Dilemma: Klipsch Cornwall IV vs Tannoy Kensington SE
- Thread starter Mike Hanson
- Start date
S-Man
StrivingON
1) You will know... the magic will go. Maybe buy a PL so you'll know
2) My KT88 amp has stable bias over years. Maybe a monthly check is too see if a valve is on its way out?
3) If the amp is properly designed it should blow a fuse and cause no other damage.
Re #2 you could elect to run the bias a bit lower than the spec. This will extend the valve life, you'll get less class A power but I doubt you need it with those coffins.
Mike Hanson
Trying to understand...
That's certainly possible, although they brag quite mightily that their transformers are one of the strengths (and are astonishingly heavy).
The PrimaLuna EVO 400 is 31kg, versus the Cary SLI-100 at 19kg, so weight clearly does not make it better.
3) You should tell that to Audio Research...
Re #2 Best to run the amp at the bias point the amp was designed for. Running less bias (more -ve on the grid) will result in a much higher HT voltage, which could over stress your power supply capacitors. Running too much bias (less -ve on the grid) will result in the amplifier drawing too much current and stressing the mains transformer HT winding and associated power supply. Best to leave it at factory settings, or what it quotes in the manual.
S-Man
StrivingON
3) You should tell that to Audio Research...
Re #2 Best to run the amp at the bias point the amp was designed for. Running less bias (more -ve on the grid) will result in a much higher HT voltage, which could over stress your power supply capacitors. Running too much bias (less -ve on the grid) will result in the amplifier drawing too much current and stressing the mains transformer HT winding and associated power supply. Best to leave it at factory settings, or what it quotes in the manual.
Audio Research should design their amps properly if they don't fail "safe".
Re #2. As far as I can see the Cary has solid state rectification. The HT voltage will therefore only be slightly higher not "much higher".
What he says. Of course tube life depends on amp design and the tube as well as usage. Small signal valves easily 5-10 years, outputs 2-4000 hours or more dependant on the above......
Don't forget what HT voltage the amp will be running at these power levels. For fixed bias it will be around 450v, sometimes 500v. I have measured 630V on some ARC amplifiers. Manufacturers use off the shelf capacitor values and voltage ratings. Therefore the HT will be running quite close to the voltage rating of the power supply capacitors. Any backing off of the bias will increase the HT voltage and may exceed the capacitor voltage rating. I have seen this many times and have measured 10 to 20 volts over the voltage rating of the capacitors. Also, if the amplifiers have 230volt mains transformers fitted and running on UK voltages, some 240v to 256v AC, this will also cause the HT voltage to increase.
Off topic but a lot of ARC power amps have serious design flaws:
[I am interested in ARC because the sound is great intimate and truly beautiful.I am an original owner of PH5, CD3mkII and LS26 and over two years I never had troubles. They all work beautifully
But the few malfunctions I experienced with the amps were different.
My newer VS115 at approx. 165 hours during the warm up period suffered a fairly catastrophic failure.
The V1 tube was glowing with a white colour, a capacitor or perhaps a resistor became overheated and flamed out with blast and smoke.
Luckily the rest of the equipment were not damaged.
After two weeks the local ARC service repaired the unit and I had to pay for the tube.
At approx. 255 hours it happens again. This time I heard only a blast.I returned the unit to the local ARC and I am waiting but I am very disappointed.
(I checked the Bias and the wall voltage every time I heard music)
The same happened 2 years ago to my VS55 I previously owned at approx. 400 hours. At that case ARC had sent me through the local dealer a new circuit board. ]
Most recently, I purchased the ARC 610s and I was stunned when one of the maps blew up within 7 seconds of turning it on. I sent the amp back to ARC, only to find that my other amp blew 2 within 2 weeks while the first amp was being repaired. That was the final straw for me. Unfortunately, I am not alone as this has happened to several others. What I found particularly dumb, is that ARC should have been cognizant of these failures and at the very least, designed their latest amps so the power resistors can be easily accessed for front of board repair. At the very least, they should have raised the resistors high enough off the board so the board does not char when the resistor blows.
