[Freo-1]

Just making sure that filament current does not get mixed up with tube bias current with indirectly heated tubes such as 6550, KT-88,    KT-120, 120, etc. 
 
The major point is that most 6550/KT-88 amps MAY not have (and more often than not cannot) provide sufficient power supply current to deal with the KT-120.  So, agree it's best to use the tubes the amp was designed for. 

[geowak]

How about the Primaluna DiaLogue Premium Integrated amp. One can use any of these tubes; 6l6GC/Kt66, EL-34/KT77, 6550/KT88 and KT120 power tubes. $3299 and I think it can be had cheaper! A nice amp for sure. Maybe not up to an ARC, but great for the money.

I think there are three audio manufacturers that give ALOT of tube amp quality for a hard working man's dime. I don't put them in order. Primaluna, Rogue Audio and Line Magnetic Audio. There I said it. Now everyone can beat me into the ground. Would I like to own a top of the line ARC? Yes I would. But those might be white collar amps, where the three I listed are blue collar amps.

[Freo-1]

How about the Primaluna DiaLogue Premium Integrated amp. One can use any of these tubes; 6l6GC/Kt66, EL-34/KT77, 6550/KT88 and KT120 power tubes. $3299 and I think it can be had cheaper! A nice amp for sure. Maybe not up to an ARC, but great for the money.

I think there are three audio manufacturers that give ALOT of tube amp quality for a hard working man's dime. I don't put them in order. Primaluna, Rogue Audio and Line Magnetic Audio. There I said it. Now everyone can beat me into the ground. Would I like to own a top of the line ARC. Yes I would. But those might be white collar amps, where the three I listed are blue collar amps.

Well played.  For me, DIY is the way to go.  You can use high quality tubes that are outside the mainstream commercial, use higher quality parts than commercial, and save some coin.  Hard to beat that.
 

[medium jim]

How about the Primaluna DiaLogue Premium Integrated amp. One can use any of these tubes; 6l6GC/Kt66, EL-34/KT77, 6550/KT88 and KT120 power tubes. $3299 and I think it can be had cheaper! A nice amp for sure. Maybe not up to an ARC, but great for the money.

I think there are three audio manufacturers that give ALOT of tube amp quality for a hard working man's dime. I don't put them in order. Primaluna, Rogue Audio and Line Magnetic Audio. There I said it. Now everyone can beat me into the ground. Would I like to own a top of the line ARC. Yes I would. But those might be white collar amps, where the three I listed are blue collar amps.

I agree that ARC makes nice gear, but the branch doesn't fall far from the tree.  After getting my VS-110, I went on a mission to hear other ARC amps.  I heard the Reference 110 and a few others and I don't feel that my amp is sonically inferior to their top cabin amps. 

They are built to last and buying used is a viable option to get a white collar amp at blue collars prices.

Jim

[geowak]

I agree that ARC makes nice gear, but the branch doesn't fall far from the tree.  After getting my VS-110, I went on a mission to hear other ARC amps.  I heard the Reference 110 and a few others and I don't feel that my amp is sonically inferior to their top cabin amps. 

They are built to last and buying used is a viable option to get a white collar amp at blue collars prices.

Jim

Listening to the Ref 110? Why would you put yourself into that situation? (ha ha) Not me, after I listened to some top McIntosh mono amps playing the Magnepan 1.7s, I said I would never do that again. Too, too sweet. Besides if I bought them, wife would
ask me to live in the garage for the next 5 years.

[Freo-1]

Listening to the Ref 110? Why would you put yourself into that situation? (ha ha) Not me, after I listened to some top McIntosh mono amps playing the Magnepan 1.7s, I said I would never do that again. Too, too sweet. Besides if I bought them, wife would
ask me to live in the garage for the next 5 years.

Hey, my wife asked me to get rid of the 1.7's     Some speakers have no WAF, and Maggies are one of those.

[geowak]

Well played.  For me, DIY is the way to go.  You can use high quality tubes that are outside the mainstream commercial, use higher quality parts than commercial, and save some coin.  Hard to beat that.
 

BTW FREO-1
I wish I had the expertise to do DIY projects, but sadly I do not. I did install a new analog board in my DAC, but Schiit Audio made it dummy proof for me.

[Freo-1]

I started many years ago, using Dyna PAS-3, MK III and Mark IV as my teething tools. Made some mistakes, learned a lot along the way.  I had a buddy make these items, as he just has a knack for putting these things together.
 
Before I retire, I plan to make a nice higher powered integrated tube amp. 

[jarcher]

I started many years ago, using Dyna PAS-3, MK III and Mark IV as my teething tools. Made some mistakes, learned a lot along the way.  I had a buddy make these items, as he just has a knack for putting these things together.
 
Before I retire, I plan to make a nice higher powered integrated tube amp.

