[David A Silva]

What is a balanced transformer?

From my simple understanding the power input and output are connected to separate coils of a large transformer. Power transfer occurs by inductance only, suppressing surges and high frequency noise on the power line. Someone can probably provide a more elegant description.
I have a Keces BP1200. Here is a review for interested members…
https://www.kecesaudio.com/download/Headfonia Review Keces BP-1200.pdf

 

[Deleeh]

Hello,

@UntilThen really difficult, but I actually prefer the pentode.
Not that the others are bad, I also like them if the combination is right.
In fact, every type of tube that runs on Ultimate is special to me.
Each has its advantages and disadvantages or sounds a little different.
But a well-stocked supply of driver tubes helps things along.

Listened to a lot of music today and maybe did some things I shouldn't have done, but everything is fine.
Thought about saying it, but decided to leave it alone.
Today I also listened to the Ultimate with both Zmf's and switched between Kt63 and Kt88.
Rectifier EZ 81 RFT has remained, but I have put in the Tungsol 6SL7 GT.
Both KT63 and Kt88 are really good.
Auteur also plays very differently here in a good way to fall in love with.
Great acoustics and texture of the instruments, beautiful soulful vocals also with Mundorf.
Atrium, on the other hand, is a little person and simply rolls out everything you could wish for.

 

[UntilThen]

I actually prefer the pentode.

Both KT63 and Kt88 are really good.

You say you prefer pentode and then say KT88 is really good.

KT88 and 807 are Beam Tetrodes. The way I look at it, there are very good tubes in both pentodes and beam tetrodes.

I'm so thrilled because my birthday present from the family is a new pair of GEC 807 ATS25.

 

[Deleeh]

You see, it's that quick.
I love every tube on Ultimate, that says it all.

Nice present from the family.
My present from my wife Tung Sol 6SL7 WGT is also on its way.
What did you get yourself for your birthday?

 

[UntilThen]

What did you get yourself for your birthday?

A haircut.

 

[OctavianH]

And you use those triode strapped anyway so, it does not matter if they are pentodes of beam tetrodes.

 

[UntilThen]

Probably a silly question but what makes the 6AS7/6080 type tube incompatible with UltimatE amps ? I’m still learningl

No question is silly. See Eric's explanation below.

UltimatE is designed for the low voltage and high current yet an audio power tube - 6Y6G. 6Y6G is special but it is still an audio power tube. Incidentally and fortunately, and luckily, the setting for this 6Y6G is also good or workable for other power tubes like 6F6, 6V6, KTs, and ELs... and all those tubes you guys tested and used, within 60mV bias.

However 6AS7 is super low mu and ultra high current - it is a voltage regulating power tube. It requires a rather high negative grid voltage where UltimatE does not provide, so the current shoots up to 90+ mV, and is of course, not suitable to be used in UltimatE...

 

[crakers7]

You say you prefer pentode and then say KT88 is really good.

KT88 and 807 are Beam Tetrodes. The way I look at it, there are very good tubes in both pentodes and beam tetrodes.

I'm so thrilled because my birthday present from the family is a new pair of GEC 807 ATS25.

When you say GEC do you mean these ones ?

 

[crakers7]

No question is silly. See Eric's explanation below.

UltimatE is designed for the low voltage and high current yet an audio power tube - 6Y6G. 6Y6G is special but it is still an audio power tube. Incidentally and fortunately, and luckily, the setting for this 6Y6G is also good or workable for other power tubes like 6F6, 6V6, KTs, and ELs... and all those tubes you guys tested and used, within 60mV bias.

However 6AS7 is super low mu and ultra high current - it is a voltage regulating power tube. It requires a rather high negative grid voltage where UltimatE does not provide, so the current shoots up to 90+ mV, and is of course, not suitable to be used in UltimatE...

An excellent and easy to understand explanation

 

[UntilThen]

When you say GEC do you mean these ones ?

Discussing GEC 807 with @OctavianH , his opinion is both GEC 807 ATS25 and GEC VT60 are good and legit but he has ATS25 and that to him sound like the good old GEC tone.

So I bought the ATS25.
https://www.ebay.com.au/itm/305133735041?

 

[UntilThen]

Australian dollar is dropping. Everyday I look at those tubes, it cost a few dollars more.

 

[crakers7]

Discussing GEC 807 with @OctavianH , his opinion is both GEC 807 ATS25 and GEC VT60 are good and legit but he has ATS25 and that to him sound like the good old GEC tone.

So I bought the ATS25.
https://www.ebay.com.au/itm/305133735041?

AH OK , Good , I bought these a few months ago , I think they are the same

 

[UntilThen]

About the same price. Cossor and GEC 807 are probably the same but I have no way of confirming that.

 

[OctavianH]

Discussing GEC 807 with @OctavianH , his opinion is both GEC 807 ATS25 and GEC VT60 are good and legit but he has ATS25 and that to him sound like the good old GEC tone.

Just some mode details. I made some assumptions there based on what I read about VT60 and what I have observed as internal construction. I never listened to VT60 version (round plates). My ATS25 (the one UT bought) has some construction elements I was able to recognize in other GEC tubes I have in my collection. I also observed that some of the sound of ATS25 reminds me of GEC L63 grey glass. But I have never listened to the one many call here Cossor VT60 (that round plate version). Might be the same or not, I have no idea, I gave the advice to @UntilThen to buy the one I have since that one has for sure the sound he searches for. For the other, I have 1 piece around here and if I'll find a second one I will compare them. I expect they are the same but since I do not know this, I advised based on what I know.

By the way @crakers7 since you both live in the same country, it would be cool to switch between you those pairs and tell us if indeed sound the same.

PS. One thing it seemed different was the getters I found on several VT60 Cossor ones:

I have here 15-20 tube types of GEC and no one has this kind of getter. The round plate is something you can find on several british tubes (GEC but also Ediswan). I have here some Ediswan with similar shape. Another thing:

What to say, do not believe me because I know nothing nor have a clue, if you ask me which of those 2 types is GEC I might say the one with square plates. The other might be, might be not, might be Ediswan or other nice british manufacturer, even Cossor can be since some claim Cossor produced tubes until '50s but later become a rebrander. I have no proof of that, I have GEC KT66 rebranded as Cossor in Cossor original boxes. So, I have no idea which is which, most probably both are GEC and we are crazy as usual. LOL

 

[UntilThen]

By the way @crakers7 since you both live in the same country, it would be cool to switch between you those pairs and tell us if indeed sound the same.

We're 4,000 kms apart. He's in the west and I'm in the east.