Leben CS600, 6L6, EL34, KT66 and KT88........

[Ian]

I really do need help on this please.......

The Leben site specifies 6L6 and EL34 valves as being suitable for the CS600.

Below is extracted part of a review of the Leben CS600

"For the tube-rollers, there are cathode resistor and plate switches which can be toggled in various combinations to allow for a wide array of driver tubes. You can use most of the 6L6 and EL34/6CA7 families of tubes. If you are fine with keeping the top cover off, you can tube-roll with even more variety of tubes, such as KT-88s, 350Bs, etc. (should a wad of cash fall from the sky and land on my head, I would like to try Western Electric 350Bs in Leben CS-600"

Clearly this suggests KT66, 88 and etc ! Could anybody please clarify/confirm that it would be cool and the gang to use these as alternatives.

I've been a bit high maintenance of late, clearly in need of attention . I'll back off for a bit after this !

Cheers all.

And this is a genuine plea for help, not a backhanded way of saying "I've just bought a Leben CS600", which I have . It's the little things.....

[rabski]

The Jadis chez Rab Villas also take a fair range of output tubes: EL34, 6550, KT88 and KT90. Not sure about KT66 though. I haven't looked it up, but I think it's got different pin connections - someone will know for sure.

I haven't gone into great depth yet, but there are plenty of generally held opinions about this range and I did a fair bit of swapping in my last amp of KT88 and 6550 variants. The usual view is that EL34 are bit 'valve like' and quite smooth, KT90 are quite sharp and 'fast' sounding and KT88/6550 give a bit of the best of both. I'vetried KT90 and 6550 in the Jadis, but so far stuck with the KT90s as the nicest sound. But that's going to depend a great deal on the s[ecific valves and the 6550s I've got lying about are definitely not the best.

KT88/6550 versus EL34 looks a good place to start if you want to play, as they aren't hideously expensive (well, not most of them) and are quite sought after (so fairly easy to sell on once you've found your favourite).

IME, the re-issue Gold Lion KT88tubes (I think they're either re-branded Chinese or Sovtek - someone will know better than me) and the Svetlana 'winged C' 6550s are as good as any for some initial experiments, though as always with valve swaps, YMMV and all amps respond differently.

[mrwippy]

Long ago, from another forum, far far away.

"…………..you need to know a little about all the different types as all are not interchangeable. Here is why:

Tube, Max power, anode voltage, screen voltage:
6L6/G/GA/GB, 19W, 360V, 270V:
KT66 (1940s+), 25W, 500V, 400V:
EL37, 25W, 800V, 800V:
5932, 21W, 400V, 300V:
5881, 23W, 360V, 270V:
6L6GB/WGB, 23W, 360V, 270V:
6L6GC, 30W, 500V, 450V:
7581, 30W, 500V, 450V:
7581A, 35W, 500V, 450V:

There are others like WE350s, 6L6 metals etc that we probably don't need to go into details about. (edit by me think that means ££££££'s)

You will see these are quite different and relate to UK / USA production ONLY.

Many Russian production tubes are actually 6P3S and are 'not really' a 6L6GC, not as we understand the USA designation [though are often labels as such]......

……I can recommend unreservedly WE350s, KT66 (originals only GEC / Marconi) and EL37s (Mullards), though several of these tube pull more current for their heaters………."



From a man who knows - not sure if it really helps, but of course there is one source you could ask - quick email to Leben



Paul

[rockmeister]

just rom interest, what dont you like about whats in it...I suspect leben source very very good valves from new?

[Hornucopia]

rockmeister wrote:

just rom interest, what dont you like about whats in it...I suspect leben source very very good valves from new?

It's just the 'itch' I think, as he hasn't even GOT the amp yet! I stuck with EL-34s until I pulled them out recently to get them checked (aborted visit to Paul in Plymouth) and decided to stick in the alternatives.
Sounded quite nice. I agree with you Rocky, the sound is fine as is!

It's the disease of reading about 'tube rolling'? (Not to mention equipment-change/cables/resonance......
Enjoy the music!

[mrwippy]

rockmeister wrote:

just rom interest, what dont you like about whats in it...I suspect leben source very very good valves from new?

the pictures of the inside of one I saw clearly shows old Russian military tubes being used for 6L6's as discussed in this thread branded as 'new' Sovtek. Very cheap, but wonderful in every way.

Paul

[Ian]

Hornucopia wrote:

rockmeister wrote:

just rom interest, what dont you like about whats in it...I suspect leben source very very good valves from new?

It's just the 'itch' I think, as he hasn't even GOT the amp yet! I stuck with EL-34s until I pulled them out recently to get them checked (aborted visit to Paul in Plymouth) and decided to stick in the alternatives.
Sounded quite nice. I agree with you Rocky, the sound is fine as is!

It's the disease of reading about 'tube rolling'? (Not to mention equipment-change/cables/resonance......
Enjoy the music!

Absolutely, not got it yet but am just bound at some stage to want to muck about and wanted to find out what's what in advance, plus I have a Quad of KT66 already that I've had knocking about for ages and want to know if I can stick them in.

