[Phantaminum]

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Things move fast here, by I am trying to catch up.Here is another Osram BVA stickered tube:

It is a GEC A1834/6AS7G. Tried to imitate UT's tube glow picture, but even though these came from Stavros, they light up a little less:

I know people will tell me to just enjoy them and don't worry, but something is bothering me when listening - don't know exactly what.
Too much emphasis on detail?
Next: To try to revive a silent Raytheon 6336B that lights up but does not produce sound any more. I asked before for advice but nobody answered - any suggestions?

I hear you on tubes complimenting each other. I've been jotting down tube combinations that zero in on the sound I enjoy. I found that I have an abundance of warm sounding tubes and in need of a few brighter tubes. The amp is just fantastic giving you the flexibility to tailor the sound the way you want it with different combinations.

 

[leftside]

yes the 12AT7 will be fine. Don't know how it will sound but sure it will sound good it is a good sounding tube.

Good to hear. I have a lot of 12AT7s and variations, as my main mono amps take 4 of these (two in each amp). Looking forward to trying them out in the GOTL. One day...…

Thanks Glenn. It is a very rare and well known tube but not sure if I want to chase more expensive tubes.

You already have an amazing collection of tubes, and I'd hate to persuade you to part with more $'s... but I tend to mainly use GEC A2900 triple mica square getter aor GEC B309 four teeth mica tubes. For fun, I sometimes mix them up with my amps (i.e. 1 A2900 and 1 B309 in each). As with most tubes, the earlier the manufacture years the better. The 1970's A2900 and B309 GEC tubes are not as good as the earlier ones. They are easy to identify as the construction is different.

GEC are my favorite tubes, so I'm biased. I think they have the perfect balance between bass/treble/brightness/warmth, but, I do agree that on some tracks the detail can be too much. With my amps, I tame that a little by also using a warmer sounding early RCA 12AX7 or mid 1950's Mullard 12AX7 (later Mullards are too warm for my liking). The GEC late 1950's KT88 single top mica always stay put in my amps

 

[gibosi]

Correct. Not all Johnny Walker are the same. Check out the 6201 Valvo blue label here.

http://www.jacmusic.com/nos/ECC81.htm

In my experience the Valvo Hamburg sound is quite cool and thin. And therefore, before you chase after that one, I would encourage you to try some less expensive Hamburg-made tubes to see if you even like that sound.

(I don't have a Valvo 12AT7, so my understanding of this sound is derived from Hamburg-made E88CC, E80CC, ECC40 and AZ12.)

 

[Phantaminum]

To my eyes it looks like a Philips 12SN7GT. Philips manufactured this tube at Endhoven, Holland, and Bruxelles, Belgium. Typically, the production code was printed on the bottom of the base between the pins.

@gibosi

I've kept the tube in pretty much all day just enjoying music and how musical this particular tube is. But, after searching for Philips 12SN7s I just kept hitting different results on different constructions and wanted to make sure I educated myself on what I'm looking for.

After looking at the bottom as you requested I didn't find a Philips factory code. I put it aside for a moment while I kept going through my box of tubes and pulled out a RCA 12SX7. While I was looking at it a light bulb went off. I checked the Osram labeled tube and back to the RCA 12SX7 and they both look almost identical. I think what I have here is a RCA 12SN7 and not a Philips tube. They almost have the same build type except for a small variance of the D-Getter.

The Mullard (Philips) that I own has the D-getter bent out and down (vertical). The other two have the D-getter bent out and horizontal.

Left: Philips (Mullard label), Middle: RCA 12SX7, Right: Unsure (Osram label) with 12SN7 in a stop sign.

 

[gibosi]

@gibosi

I've kept the tube in pretty much all day just enjoying music and how musical this particular tube is. But, after searching for Philips 12SN7s I just kept hitting different results on different constructions and wanted to make sure I educated myself on what I'm looking for.

After looking at the bottom as you requested I didn't find a Philips factory code. I put it aside for a moment while I kept going through my box of tubes and pulled out a RCA 12SX7. While I was looking at it a light bulb went off. I checked the Osram labeled tube and back to the RCA 12SX7 and they both look almost identical. I think what I have here is a RCA 12SN7 and not a Philips tube. They almost have the same build type except for a small variance of the D-Getter.

