@What-watt Playing around with your tubes is certainly part of the hobby. But honestly, as others have said, stick with the tubes your amp is made for. If you don't like the sound after two months, then change the tubes very carefully, only the tubes of one function at a time, not several at the same time. In the meantime, you can learn which other tubes are electrically suitable and which are not. The line between fine tuning and disaster can be very thin.

Hi everyone, I have an SPL-120 that has started producing a heartbeat-like sound every 2–3 seconds. After researching similar issues in this forum, it seems the amplifier might be failing. I’ve already replaced some capacitors commonly associated with this problem, based on online recommendations, but unfortunately, it didn’t resolve the issue.   Does anyone know which components might be causing this? I’m comfortable with desoldering and soldering new parts if needed.   I’ve uploaded videos of the sound and pictures of the amplifier here: https://imgur.com/a/GFGjIKI   Any advice or guidance would be greatly appreciated! Thank you!

Happy New Year everyone!

They look terrific!  What speakers are you driving with them?   Maynard

Thank you very much, wuzzzer.

I want to have  full fledged 5.1.4 system until the end of the 2025. So far I have just a avr and a pair of RP-6000F II . My next purchase is going to be  a 504 CII as a center channel.   Then I will get a sub in march or april. Have not decided one which sub I will get. in summer or autum I will going to get the rear speaker.

It’s 15° in Spruce Pine and finally cool enough to pull my  Lands’ End expedition parka out of the closet. We had some flurries this evening but not enough to accumulate. The schools are on a 2 hour delay tomorrow after being off all week due to “weather”.    I ran up to my guitarists studio earlier and we worked out the shot list for some music videos we are shooting this weekend. It will be interesting to see how we can make it work since the guitarist and I are  going to be the videographers.        

Not sure about those subs in particular but typically the k-48 is a 4 ohm driver but I have seen on rare occasions an 8 ohm version. Re-cones that I've had done locally used to be $75-$100 but it's been quite awhile since I've had one done. Klipsch does sell new k-48-st drivers but I have no idea how much they charge for them. Ebay has them used every so often. That driver is pretty stout- I've only ever seen one blow and that was due to an amp failure. 

Hello, I have one of those 110SW sub amps as well. I already did the diagnostics and tried repairing it some time ago, turned out to be pretty much waste of time as the fault is propably in IRS chip itself and replacing that is pointless from labour point of view. And quite frankly too difficult to do with my equipment. So I just bought another complete power amp section. Thing is that I would still like to use the processed input signal from the original amp board. It goes through the volume control and propably some kind of fixed filter also, plus there's the adjustable crossover. I believe the preamp section should be fine, but can anybody help and tell me where would be the correct point to "take out" the signal for the new power amp? Directly from pin3 of the IRS2092 chip? Some other place? Has someone done it? As it is all built as one pcb, its kind of difficult to make out, where exactly does the socalled preamp section end and power amp section start.   The replacement amp by the way is exactly the same thing, as is it uses IRS2092 too, it has a signal in connector, I just need the signal and would like to retain the ability to control gain and filter frequency. New amp board will be attached to the original plate.

Thank you Derrickdj1!