Waffling on a tube amp

[valve_integrator]

"
I was afraid the tube amps would kill the cat.

"

Gives a whole new meaning to carelessness with high tension cables then...

"frying tonight" top caps unite, all you have to fear is the smell of cat guts...
(violinists abstain).

 

[valve_integrator]

Seriously now.
My next major undertaking should be a whopper for which I've been collecting rare bits for a few years.
PSU transformer came from a ship-shore transmitter which came up cheap on EBAY (does 2.2KV at 0.6A) etc etc.

The output stage has had some advice from a real cracking guy called Chambers at chambonino who has actually made and sold the 1KW monsters..
Nottinghamshire people tend to be a bit down to earth...

1.5-2kV is not something really to be messed with, cat or no cat.
It tends to make class D look a little tame, with enough go to blow the doors out of your house.

Talking of which I have a spare pair of Hiwatt 200W output transformers.
Now who said guitar amps were rubbish distorting machines that couldn't be hifi?

Dave Reeves who started Hiwatt worked down the road at Mullards, and used no less than Partridge for his transformers. All of them.

references?
David Gilmour, Peter Townsend, Glen Cornick....

 

[Godataloss]

Seriously now.
My next major undertaking should be a whopper for which I've been collecting rare bits for a few years.
PSU transformer came from a ship-shore transmitter which came up cheap on EBAY (does 2.2KV at 0.6A) etc etc.

The output stage has had some advice from a real cracking guy called Chambers at chambonino who has actually made and sold the 1KW monsters..
Nottinghamshire people tend to be a bit down to earth...

1.5-2kV is not something really to be messed with, cat or no cat.
It tends to make class D look a little tame, with enough go to blow the doors out of your house.

Part of the 'charm' of class d is the distinct lack of drama.

 

[valve_integrator]

Part of the 'charm' of class d is the distinct lack of drama.

Part of the charm of a proper kick-A valve amp is the beauty of the sound, with pretty lively dyamics, compared with those horrible knock offs from PRC or your class D with it's nasty sterile lifeless dead body tat.
There you are, throw a stone in the pond and watch the ripples spread out!

A quote from a famous cellist: "don't play notes play music". (PC).
I hear the same out of the mixing desk after being fooled around with all those "plug ins and effects".
If I want to hear Carnegie hall recordings in my local opera house I go to NY and Carnegie hall.
(I'm not so easily fooled by fake Carnegie).

I often ask my sound engineer friend "WTF did you do here?"
This sounds awful.

If your experience of "good stuff" was limited to those awful modern crap "hi end" tube amps, or the equally awful dynaco stuff then what hope? I can say the same of most "hi end" cans.

What hope indeed for those thinking stereo is brilliant with all that non existent "sound stage" stuff.
If you want to hear something close to live recording, while incredibly difficult to reproduce, go full SURROUND sound.

I have to say, doing surround live is one of the most difficult challenges I ever did, valve or no valve, and never mind the reproduction chain and all the other stuff in it....(ask Neil Wilkes!).

 

[fpitas]

Part of the 'charm' of class d is the distinct lack of drama.

Yes; and if you're getting a warm glow, you have serious problems!

 

[fpitas]

ahh, I see the antecedent now.
whoops.

At least Lux hasn't started putting LEDs under their tubes, AFAIK.

Maybe they're biasing the tubes with the LEDs

 

[computer-audiophile]

Maybe they're biasing the tubes with the LEDs

Morgan Jones, the British author of the book 'Valve Amplifiers' recommends this method. He also explained it once at a European Triode Festival which I attended. I tried it several times on preamplifiers and driver stages of power amps. But it didn't convince me sonically, I always went back to R/C. I think there are small disturbing non-linearities with LED bias.

 

[fpitas]

Morgan Jones, the British author of the book 'Valve Amplifiers' recommends this method. He also explained it once at a European Triode Festival which I attended. I tried it several times on preamplifiers and driver stages of power amps. But it didn't convince me sonically, I always went back to R/C. I think there are small disturbing non-linearities with LED bias.

