[gibosi]

The fat bottle is actually a Cossor 53KU and the skinny bottle is a Mullard GZ37, and yes, they sound quite different. To my ears, the 53KU is better and in fact, it is one of my favorites. Whether it is actually worth the extra price is a question that only you can answer.

 

[Smallpie]

The fat bottle is actually a Cossor 53KU and the skinny bottle is a Mullard GZ37, and yes, they sound quite different. To my ears, the 53KU is better and in fact, it is one of my favorites. Whether it is actually worth the extra price is a question that only you can answer.

Thanks, both say cv378 so I am just referring them that way. I don’t understand how they are different.(53ku vs. gz37)Interested in getting a skinny bottle as well as a fat bottle to see how they compare.

 

[gibosi]

CV378 is a British military specification, and both the Cossor and the Mullard match up. And every so often, I see a Mullard GZ33 labeled as a CV378, as well, because it too is very similar electrically. But even though they are very similar electrically, they sound quite different. In the same way, during WWII, the US government referred to all 6SN7 as VT-231 and the British referred to all 6SN7 as CV1986 / CV1988. But of course, not all 6SN7 sound the same.

The Cossor is among the darkest rectifiers I own (about 100), with very good bass, and in a fairly bright system it complements brighter output tubes and drivers very well. Recently, I have been enjoying the Cossor with Telefunken 6080.

In my opinion, the GZ37 is nothing special. But as is typical for most Mullard tubes, it too is dark with a rather rich upper bass and lower midrange. However, to my ears, the GZ32 is the best of the Mullards. But again, my ears and my gear. YMMV.

 

[Monsterzero]

Does anyone have a quiet pair of metal base Sylvania 6 or 12j5s they can spare for sale?

 

[Smallpie]

I plugged my potato masher 5r4wgb in and before the filament glows at the top there are purple sparks. I have a video of it if anybody wants to see.

the tube seems to work fine after the initial spark but what could the problem be?

 

[Monsterzero]

I plugged my potato masher 5r4wgb in and before the filament glows at the top there are purple sparks. I have a video of it if anybody wants to see.

the tube seems to work fine after the initial spark but what could the problem be?

I believe @gibosi once told me that the Chatham potato masher wont work in the GOTL.
I use them in my DAC though. Good sound for very little plata

 

[gibosi]

I believe @gibosi once told me that the Chatham potato masher wont work in the GOTL.
I use them in my DAC though. Good sound for very little plata

No it wasn't me.

The potato masher should work fine. After all, it is just a ruggedized 5r4. It would appear that the tube is arching. In some tubes, it is necessary to preheat the cathode before applying plate voltage to prevent arching, but this shouldn't be necessary with the potato masher. So I would suspect that the potato masher is slightly defective. But it just might work fine for many years before going to tube heaven.

 

[mordy]

No it wasn't me.

The potato masher should work fine. After all, it is just a ruggedized 5r4. It would appear that the tube is arching. In some tubes, it is necessary to preheat the cathode before applying plate voltage to prevent arching, but this shouldn't be necessary with the potato masher. So I would suspect that the potato masher is slightly defective. But it just might work fine for many years before going to tube heaven.

Off topic but the potato masher reminds me of a definition of a banjo: "Acoustic egg slicer".

 

[gibosi]

Off topic but the potato masher reminds me of a definition of a banjo: "Acoustic egg slicer".

When you see it, the name makes sense.

https://www.ebay.com/itm/Jan-CAHG-5R4WGA-Rectifier-Tube-Chatham-Electronics-Tung-Sol/284207481384

 

[Smallpie]

I believe @gibosi once told me that the Chatham potato masher wont work in the GOTL.
I use them in my DAC though. Good sound for very little plata

Yea Lukas told me it’s the best tube with their Lampizator Atlantic dac AND it’s super cheap! Can’t get better than that. It doesn’t spark in the Dac at all

 

[whirlwind]

Does anyone have a quiet pair of metal base Sylvania 6 or 12j5s they can spare for sale?

https://www.ebay.com/itm/2-NOS-Sylv...838424?hash=item443fe65f58:g:PXIAAOSwupRdDpEk

I have a pair of these 12 volt ...they do not have the metal base, I have not seen any 12 volt with metal base...but these tubes sound real good,
just like about all tubes from the 40's seem to sound nice to me.
https://www.ebay.com/itm/NOS-NIB-Ma...640029?hash=item2617e4fc5d:g:eEUAAOSwS3NclGRt

There is also the metal can Sylvania's which are cheaper, but I have no experience with those.

 

[mordy]

https://www.ebay.com/itm/2-NOS-Sylv...838424?hash=item443fe65f58:g:PXIAAOSwupRdDpEk

I have a pair of these 12 volt ...they do not have the metal base, I have not seen any 12 volt with metal base...but these tubes sound real good,
just like about all tubes from the 40's seem to sound nice to me.
https://www.ebay.com/itm/NOS-NIB-Ma...640029?hash=item2617e4fc5d:g:eEUAAOSwS3NclGRt

There is also the metal can Sylvania's which are cheaper, but I have no experience with those.

I looked on eBay yesterday and although most Sylvania 12J5 have black bases, there was a single sold with the metal base, but it appears very rare. The 6J5/VT-94 metal base are much easier to find.

 

[Monsterzero]

I grabbed these. Hopefully the 5th time is the charm.

https://tubeworldexpress.com/collec...5gt-sylvania-lightning-logo-nos-1945-1946-p11

 

[chrisdrop]

I grabbed these. Hopefully the 5th time is the charm.

https://tubeworldexpress.com/collec...5gt-sylvania-lightning-logo-nos-1945-1946-p11

Did you really get 4x bad pairs via eBay? That is epic bad luck! Were they listed as NOS? What evil sellers shall we boycott ?

 

[Monsterzero]

Yeah, four crappy pairs, and one was listed as NOS. All of my other j5/L63 purchases have worked out fine, but the universe doesnt want me using Sylvania for some reason.