As suggested, I've dropped Leben an email.

I don't propose to be an obsessed tube roller, but when tou see a Quad of valves for forty quid or less in here, what'you going to do.............? Especially when you can play with them for a bit and move them on to someone else to try. It's better than telly !

[Ian]

Ian wrote:

Hornucopia wrote:

rockmeister wrote:

just rom interest, what dont you like about whats in it...I suspect leben source very very good valves from new?

It's just the 'itch' I think, as he hasn't even GOT the amp yet! I stuck with EL-34s until I pulled them out recently to get them checked (aborted visit to Paul in Plymouth) and decided to stick in the alternatives.
Sounded quite nice. I agree with you Rocky, the sound is fine as is!

It's the disease of reading about 'tube rolling'? (Not to mention equipment-change/cables/resonance......
Enjoy the music!

Absolutely, not got it yet but am just bound at some stage to want to muck about and wanted to find out what's what in advance, plus I have a Quad of KT66 already that I've had knocking about for ages and want to know if I can stick them in.

As suggested, I've dropped Leben an email.

I don't propose to be an obsessed tube roller, but when tou see a quad of valves for forty quid or less on here, what'you going to do.............? Especially when you can play with them for a bit and move them on to someone else to try. It's better than telly !

[mrwippy]

Ian wrote:

Ian wrote:

Hornucopia wrote:

rockmeister wrote:

just rom interest, what dont you like about whats in it...I suspect leben source very very good valves from new?

It's just the 'itch' I think, as he hasn't even GOT the amp yet! I stuck with EL-34s until I pulled them out recently to get them checked (aborted visit to Paul in Plymouth) and decided to stick in the alternatives.
Sounded quite nice. I agree with you Rocky, the sound is fine as is!

It's the disease of reading about 'tube rolling'? (Not to mention equipment-change/cables/resonance......
Enjoy the music!

Absolutely, not got it yet but am just bound at some stage to want to muck about and wanted to find out what's what in advance, plus I have a Quad of KT66 already that I've had knocking about for ages and want to know if I can stick them in.

As suggested, I've dropped Leben an email.

I don't propose to be an obsessed tube roller, but when tou see a quad of valves for forty quid or less on here, what'you going to do.............? Especially when you can play with them for a bit and move them on to someone else to try. It's better than telly !

Don't forget to post Leben's response - which hopefully won't be a blanket "speak to your dealer" or "just use the ones as supplied" Usually the Japanese understand the need to try other flavours! This amp is on my 'maybe one day' list -well I do have a lifetimes supply of tubes, but I'd need to hear it against my Romulus to see if it offers any real benefit.

Paul

[early]

This page should be in every tube rollers " favorites " .

http://tdsl.duncanamps.com/tubesearch.php

[opusover21]

Blimey Ian - bet you wished they never mentioned it! I would roll the signal valves first anyway...forget about the driver tubes for a bit

[mrwippy]

early wrote:

This page should be in every tube rollers " favorites " .

http://tdsl.duncanamps.com/tubesearch.php

Or better still browse here which has that link and so much more

Paul

[Ian]

This is all useful and interesting, thanks all.

And Stuart, please complete the following !

Tube rolling is like making love to a beautiful woman, you.........

[TheMooN]

Ian wrote:

And this is a genuine plea for help, not a backhanded way of saying "I've just bought a Leben CS600", which I have . It's the little things.....

Hope this works out well for you Ian

[opusover21]

Ian wrote:

This is all useful and interesting, thanks all.

And Stuart, please complete the following !

Tube rolling is like making love to a beautiful woman, you.........

Stick it in by holding the base...turn her on..wait for her to warm up and pretend she's the best thing sinced sliced bread? that is until a nice german or Russian turns up...either way if its got tubes, tits or an engine prepare to get you're wallet spanked..

[Gerard]

Ian

I was wondering how you've got on with the Leben?
I would have thought a KT77 would work, not at KT88/6550 as these draw too much current.
In fact I remember finding a post by someone who was using Gold Lion KT77s (in the USA...Audiogon maybe) to great success. They may have had to change the grid resistor...I'll see if I can find it.
I'm interested in getting a Leben CS600 so would be interested in your thoughts.
Regards
Gerard

[Ian]

Hi Gerard,

It's simplystunning but I'm moving it on. I knew I couldn't really afford to keep it whenI bought it but it's been great to own and I'm pretty confident I can move it on at no or little loss.

I've promised somebody first refusal and I'll know by the end of the weekend if they wish to have it. If not I'll stick it on the 'Wam.

Oh, and after mucking about a bitI found Sovtek 6L6GC to suit me most, not expensive valves by any means. If I were keeping it I'd try some RCA NOS of these.

[Gerard]

Ian

Thanks for the update. I might well be very interested if your other deal doesn't go through.

Regards
Gerard

[Ian]

I'll let you know Gerard, do you want to just let me know or PM me where you are ?

[Gerard]

Cool thanks Ian, I've sent you a pm.