As a few of you guys know, I am a luck guy and own a set of Bob’s Cherry 180’s, now Cherry 260’s
Well I thought it was about time for a tube change, and I had heard a lot of good things about the new KT-120 tube’s I thought I would try them.
So at Carverfest 10 I asked Bob if the tube would work OK in the Cherry’s He said “O” yes, the transforms are powerful to run them at 80% capacity.
So that would bring the power output to 260 watts.
To get the most out of the tubes the Power and Output Transformer’s would have to be redesigned and I am working on that at the moment hence the new set of Black Beauties he just sold on Ebay.
So thanks to a forum member, I was able to get a fair price on a set of 12 KT-120 tubes. So in early January I ordered 12, guess what they where on back order. Well finally on Friday 25 March I received the Tubes.
I installed the tubes on Saturday 26th and never turned the amps off for 14 days, to burn the new tubes in, so after the tubes had over 300 hrs on them
I thought it was time to give them a listen. So I spent a day playing.
1st album (vinyl) Pink Floyd Dark Side of The Moon. Well it sounded like shit.
No bass, all vocals very muddy, no sparkle in the highs. The sound stage was very minimal.
Time to change the controller tubes. So I removed a Telefunken 12AT7 and a Siemens 12AX7 both 1960 vintage tubes, supplied by Bob, and replaced them with Pvane Reference Tubes from Grant Fidelity. (I ordered grade A).
Guess what, the bass showed up it was deep and not boomey, and the highs started to sparkle. The low vocals where still a bit muddy buy very improved the mid vocals where crisp and clear and the sound stage opened up.
Now time to try some female focal, Diana Krall. So out came
The Look Of Love (vinyl)
Diana’s voice was open, airy, crisp and clear with just the right amount of sibilance on S’Wonderful. No hint of sibilance on the other tracks.
Piano and other instrument’s sounded very good, fast, precise and that live felling was back in my living room.
Dire Straits (vinyl)
Romeo & Juliet, Telegraph Road and Private Investigation.
All sounded great to me, crisp vocals, airy guitar with room filling sound, sound stage, placement and depth sounded very good to me.
I reinstalled the Telefunken 12AT7 and Siemens 12AX7 controller tubes and played Romeo & Juliet what a bad move, sound stage had collapsed
everything a little muddy like covering my head with a paper bag.
Removed the Telefunken 12AT7 and Siemens 12AX7 and went back to the Psvane Tubes the room was alive again. It looks like the Psvane Tubes
are a better match to the KT-120’s
If anybody is in the Ottawa, Canada area please drop by I would love to try this again with somebody who has a better set of ears.
I say SET of ears as I am 100% deaf in my right ear, and that messes up sound stage and depth for me.
What tube was better in my system, that’s hard to say? The KT-120’s
Have a lot more power, but have a little less bass.
The KT-88z where a little more musical, better bass but less power, for me I think it’s the KT-88z
I am going to give myself a couple of months with this setup and switch back to my Shuguang Treasure KT-88z tubes with the
Psvane controller tubes, that could be interesting.
Comment. The KT-120's are a good sounding tube, considering that they cost me exactly 1/3 the cost of the Shuguang Treasure KT-88z tubes
Test Equipment:
Sunfire Classic Vacuum Tube Control Centre
Set of Cherry 180/260 amp’s
VPI Classic Turntable
Shelter 901 Cartridge
B&W 802d Speakers
Brian