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Linn newbie questions

Mike T

Mike T

Member
Hi. I purchased a vintage Linn system lately. Its an Aktiv LK140x3 with av5140s. First...hooking up the speakers...are the top lugs for treble, middle lugs for mids and bottom for bass? I want to make sure...
Next, can I use an equalizer with the system since the amps are already separately crossed over with the Aktiv cards? If anyone can give me advice I would surely appreciate it! Thanks:)
 
You could really do with someone who knows who can help set the active crossovers up as there are internal pots to trim them. Whatever you do, make sure that you connect the correct amp to the correct pair of terminal as if you connect the bass amp to the HF, you'll make an expensive mistake. Adjustment is a two-person job really as you need someone with the covers off the amps, making adjustments, whilst you listen. Putting eq into an active Linn system really shouldn't be necessary as you already have an awful lot of adjustment.

There's a user guide here: https://www.google.co.uk/url?sa=t&s...FjAAegQIBBAC&usg=AOvVaw2IworbJBD3uoSkKxtpwLNU
 
The above link doesn’t work for me unfortunately so not sure how Linn actually wire this set up.

As mentioned above I hope everything is clearly labelled as to which driver each amp should feed as getting this wrong may end in tears!

Which pre amp are you using? An equaliser could be used on one of the line level inputs between the source and the pre amp. Using one after the pre amp will be dependant on how it’s wired!
 
Yes, whether 'Aktiv' or passive, the top, middle and bottom pairs of sockets are tweeter, mid, and bass respectively.

If the AV5140 were purchased separately, it would be prudent to test them to ensure that they have been modified for 'Aktiv' use. Simply removing the link plates only converts the standard pair for bi- or tri-wiring/bi- or tri-amping (passive). The modification to Aktiv requires the crossover boards to be removed and replaced with a terminals only board.

If unsure, a simple test here is to run a full-range signal into the bass sockets only, via a normal amp; if you hear mids and highs then the crossovers have been removed.
WARNING: Under no circumstances should you test the tweeters in this fashion.

If the speakers are confirmed to have been modified for active use, then the above warnings to make sure that the appropriate amps for bass, mid, and treble are connected accordingly are not to be taken lightly. Mistakes here are very expensive these days. Labeling everything*, including both ends of the loudspeaker cables, is a good idea.

As to which amp connects to which drivers, the Aktiv cards have tabs that protrude though slots in the back panel of the LK amp for each channel, upon which the function of the card is labelled. Also, labels that affix to the back panel of the amplifiers came with each Aktiv kit.

Here is an LK140 that had been configured with 'Twtr' cards (since removed)...
1638157-24ee0fe2-linn-lk140-power-amp.jpg
 
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Craig B, how are the Linn power amps fed? Was it three stereo channels from the pre into the three power amps or was it a stereo pre out into the first power amp then linked using the in/out connections on the rear?
 
Just got back on-line with my cloudy storage. Apparently, the manual I have is less than clear on the system interconnection possibilities. It's the 'ACCURATE AKTIV Installation Manual' (PACK 941/3). There is a section creatively entitled 'Into LK85/LK140 power amplifier' (pgs 13-14) which indicates that LK85/LK140 can be fitted with a single ‘2-channel’ or stereo AKTIV module, however, other than covering physical installation of the card, and including warnings re connections to the correct drivers. the connection options to the rest of the system are a bit vague.

You are welcome to a copy, if you'd like to PM your e-mail address.

Speaking of Linnfo, perhaps our helpful friend @linnfomaniac83 might offer some assistance? He likely has, or has had, this exakt setup. (I did't have to underline that, did I?)
 
I don’t have that exakt setup but I do have tri-amp active Ninkas, with the LK range of amps, when active cards are installed you can either connect them individually to the preamp or daisychain them, it doesn’t matter as the line inputs and outputs are connected internally. If anyone needs any detailed advice or clarification, drop me a PM and I can arrange a phone/video call if necessary to help you.

Also, with LK85/140 and AV2250/5125, you don’t really need two people for tuning a system, it can be done over a longer period of time because the gain settings can be adjusted with trim pots which are accessible with the covers on. It’s not a process I like to rush, I start with the gain settings all level between the amps and sort out speaker placement first, once I’ve got that as good as possible, I turn my attention to gain settings and if necessary, I adjust them gradually, taking time to listen to and evaluate any changes properly.
 
