[gibosi]

Ohh, I missed that news! Details?

https://www.head-fi.org/threads/2359glenn-studio.600110/page-2580#post-16300598

 

[Celty]

https://www.head-fi.org/threads/2359glenn-studio.600110/page-2580#post-16300598

Fantastic. Thanks much.

 

[Smallpie]

Sadly I need to come up with some cash and thought I’d reach here first. Anybody interested in a NOS pair of Bendix 6080WB’s? Send me a message if interested. I have a couple pairs but only want to sell one pair.

 

[Monsterzero]

For anyone with an adapter that allows the use of a 4 volt rectifier in their GOTL,

https://www.ebay.com/itm/3527821134...5&toolid=10001&customid=knz2omlswn01zlp100004

I bounced this off of our resident rectifier guru, @gibosi , who swapped out a Telefunken ($$$) and rolled in this tube, proclaimed it to be a "poor mans Telefunken". Spacious airy and a bit of extra energy in the treble area, I figured at this price it was worth the plunge to pair it up with some warmer, bassier tubes for my ZMFs.

 

[whirlwind]

For anyone with an adapter that allows the use of a 4 volt rectifier in their GOTL,

https://www.ebay.com/itm/352782113448?_trkparms=aid=555023&algo=HOMESPLICE.SIMRVI&ao=1&asc=20190711100440&meid=43e693d72b944f47a102612a1258c226&pid=100752&rk=1&rkt=24&mehot=pf&sd=324486653639&itm=352782113448&pmt=1&noa=0&pg=2047675&algv=SimplAMLv5hPointwiseWebNoToraCoCoViewsNoHighIdfOrRoundRobinBlenderWithPromotedViewItems&brand=Tungsram&_trksid=p2047675.c100752.m1982&mkevt=1&mkcid=1&mkrid=711-53200-19255-0&campid=5338093425&toolid=10001&customid=knz2omlswn01zlp100004

I bounced this off of our resident rectifier guru, @gibosi , who swapped out a Telefunken ($$$) and rolled in this tube, proclaimed it to be a "poor mans Telefunken". Spacious airy and a bit of extra energy in the treble area, I figured at this price it was worth the plunge to pair it up with some warmer, bassier tubes for my ZMFs.

Yeah...with some warmer tubes this rectifier should sound nice.
Good price too for a NOS tube 40 years old.

 

[gibosi]

Here's an obscure tube that might be fun to try: Raytheon CK5755, which is a tweaked 12AT7 with a non-standard pinout, so another adapter! lol

https://bms.isjtr.ro/sheets/138/5/5755.pdf

I know of one application, an analog computer built by Western Electric, used to guide the Nike-Ajax missile:

http://www.ed-thelen.org/computer.html

But I have absolutely no idea how it might sound. Anyone feeling adventurous?

 

[gibosi]

Oh, it turns out that at one time, someone was selling rebased 5755 tubes as “12AX7 Overlords” for outrageous prices. Search for “12AX7 Overlord” and enjoy.

 

[mordy]

Is there someone who can explain what GT/G means in a tube designation (as opposed to G or GT)?
I may have an answer but not sure if it is correct and that's why I am asking.

 

[mordy]

So there I am, happily listening when there is a sudden medium loud pop - and the left channel goes dead!
Don't panic - the amp should be OK, probably a tube went? The driver tubes are metal and both feel warm; the power tubes both light up.
Must be one of the RCA 6J5 metal tubes - switched out the left one for another one - same problem; L channel is dead. Could it be that the amp broke? Perish the thought!
Wait, maybe the Chatham 6AS7G power tubes. Switched them around - yep; the right channel is dead now! But both power tubes light up - how can it be? Actually I originally had three Chathams, but one rolled off my desk when I took a picture of it with, disastrous results. No replacment available ATM. I miss the sound...

OK, let's put in the Bendix 6080WB tubes.
Phew! -all is back to normal, both channels working. Shouldn't have doubted the GOTL which is built like a tank.
Actually, although both Chathams light up, but one of them (L) is not as hot as the other one.
How can it be that the tube dies in action (DIA) and still lights up?

Just checked eBay - only one Chatham 6AS7G available for $200 - forget it.

Oh well, have to try to hunt down one at a reasonable price...

