Trimming Lejonklou Amps in an Active System

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sunbeamgls
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Trimming Lejonklou Amps in an Active System

Post by sunbeamgls »

What's the experience / advice please?

Should each amp be indivdually trimmed or should they be trimmed consistently to the same setting?
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Re: Trimming Lejonklou Amps in an Active System

Post by David Neel »

Each amplifier has an individual setting which is noted on the multimeter. You should use this. The optimum setting may vary slightly between different units. I can't think why an active system should make any difference if monos could be different side to side (mine are the same).
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Re: Trimming Lejonklou Amps in an Active System

Post by lejonklou »

First of all, if you have multiple amps, you need only use the measuring instrument of one amp. They are all supplied with one each, but as they are identical you need only unpack one.

It's important to note that the amps should be switched on for several hours before trimming. Otherwise you will be compensating for the initial lower temperature, only to later trim it back when the temperature has risen.

If you trim it once after a couple of hours, it's a good idea to do it again after a week, a month and then once a year. If you physically move your system to a new location or into/out of a cabinet, you will benefit from trimming again.

There's no difference whether the amps are used in a passive or an aktiv system, the optional value will be the same.
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Re: Trimming Lejonklou Amps in an Active System

Post by lejonklou »

sunbeamgls wrote:Should each amp be indivdually trimmed or should they be trimmed consistently to the same setting?
Start with trimming them all to the same value. For Tundra stereo 2.5, the optimal value is 16.0.

If you enjoy tweaking your system without any guaranteed benefits in performance, you can try fine tuning the Trim value of each Tundra stereo. I find that differences of 0.1-0.2 are difficult to hear, so test for instance 15.7. The optimal value may lie slightly below 16.0, but very unlikely above 16.0. Usually it's perfect at 16.0.

Tundra Mono is more precise in its Trim setting and doesn't benefit from any individual tweaking of the idling current. This is because it has only one channel, while Tundra stereo has two, which will interact with each other.
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Re: Trimming Lejonklou Amps in an Active System

Post by sunbeamgls »

David Neel wrote:Each amplifier has an individual setting which is noted on the multimeter. You should use this. The optimum setting may vary slightly between different units. I can't think why an active system should make any difference if monos could be different side to side (mine are the same).
Thanks David. I was thinking that the value might need to be consistent for consistent effect (there are a few posts on the forum about how having multiple amplifiers of an active system is thought by some as being a problem because of a perecption of different amps perform differently) but it would seem from Fredrik's posts that the trimming takes the amps to a point where they are performing equally AND optimally, which is what I wanted to understand.
Last edited by sunbeamgls on 2018-09-04 13:16, edited 1 time in total.
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Re: Trimming Lejonklou Amps in an Active System

Post by sunbeamgls »

lejonklou wrote:
sunbeamgls wrote:Should each amp be indivdually trimmed or should they be trimmed consistently to the same setting?
Start with trimming them all to the same value. For Tundra stereo 2.5, the optimal value is 16.0.

If you enjoy tweaking your system without any guaranteed benefits in performance, you can try fine tuning the Trim value of each Tundra stereo. I find that differences of 0.1-0.2 are difficult to hear, so test for instance 15.7. The optimal value may lie slightly below 16.0, but very unlikely above 16.0. Usually it's perfect at 16.0.

Tundra Mono is more precise in its Trim setting and doesn't benefit from any individual tweaking of the idling current. This is because it has only one channel, while Tundra stereo has two, which will interact with each other.
Thank you for your responses Fredrik. I take this as setting each amp optimally (as per the instructions about warm up etc.) also sets them to perform equally.

I had a thought about leaving the amps powered up too please - I understand that they should be switched off when not in use for "prolonged periods". When I get the chance to listen its often only for an hour or 90 mins so waiting an hour for temperature stability is not an option. Is it OK to leave them on for 24-48 hour periods without use so that they can be enjoyed immediately they're needed? Also, what is the power consumption at idle?

Thanks
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Re: Trimming Lejonklou Amps in an Active System

Post by lejonklou »

I never switch my amps off, unless I go away for more than a few days.

The idling power of a Tundra is close to 30 W.
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Re: Trimming Lejonklou Amps in an Active System

Post by sunbeamgls »

lejonklou wrote:I never switch my amps off, unless I go away for more than a few days.

The idling power of a Tundra is close to 30 W.
Thanks :)
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Re: Trimming Lejonklou Amps in an Active System

Post by ThomasOK »

Likewise, I keep my system powered up 24/7. When I go on vacation I unplug the whole thing from the wall as that is the only true way to protect it from a lightning hit. In addition the system appears to sound better after playing music for a while - one of my customers says he plays a "sacrificial album" to warm up the system before he has an actual listening session. Therefore, I take it a bit farther and leave music playing off the streamer at a low level so everything is warmed up when I throw on a record.
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Re: Trimming Lejonklou Amps in an Active System

Post by sunbeamgls »

^ Thanks
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