[Zachik]

Are the 6C5G compatible with GOTL using the 2x6J5 --> 6SN7 adapter?
(6C5G are not in my compatibility table. Yet...)

Yes

Added! Thanks

You can throw the 6P5G in there as well, will work with the same adapter. Thanks, Z.

6P5 is already on the list, BUT: it is separate row than 6J5, and adapter needed (according to my table) is "Dual 6P5 to 6SN7 adapter" (as opposed to "Dual 6J5 to 6SN7 adapter").
Is that a mistake? Is the Dual 6J5 to 6SN7 adapter compatible with 6P5, or does it require yet another adapter?!

 

[Zachik]

Question to the tube historians and experts:
I bought a batch of various tubes, all labeled Beckman, and I need help identifying some of them (plus whether or not they're compatible with GOTL)...

• First up, a couple 6336A (which is the reason I bought this batch!) - any idea who actually is the manufacturer?

• Next, 6Y6GA (again, no idea who is the manufacturer)...

• 12AX7 (I think) - any good? who made it?

• A pair of 6X4 - never heard of these... any good for anything?!

• Lastly, a pair of tubes that I have no idea what they are...

 

[UntilThen]

You must have raided Beckman's factory.

 

[UntilThen]

Took out my RFT EL11 for a photo shoot. NOS and NIB. Why did I keep it low profile? This should go into Berlin too. I found out that RFT stands for Rundfunk- und Fernmelde-Technik. That's a mouthful to pronounce. It's a group of state-owned technology companies in the former German Democratic Republic (East Germany). This company produced valves for Telefunken and Siemens and made the famous Siemens EL34. These valves are of very good quality and have excellent consistency. I sure hope so !

 

[UntilThen]

Ouch these are US$108 each now. How prices have shot up since I first started buying EL11 in the days of Elise.

 

[L0rdGwyn]

6P5 is already on the list, BUT: it is separate row than 6J5, and adapter needed (according to my table) is "Dual 6P5 to 6SN7 adapter" (as opposed to "Dual 6J5 to 6SN7 adapter").
Is that a mistake? Is the Dual 6J5 to 6SN7 adapter compatible with 6P5, or does it require yet another adapter?!

Nope, same exact adapter, same pinout as the 6J5.

 

[mordy]

Question to the tube historians and experts:
I bought a batch of various tubes, all labeled Beckman, and I need help identifying some of them (plus whether or not they're compatible with GOTL)...

• First up, a couple 6336A (which is the reason I bought this batch!) - any idea who actually is the manufacturer?

• Next, 6Y6GA (again, no idea who is the manufacturer)...

• 12AX7 (I think) - any good? who made it?

• A pair of 6X4 - never heard of these... any good for anything?!

• Lastly, a pair of tubes that I have no idea what they are...

Hi Z,
The 6336A has graphite plates and was made by Bendix. It draws 5A and you can only use two in the GOTL.
The 12AX7 has EIA number 188 which is GE, as well as those white sandblasted dots which is a giveaway of GE manufacture.
The 6X4 also has the sandblasted white dots which means - you'll guess.....
The last tube with the anode cap probably has something written under those yellow labels - need more information to identify them.
I am sure the 6Y6GA has some numbers on the base - let me know what they are.

 

[mordy]

Hi Z,
The 6336A has graphite plates and was made by Bendix. It draws 5A and you can only use two in the GOTL.
The 12AX7 has EIA number 188 which is GE, as well as those white sandblasted dots which is a giveaway of GE manufacture.
The 6X4 also has the sandblasted white dots which means - you'll guess.....
The last tube with the anode cap probably has something written under those yellow labels - need more information to identify them.
I am sure the 6Y6GA has some numbers on the base - let me know what they are.

PS: OK - identified the last tube with anode cap - it is a Sylvania 1229 tube; 2V and for electrometer applications (whatever that means).
https://www.ebay.com/p/NOS-Beckman-2532-932-Electrometer-Tube-sylvania-1229/757934680

 

[gibosi]

Hi Z,
The 6336A has graphite plates and was made by Bendix. It draws 5A and you can only use two in the GOTL.
The 12AX7 has EIA number 188 which is GE, as well as those white sandblasted dots which is a giveaway of GE manufacture.
The 6X4 also has the sandblasted white dots which means - you'll guess.....
The last tube with the anode cap probably has something written under those yellow labels - need more information to identify them.
I am sure the 6Y6GA has some numbers on the base - let me know what they are.

