KT-150s - anyone use them or too pricey?

[mdlewis]

Just walked buy an audio store in NYC that had an audio amp on display that used Tungsol KT-150s, which I had never seen before. Really cool looking tubes, and according to the guy at the store capable of delivering quite a bit more power than the KT-88 100s I'm familiar with. Just wondering if any one of the committed out there has considered using them, or plans to do so, etc.

 

[Mr. Foxen]

Don't think there are any amps built to use them. You only get more power from different valves when the amp is made to do so.

 

[bassboysam]

There were apparently a lot of reliabiliy issues with the KT-150.

 

[Bassmec]

Don't think there are any amps built to use them. You only get more power from different valves when the amp is made to do so.

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^+1 to this.
You know the old GEC KT 88 (Genalex in the States) was the wheel and it does not need reinventing. I just needs to be properly reproduced again today.
Not very happy that Winged C's have ceased production either.:-(

 

[bassboysam]

I think for bass amplicifcation the JJ KT88s are fine. I've never had issues with them. JJ 12DW7s and 12AX7s I avoid like the plague.

 

[Mr. Foxen]

The Shuguang GE-KT88 seem to do well, Chambo said they compared favourably to the GECs. Just picked up a quad of Gold Lion reissues, see how they work out.

 

[T-Bird]

Hi.

You know the old GEC KT 88 (Genalex in the States) was the wheel and it does not need reinventing. I just needs to be properly reproduced again today.

^This.

How many "new" tubes are they going to invent?

KT90 was a failure.
KT120 was a failure.
KT150 will be a failure, if the past is any indication.

The few more watts that can be squeezed out when an amp that has been designed for those tubes is used is meaningless if there's only one tube to choose from and even that tube can vanish into oblivion in a few years.

For "KT88" we have at least half a dozen "different" ones to choose from and all of them IMLE do sound different.
Granted, a few of them are 6550 internals on a lantern/coke bottle, but still.

Anything over 50W/tube needed, just use one more pair or switch to the readily available industrial tubes that are capable of delivering (a lot) more power.

Regards
Sam

 

[JGR]

Yup, I wouldn't design anything around the 120 or the 150; from what I've seen, they don't live up to the claims.

 

[Steve Dallman]

Why not build a 1000 watt amp around radio transmitter tubes? A pair would get you that and more.

 

[Mr. Foxen]

Voltages impractically high. Weight too great, 1000w isn't needed enough to be worth that hassle. One with 4 got made: http://www.chambonino.com/construct/const9.html

 

[pylet2000]

I am in the process of building a bass amp around the KT-150. I'm using a pair at 650vdc and big iron on both the power and output transformers. I built it originally around the KT-120's, but when the KT-150 came out I had to experiment with it. I'm sure I'll do a full write-up with pics once the thing is done, which should be in the next few weeks.

Should sound cool with my fEarful 15/6.

In my experience, the KT-120 was a fine sounding tube with richer bass than the (non-NOS) KT-88's I've used. I hear the KT-150 broadens the low end even more. We'll know soon...

 

[BioWeapon]

I am in the process of building a bass amp around the KT-150. I'm using a pair at 650vdc and big iron on both the power and output transformers. I built it originally around the KT-120's, but when the KT-150 came out I had to experiment with it. I'm sure I'll do a full write-up with pics once the thing is done, which should be in the next few weeks.

Should sound cool with my fEarful 15/6.

In my experience, the KT-120 was a fine sounding tube with richer bass than the (non-NOS) KT-88's I've used. I hear the KT-150 broadens the low end even more. We'll know soon...

I am definitely interested in hearing your findings.

 

[T-Bird]

Hi.

Why not build a 1000 watt amp around radio transmitter tubes? A pair would get you that and more.

Just like in so many other things in life, the will/need and desire to build something like that has vanished now that it's possible to do so.
Not even for gits and shiggles .

Legislation getting a transmitter tube amp approved to be used on stages has also been made prety much impossible, and what's the use for a monstrous MI tube amp if it can't be taken out of the house?

That said, I've been contenplating whether to use a pair or a quad 5868 .

Regards
Sam

 

[BassmanPaul]

Just like in so many other things in life, the will/need and desire to build something like that has vanished now that it's possible to do so.
Not even for gits and shiggles .

I'm in complete agreement Sam. I feel that even though such an amp is "doable" I don't feel any interest in working with that kind of B+ voltage. I simply feel that it's a path with ever diminishing returns. I like tubes for bass, all of my systems have a tube somewhere in the signal chain, but the interface between the amplifier and speakers is, IMHO, more elegant using SS. Especially now that powerful Class D amplifiers are available.

The tube amplifiers I design and build are all designed for guitar purposes.

 

[chaosMK]

Sounds like stuff for the audiophile market.

 

[xk49w]

Yup, I wouldn't design anything around the 120 or the 150; from what I've seen, they don't live up to the claims.

FWIW, Audio Research is showing the KT-120 in all of their tube power amp offerings up to and including the behemoth Reference 750. One problem with this tube, and maybe the KT150 is the somewhat high grid leak current. The only designs I have looked at have used a DC coupled MOSFET driver for this thing. Other than for amusement I would stick with something more conventional with a wider usage base, KT88, etc.

 

[subbasshz]

I wouldn't buy / design an amp based around a tube that's made by 1 manufacturer.

 

[BioWeapon]

Legislation getting a transmitter tube amp approved to be used on stages has also been made prety much impossible, and what's the use for a monstrous MI tube amp if it can't be taken out of the house?

Hold on - could you explain this to me? I don't understand why you couldn't use a trans tube on stage...

 

[xk49w]

Hold on - could you explain this to me? I don't understand why you couldn't use a trans tube on stage...

I'm not sure either, the 6146B comes to mind definitely a transmitting tube. A 6L6 is a sort of classic ham transmitter tube.

 

[T-Bird]

Hi.

Hold on - could you explain this to me? I don't understand why you couldn't use a trans tube on stage...

1KV operating voltage is AFAIK the limit in most places.
Not limited to amps of course, very few AF amps of any significant grunt use voltages over 800V.

Sure, there's quite a number of transmitter tubes that operate (or can be operated) on lower voltages, and sure, it's not a real problem if You don't tell anyone or if nothing happens, but if number two hits the fan, quite bad things happen.

Not that one can legally use or sell any wall voltage DIY stuff that hasn't been built by a licensed person and/or passed the safety inspection in EU anyway.
I can't imagine it being easier in the sue-happy US of A .

Regards
Sam