peniku8

Seen this a few days ago, but it didn't quite impress me. Especially since it'll be more expensive for me than a 21IPAL and well.. ferrite magnets are unattractive to me.

Afaik Ricci had two of their older models, which were identical to some Crown amp. I think you can combine multiple of those newer amps to gain even greater power. But it‘s pretty apparent that they‘re not designed with moving around in mind

Non-dsp amps will not cause latency issues. The K line dsp, as an example, has a latency of 6ms, which equals 1/3rd of a wavelength of 55,6Hz (below 1/3rd of a wavelength delay, signals will combine well). Having the same amps is good for flexibility, usability, serviceability and peace of mind. Using different amps will require some work (gain matching in your case) and if you change the setup, it might not be as straight forward as with the same type of amps. If you don't change your setup much and nobody messes with the volume controls, I doubt you'll have any issues with running two different amps.

Ask for a trade on AVS. I'm sure somebody there has 8 Ohm drivers and would prefer 4 Ohm. Make your 6 subs 8 Ohm and run them in parallel, 3 off each channel of the K10 for a ~2Ohm(?) impedance minimum. Maybe a stupid question, but have you tried running 3 of your current subs parallel on a K10 channel? Ricci ran even lower impedances on the K20 which basically only resulted in sustained output power loss iirc. Maybe try it out and see if it works for you.

That's why I suggested making a new top plate if he doesn't want to cut to original one. The layout of the heatsinks make cooling like that really easy and efficient. The fans just need to touch the fins to turn the heatsinks into closed-off paths for the airflow. If theres too much of a gap, the fans will draw air from the sides and cooling won't be efficient.

I'm not 100% sure about the cooling system in the K line, as the radial fans don't give a great insight on air flow, but if you took those out and mounted a few 80mm fans to the heatsinks (with the fans blowing air up), leaving the top panel off, or better: making cut outs for the fans, the cooling would likely be better and very quiet. If you don't want to cut holes into the top panel, make something out of acrylic for example. That guides the cold air through the components and the hot air ventilates through the fans in the top. Keep in mind that this solution will require additional dust filters at any point where air can be sucked into the amp (like the holes in the back after removing the og fans).

I measured the idle power draw and it looks like it went up to 160W (from 115). I can only measure in 0.1A steps, which is 23W, so the possible difference ranges from 23W to 69W. Not really a good sign, but it's not a huge amount either, so I'm not necessarily concerned about it. Their 4 channel amp draws almost 200W in idle. One reason for me to not switch the TSA1400 in the theater back out for the FP13000.

Well the PSU blew up during testing. I only had to replace the amp boards because I damaged them by accident while trying to repair the PSU. If the mix was on purpose, why use different amounts on both channels? I also have the feeling that the amp gets hotter in idle now. So either the heat transfer from the transistors to the heat sink is better now or something else is the problem. I also reversed the fan mod I did and let the fans run full tilt now. I‘ll have a look at the idle power draw and see if it‘s higher than the ~150w it was before. Either way, the bad gut feeling will now never subside when I bring that amp to a gig. I don‘t have any use for it at the moment anyways, so I might just sell it and call it a day.

Quick update on the Sanway: I've recieved two replacement amp boards they sent me for 300$ including shipping. Amp is operational again. The amp boards which I had were version 2, the new ones are version 10. They now also use the same type of transistors throughout.

I ordered two replacement modules, will see if the current ones are the same. This amp is 7 years old after all.

Yea I returned it. With the phase plug I was just refering to the general direction. I had 12 woofers in series and it was clear that this one made noise well before reaching Xmax and it was about 5db earlier compared to the other woofers.

This is so annoying. I was just way too curious to see if I could improve the amp's performance by adding those components and now I caused 150$ damage again. Well, heres more random info on the PSU: when both amp stages are disconnected, the PSU hold over 200V for an hour. I used a light bulb to quickly drain it. When it's down to 0.1V, it takes about 10 seconds to climb back to 2V. I immediately connected the 230V light bulb after I powered the amp off, when the PSU was still at around 350V from positive to negative. It was a 30W light bulb or smth, it lit up brightly for a second and the light faded completely after some 20 seconds. Very convenient way when you're working on this kind of stuff.

Seems like this amp is haunted by Hoffmann's Law. I'm not sure why but the modifications I made (wich was adding the two missing resistors and transistors) broke the amp stage. The fuses melted so I removed the components again but it's still inoperational. Welp, now the amp doesn't work at all anymore, since both output stages are broken. I'm guessing that it's a relatively minor thing, but I'm not the one to track down a broken component and I'm fairly certain that getting it fixed will be more expensive than the 150$ for the replacement board.

What confused me even more was the seemingly random choice of output transistors, as two different models were actually used in the amp. One output channel has an even distribution of both types, while the other one has 5 of one type and 9 of the other. Both are the NPN type. https://www.onsemi.com/pub/Collateral/NJW0281-D.PDF https://www.onsemi.com/pub/Collateral/NJW21193-D.PDF Looks like the 21193 is a bit better. I'll solder two from the broken pcb to the working pcb to "upgrade" the FP-13000 to Fp-14000 on the output stage. It might make a slight difference into lower impedances. 14 vs 16 transistors is still a decent upgrade.