Are you sure about this Mordy? I don't believe I have ever seen a 6336 manufactured by Bendix. However, I have in my collection 6336 manufactured by Chatham/Tung-Sol and Raytheon. And the EIA code printed on the base of the one pictured above is 280, which corresponds to Raytheon....

 

[DecentLevi]

This is the build I'm going for, and haven't changed my mind since coming up with the 6J5 + 6V6/EL34/KT66/KT77 idea. My only question to @2359glenn is 4 6V6/EL34/KT66/KT77 or 2 6V6/EL34/KT66/KT77, and whether it would be worthwhile to have a 6V6/EL34/KT66/KT77 selection switch?

They all use the same impedance output transformer.
Guess could switch for the different cathode resistors Kt77 470 ohm KT66 500 ohm EL34 130 ohm 6V6 180 ohm.
This way they will all be operating at optimum operating point.

Leftside your amp is very similar to the one I'm getting. But mine will use a single 6SN7 driver, along with a 1-2 stage knob and output impedance knob for speakers. Personally I'm going with 4x power sockets allowing me to choose either 2x or 4x depending on what sounds best, which I'm thankful for Glenn agreeing to.

Here are the power tubes I plan to use: (including with adapters)

EL3N, EL12, EL12 Spez, EL32, EL34, EL38, EL39, 6V6, KT66, KT77

@2359glenn would it be possible to also add a knob to switch the cathode resistor settings to allow all the above power tubes to operate optimally? Granted it would not be practical to have 10 different settings, so perhaps would you be able to let me switch between... say the top 3-4 'main' operating points? For example 1 setting for 500ohm for KT66 and KT77 since they're close, 1 setting for EL12, 1 setting for EL 38/39 and 1 setting for EL3N. Those are the most important to me and the others I can make do with between those 3-4 settings. Unless of course you have a better recommendation for the average resistor switch ohm values and number of switch positions based upon the above list.

However, would 4 knobs be too impractical for you to build? The resistor switch knob in addition to volume, 1-2 stage and output impedance knob. I'm really interested in this configuration and I'm willing to pay even more or have an even larger chassis if necessary, so please let me know. And this should be my final revision for this request.

Finally RE the CCS. I'm assuming this is for the driver tubes right? And if I understand correctly this should allow 6SN7, 6N7 and dual 6J5 (with adapters) and most miniature 9-pin novals to operate optimally; but would there be any recommended adjustment option for EL11 and EL32 to operate optimally as drivers?

 

[mordy]

Are you sure about this Mordy? I don't believe I have ever seen a 6336 manufactured by Bendix. However, I have in my collection 6336 manufactured by Chatham/Tung-Sol and Raytheon. And the EIA code printed on the base of the one pictured above is 280, which corresponds to Raytheon....

Thanks for correcting me - I thought that all graphite plates were made by Bendix with different names on them - don't know where I got this idea from....
When it comes to the graphite plates 6080, there are a number of brands - were they all made by the different manufacturers?

I have 6336 tubes labeled Cetron, Raytheon and RCA. In addition, there are a number of more name brands and rebranded names for the 6336 - GE, Chatham, Tung Sol, United, Beckman etc.

 

[mordy]

Add Mullard to the list:

https://www.ebay.com/itm/Pair-of-NO...383726?hash=item26271410ee:g:flMAAOSwxktdbHW1

Honorable mention goes to the person who figures out which US factory made this Mullard branded tube (at least I think I have the answer, but I have been wrong before lol....)

 

[gibosi]

To the best of my knowledge all 6080 with graphite plates were manufactured by Bendix, regardless of brand. And all American-made 6336 and 6528 with graphite plates were manufactured by Chatham/Tung-Sol/Cetron or Raytheon.

 

[gibosi]

Add Mullard to the list:

https://www.ebay.com/itm/Pair-of-NO...383726?hash=item26271410ee:g:flMAAOSwxktdbHW1

Honorable mention goes to the person who figures out which US factory made this Mullard branded tube (at least I think I have the answer, but I have been wrong before lol....)

Chatham/Tung-Sol.

 

[mordy]

To the best of my knowledge all 6080 with graphite plates were manufactured by Bendix, regardless of brand. And all American-made 6336 with graphite plates were manufactured by Chatham/Tung-Sol/Cetron or Ratheon.

Now I feel better, even though I made a mistake...lol.
In summary, I must have gotten the idea that all graphite plate tubes were made by one manufacturer because all the 6080 graphite tubes were made by Bendix regardless of brand.
And all 6336 graphite tubes were made by either Tung Sol or Raytheon.
Thanks for clarifying this.