The Mullard (Philips) that I own has the D-getter bent out and down (vertical). The other two have the D-getter bent out and horizontal.

Left: Philips (Mullard label), Middle: RCA 12SX7, Right: Unsure (Osram label) with 12SN7 in a stop sign.

I suspect you are correct. All my RCA and Philips 6SN7 have gray glass so it's hard to get a good view of the internal construction. So I missed the difference in the getters. And I also missed the fact that the Philips has teeth on the shorter ends of the bottom mica, whereas, the RCA and your GEC are smooth.

And can I assume that the GEC sounds like your RCA?

 

[UntilThen]

Thanks Leftside for recommending the Gec A2900. I found out about this tube while researching the Valvo 6201 blue label gold pins. Thanks Gibosi too on considering the cheaper options first but my mind is far from 12AT7 tubes and it's variants right now.

The adapters have arrived and it's time for the moon landing....

 

[UntilThen]

First the good news. It works with dual EL11 as drivers and Gec 6080 as power tubes. Works brilliantly.

 

[UntilThen]

Next dual EL11 as drivers and 2 x EL12 + 2 x EL12n as powers tubes. Brilliant !!!

Glenn you should build an OTL amp to run these tubes. These German tubes sound amazing and they are not even burn in yet.

 

[UntilThen]

Next I tried dual EL11 as drivers and quad EL12 spez as power tubes. This is the bad news. Staccato fire sound spew from my headphones. Not good ! Not sure why because it's not the adapter or the EL12 spez tubes. The following 2 pictures will show why it's not the adapters or the EL12 spez tubes problem.

 

[UntilThen]

Dual Tesla EL12 spez as drivers and 2 x EL12 + 2 x EL12n as power tubes. This is even better. The Tesla tubes are cheap but amazing tone. I really like it. Bear in mind these are initial impressions of these tubes on the GOTL.

The best part is these tubes are quiet and well behaved. This surprised me because I have no such luck with these tubes on Elise but admittedly I did spend and got the best tubes for this trial.

 

[UntilThen]

Finally I'm settling on dual Telefunken EL12 spez as drivers and 2 x EL12 + 2 x EL12n as power tubes for the longer term listening. Going to let the tubes burn in good for 150 hours before I post any meaningful impressions.

 

[UntilThen]

My first thoughts are that GOTL with these tubes sound BIG ad BOLD. My LCD-2f takes on a different meaning.

It's like I'm listening to a JBL 4355.

 

[2359glenn]

Next I tried dual EL11 as drivers and quad EL12 spez as power tubes. This is the bad news. Staccato fire sound spew from my headphones. Not good ! Not sure why because it's not the adapter or the EL12 spez tubes. The following 2 pictures will show why it's not the adapters or the EL12 spez tubes problem.

I don't know what the problem was? Maybe the tubes were oscillating don't know why.
What do you mean fire sound??

 

[Phantaminum]

Finally I'm settling on dual Telefunken EL12 spez as drivers and 2 x EL12 + 2 x EL12n as power tubes for the longer term listening. Going to let the tubes burn in good for 150 hours before I post any meaningful impressions.

That looks amazing and scary at the same time. Looks like it's a winner right off the bat from your description and the tubes haven't even been burned in.

 

[Phantaminum]

I suspect you are correct. All my RCA and Philips 6SN7 have gray glass so it's hard to get a good view of the internal construction. So I missed the difference in the getters. And I also missed the fact that the Philips has teeth on the shorter ends of the bottom mica, whereas, the RCA and your GEC are smooth.

And can I assume that the GEC sounds like your RCA?

The GEC (RCA) tube sounds a tad bit more refined but I've given the tube minimum of 40 hours so it's opened up compared to the RCA 12SX7 which still sounds a bit flabby. Personally I think they sound the same but it's a sad day for me (I over payed for a tube and need to educate myself more on construction types) and a good day being as the RCA 12SN7s are very cheap. I just purchased 3 of them for $30 and still have the 1633 smoked glass and the 12SX7. This should hold me over as day to day listening tubes and switch over to the more refined tubes on the weekend.