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Ah, daisy chain. Those were the words I was looking for! That makes sense with the in and out connections on the LK power amps and also the supplied stickers.
 
I hate to say it but i am hugely disappointed with the bottom end of the system. Especially at low volumes. There’s no bass...and although the mids and highs are crystal clear...beautiful but almost harsh...I wanted to tame those down and warm up the bottom end without having to turn up the volume all the time to hear the bass parts of the music...clue me in....am I running the system wrong? There are small gain knobs on the back but the one on the bass unit just turns and turns and there’s no difference in bass output.
 
First of all, I should have thanked all of you wonderful and helpful people for the tons of technical knowledge that is very helpful....THANK YOU!:):):):)
 
That system really shouldn’t be lacking in bottom end or sounding harsh, it almost sounds as though the bass amp is passing a full range signal which could happen if the wiring harness between the active card and the main board isn’t connected properly. The fact that the trim pot isn’t having any effect reinforces my suspicion.
 
Firstly, did you hear this combination working together correctly before it was disconnected?

When you say turns and turns do you mean the pot rotates more than 360 degrees, in other words no end stops?
Also , you mention gain knobs, I’d have thought there would only be a small screwdriver hole in the rear chassis to make adjustments as in Craig B pic. If there are external knobs are you sure the knob isn’t slack and requires tightening of a grub screw?

Linnfomamiac83 is way more experienced on Linn kit and he’ll confirm if this is the way the pots operate or not.

Checking the internal connections of the bass LK140 amp is worth doing as well.

Craig B has covered everything in post 5 really, I would be tempted to switch on only the bass LK140 amplifier (assuming it’s first in line) and check how the output level changes when turning up the pre amp volume and also when adjusting the pot without the midrange and tweeter amps on.

If there’s no sound then I’d feed a full range signal into the bass drivers only as described by Craig B. If no output from the bass drivers then with everything disconnected I’d check the bass drivers with a meter.

I’ve never heard the 5140 speakers but I’d be surprised if they were lacking bass.
 
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wow&flutter said:
Firstly, did you hear this combination working together correctly before it was disconnected?

When you say turns and turns do you mean the pot rotates more than 360 degrees, in other words no end stops?
Also , you mention gain knobs, I’d have thought there would only be a small screwdriver hole in the rear chassis to make adjustments as in Craig B pic. If there are external knobs are you sure the knob isn’t slack and requires tightening of a grub screw?

Linnfomamiac83 is way more experienced on Linn kit and he’ll confirm if this is the way the pots operate or not.

Checking the internal connections of the bass LK140 amp is worth doing as well.

Craig B has covered everything in post 5 really, I would be tempted to switch on only the bass LK140 amplifier (assuming it’s first in line) and check how the output level changes when turning up the pre amp volume and also when adjusting the pot without the midrange and tweeter amps on.

If there’s no sound then I’d feed a full range signal into the bass drivers only as described by Craig B. If no output from the bass drivers then with everything disconnected I’d check the bass drivers with a meter.

I’ve never heard the 5140 speakers but I’d be surprised if they were lacking bass.
Click to expand...
There’s no card installed on the amp Craig B showed, just an aktiv treble identifier label.

When a card is installed, there are two PCB tabs that protrude through slots in the back panel, and in three way active systems there will be a gain trim pot that will stick out of a small hole on the bass and treble cards, there’s no trim pot on mid range because the low and high frequencies are adjusted around the mids.

If you want to test the amps individually, you need to have just the amp you wish to test connected to the preamp, this is because the input impedance of the cards drops drastically when they’re powered off, this has a significant effect on the frequency response, in particular it will kill the bass and render any testing of the card/amp meaningless.

I would test the bass amp in isolation, if you hear nothing, something must be wrong, I’d expect the power indicator to stay red if the amp/card wasn’t passing a signal at all because the LK85/140 has automatic signal sensing (to the OP, on that note, make sure you’re turning the card gain trim pot and not the signal sensing pot). If you hear mid range/vocals as well as bass, it means the amp is passing a full range signal, the only reason this would happen is if the card wasn’t connected to the main board properly, since the amp automatically detects the presence of an active card (if installed correctly).

PS, the “trim pot” is actually a rotary switch that controls a resistor ladder, it does turn continuously, that’s not a fault.
 
Just for reference I’ve attached an image of the rear of an LK140 with a card installed, it’s the upper pot that adjusts the gain.
kvXUHMn.jpg
 
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