That preamp & amp look sweet.  If you don't mind the question : what did it set you back to get that done - parts + labor?  You can also PM me as I guess we might be straying too far from the original topic......

Re: Rogue / Prima Luna / and Line Magnetic all great gear at great prices.  Jolida might fit in there, but a more distant fourth - those other brands have a considerably nicer fit & finish (particularly Prima Luna & LM).  Beside going used, don't know how you can do better.  Sonic Frontiers stuff I think makes incredibly well built gear that can be had reasonably cheap used - and you can still get parts & servicing out of Canada from PartsExpress - ex SF folks.

[geowak]

Getting back on topic, I like the KT-88s. But I think I would like to listen to the KT-120s. If you can get more power, great....
Most speakers I have had, do sound better with more quality power. IMHO

Also I tend to like USA NOS tubes more than others. My buddy at work, who is slightly older than me is always telling me "Older is better". With audio, many times that is the case.

[Golden Ears]

I agree that ARC makes nice gear, but the branch doesn't fall far from the tree.  After getting my VS-110, I went on a mission to hear other ARC amps.  I heard the Reference 110 and a few others and I don't feel that my amp is sonically inferior to their top cabin amps. 

They are built to last and buying used is a viable option to get a white collar amp at blue collars prices.

Jim

After getting a questionable batch of 6550c (last batch of Svetlanas ...out of 8 tubes infant mortality is now 3 )  I am considering the KT120 route vs 6550w from ARC.

I have a GNSC modded ARC VS-110 and compared it to the ARC VS-115 with KT-120 and preferred it as well as compared to a Ref 75 whcih lacked slam and midrange "eveness" and sounded less " hi-fi"  than the Ref 75. Could it be not having the FET input stage makes me like this... just like I preffered the ARC VT-100MKII vs the ARC VT-100MKIII?

I was biasing at 57mA instead of 65mA which if I understand correctly will make the idle current higher?? I was told if I ran at lower bias like 57 this would put less stress on the tubes for negligible impact on the output... is this incorrect?

To what I hear... the St. Petersburg winged 6550c has a midrange believeability of nuance and vocal prescence and lets you hear  " a breath of life of the performer" and reveals  a fantastic " scaled rendering of depth" in my soundstage. Bloom is believeable and not over blown, and detail in artifical reverb is not overly hyped....pretty captivating when heard with precisely positioned  (by ear)  speakers that are capable of fine resolution without sounding clinical.

I have not tried the KT120 but would like to try them in my amp. I am hesitant to do this for fear of losing the mdirange emotion life as it breathes...I have enough hard hitting bass with the 6550c that a kick drum is presented as real with my transmission compression line- so more KT120 bass is not a big draw. Speed of the 6550c presents believable cymbals and the ride and crash cymbals are totally rendered distinct with the correct amount of decay and sheen. Piano notes and harmonics and pedal weight  also are rendered as believable. Sax loses a bit of bite.(normal in all but some horn speakers) ..but that is not euphonically unpleasing to me...even though not real....so in general I am pretty happy.


I hunted for NOS 6550c....and found 2 pairs of matched 8 ... but if there is something better in all respects..I would go there.

My ARC VS-110 will handle KT120 according to Kalvin but I also lost a power transformer and had to replace it....possibly due to power cycling too quickly when making comparisions on wire. So in rush current is a concern, particularly with GNSC using double capacitance on the power supply.

Other amps I have tried with my system Quicksilver Silver 88's (which did nothing wrong or objectionable and sounded very good when using Audio Magic Super fuses- but lost in bass slam and detail to the GNSC ARC VS-110). VAC PHI 200 which has a larger soundstage...also smoother with a Audio Magic Super fuse, does piano very very well and runs KT88's but lacks that last bit of bass slam and vocal nnuance while oddly having more soundstage detaila nd better separation of singers singing in the same key.

I like the MIT Oracle MA-X interconnect and the MIT 120 pole Oracle SHD speaker cable, and also enjoy (but to a lesser extent) DH Labs Q-10 speaker cable bi-wired and cryroed - can have great depth of soundstage and great bloom and body.

VAC PHI 200 can not use the KT120, according to Kevin Hayes but my ARC VS-110 can... just wondering of anyone else pulled the trigger and got KT120 for that amp and what speakers and cables they were using.

[jupiterboy]

I am still settling in with my EE M88. The (now NOS) winged 6550s were very good. Having switched to the KT120 I would say something is lost and something is gained. I actually had to add some isolation to my rack and speakers to deal with the additional base energy of the KT120s. If the 6550s are lean and controlled, the KT120s are simply controlled. The midrange and top are different, a little softer with the KT120s but not by much. It will be interesting to switch back after a couple of months.

