Natural Sound

[Salectric]

@Amir
Thanks for posting the link. Romy makes some interesting points although trying to decipher his writing quickly gives me a headache.

 

[DasguteOhr]

Peter

I remember Romy find an interesting design concept in Lamm pre-amplifier and called it x-factor . It was like Magic sound, it seems Lamm used a special method to get very fine and spacious sound and this is the link :

http://goodsoundclub.com/Forums/ShowPost.aspx?PageIndex=1&postID=1861#1861

the magic lies in the working point of the tube. She is a wild beast, voltage and current should be stabilized.
Exsample LL 1.1preamp
the 6h30n is an amazing tube, i know no other 9 pin tube that you can easily drive with 40mA working current. a powerful, beautiful sound, that's why i use it too. you could use 6n6 tube, but that's the end at 30mA. depends on the working point at lamb. it sounds a little softer and rounder with a little higher impedance. but there is a downside to the medal, it can quickly become highly microphonic. lightly tap the tip of the tube with your fingernail.
Tube working points max.

 

[morricab]

the magic lies in the working point of the tube. She is a wild beast, voltage and current should be stabilized.
Exsample LL 1.1preamp
the 6h30n is an amazing tube, i know no other 9 pin tube that you can easily drive with 40mA working current. a powerful, beautiful sound, that's why i use it too. you could use 6n6 tube, but that's the end at 30mA. depends on the working point at lamb. it sounds a little softer and rounder with a little higher impedance. but there is a downside to the medal, it can quickly become highly microphonic. lightly tap the tip of the tube with your fingernail.
Tube working points max.
View attachment 109513

Unless you can find the unobtainium 6N30P-DR I have found the 6N6P sounds better in the same circuit.

 

[DasguteOhr]

Unless you can find the unobtainium 6N30P-DR I have found the 6N6P sounds better in the same circuit.

nice if you can just switch. both have their charm
you need a russian or ukraine connection then the prices are just about bearable.

 

[Amir]

the magic lies in the working point of the tube. She is a wild beast, voltage and current should be stabilized.
Exsample LL 1.1preamp
the 6h30n is an amazing tube, i know no other 9 pin tube that you can easily drive with 40mA working current. a powerful, beautiful sound, that's why i use it too. you could use 6n6 tube, but that's the end at 30mA. depends on the working point at lamb. it sounds a little softer and rounder with a little higher impedance. but there is a downside to the medal, it can quickly become highly microphonic. lightly tap the tip of the tube with your fingernail.
Tube working points max.
View attachment 109513

I have no valid information about working with different tubes but are you sure about x-factor is realated to tubes?
I read some information about mixing of two channels in a special way can increase sense of space in pre-amplifier . Finally I am not sure about it

 

[DasguteOhr]

I have no valid information about working with different tubes but are you sure about x-factor is realated to tubes?
I read some information about mixing of two channels in a special way can increase sense of space in pre-amplifier . Finally I am not sure about it

ok you mean a crossfeed circuit like a headphone amplifier is used. to create the feeling of sitting in front of loudspeakers. a controlled crosstalk is inserted there without degrading the sound quality. I can not imagine that lamm would worsen the channel separation.
Exsample crossfeed shematics

 

[PeterA]

But this simply begs the question as to what ages tubes. You seem not to be acknowledging the significant aging effect on tubes of the on/off/on cycling process.

As I understand it, Vladimir Lamm felt the sudden rush of electricity stressed the components and the tubes more than simply leaving them on all the time. He kept his gear on all the time.

Now that it is getting warmer and I do not have air-conditioning, I may turn my gear on/off once a day when listening to keep the room cooler and reassess next winter.

 

[Atmasphere]

Sorry Tim, IMO this looks mostly like superstition to me, unless our tubes have a thick layer of dirt on them.

Fingerprints allow dust to collect more easily. Heat, especially in class A circuits, is an enemy of tubes. It is important to keep the envelopes clean.

 

[Ron Resnick]

As I understand it, Vladimir Lamm felt the sudden rush of electricity stressed the components and the tubes more than simply leaving them on all the time.

Sudden in-rush is a real problem, especially in big, high-power tube amps. For my old MB-750s VTL developed outboard, in-line "soft-start" boxes.

With the Siegfried IIs there is a 240 second slow-start warm-up sequence upon power on.

 

[Gregadd]

Some claim it is less wear to leave a light bulb on than to subject it to the sudden surge of electricity. I have a delay swatch.

 

[tima]

With the Siegfried IIs there is a 240 second slow-start warm-up sequence upon power on.

Lamm electronics are similar. From my M1.2 review at TAB:
Each amplifier uses a biasing circuit designed to achieve the thermal stability of its output transistors and other components. Further evidence of quality is the attention paid to boot time -- perhaps the most precarious moments for any high-powered amplifier. The M1.2 features a soft-start protection circuit where filter capacitors do not receive initial voltage for 2.5 seconds after turn on; then time relays initiate, delaying readiness for one minute to allow warm-up. If internal tests find an issue, the amp turns off and waits; if the issue resolves itself, it turns back on.

