Feliks Audio Elise Tube Rolling Guide 6SN7/6AS7G/6080/5998
Oct 26, 2015 at 12:07 PM Post #256 of 384
Those two tubes were pictured on the 6AS7 thread recently. The information given is that one tube said 188-4 and the other 188-5. Would the 4/5 indicate different factories, or is it just a bogus designation on a RCA tube?


IIRC, 5 is a factory is PA (I could be wrong). 4, no idea.
 
Oct 26, 2015 at 12:10 PM Post #257 of 384
Good info. I always assumed the 188 was indicative of a GE manufacturing.

Do you know if Raytheon acted similarly with their EIA 280?

 
I can't say for sure, but I have a pair of Raytheon 6SN7GTB manufactured by Toshiba, and Raytheon's EIA number is not on the tube.
 
Those two tubes were pictured on the 6AS7 thread recently. The information given is that one tube said 188-4 and the other 188-5. Would the 4/5 indicate different factories, or is it just a bogus designation on a RCA tube?

 
I would guess that 4/5 are different manufacturing plants, but again, I can't be sure. With GE, my rule of thumb is, if I don't see sandblasted numbers and dots, then GE didn't make them. I actually have a pair of RCA 6AS7G rebranded as GE, with 188-5 on the base, but "6AS7G" enclosed in a hexagram etched in the glass. No sandblasted numbers and dots, so GE didn't make them.
 
Oct 26, 2015 at 12:38 PM Post #258 of 384
I'm looking at a GE 5U4G rectifier ATM. No white dots, tube type on the glass enclosed in a stop sign, bottom D-getter, looks exactly like its RCA equivalent.

On the base:
2-48
188-5

It was advertised as a relabeled RCA. I had my doubts due to the EIA code, but I guess we've eliminated that constraint.
 
Oct 26, 2015 at 1:04 PM Post #259 of 384
I'm looking at a GE 5U4G rectifier ATM. No white dots, tube type on the glass enclosed in a stop sign, bottom D-getter, looks exactly like its RCA equivalent.

On the base:
2-48
188-5

It was advertised as a relabeled RCA. I had my doubts due to the EIA code, but I guess we've eliminated that constraint.


I read some time ago an article  on the 188-5 GE number.
 
About dates i did find a very interesting article.  if someone have Tube Collector (Vol 12, Number 6 - December, 2010)  the complete article is inside !
 
Oct 26, 2015 at 1:13 PM Post #260 of 384
A day in a tube roller's life:

Checked the temp of the Elise in the morning after running overnight with the fans on. Temperature checker is my hand - touching the side - cool, the top of the transformer - cool, bottom a little warm, the socket extender to the power tube - warm, the socket extender driver tube - cool.
All systems go, OK.

Looking at the clock - 30 hours on the little sub miniature buggers. Let's crank up the volume. Sounds good. Did the driver tubes change over time? Yes.

Sounds really good. Very good detail, all the instruments stand out in relief with excellent separation. Neutral presentation, not warm. Reminds me a little of the C3g. Guess that that these tubes are pretty much burned in. Surprisingly good mid bass.

Well, let's try something different. Goofy different.

Put in the C3g driver tubes into the power tube sockets, left the Sylvania 7963 as drivers. Holding my breath, flipping the power switch on. Yes, it works. How does it sound? Not bad, but thin in the bass; very good detail and treble. So we need more power for the power tubes.

Let's try something a little crazy, cringe-worthy, different. Let's create two different channels: Siemens C3g with Syl 6AS7GA on one side, and Tung Sol Reissue 6SN7GTB SE with a 5998 on the other channel. Heard that 6SN7 and 5998 match well.

Sound? Not bad, pretty coherent and more similar than dissimilar/channel. OK, so the amplification factor is 5.5 for the 5998 and 2 for the 6AS7GA. Moving the balance control a little to compensate. Not bad; the 5998 definitively adds great bass and mid bass.

OK, enough dissimilarities - let's go for the gold! Magic sound - ze best!

Plopping in my two Mazda 6N7G unobtaniums with the Syl 6AS7GA. Flicking the on switch - oh no! Large hum, no sound. Hmmmm.
Instant shut-off. Check the connections. Check the socket extenders. Let the amp cool off. Switching the tubes around. Doubts - are the tubes too old? Did they lose it? What's going on??? Gingerly switching on the power again. LOUD HUM. WHAT'S GOING ON? HIT THE OFF SWITCH. NOW!

Scratching my head. Wait a second - the Mazda's had too much space above them in my rack - not flying high - after all they have two sets of wings...Yes, that's the problem - forgot to use the adapters switching from ECC32 to ECC31.

Power on. Bliss. Wall of music. Concert Hall fifth row. Yes, everybody is right about the ECC31 - in a class of its own. Does it apply to my Mazdas? Could be, I would describe them in the same way, but have not heard the ECC31s.

Fell asleep in my listening chair at 1:20am....

And so ends a day in a tube roller's life. Addiction? Crazy? Yes and Yes. Period.
 
