[leftside]

Is there a difference in sound between 4654 and 4654k?

No. Not if from same manufacturer and factory.
https://www.radiomuseum.org/tubes/tube_4654.html

All are predecessors to the famous metal base EL34. And better. And cheaper

 

[triod750]

But octal socket is more convenient (4654k). That's the real difference...?

 

[leftside]

But octal socket is more convenient (4654k). That's the real difference...?

Yes, but why Philips decided they needed a 4654/EL50 (ST and metal base), 4654K and EL39 is beyond me. Probably to torment collectors in the next century

 

[OctavianH]

What am I going to do with these now.

Maybe go back to an amp of Eric McChanson? I know you liked those.

 

[OctavianH]

All are predecessors to the famous metal base EL34. And better. And cheaper

Even if I like a lot what I hear from this pair of Philips 4654K I do not consider it the typical EL34 sound. For me it does not have that sweet a little bit forced midrange all EL34 have. I even had to sweeten a little bit the sound with a Fivre 6SL7 to be exactly where I like to be. Do you consider this one in the same sound signature of EL34? It is, however very detailed and natural sounding. It is incredible to listen to acoustical instruments on it. You hear the strings of the acoustical guitar vibrating.

 

[UntilThen]

Maybe go back to an amp of Eric McChanson? I know you liked those.

Such a brilliant idea. It so happen that I will be buying back Destiny.

 

[OctavianH]

I was able, hopefully, to measure and decypher where and when my ECC40 were built. Of course, preliminary info.

Please ignore T2 and T1 columns, are Eternity's specific grid bias to reach 180V/4mA. Of course, what I'll set on the amp would be an average of both values which will keep both triodes as close as possible to the desired 4mA. I was lucky so 13/14 are almost perfectly matched. The LCC DX goes a little bit out of my 3-5mA so I guess I'll skip it. I do not really need to try all these, I've selected to try numbers 1/2/6/13:

LC3 / X7B - what I was using
LC2 / 58 - oldest one I have, Eindhoven
LCC / 5M - this one looks identical with the above one but, well, I'll try it
LCC / D8 - one from Hamburg.

And I guess that's it, the LC3 F5H went to storage, I do not quite consider it on par with the rest.

 

[OctavianH]

I had to check if my newest pair of RCA 807 works fine, that one measured several days ago. Well, works perfectly and sounds excellent. RCA 807 never disappoints, such an underrated tube. I put also the Philips ECC40 LC2 58 with it and goes somehow nice. Not as detailed as the Philips 4654K with Fivre 6SL7 but still rich and with better bass. Good times are these when whatever you combine sounds good.

 

[OctavianH]

I have not changed anything on the amp lately, but I have observed something interesting. I told you I matched almost perfectly a pair of RCA 807 to use here daily. Both needed around -19.8V to have 20mA. All good. But several days in a row I have observed that I needed to adjust the grid voltage to have the needle pointing towards 20mA. It was always a little bit more towards 21-22mA. Well, I said maybe I touched it by mistake. Yesterday I said, let's verify both tubes again and ... one of them became now stronger, the difference between them is around 3mA at the same bias. One remained as measured, needs -19.8V and other now needs -21.3V for the same 20mA. Interesting isn't it? In the first hours both were perfectly matched, in a few days they continued to evolve. This leads me again to the conclusion that these continue to evolve/change until they will finally die. But we usually check them only at the beginning. The ECC40 remained exactly the same, both triodes need -4.4V for 4mA... Interesting.

 

[Thaddy]

For those interested I put my pair of La Radiotechnique EL39's + adapters up for sale in the Classifieds.

 

[OctavianH]

Wel, I got some time today so I matched another pair. 1mA between this time. Let's see if these will evolve in the same way as the others.

By the way, I have one with loose top cap, I guess I'll have to glue it with something which does not loosens at high temps, right?

 

[OctavianH]

I have decided to edit the previous post related to my musical preferences because it is off topic. However, there is a big truth in it which I encountered again while testing the ECC40. If a tube makes the string instruments (violin and so on) sound natural, it will not make the same thing for the electric guitar which has a kind of distorted sound. ECC40 is majestic for classical, but it is not perfect for the electric guitar. Tubes which are very good for that (here we can put KT66 or EL34) are not so natural sounding as this one. For rock music there will always be a compromise between these 2 categories of instruments. I know that I am mixing somehow tubes used in input with tubes used in output and so on, because for me it does not really matters, I know all of them will impact what I hear. If I want to think about an input tube which makes what KT66 makes for guitars on output, I will mention ECC35. This 6SL7 with a strong british flavour is really making on input what GEC KT66 clear glass is doing on output. But it will not be a natural sound, it will make those electric guitars sound more aggressive in the detriment of the rest of the instruments.

 

[OctavianH]

After 24h check: both tubes are almost similar (the one 1mA behind recovered). Strange are the ways of tubes, but I will, for sure, pay more attention to what happens on a tube pair after days/weeks/months of usage. I start to think more and more about the sellers selling matched pairs, does that really matters? I bought this measurement device from France from here and since then I am buying only untested and ugly looking tubes. Stop feeding greedy ebay sellers, they are destroying our hobby (I know you read this).

 

[OctavianH]

And now definitely another off topic post. Damn guys I tried a Whiskey.

I am a beer guy, as Tomas was, I never understood these but today I found a Whiskey bottle in my house and wanted to try it. Damn, awful, this is what people from US drink? I haven't tried a whiskey in 20 years. Hmm.. maybe some ice would help it? I doubt.

 

[triod750]

That's a bad whiskey. Almost synthetic. Solid state kind of whiskey

You should try whisky instead, single malt.