 

[DasguteOhr]

Some claim it is less wear to leave a light bulb on than to subject it to the sudden surge of electricity. I have a delay swatch.

An Edison lightbulb has been on for over 108 years. on the subject of dust.
tube radio phillips not open for at least 50 years. cleaned very carefully too much water causes the old wood to swell. two tubes and one capacitors changed lasts again for next century.

P.S Radio ran before repair

 

[Audire]

An Edison lightbulb has been on for over 108 years. on the subject of dust.
tube radio phillips not open for at least 50 years. cleaned very carefully too much water causes the old wood to swell. two tubes and one capacitors changed lasts again for next century.
View attachment 109531 View attachment 109532
P.S Radio ran before repair

That‘s amazing!

 

[Al M.]

Lamm electronics are similar. From my M1.2 review at TAB:
Each amplifier uses a biasing circuit designed to achieve the thermal stability of its output transistors and other components. Further evidence of quality is the attention paid to boot time -- perhaps the most precarious moments for any high-powered amplifier. The M1.2 features a soft-start protection circuit where filter capacitors do not receive initial voltage for 2.5 seconds after turn on; then time relays initiate, delaying readiness for one minute to allow warm-up. If internal tests find an issue, the amp turns off and waits; if the issue resolves itself, it turns back on.

Great. If the same soft-start procedure holds for their tube gear, even less reason to keep it on all the time.

 

[Argonaut]

Great. If the same soft-start procedure holds for their tube gear, even less reason to keep it on all the time.

Quite ! In a well designed and implemented valve amplifier power inrush once or twice a day should have virtually no ill effect on the potential operating life span of the incumbent valves … leaving them powered up 24/7 on the other hand !

 

[Atmasphere]

Sudden in-rush is a real problem, especially in big, high-power tube amps. For my old MB-750s VTL developed outboard, in-line "soft-start" boxes.

With the Siegfried IIs there is a 240 second slow-start warm-up sequence upon power on.

Sheesh.

Current inrush can be controlled by a simple device called

wait for it....



....



A Current Inrush Limiter.

They cost a dollar or so. No box or special circuitry needed.

We've used them for decades- all of our OTLs (which have a lot of current inrush) use them. You can turn them on and off as much as you like no worries. CILs are a kind of thermistor with an inverse resistance characteristic- when cold their resistance is high, when hot their resistance is low. Not only does this take care of all issues regarding tube warmup (we do have a Standby Switch to prevent cathode stripping during warmup- it has its own CIL) and filter capacitor charging, it also helps switch contacts to survive. They are very reliable- we've never had one fail ever.

Why would a designer not use this sort of thing?? I'm serious- you need a really good excuse for this one.

 

[DasguteOhr]

Sheesh.

Current inrush can be controlled by a simple device called

wait for it....



....



A Current Inrush Limiter.

They cost a dollar or so. No box or special circuitry needed.

We've used them for decades- all of our OTLs (which have a lot of current inrush) use them. You can turn them on and off as much as you like no worries. CILs are a kind of thermistor with an inverse resistance characteristic- when cold their resistance is high, when hot their resistance is low. Not only does this take care of all issues regarding tube warmup (we do have a Standby Switch to prevent cathode stripping during warmup- it has its own CIL) and filter capacitor charging, it also helps switch contacts to survive. They are very reliable- we've never had one fail ever.

Why would a designer not use this sort of thing?? I'm serious- you need a really good excuse for this one.

in almost every musician amp inside and old tube stuff. too simple some must be more complicated looks more exciting

 

[tima]

Why would a designer not use this sort of thing??

So you agree that current in-rush is a genuine issue?

 

[Atmasphere]

So you agree that current in-rush is a genuine issue?

Of course. But its easily solved by a competent designer by the simple use of current inrush limiter. No need for care about when the unit was last on, no worries about damaging something. It eliminates the problem.

They have not been around forever, which is why you don't see them in vintage equipment. But with any modern gear going back 35 years there really wasn't/isn't an excuse for not using them. They are cheap, reliable and they work.

 

[Kcin]

Of course. But its easily solved by a competent designer by the simple use of current inrush limiter. No need for care about when the unit was last on, no worries about damaging something. It eliminates the problem.

They have not been around forever, which is why you don't see them in vintage equipment. But with any modern gear going back 35 years there really wasn't/isn't an excuse for not using them. They are cheap, reliable and they work.

This issue was solved over 50 years ago as well

Current in rush limiters are a simple solution if they are sized correctly.

While in rush current on start up can cause concern in a poor design, the on - off of consumer use is not generally the end of the world.

I use in rush limiters in some of my designs- they're cheap and effective.