Regarding power amps, had a D70 for a year, and then a D125 for 8 years(both second hand) - in both cases they developed faults which the local (Sydney, Australia)technicians could not fix, despite repeated costly attempts. Loved the sound, especially of the D125, but ownership was frustrating - for the last two years the D125 pretty much sat unused, and old Luxman SS amp filled the gap.
I'm afraid I wouldn't buy another ARC power amp.
[ok correct it should be 65mV and the multimeter is not defect, but this is not the point. By "blast" i mean a noisily explosion -- although i was scared i checked the bias and i measured at all tubes 89-90 mV. ]
Years ago, I owned a D-250 Servo. After a few months, with not that many hours on the stock ARC 'selected' tubes, a loud dramatic explosion occurred with smoke, etc. I had to send "Big Bertha" back to Minnesota for repairs. When it returned, I sold it.
Its a common problem for ARC. The same thing happened to my VT-100. When it blew, a piece of the resistor hit me right in the face while sitting in my listening chair.
I had two VT50s over the review period. The first broke in well and everything was progressing nicely until, in the middle of a quiet listening session, one of the bias-control resistors literally blew apart. The bang was quite loud and accompanied by a flash and smoke,
[I am interested in ARC because the sound is great intimate and truly beautiful.I am an original owner of PH5, CD3mkII and LS26 and over two years I never had troubles. They all work beautifully
But the few malfunctions I experienced with the amps were different.
My newer VS115 at approx. 165 hours during the warm up period suffered a fairly catastrophic failure.
The V1 tube was glowing with a white colour, a capacitor or perhaps a resistor became overheated and flamed out with blast and smoke.
Luckily the rest of the equipment were not damaged.
After two weeks the local ARC service repaired the unit and I had to pay for the tube.
At approx. 255 hours it happens again. This time I heard only a blast.I returned the unit to the local ARC and I am waiting but I am very disappointed.
(I checked the Bias and the wall voltage every time I heard music)
The same happened 2 years ago to my VS55 I previously owned at approx. 400 hours. At that case ARC had sent me through the local dealer a new circuit board. ]
Most recently, I purchased the ARC 610s and I was stunned when one of the maps blew up within 7 seconds of turning it on. I sent the amp back to ARC, only to find that my other amp blew 2 within 2 weeks while the first amp was being repaired. That was the final straw for me. Unfortunately, I am not alone as this has happened to several others. What I found particularly dumb, is that ARC should have been cognizant of these failures and at the very least, designed their latest amps so the power resistors can be easily accessed for front of board repair. At the very least, they should have raised the resistors high enough off the board so the board does not char when the resistor blows.
Regarding power amps, had a D70 for a year, and then a D125 for 8 years(both second hand) - in both cases they developed faults which the local (Sydney, Australia)technicians could not fix, despite repeated costly attempts. Loved the sound, especially of the D125, but ownership was frustrating - for the last two years the D125 pretty much sat unused, and old Luxman SS amp filled the gap.
I'm afraid I wouldn't buy another ARC power amp.
[ok correct it should be 65mV and the multimeter is not defect, but this is not the point. By "blast" i mean a noisily explosion -- although i was scared i checked the bias and i measured at all tubes 89-90 mV. ]
Years ago, I owned a D-250 Servo. After a few months, with not that many hours on the stock ARC 'selected' tubes, a loud dramatic explosion occurred with smoke, etc. I had to send "Big Bertha" back to Minnesota for repairs. When it returned, I sold it.
Its a common problem for ARC. The same thing happened to my VT-100. When it blew, a piece of the resistor hit me right in the face while sitting in my listening chair.
I had two VT50s over the review period. The first broke in well and everything was progressing nicely until, in the middle of a quiet listening session, one of the bias-control resistors literally blew apart. The bang was quite loud and accompanied by a flash and smoke,
Mike Hanson
Trying to understand...
I don't need it to sound better than it does, but addressing convenience issues is definitely worthwhile.I thought the OP’s hifi journey was now at an end?