It really depends on the tube and use. It's more like constant voltage grid bias, whereas some tubes are better with the regular cathode bias.

 

[Bob from Florida]

My current setup is a Rega Planar 3/yellow Exact cart, Rega Fono MM Mk3, Rega Brio, Monitor Audio Silver 300. I also use a cheapo WiiM Streamer for the rare times I stream (this is slated to be replaced with a Cambridge CXN V2 next year).

I've decided that my next step in building my home stereo outfit is going to be a tube amp. I had selected a Rogue Cronus Magnum III as a nice starting point, but I'm having trouble pulling the pin on a 5 grand Cdn unit when I'm just not sure if I'll enjoy it or not. I've listened to several tube amps over the last couple months, loved the sound, but none at home with my setup in my room.

I keep eyeing up a Willsenton R8, and I'm wondering if this unit would indeed give me a proper taste of tube amplification and allow me to decide whether I'm going further down that rabbit hole, or if I should be upgrading my turntable instead. I've tried to find direct comparisons online, but haven't had much luck. Anyone on here had a Willsenton and then switched to higher end unit like the Rogue or a Linn? Does the Willsenton really give good enough results to tell someone if they want tube amplification?

Thanks in advance for any opinions and advice.

Rod

Quicksilver Audio - KT Mono amps. 80 watts with KT88's or 100 watts with KT150's. Mike Sanders actually uses measurements to validate his designs. See below and these will be on the neutral side of things. If you want coloration look elsewhere.

KT Mono Amplifier – Quicksilver Audio

quicksilveraudio.com

 

[Push]

Here's what I'd do, were I you. Look for a restored ("resto-mod'ded" is probably even better) Dynaco ST-70. Excellent output transformers, especially for the $ I'd have suggested a modern "Dynakitparts" ST-70 kit, but they seem to be NLA. You could consider one of Bob Latino's latter-day ST-70 variants, but opinions on them, and him, seem to be mixed.

<snip>

Do you have any experience with vacuum tube amplification -- listening or owning? Why do you want (or think you want) to switch to vacuum tube amplification?
Depending on what you want to accomplish, you might get more bang for your buck with a decent quality vacuum tube preamplifier and whatever (ss) power amplifier you'd prefer. Much easier (cheaper!) to get the best of what vaccum tube circuitry can offer with line level circuits than with a power amplifier. If nothing else, no pesky output transformers required for a preamp! Good output transformers are expensive.

I've looked at the Dynaco, but then I have to mess with pre-amps, etc, so I decided to stay with integrated.

When I was in a shop in Saskatoon, I was auditioning speakers, with a Brio amp and Rega Planar 6 (they didn't have a 3 in stock). As I walked by another audition room on the way, I heard an outfit that really caught my attention, so I went in. It was a high end tube amp, mated to some higher end speakers. I couldn't believe the dynamics and the sound stage, it was incredible. I made a crack about never being able to afford something like that, so the salesman took me back into the original room, switch the speakers over to the Rogue Cronus and started playing at lower volume levels, gradually working up the scale. I could not believe the difference in sound and staging, timing, with the tube amp. So I decided to see how one would work in my room.

 

[computer-audiophile]

It really depends on the tube and use. It's more like constant voltage grid bias, whereas some tubes are better with the regular cathode bias.

Yes, that is correct. But I have also discussed this with Morgan Jones himself and other experienced colleagues. Morgan was even kind enough to send me special LEDs from his collection in England. All colleagues have given it up again for sonic reasons, although measurements do not look bad. Since I like absolute minimalistic circuits I would have loved to do it that way.

Here is a picture my experimental 300B amp with LED bias. You can see the red LEDs beside the driver tube. It works, that's no question.

