KT120 quad. Recommendations chaps

[BarneysDad]

30 year old, recently serviced, Art Audio Concerto Power amp powering Quad 2905s electrostatics.
Have 4 x 1970s GEC KT88s which sound lovely.
And a quad of Art Audio branded KT90s, made by Ei Yugoslavia.

Maker Tom Willis recommends getting 4 x KT120s.
Watford Valves have these
https://watfordvalves.com/product_detail.asp?id=3045
Any thoughts?

 

[Jules_S]

If the amp is that old, will it even cope with KT120s?

 

[BarneysDad]

As mentioned, maker Tom Willis (Art Audio) has recommended.

 

[John (big)]

30 year old, recently serviced, Art Audio Concerto Power amp powering Quad 2905s electrostatics.
Have 4 x 1970s GEC KT88s which sound lovely.
And a quad of Art Audio branded KT90s, made by Ei Yugoslavia.

Maker Tom Willis recommends getting 4 x KT120s.
Watford Valves have these
https://watfordvalves.com/product_detail.asp?id=3045
Any thoughts?

If the amp is that old, will it even cope with KT120s?

I have a Rogue Atlas Magnum with 4 x KT120's 100wpc (Atlas 55 wpc) gently powering a pair of OTA Quad 57's.

A few years ago I tried KT88/KT99's whilst waiting for x 4 replacement KT120's, no comparison it's why the Atlas Magnum was created when Rogue found the transformer had enough reserve. The KT120's do everything so much better with ease, as Jules_S: cautioned only if there is sufficient reserve however since the maker Tom Willis recommends getting 4 x KT120s. there must be one would think.

I'm told KT150's are even better KT170's I don't know. One day finances permitting with an eternal heater transformer I may try KT150/170

The fly in the ointment is when Watford Valve & Hot Rox UK run out will you be able to buy Tung-Sol KT anything, Russia banned their export they were not initially sanctioned, buying from China price up 400% +.

With the help of Kevin Cagey H I was able to buy a quad of KT120's a couple of months ago from Watford Valve before Chinese price hikes.

 

[JANDL100]

My old Primaluna amps took KT120, among many others. Really good, I enjoyed them a lot. A robust, powerful, open sound.
Well worth trying imo

 

[montesquieu]

Personally not had a great experience with KT120s. KT90s are generally my preference in the KT88 family. Have tried all three in my Radford STA100. Preferred KT90s in my Leben CS1000P as well, also in a Tsardakas PP amp which like the Leben was designed around KT120s (there were only KT88s at this sort of power output when the Radford was built). KT120s maybe a shade bolder/beefier but lose on subtlety/air/grace. As ever though it all depends on the amp involved - I don't think there's any alternative but to suck it and see.

 

[JANDL100]

Hmm, interesting, Tom.
I had an Icon KT90 amp, and I would say it was ballsier and less subtle than my KT120-ed Primaluna.

But there is much more to the sound than just the valve type.

I agree, you just gotta try it and see.

 

[Juancho]

Hmm, interesting, Tom.
I had an Icon KT90 amp, and I would say it was ballsier and less subtle than my KT120-ed Primaluna.

But there is much more to the sound than just the valve type.

I agree, you just gotta try it and see.

Maybe it's system dependent to an extent. I've had exactly the same amps as Tom and agree with you: kt90s were less subtle than 120s. I would exclude the Leben from the sample as it's HT was too low to get max performance from the 120s

 

[BarneysDad]

Have bitten the bullet, KT120s arrive tomorrow from Hot Rox, Nottingham.
Any problems they're not far from me, in downtown Melton Mowbray.
Watford Valves being closed until 10th July, stocktaking.

Will let you know.

 

[Ian]

Have bitten the bullet, KT120s arrive tomorrow from Hot Rox, Nottingham.
Any problems they're not far from me, in downtown Melton Mowbray.
Watford Valves being closed until 10th July, stocktaking.

Will let you know.

Nice one, I'd love a quad myself but have been spending recently. I've bought three different quads from Hot Rox over the years with no problems whatsoever.

Enjoy, though is there a heatwave coming ?

 

[Juancho]

Nice one, I'd love a quad myself but have been spending recently. I've bought three quads from Hot Rox over the years with no problems whatsoever.

Enjoy, though is there a heatwave coming ?

+1 kt120s have always proved reliable and rugged IME

 

[John (big)]

Have bitten the bullet, KT120s arrive tomorrow from Hot Rox, Nottingham.
Any problems they're not far from me, in downtown Melton Mowbray.
Watford Valves being closed until 10th July, stocktaking.

Will let you know.

Bought KT120's from Hot Rox a few years ago quick delivery.

Do not forget to give them time to settle could take a few days for everything to gel together.

Please update on their progress please

 

[BarneysDad]

Bought KT120's from Hot Rox a few years ago quick delivery.

Do not forget to give them time to settle could take a few days for everything to gel together.

Please update on their progress please

Will do chaps

 

[BarneysDad]

48 hours down the track, how are the KT120s performing?
Surprisingly good.
Bigger soundstage than the KT88s or 90s and more open.
Top end is a little harsh, but expecting that to soften with time.

Perfect weather for bigger hotter valves.

 

[DUVET]

The idea as of a class D as a spare is highly appealing in this weather .

 

[BarneysDad]

The idea as of a class D as a spare is highly appealing in this weather .

Open a window...sorted

 

[John (big)]

48 hours down the track, how are the KT120s performing?
Surprisingly good.
Bigger soundstage than the KT88s or 90s and more open.
Top end is a little harsh, but expecting that to soften with time.

Perfect weather for bigger hotter valves.

Top end improving ?

 

[BarneysDad]

Top end improving ?

getting there but still a bit shrill

 

[John (big)]

getting there but still a bit shrill

They can take a while to settle, I assume the bias is correct.

I have noticed a difference with some driver tubes particularly ECC82/12AU7.

As often used as a substitute in the USA I found RCA clear top 6CG7 were the best 9 pin valve.