Hi, I am a longtime reader that now finally has a question that the search could not solve...
I have a Linn Klout (that I like very much) that hisses on the left channel for a while at startup. After ca. 2-5 minutes the signal clears up and everything is as it should be. This is of course rather inconvenient and might also point to bigger trouble in the future. So I asked my father-in-law (who is an electronics technician) for help and we tried to get to the bottom of this.
A lot of coffee and headscratching later I had learned quite a bit about my amp and that all the caps are still ok, although we changed a few that were on their way out. But it still has that hiss when being switched on. The preliminary result is that the Klout has a soft start and that something with that seems to be the issue. On startup the + voltage for the left channel builds up as expected, but the -voltage doesn't. It starts to do so and then hovers around until it finally gets up to the expected level. It is however possible to give it a "push". Even the measuring voltage was sometimes enough to get it running.
Unfortunately this is where we are stuck. Has anyone seen this problem before? Any suggestions are very welcome.
cheers,
Julius
p.s.: does anyone have proper (original) schematics for a Klout? I have found some retroengineered ones that were helpful, but not completely accurate.
I have a Linn Klout (that I like very much) that hisses on the left channel for a while at startup. After ca. 2-5 minutes the signal clears up and everything is as it should be. This is of course rather inconvenient and might also point to bigger trouble in the future. So I asked my father-in-law (who is an electronics technician) for help and we tried to get to the bottom of this.
A lot of coffee and headscratching later I had learned quite a bit about my amp and that all the caps are still ok, although we changed a few that were on their way out. But it still has that hiss when being switched on. The preliminary result is that the Klout has a soft start and that something with that seems to be the issue. On startup the + voltage for the left channel builds up as expected, but the -voltage doesn't. It starts to do so and then hovers around until it finally gets up to the expected level. It is however possible to give it a "push". Even the measuring voltage was sometimes enough to get it running.
Unfortunately this is where we are stuck. Has anyone seen this problem before? Any suggestions are very welcome.
cheers,
Julius
p.s.: does anyone have proper (original) schematics for a Klout? I have found some retroengineered ones that were helpful, but not completely accurate.
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I doubt if anyone can help with service manuals as these are subject to confidentiality agreements with service agents and UK manufacturers do try to keep their secrets longer than others...like forever.
Anyway, a 2-5 min period of hiss at start-up suggests either a capacitor or thermal problem. As it works okay after after a few minutes plus you have treated the capacitor question already and narrowed the voltage problem to the left channel, it leaves a problem with heating of other components or perhaps bad solder connections to them, as the amplifier warms up.
I'm not familiar with the soft-start circuit but these normally are fitted to the primary side of the power supply and should only very briefly limit AC mains inrush current (listen for a relay click if one is fitted) which affects all secondary windings and most likely, both rails of both channels equally. So, as the left negative rail only is slow to rise, the problem is after the 27R resistor shown on Tiefbassuebertrauer's "Klout" schematic as R49 (assuming that is what you used as a guide) If there is another schematic that is closer, please ignore this and post a link to it so that we can all understand the circuit a little better.
Anyway, a 2-5 min period of hiss at start-up suggests either a capacitor or thermal problem. As it works okay after after a few minutes plus you have treated the capacitor question already and narrowed the voltage problem to the left channel, it leaves a problem with heating of other components or perhaps bad solder connections to them, as the amplifier warms up.
I'm not familiar with the soft-start circuit but these normally are fitted to the primary side of the power supply and should only very briefly limit AC mains inrush current (listen for a relay click if one is fitted) which affects all secondary windings and most likely, both rails of both channels equally. So, as the left negative rail only is slow to rise, the problem is after the 27R resistor shown on Tiefbassuebertrauer's "Klout" schematic as R49 (assuming that is what you used as a guide) If there is another schematic that is closer, please ignore this and post a link to it so that we can all understand the circuit a little better.
Geeez.... Lookit ALL the parts in that contraption.
Move on ..you've gotten yer 2 pence worth.. years ago.
Technology / state of the Amplifier art has moved well off field since that thing was penned.
Move on ..you've gotten yer 2 pence worth.. years ago.
Technology / state of the Amplifier art has moved well off field since that thing was penned.
Send me your email via pm, I have all the service manuals. It is a great sounding amp and still competes with the best out there today.
.. dB
.. dB
Some detailed pictures.
Amp woes and restoring a "vintage" treasure | Super Best Audio Friends
Sajti
Amp woes and restoring a "vintage" treasure | Super Best Audio Friends
Sajti
... thanks for all your responses!
I am not going to move on, @Bare 😉 I do like my setup as it is (Karik, 3 Klouts, a pair of active Kabers and an AV5150 as sub) I don't need it to be better than something else and of course it is no longer state of the art in engineering terms, but it sounds lovely and I haven't had the itch to change anyhting since I added the sub 10 years ago. If I have to, I will send the Klout to Linn for repair, but for now I would like to try myself as I am not yet convinced that it is not just some trivial element that has failed.
@db: Thanks! that is service! pm is out.
@sajti: I actually used that thread to get an Idea of what I had to expect in there, but I couldn't find it anymore when writing my post... thx
@ Ian Finch: yes, I am indeed using that schematic and you are probably correct that the error has to be behind that restistor. Unfortunately the schematic doesn't seem to correspond exactly to my amp - maybe I have more luck with dBs manuals.
Just for future referece: yes there is a relais on the primary side and it clicks very audibly, but it is not the problem - everything checks out and - as you wrote - any damage there would be audbile on both channels.
cheers,
Julius
I am not going to move on, @Bare 😉 I do like my setup as it is (Karik, 3 Klouts, a pair of active Kabers and an AV5150 as sub) I don't need it to be better than something else and of course it is no longer state of the art in engineering terms, but it sounds lovely and I haven't had the itch to change anyhting since I added the sub 10 years ago. If I have to, I will send the Klout to Linn for repair, but for now I would like to try myself as I am not yet convinced that it is not just some trivial element that has failed.
@db: Thanks! that is service! pm is out.
@sajti: I actually used that thread to get an Idea of what I had to expect in there, but I couldn't find it anymore when writing my post... thx
@ Ian Finch: yes, I am indeed using that schematic and you are probably correct that the error has to be behind that restistor. Unfortunately the schematic doesn't seem to correspond exactly to my amp - maybe I have more luck with dBs manuals.
Just for future referece: yes there is a relais on the primary side and it clicks very audibly, but it is not the problem - everything checks out and - as you wrote - any damage there would be audbile on both channels.
cheers,
Julius
Check those service manuals for this series. They are similar but there are some differences even for same model from another year.
Hi everyone,
I know it has been a while, but we didn't get around to test your suggestions immediately and then there was christmas etc., but I am happy to report that the Klout is back up and running.
As it turned out it probably was a cap in the start circuit. We had checked and partially replaced them before, but when we just changed them all the problem was gone.
I thank you very much for your help and suggestions and particularly dB for his service manuals - they really were a huge help in understanding the circuit
cheers,
Julius
I know it has been a while, but we didn't get around to test your suggestions immediately and then there was christmas etc., but I am happy to report that the Klout is back up and running.
As it turned out it probably was a cap in the start circuit. We had checked and partially replaced them before, but when we just changed them all the problem was gone.
I thank you very much for your help and suggestions and particularly dB for his service manuals - they really were a huge help in understanding the circuit
cheers,
Julius
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