KT66s or 6L6s

hotpickups

What would say the main difference would be? I'm used to 6L6s so that would be my first choice however, and I missing something that a KT66 would give me. All cork sniffing type question maybe which I usually hate LOL

@ICBM ?

karltone

Not all 6L6 amps can take KT66's. I'd check whether the mains transformer can accommodate the extra filament current needed for the KT66's. Thought i'd mention it in case you are not aware of this. 

ESchap

Also the size of the bottle can mean that they won't fit side by side in some amps designed to take 6L6's, they need more space between the valve bases and also they can be quite a bit taller, meaning they won't fit in the cab.

hotpickups

Either will fit I know that much so I'm mainly interested in the sound differences like headroom etc? If there is anything significant ?

hotpickups

karltone said:

Not all 6L6 amps can take KT66's. I'd check whether the mains transformer can accommodate the extra filament current needed for the KT66's. Thought i'd mention it in case you are not aware of this. 

Hi @karltone . I think the transformer would need to be more powerful for KT66s. 6L6 needs less power. Would that mean if a KT66 valved amp would be able to have 6L6s safely installed as they don't need as much? Or will it fry the valves.

Yep you guessed it I am totally a newbie when it comes to this stuff

ecc83

I always took the KT66 to be more "hi fi" than the 6L6 or EL34 (else why would Quad have chosen them? The 34 would have been cheaper and has a higher sensitivity and Radford seemed happy with them? )

A 6L6 will be perfectly safe on a "meatier" power traff. A moments thought perhaps? The ECCs need only 300mA and go in everything!

Dave.

hotpickups

ecc83 said:

I always took the KT66 to be more "hi fi" than the 6L6 or EL34 (else why would Quad have chosen them? The 34 would have been cheaper and has a higher sensitivity and Radford seemed happy with them? )

A 6L6 will be perfectly safe on a "meatier" power traff. A moments thought perhaps? The ECCs need only 300mA and go in everything!

Dave.

Really not sure what you are saying i.e. 300ma, Quad?Radford? So not much of a difference in sound then? They're similar apart from their power requirements?

wellsyboy

Ran  my Carr mercury with a KT66 and my royalist - both sounded stunning and I preferred it to the EL34 - I've no idea why - I just thought it sounded better

hotpickups

wellsyboy said:

Ran  my Carr mercury with a KT66 and my royalist - both sounded stunning and I preferred it to the EL34 - I've no idea why - I just thought it sounded better

That's probably good enough for me. Those kt66s are enormous aren't they. Not that it matters As long as they are enormous in sound too lol

Lebarque

I've read many amp experts saying that circuit design has a bigger effect on tone and character than the type of output valve used, although there are some differences of course.

olafgarten

I've always thought of the KT66s as slightly cleaner and fatter than 6L6s

p90fool

There is an undeniable but subtle sonic difference between the two valve types, but I suspect a lot of people just really like the look of KT66s...

ICBM

To me, KT66s sound thicker and softer, 6L6s clearer and brighter. Not a lot in it though - there's probably as much difference between different 6L6s.

The circuit design is *much* more important.

hotpickups

ICBM said:

To me, KT66s sound thicker and softer, 6L6s clearer and brighter. Not a lot in it though - there's probably as much difference between different 6L6s.

The circuit design is *much* more important.

Thanks @ICBM . I know KT66s need a bigger transformer power than 6L6s but would you say it'll be ok to put 6L6s in a KT66 spec'd amp without causing damage to the valves or something? KT66s wouldn't work with a 6L6 spec'd transformer I gather

ICBM

hotpickups said:

I know KT66s need a bigger transformer power than 6L6s but would you say it'll be ok to put 6L6s in a KT66 spec'd amp without causing damage to the valves or something? KT66s wouldn't work with a 6L6 spec'd transformer I gather

It depends on the amp. 6L6s should always be safe in a KT66 amp, but not necessarily the other way round. The heater current issue is only marginal and doesn't affect most amps (the only one I know of which is a bit risky is the Jet City JCA50, although there may be others) but also in some amps which are designed for the highest-rated 6L6GCs, the voltages may be too high for KT66s to run safely (ultra-linear Fenders, Mark series Boogies etc) - there are 6L6s which aren't really reliable in these too.

As ever (and I'm surprised Dave hasn't asked this ) - what amp is it?

hotpickups

All sorted. If you're interested yes you can put in 6L6s into a KT66 spec'd amp

ecc83

ICBM. "Dave" only knows Blackstars! And they put most power valve heaters in series and DC heat the rest. As for the extra current a 66 needs? I would be very surprised if any of the amps objected. The traffs are heat rise tested safe at local mains + 10% so in this country, no worries.

Dave.

ChrisCox1994

The redplate BM66 sounds great with them  

oh look, one for sale! http://www.thefretboard.co.uk/discussion/comment/1319947

hotpickups

ChrisCox1994 said:

The redplate BM66 sounds great with them  

oh look, one for sale! http://www.thefretboard.co.uk/discussion/comment/1319947

Oh yeah Too expensive for my tastes though unfortunately