Anyone Compared the New 6550/KT88s out there in their Amps?

May 30, 2010
15,083
491
83
Portugal
I have avoided posting about them, as I have a horse in this race - I will be selling a pair of cj LP275's monoblocks soon - but these amplifiers represent some of the best that cj have designed, the differences between them and the ART's are not night and day. They share most of the elements and design. I have used them with the KT150s' and they sound very powerful, but clearly musical with all the flavor of cj.

Most of the time when people say that circuits must be modified to use the KT150 they address getting all the power these tubes can deliver - they can operate with an higher HV than KT120's and give more power per tube.
 

bonzo75

Member Sponsor
Feb 26, 2014
10,985
1,084
113
London
Ok if you don't like Luxman and accuphase try the Berning quads, though rare to find, and Soulution. Not at a show or something though please
 

dminches

Active Member
Oct 22, 2011
801
70
28
I recently purchased a quad of GEC KT88s for my Zesto BIA 120 amp. They completely blow away the Gold Lion KT88 reissues. While this isn't a real surprise to me, it does make me wonder why many reissues are inferior to older production. The same was the case for the JJ 12AU7s which were replaced with a quad of NOS Mazdas.
 
Feb 14, 2012
71
4
8
GTA
I recently purchased a quad of GEC KT88s for my Zesto BIA 120 amp. They completely blow away the Gold Lion KT88 reissues. While this isn't a real surprise to me, it does make me wonder why many reissues are inferior to older production. The same was the case for the JJ 12AU7s which were replaced with a quad of NOS Mazdas.
A couple of reasons come to mind:
1. NOS tubes were made with materials that today would be considered hazardous so they could not be used.
2. The master craftsman tube builders (every major factory had a few in the 1950s and 60s) are gone, replaced by low wage workers.
3. Tubes are now a disposable product used manly by guitarists and home audio enthusiasts , whereas in the 1950s they ran all electronic devices so quality was more critical.
4. Due to lower worldwide demand, tubes must be produced more cheaply and efficiently to allow producers to make a profit. They can't afford to screen production as closely as before and toss out as many non spec tubes.
 

dminches

Active Member
Oct 22, 2011
801
70
28
I knew the materials were an issue. However, I wondered whether China or Russian actually had any regulations about this.
 
May 30, 2010
15,083
491
83
Portugal

Ron Resnick

Site Co-Owner, Administrator
Jan 25, 2015
6,380
833
113
Beverly Hills, CA
I’m afraid I cannot tell you. I have never seen the amplifiers.
 
Feb 14, 2012
71
4
8
GTA
After much research, tearing of hair and gnashing of teeth, I bought a used set of Psvane KT120 tubes for my Cary SLI-80. They were burned in for 150 hrs by Grant Fidelity and around 30 hrs by the original owner. I've put about 20 hrs on them and their biasing so far has been steady.

My previous tubes were the stock EH KT88's and I had no idea how shrill they are til now. The amp has the ability to change from 80 watt ultra linear operation to 40 watts triode (on the fly.) I had been listening almost exclusively in triode because ultra linear was too forward. Now, with the Psvane KT120, I prefer ultra linear.

They tick all the audiophile boxes; the amp's performance is better in every way.
Now if they'll just endure for a reasonable amount of time...
Hi ER.
Just wondering if your Psvane KT120s are still working reliably in your amp and holding steady bias.
It would be great if the answer is yes, they are likely much better sounding than the “Tung Sol” reissues.
My experience with the Treasure KT120 (from about 3 years ago) was that they sounded great, but after 2 months of use the bias became wildly unstable in two tubes of the quad.
 

About us

  • What’s Best Forum is THE forum for high end audio, product reviews, advice and sharing experiences on the best of everything else. A place where audiophiles and audio companies discuss existing and new audio products, music servers, music streamers and computer audio, digital to audio convertors (DACS), turntables, phono stages, cartridges, reel to reel, speakers, headphones, tube amplifiers and solid state amplification. Founded in 2010 What's Best Forum invites intelligent and courteous people of all interests and backgrounds to describe and discuss the best of everything. From beginners to life-long hobbyists to industry professionals we enjoy learning about new things and meeting new people and participating in spirited debates.

Quick Navigation

User Menu

Steve Williams
Site Founder | Site Owner | Administrator
Ron Resnick
Site Co-Owner | Administrator
Julian (The Fixer)
Website Build | Marketing Managersing