[jarcher]

My understanding is that generally speaking 6550's are really the most robust vs the next larger tubes (KT88 - KT120).  At least according to Upscale Audio there are vendors selling "subprime" 6550C's, and that may account for the problem you had with your batch.  http://www.upscaleaudio.com/svetlana-sed-winged-c-6550c/

Last year I bought a quad of used low hour "Winged C" 6550c's and touch wood, still going strong.  But perhaps just got lucky.  With this factory now closed, they are now considered NOS, and asking prices have gone up considerably.

Rumor has it that the KT120 is not that robust in construction, leading Tung Sol to come out with the KT150, supposedly a similar tube to the KT120, but more robust / reliable with better life.  With that said, in some brief tests between an Electro Harmonix KT88 and Tung Sol KT 120, I definitely preferred the TS KT120.  But for a big ARC amp, I think I'd go for "Winged C" 6550c's as they are more robust, were the tube that amp was designed for, and are more likely to give an ARC amp a more "tube" amp sound.  I demoed recently am ARC VT100 (original not MKII or III), and it had Svetlana 6550c's (not "Winged C") and the sound was already quite "solid state" vs say a Conrad Johnson tube amp.  So with ARC I'm supposing that if you want something more tube sounding, the "Winged C" 6550C is going to be the best choice. For maximum safety and as you might need matched sets, I'd probably buy them from Upscale Audio. 

P.s. I would mostly agree w/ jupiterboy re: Winged C 6550C vs KT120 sound, though I demoed on different amps.  For a big ARC amp I'd probably still go for Winged C 6550c's for reliability though.  The ARC VT100 didn't have a ventilation amp like the MK II / III, and it got super hot!

[mick wolfe]

Anyone have experience with substituting KT120's in their amp ?
Thinking of purchasing a 6550/KT88 amp that can run KT120's.
I called Audio Research interested in subbing tubes for a Classic 60...
they advised against it, the amp circuitry is not designed to support the higher voltages and currents the tube requires.
They say their older VS 110 can be upgraded.
I have not decided on a manufacturer yet..maybe Quicksilver V4 or VTL.
My primary reason for wanting the KT120 is they are said to be a more robust tube made for audio application and their replacement cost is similar to the 6550/KT88.
                                         Greg

For the record, I think Mike Sanders at Quicksilver is using the new KT 150's in his Silver 88's for one. Not sure about the V 4's. The KT 150 may be the one to aim for at this point. Seems preferred over the 120, but it's pricier.

[GT Audio Works]

For the record, I think Mike Sanders at Quicksilver is using the new KT 150's in his Silver 88's for one. Not sure about the V 4's. The KT 150 may be the one to aim for at this point. Seems preferred over the 120, but it's pricier.

After I posted that I talked to Mike Sanders about his Silver 88 monos....they seem like a great amp...Hopefully I will get to hear one.
                                                                                                                 Greg

[rpf]

For the record, I think Mike Sanders at Quicksilver is using the new KT 150's in his Silver 88's for one. Not sure about the V 4's. The KT 150 may be the one to aim for at this point. Seems preferred over the 120, but it's pricier.

According to Quicksilver's website, the KT150s are available for both the Silver 88s and the V4s, where they put out 90 and 170 wpc respectively.   

[Housteau]

I have a set coming for my Primaluna Prologue 7 monos.

[Steve]

I agree with you Goldenears.

Imo, I will state the St. Pete Cs are the best sounding of the new tubes, and maybe of the NOS as well.
Just outstanding clarity, balance, inner detail, naturalness. But then the best always seems to be sent to the extinction category,
for St. Pete is not producing tubes as of last February. Sad indeed.


Steve

[Octadyn]

When I had Dyn C1 sig speakers I hated the KT120's and preferred a warmer sound like the original TS 6550 solid black plates. To me the SED winged 'c' was similar to the KT120's where the SED KT88's are warmer sounding like the TS black plates but lacked the midrange magic of the TS.  That said I replaced the DYn's with Raidho D1's. Now the KT120 is more of my favorite followed by the Ei KT90. BTW the Ei KT90 was and is my second favorite. Oh I have an Octave V110 integrated. Funny how a speaker change makes for such an overall sound difference.

I heard that TS is working on a KT180

[Steve]

When I had Dyn C1 sig speakers I hated the KT120's and preferred a warmer sound like the original TS 6550 solid black plates. To me the SED winged 'c' was similar to the KT120's where the SED KT88's are warmer sounding like the TS black plates but lacked the midrange magic of the TS.  That said I replaced the DYn's with Raidho D1's. Now the KT120 is more of my favorite followed by the Ei KT90. BTW the Ei KT90 was and is my second favorite. Oh I have an Octave V110 integrated. Funny how a speaker change makes for such an overall sound difference.

I heard that TS is working on a KT180

Depends upon the design of the system Octa. It just so happened that your system was optimum for the old TS black plates. The same could
be done for the winged Cs, but for less money, if designed around.

Cheers