 

[Blumlein 88]

The OP named amp seems to make biasing and such easy. I modified some I've had over the years. I replaced the pots with 10 turn pots and moved them to the front corners of a stereo amp. Also put in small connectors so the ends of a multimeter probe would slip right in. Put your multimeter in the right hole and turn the ten turn pot and it was easy peasy to get exact bias values. Even in those amps that don't do all this I have no idea why all bias pots aren't 10 turn linear pots. C-J on some amps used LEDs, but mainly so you didn't need a voltmeter. The LEDs were indicators not actual bias elements. You turned the adjustment until they came on and backed off them just enough they turned off.

 

[Waxx]

Unabashed tube amp owner and vinyl aficionado here. I use a Hypex mostly now because I was afraid the tube amps would kill the cat.

My cat is affraid of tubes, so i don't worry about that. But a Hypex is also used here for some stuff, as not all speakers like low damping factor like tube amps have. I like to have options. And i actually drive my hypex now with a tube preamp to have my dose of colourations...

 

[Bob from Florida]

The OP named amp seems to make biasing and such easy. I modified some I've had over the years. I replaced the pots with 10 turn pots and moved them to the front corners of a stereo amp. Also put in small connectors so the ends of a multimeter probe would slip right in. Put your multimeter in the right hole and turn the ten turn pot and it was easy peasy to get exact bias values. Even in those amps that don't do all this I have no idea why all bias pots aren't 10 turn linear pots. C-J on some amps used LEDs, but mainly so you didn't need a voltmeter. The LEDs were indicators not actual bias elements. You turned the adjustment until they came on and backed off them just enough they turned off.

Ten turn pots are the ticket and nobody uses them because of cost. The last tube guitar amp I built - I used individual 10 turn pots for bias of each individual output tube. Any future fixed bias builds will be done this way.

 

[mhardy6647]

I mean... some tubes here. Some.

I've looked at the Dynaco, but then I have to mess with pre-amps, etc, so I decided to stay with integrated.

When I was in a shop in Saskatoon, I was auditioning speakers, with a Brio amp and Rega Planar 6 (they didn't have a 3 in stock). As I walked by another audition room on the way, I heard an outfit that really caught my attention, so I went in. It was a high end tube amp, mated to some higher end speakers. I couldn't believe the dynamics and the sound stage, it was incredible. I made a crack about never being able to afford something like that, so the salesman took me back into the original room, switch the speakers over to the Rogue Cronus and started playing at lower volume levels, gradually working up the scale. I could not believe the difference in sound and staging, timing, with the tube amp. So I decided to see how one would work in my room.

Sounds like you should buy the Cronus, then.

 

[valve_integrator]

The KT150 is a pile of badly designed Russian sh...t made in Saratov.
Most of that "new sensor" stuff from that factory has always been crap.
Ask me how I know, I spent so many years in Russia and actually met the designers from Svetlana who explained the problems to me.
That thing is violently thermally unstable thanks to the stupidly oversized anode and a load of other problems which make us run away from that low grade GEC KT88 clone.
Hype it up, why not?
Marketing people have got loud voices., especially Matthews and his ilk.

I simply don't get it, but I may upset more people of course.
The Americans made fantastic TV horizontal scan valves, some of which are still stupidly cheap.
(I bought some for the 2USD sort of prices).
The compactrons particularly were highly advanced devices with excellent quality control.

The 12 pin compactron is unique to the USA, as were some of the excellent mil spec missile guidance devices.
If a device is designed to stand 250g without going pop, high radiation, and still remain structurally intact with incredibly tight tolerances (gold gilded grids finer than a human hair) you can bet your butt the miitary weren't messing about.

I simply don't really get why people are going back to those awful ancient obsolete designs, and quicksilver are just another one of them, as they always had.
(Their first 8417 amp was a byword in blow ups, red plating and melt downs, thanks to basic design ignorance.)

Since Peter Millett's red board we have watched in astonishment as screen grid drives on dirt cheap TV valves via Mosfets just blows any of that old crap out of the water.

It's cheap very reliable and amazingly linear...but of course people hate to be told the obvious, which is about low impedances, high currents and stuff that can be run cherry red for yonks and chuck out 100s of low distortion watts for hours and hours.
In fact that is what they were designed for in colour TVs, as was some military Russian stuff.

