FWIW dept.:Thanks Everyone. I understand the issue was solved years ago. Can me move on from that discussion now?
If what you say just above is correct, it suggests that you might want to look into this. If they are not installed, its easy for any tech to add them without messing with the amp otherwise.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.
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.
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.
Cognatulations - they look great. Are you cutting and building them yourself?I have designed and begun to build the supplementary rack for the power supplies for the new phonostage. It is a mahogany framework to support two steel plates, one under each supply. It will be on lockable rollers so that I can move it into place. The narrow end will be facing forward to expose the side of the component.
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Cognatulations - they look great. Are you cutting and building them yourself?
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.
Peter,
I think you are misreading Vladimir Lamm manuals. They just refer to the soft-start circuit avoids the inrush mains current peak, inoffensive to the amplifier but that can be a problem with some poor mains supplies or generate noise or trigger functions in other equipment that is switched on. He also says that the inbuilt delay in applying HV extends tube life, avoiding the effect you claim. It would be ridiculous if a manufacturer of high quality high price electronics could not avoid the effects of switching on and off equipment normally.
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.
I am not talking about anything in the manual. I’m just following the advice from my dealer DDK who heard it from Vladimir Lamm himself. As I wrote, I may change my practice this summer.
Aesthetics aside (as ifI have designed and begun to build the supplementary rack for the power supplies for the new phonostage. It is a mahogany framework to support two steel plates, one under each supply. It will be on lockable rollers so that I can move it into place. The narrow end will be facing forward to expose the side of the component.
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Aesthetics aside (as if).. still managed with lovely proportions Peter.
It’s looks great Peter. Looking forward to the end result!Thank you Graham. The proportions were dictated by the dimensions of the supples (14” X 19”) and 6” clearance for circulation and the narrow space in which I will need to roll this 200+ lbs loaded rack. It is 14W X 22”D X 16.5”H.
No, they were not "soft-start" boxes.
I remember that old class A Krell amplfiers sounded best after a full day warm-up.
Ron, you sure you have the right forum?What methodologically and analytically valid blind testing did you implement to quantify and verify sonic improvements among a 12 hour warm-up versus an 18 hour warm-up versus a 24 hour warm-up?
just mess'n with ya....Francisco often holds members' feet to the fire of precision, so I assumed, perhaps incorrectly, that there was academic-quality data backing up his assertion.
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