Oct 26, 2015 at 2:21 PM Post #261 of 384
Can't say that I'm doing anything as fun as Mordy:

The DV is shod with a CBS 6SN7GT and a JAN Chatham 6080. Once the 6080 is fully burned in, I'll likely roll another set of bottles into the amp for a change of pace. Typically, I prefer a 7AF7 driver.

The Elise is running a pair of Sylvania 6AS7GTA and the stock Russian output tubes. That reminds me that I really should pick up a few more pairs of Russians one of these days.

The WA6 has a pair of Tung-Sol 6CY7 signal tubes that I'm trying to debuzz and a RCA Type 80 Rectifier. If the debuzzing works, I'll try a 6DR7 next. This is very exiting; I can actually listen to music with low-level passages, which includes most of it!

Of course, I'm working right now. Kinda. Most of it was finished by the morning and now I'm making some final recommendations. Trying to be kind. lol
 
Oct 26, 2015 at 3:31 PM Post #264 of 384
Turns out that my daughter's male friend - they're 16 - is into headphones. I had her invite him in. The kid's eyes popped when he saw the entire setup. Naturally, all the tube amps were lit with the brightest bottles. lol

Talking to him about the amps, as he was terribly curious, I mentioned how good tubes can be had for relatively little money. This was one of his concerns. I explained relabeling and showed him a pair of tubes that were really Sylvania 6SN7GT, but were labeled differently, and were just sitting there priced very low. After he left, it occurred to me that I'm an idiot for not buying them, so clicked on the big, blue button. We'll see how they work out.


The tubes are here. I was wrong. They're not Sylvania 6SN7GT, but a heavily chromed Sylvania 6SN7GTB. They look essentially identical to the GTAs they replaced, but with a touch more chrome. Branded as Philco. $11 shipped. I think I did OK.
 
Oct 26, 2015 at 3:50 PM Post #265 of 384
I'm expecting some WE 396A, courtesy of a very kind Elise owner, and picked up a pair of JAN GE 5670 to have a point of comparison. By the time everything arrives, including the adapters, we're talking at least a month. In the meantime, I get to look at the 5670Ws. Man, are they tiny!

Any experience with this tube type?
 
Oct 26, 2015 at 6:09 PM Post #266 of 384
I'm expecting some WE 396A, courtesy of a very kind Elise owner, and picked up a pair of JAN GE 5670 to have a point of comparison. By the time everything arrives, including the adapters, we're talking at least a month. In the meantime, I get to look at the 5670Ws. Man, are they tiny! Any experience with this tube type?

 
Bendix Eclipse-Pioneer 2C51
 

 
Oct 26, 2015 at 9:18 PM Post #268 of 384
Too many tubes... not enough hours... lol. :)
 
I rolled through these back in my LD days, but haven't gotten around to trying them in the Glenn. Going through my stash, I see WE 396A, Sylvania 5670 (gold pins) and CBS 5670. I recall liking the Bendix and Sylvania best. But again, that was a long time ago with a different amp...
 
Back to the present, I spent an hour with the 5694 last night and I think I am going to like this tube. :)
 
Oct 26, 2015 at 9:41 PM Post #269 of 384
It's the middle of the night here but something wake me up (might be the full moon), thought I'd check my mail and I to my surprise there are 7 new messages here, couldn't not read them :wink:
 
 
I'm expecting some WE 396A, courtesy of a very kind Elise owner, and picked up a pair of JAN GE 5670 to have a point of comparison. By the time everything arrives, including the adapters, we're talking at least a month. In the meantime, I get to look at the 5670Ws. Man, are they tiny!

Any experience with this tube type?

 
  Too many tubes... not enough hours... lol. :)
 
I rolled through these back in my LD days, but haven't gotten around to trying them in the Glenn. Going through my stash, I see WE 396A, Sylvania 5670 (gold pins) and CBS 5670. I recall liking the Bendix and Sylvania best. But again, that was a long time ago with a different amp...
 
Back to the present, I spent an hour with the 5694 last night and I think I am going to like this tube. :)

When I heard the 396A (also in a different amp, the P8 in fact) I found them to be quite a step up from the GE 5670s I had in there before. A NOS pair of these would be about $100 on ebay, a bit more pricey than most other 5670/2C51s. Not sure if that is any indication of sound quality but I guess the're in demand so somebody must like 'm. :wink: Never tried them in the Elise so I'm curious to your experience with these Shaffer. One thing I noticed with the 5670/396A is they are much less susceptible to microphonics.
 
The 5670s hold a special place for me as they were the first tubes I heard/bought and what got me interested in tubes. They couldn't be half bad than :)
 
Have you ever tried any GE 5670 gibosi? Might be nice to have a point we could cross-reference :)
 
Oct 26, 2015 at 10:22 PM Post #270 of 384
  The 5670s hold a special place for me as they were the first tubes I heard/bought and what got me interested in tubes. They couldn't be half bad than :)
 
Have you ever tried any GE 5670 gibosi? Might be nice to have a point we could cross-reference :)

 
I don't have a GE 5670, only Sylvania, WE, Bendix and CBS. But before I get try to reacquaint myself with 396A/5670/2C51, I still need to compare the gray-glass NU and the ECC31... and the 5694. :)
 

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