And occasional tweaking is to be expected.
coltrane
electrobaroCKjazzer
well, this experience coincides with mine with PL amps - that's why I told you earlier that they aren't special at all. how we here define these amps is like they're a brand that make amplifiers with valves, but not valve amplifiers......All of the dynamics that I loved were gone. The bass was deeper, but exaggerated and flabby. There was no sparkle in the presentation. The seller felt that the it sounded less colored, but I've never perceived the Cary as sounding colored. It was still early, though, so I patiently waited for the magic to happen.
...And it never happened!
In retrospect, if I had tried the lesser PrimaLuna EVO 100, I would have sworn that tubes were awful...
. anyway, hope you're now really happy with your purchase > enjoy 
Locheeboy
pfm Member
Prima Luna output transformers are very high quality, American designed by a well-respected US company. They are made in USA, not China, although if they were Chinese made, I’m sure they would be the same extremely high quality as the rest of their products…
”negligible defect rate of just one-half of one percent—unheard of in the industry—which makes it more reliable than a lot of solid-state gear."
“The equally beefy output transformers are wound in-house, and the entire signal path is wired by hand using Swiss-made, silver-plated oxygen-free copper wire.”
“Rife with detail and dimensionality. Inviting, slightly warm, and opulent. Also, solid density of textures; plush.”…Stereophile…
“Prima Luna make very high quality output transformers” …Stereophile…
Ah think ye should look elsewhere in yer system for flat and uninvolving…
Mike Hanson
Trying to understand...
I think it's more taste than anything else. The midrange from the PL was quite lovely, and overall tonal balance seemed strong. It just didn't have those things that I critically demand from my system.Prima Luna output transformers are very high quality, American designed by a well-respected US company. They are made in USA, not China, although if they were Chinese made, I’m sure they would be the same extremely high quality as the rest of their products…
”negligible defect rate of just one-half of one percent—unheard of in the industry—which makes it more reliable than a lot of solid-state gear."
“The equally beefy output transformers are wound in-house, and the entire signal path is wired by hand using Swiss-made, silver-plated oxygen-free copper wire.”
“Rife with detail and dimensionality. Inviting, slightly warm, and opulent. Also, solid density of textures; plush.”…Stereophile…
“Prima Luna make very high quality output transformers” …Stereophile…
Ah think ye should look elsewhere in yer system for flat and uninvolving…
I should mention that my expectations for certain things are very high, especially dynamics, speed, and rhythmic communication. I hear those aspects mostly from horn-based and planar speakers (and perhaps some conventional boxes that cost far more than I'm willing to spend). Many "exceptionally good" systems sound positively sleepy to my ears.
I have some appreciation for things like soundstage and imaging, and liquid midrange is nice, but I don't need those to be the strongest elements.
For whatever reason, the Cary scratches my itch. The PrimaLuna did not.
joe9407
actress/activist
And occasional tweaking is to be expected.
Hiya Mike,
I agree with @Tony L that a Leben amp would be worth a try, should one come up locally. On a bit of a whim, I bought a CS-600 and I prefer it to my Naim 282/250 setup, which is going up for sale. There's just a whole lot more "presence" with the Leben, but nothing I would characterize as overly warm or tubey. Seems like it would meet your requirements.
As for tubes, I'm with you: this is my maiden voyage with them! My Leben came with 4 sets of NOS preamp tubes, which should do me for a quite a while. On the output tube front, the Leben is auto-biasing and I feel like I'd probably want to tinker and change them around every year or two anyway.
Glad you're enjoying the Cary!
Joe
Mike Hanson
Trying to understand...
I realize now even more than I did before that my system has hit a very special level. The only way I would consider changing things now is to do an addition in my house of the new equipment. Perhaps that Leben would do it, but I don't know that one would show up nearby. I think it's also more money than the Cary. I'll save a search for it.
coltrane
electrobaroCKjazzer
oh no, you're lost, man
Locheeboy
pfm Member
iirc the Lebens are cathode biasing , not auto-biasing…but, of course, I stand to be corrected…
James Evans
Bedroom Bodger
Mike, you're in the honeymoon phase, it'll soon wear off and you'll be hearing niggles and mentally compiling a list of compromises that need addressing. Normal service will be resumed