 8, single ended EL84. He is really picky and has a specific measuring 6n14n that he prefers (low ma break to early, high are to clean, he likes just a bit higher than average). I happened to have a 1963' 6n14n that measured precisely where he likes, sent it to him for evaluation. He said it had a bit more 'crispness' up top, otherwise the character was the same as an 80's production.

I refer to these 'good' ones as 'Soviet Union Era 6n14n'. After Dec 1991 things changed, it took a while, but they changed. I suspect a part vendor changed first, probably a part that only the Military could specify and when that part ran out that was it. I'm sure Manufacturing quality likely slipped (no Military certifications), I have boxes with 'OTK' certifications stamped on each tube in blue ink (that burns off during my 6hr burn in, see pic below). So ya, 'Soviet Union Era 6n14n' is the one.

Regarding the tone, well Ken obviously thought they were outstanding, he basically put it above everything but a Telefunken. And at the time in the late 80's early 90's, EI, Tungsram, GE, there were lots of cost effective choices and Ken picked the 6n14n. I have Tungsram, EI, Mullard, Siemens, all very killer tubes, but the 6n14n definitely has a sound that is different. Its full through the mids, very warm and has amazing top end sparkle. The 6n14n cleans are as good as it gets IMO (in my JM Rocket & Zwrecks). Some find the 6n14n a bit bloated in the mids, too pretty or not aggressive enough, and that may be true. But when you lean into the Soviet Union Era 6n14n and really listen, they have a complexity that steps out in front of the competition. Its a warm and harmonic bloom and I'm sure thats what grabbed Ken's ear.