 

[Godataloss]

Part of the charm of a proper kick-A valve amp is the beauty of the sound, with pretty lively dyamics, compared with those horrible knock offs from PRC or your class D with it's nasty sterile lifeless dead body tat.
There you are, throw a stone in the pond and watch the ripples spread out!

A quote from a famous cellist: "don't play notes play music". (PC).
I hear the same out of the mixing desk after being fooled around with all those "plug ins and effects".
If I want to hear Carnegie hall recordings in my local opera house I go to NY and Carnegie hall.
(I'm not so easily fooled by fake Carnegie).

I often ask my sound engineer friend "WTF did you do here?"
This sounds awful.

If your experience of "good stuff" was limited to those awful modern crap "hi end" tube amps, or the equally awful dynaco stuff then what hope? I can say the same of most "hi end" cans.

What hope indeed for those thinking stereo is brilliant with all that non existent "sound stage" stuff.
If you want to hear something close to live recording, while incredibly difficult to reproduce, go full SURROUND sound.

I have to say, doing surround live is one of the most difficult challenges I ever did, valve or no valve, and never mind the reproduction chain and all the other stuff in it....(ask Neil Wilkes!).

Sorry, my ears have become less tolerant of euphonics and their associated evangelists in my old age. The idea of a kilowatt tube amp gets me about as excited as this device but to each his own

 

[Bob from Florida]

The KT150 is a pile of badly designed Russian sh...t made in Saratov.
Most of that "new sensor" stuff from that factory has always been crap.
Ask me how I know, I spent so many years in Russia and actually met the designers from Svetlana who explained the problems to me.
That thing is violently thermally unstable thanks to the stupidly oversized anode and a load of other problems which make us run away from that low grade GEC KT88 clone.
Hype it up, why not?
Marketing people have got loud voices., especially Matthews and his ilk.

I simply don't get it, but I may upset more people of course.
The Americans made fantastic TV horizontal scan valves, some of which are still stupidly cheap.
(I bought some for the 2USD sort of prices).
The compactrons particularly were highly advanced devices with excellent quality control.

I simply don't really get why people are going back to those awful ancient obsolete designs, and quicksilver are just another one of them, as they always had.
(Their first 8417 amp was a byword in blow ups, red plating and melt downs, thanks to basic design ignorance.)

Since Peter Millett's red board we have watched in astonishment as screen grid drives on dirt cheap TV valves via Mosfets just blows any of that old crap out of the water.

It's cheap very reliable and amazingly linear...but of course people hate to be told the obvious, which is about low impedances, high currents and stuff that can be run cherry red for yonks and chuck out 100s of low distortion watts for hours and hours.
In fact that is what they were designed for in colour TVs, as was some military Russian stuff.

I have owned 3 pairs of different Quicksilver monoblocks over the years. Mini Mono's, Mid Mono's, and Silver 88's. Only failure I had - other than wearing out output tubes - was a bad high voltage cap in the power supply. Mike sent me a new one and I replaced it out of warranty.

Sounds like you have an "axe to grind". Why not tell us what you really think?

 

[MattHooper]

C-J on some amps used LEDs, but mainly so you didn't need a voltmeter. The LEDs were indicators not actual bias elements. You turned the adjustment until they came on and backed off them just enough they turned off.

That's how my CJ Premier 12s bias - adjusting the screws with the LEDs.

Do you happen to know how accurate that method is for getting decent bias?

 

[MattHooper]

It's a known fact any male over 45-50 is incapable of hearing much over 8khz, and it gets worse with each decade older.

Where did you get this "known fact?"

It doesn't comport with what I've seen on the subject. If you are 45, most can hear at least 12,000Hz, and that tends to go up to 50 years old (above which point it gets harder for most to hear that high - but 12k is certainly significantly higher than 8khz, and covers most of what we percieve as "high frequencies" in music playback.

I'm 59 and can hear at least up to 14,000Hz.