 

[Velozity]

So there I am, happily listening when there is a sudden medium loud pop - and the left channel goes dead!
Don't panic - the amp should be OK, probably a tube went? The driver tubes are metal and both feel warm; the power tubes both light up.
Must be one of the RCA 6J5 metal tubes - switched out the left one for another one - same problem; L channel is dead. Could it be that the amp broke? Perish the thought!
Wait, maybe the Chatham 6AS7G power tubes. Switched them around - yep; the right channel is dead now! But both power tubes light up - how can it be? Actually I originally had three Chathams, but one rolled off my desk when I took a picture of it with, disastrous results. No replacment available ATM. I miss the sound...

OK, let's put in the Bendix 6080WB tubes.
Phew! -all is back to normal, both channels working. Shouldn't have doubted the GOTL which is built like a tank.
Actually, although both Chathams light up, but one of them (L) is not as hot as the other one.
How can it be that the tube dies in action (DIA) and still lights up?

Just checked eBay - only one Chatham 6AS7G available for $200 - forget it.

Oh well, have to try to hunt down one at a reasonable price...

Hey Mordy, I think this is a Chatham moonlighting as a GE. Internal construction matches perfectly from what I can tell. Worth a shot for $25 I think.

https://www.ebay.com/itm/144023393395?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649

 

[whirlwind]

Hey Mordy, I think this is a Chatham moonlighting as a GE. Internal construction matches perfectly from what I can tell. Worth a shot for $25 I think.

https://www.ebay.com/itm/144023393395?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649

I think so too as I see the copper rods.
Unreal that the Chatham prices have jumped this much...these used to be very affordable tubes.
Still have mine in my amp paired with Brimar 13D1.

 

[bcowen]

So there I am, happily listening when there is a sudden medium loud pop - and the left channel goes dead!
Don't panic - the amp should be OK, probably a tube went? The driver tubes are metal and both feel warm; the power tubes both light up.
Must be one of the RCA 6J5 metal tubes - switched out the left one for another one - same problem; L channel is dead. Could it be that the amp broke? Perish the thought!
Wait, maybe the Chatham 6AS7G power tubes. Switched them around - yep; the right channel is dead now! But both power tubes light up - how can it be? Actually I originally had three Chathams, but one rolled off my desk when I took a picture of it with, disastrous results. No replacment available ATM. I miss the sound...

OK, let's put in the Bendix 6080WB tubes.
Phew! -all is back to normal, both channels working. Shouldn't have doubted the GOTL which is built like a tank.
Actually, although both Chathams light up, but one of them (L) is not as hot as the other one.
How can it be that the tube dies in action (DIA) and still lights up?

Just checked eBay - only one Chatham 6AS7G available for $200 - forget it.

Oh well, have to try to hunt down one at a reasonable price...

Have you tried resoldering the pins? Could easily be that. The filament wiring inside the pins is still making good electrical contact allowing the tube to light up as normal, but if the pin connection to the plate or cathode in one of the triodes has been compromised....no sound in that channel.

 

[mordy]

Have you tried resoldering the pins? Could easily be that. The filament wiring inside the pins is still making good electrical contact allowing the tube to light up as normal, but if the pin connection to the plate or cathode in one of the triodes has been compromised....no sound in that channel.

Thanks - did not think of that; will give it a try.

Old Russian saying: Here we do not use what we need; here we use what we have.
Since I do not have a spare Chatham 6AS7G I reminded myself that I have a single Tung Sol 6AS7G. This tube was bought from a Canadian seller - at least the red print is the same color as the GE 6AS7G tube mentioned above.The construction is somewhat different with what looks like two getters: a top getter and a side getter, whereas the Chatham only has a side getter. The Chathams have copper rods (which i think always is a good sign) and the TS silver color rods. The TS is a little larger than the Chatham. The Chatham micas are black, the TS silver. I think the Chathams are from 1958 and the TS is from 1965.

First impression is that they sound a little different but good enough for now.
Tried to find information on Chatham tubes but could not find anything - only that Tung Sol bought the company, but no timelines.

 

[mordy]

Hey Mordy, I think this is a Chatham moonlighting as a GE. Internal construction matches perfectly from what I can tell. Worth a shot for $25 I think.

https://www.ebay.com/itm/144023393395?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649

Thanks for the tip! Will look into it.

 

[mordy]

Have you tried resoldering the pins? Could easily be that. The filament wiring inside the pins is still making good electrical contact allowing the tube to light up as normal, but if the pin connection to the plate or cathode in one of the triodes has been compromised....no sound in that channel.

Tried reheating the pins - tube did not respond to treatment. Tried whacking it but no response to shock treatment. Another pretty tube decoration...
The only thing I can see is a thickening on one spot of one of the filament heating rods.