I somehow feel like this is bad design or something isn't working as it should. The 4 transistors I replaced in the PSU, which all broke after about 2 minutes of 4KW output generate a humongous amount of heat even in idle. The heatsink seen below reaches 80°C (176°F) in idle and SOMEHOW I measure over 1KV from heatsink to ground and when I touch it with the thermo sensor I see small sparks. What is going on here??

Interesting, I also had a problem with one of the 14 Dayton woofers I recently got. Very similar noise, just that I was testing at 20Hz so the "clicking" was slower. The issue doesn't seem to come from the surround on the Daytons, more like the noise comes from the phase plug (those woofers have a solid phase plug in the center instead of a dust cap).

Ported subs are easy to integrate if they are the lowest playing speakers in the system. If you have ported subs and want to run something below that (like sealed or other deeper ported subs), you'll have a hard time on doing so. FIR filtering might be the only solution, at the cost of delay and ringing. But since that's not the case you won't have to worry about that.

You might wanna ask this question on AVS again, but unless your cab is severely mistuned, the issues you‘re hearing are likely room issues. I have no experience with the um-18, but apparently it‘s also pretty capable in the mid-bass region. I‘m not sure if dropping those drivers in sealed cabs would yield your desired improvements. I have seen other people using (multiple) um-18s seeking for better misbass performance, which makes me wonder why not go for the 21ds115 or similar instead. I know in the states they‘re similarly priced and you‘ll lose a bit of deep bass (displacement), but you‘ll gain a lot of sensitivity. If those magnum drivers are high sensitivity drivers, I‘d give them a shot. Should work rather nicely in sealed cabs. What other subs are you using in your setup, for which you‘re hoping for better integration?

What‘s the purpose of those caps? DC blocking? Wouldn‘t it possible to just short em instead then?

https://en.wikipedia.org/wiki/Capacitor#Energy_stored_in_a_capacitor You can see that the charge is proportional to C*V while the stored energy is proportional to C*V². If it wasn't "that simple", these formulas would not be that simple either

The stored energy is the capacitance times voltage squared, so at 50% voltage the cap will be 25% charged. Double the voltage and you quadruple the ‚power‘, seems familiar, doesn‘t it! Static electricity doesn‘t kill you because your capacitance is very low, so you only store a minuscule amount of energy.

@SME And luckily we have breakers in our homes to prevent that from happening inside a wall. I hope..! @kipman725 If the cap has been discharged, a simple shorting wire will do the trick even. Leaving them open is very dangerous. I'm not sure what to think about that video. I have seen it before, but he almost seems to "fanboy" over those amps and I'm not convinced if what he is saying is genuine. At times he almost sounds like a salesperson. Minor detail, but he uses the term slew rate incorrectly. Slew rate is not the time it takes for the caps to charge back up. Either way I'd of course be very interested to test the CVR amps. Looks don't tell the whole story. The Sanway also looks very well made internally, as do the Sinbosen amps, but they lack protection. Of course you won't care much about that in your HT but if your system goes silent on a gig you're in for trouble and I'd surely not want to risk that. I know Sanway have changed their PSU and it might be better now. They added a fan where my blown transitors sat. There are very few reviews or even general info about CVR.

A high displacement 15" driver will do very well even at loud levels down to like 20Hz. Since most movies nowadays don't have much content below that point, a single sub like this will do the job very well. When you start with BEQ and you're aiming for a good seat-to-seat variance it starts getting ridiculous, which is why you often see guys at AVS with 4 18" drivers in huge cabs or well.. more than that. I think that my 2x21" rig is overkill for my use, but better have too much headroom than not enough..! Adding a BOSS riser to the setup (really just a sheet of plywood with two 12" drivers mounted to it, was 30 minutes of work) was the icing on the cake, since I get no low tactile response in my room (all stone and cement). If you're into "feeling the bass" you might want to look into that. And as I said, since it's basically just a sheet of plywood with two holes in it, it wouldn't steal much of your time. And since you're looking to get a miniDsp already, the total cost for that might be around 150 bucks. It's far less gimmick-y than it seems.

It will be safe to work with from a humanoid standpoint after two minutes, but that still might damage electronics when working on the amp. I'd leave it disconnected for at least 10 minutes before working on it again or using a ~400R bleed resistor to shorten the PSU, which would result in a 1A current flow at 400V, which might be useful to be connected with a switch if you plan on working on the amp a lot. I think I have a 50W 32R resistor somewhere, which would already quicken the process from 50V down to zero. But oh boy if I leave it connected and then switch the amp on... Heres a fun vid about capacitors. He has a shorting wire for storage on that thing or it would probably kill you if you touched it. This thing does over 80000A at 4000V.

@Boomer1950Looks like you've done your homework, your driver falls into the low impedance category ("Low Z") and your amp seems to be 2 Ohm stable, which is why you can run it in bridge mode on the 4 Ohm load. You can let your AVR handle crossover and delay as you mentioned. I think the SI driver will be able to handle all that your amp can give, so I'd not bother with the limiter.