or Connect
AVS › AVS Forum › Audio › DIY Speakers and Subs › Lab Gruppen FP14000 clone amplifiers
New Posts  All Forums:Forum Nav:

Lab Gruppen FP14000 clone amplifiers - Page 107

post #3181 of 4398
I think I can help all of you experiencing problems.

just send email

Gear mentioned in this thread:

post #3182 of 4398
Quote:
Originally Posted by notnyt View Post

It's possible the PS was damaged during your low voltage situation. It's also possible you need to adjust the potentiometer on the power board as described previously in this thread. If you don't know what you're doing, take it to someone who can repair amps.

Thanks for mentioning the pots. I measured the output at 198.x and it would continuously power cycle on its own. I started off with the pot on the left as looking from the front of the amp and it did nothing. Like Trike had mentioned on his post, it was all the way clockwise so I returned it to its original position. The pot on the right was also turned all the way clockwise. As soon as I turned it down the amp stabilized. Again, Trike was correct. Breath on it wrong and it will send the voltage rocketing in one direction or the other. After about an hour of fidgeting with it it's been hovering between the high 190.x and low 191.x.

Crossing my fingers that this has fixed my amp. What I do know is that my amp will start power cycling as soon as the voltage goes north of 198V.

Thank you to you and Trike for the help.
post #3183 of 4398
Thread Starter 
Quote:
Originally Posted by duc135 View Post

Thanks for mentioning the pots. I measured the output at 198.x and it would continuously power cycle on its own. I started off with the pot on the left as looking from the front of the amp and it did nothing. Like Trike had mentioned on his post, it was all the way clockwise so I returned it to its original position. The pot on the right was also turned all the way clockwise. As soon as I turned it down the amp stabilized. Again, Trike was correct. Breath on it wrong and it will send the voltage rocketing in one direction or the other. After about an hour of fidgeting with it it's been hovering between the high 190.x and low 191.x.

Crossing my fingers that this has fixed my amp. What I do know is that my amp will start power cycling as soon as the voltage goes north of 198V.

Thank you to you and Trike for the help.

Glad you got it sorted!
post #3184 of 4398
Here's a NOOB question...

I see a lot of ppl are using the LAB clone as subwoofer amp.. but if the amp is rated only 20hz-20Khz, how do you get bass down to the single digit? I mean, wouldn't that mean the amp won't even amplify any sound below 20hz?

I mean, is there a difference between amps designed for subwoofer and regular amps?

Also, another 'might be stupid' question.

If a sub is rated down to say 20 hz, and then the specs says it can go down further depending on room gain.. what does that mean.. how is it that if the sub is only producing sounds at 20 hz that the room can change it to say 10hz?
post #3185 of 4398
Quote:
Originally Posted by coolgeek View Post

Here's a NOOB question...

I see a lot of ppl are using the LAB clone as subwoofer amp.. but if the amp is rated only 20hz-20Khz, how do you get bass down to the single digit? I mean, wouldn't that mean the amp won't even amplify any sound below 20hz?

I mean, is there a difference between amps designed for subwoofer and regular amps?

Also, another 'might be stupid' question.

If a sub is rated down to say 20 hz, and then the specs says it can go down further depending on room gain.. what does that mean.. how is it that if the sub is only producing sounds at 20 hz that the room can change it to say 10hz?

Usually power ratings are given for 20-20khz, because that is the most typical use and gets higher power than the 2 Hz - 34.2 kHz the LG can do flat. According to the spec sheet it's flat to 2 hz, which is why it's so good for subwoofers. http://labgruppen.com/media/downloads/product/TDS-FP14000.pdf

Even if an amp doesn't do flat below 20 hz it will just slowly roll off, it doesn't just cut off at a certain point. Usually amplifier frequency response looks something like this http://www.circuitstoday.com/wp-content/uploads/2011/12/RC-coupled-amplifier-frequency-response.png

The smaller your room the more room gain you get. it doesn't change the frequency, room gain just makes low frequencies louder. A sub will produce "sound" all the way to 1 hz, but it will usually be very low SPL so you can't hear it or feel it. Room gain will add some SPL to your low frequencies. So if a subwoofer is flat to 20 hz, then room gain will add a certain amount of SPL from 1-40 hz, adding more SPL to the lower frequencies, which will make it flat lower, maybe to 15 hz or something. Room gain is 12 dB per octave as you decrease in frequency. It starts at the longest dimension of your room's half wavelength. Say it's 40 hz (meaning the longest dimension in your room is about 14 ft), then you get 12 dB gain at 20 hz, 24 dB gain at 10 hz, and 36 dB gain at 5 hz.
Edited by JWagstaff - 8/6/13 at 6:24am
post #3186 of 4398
FYI, I have my fp14k posted on the classifieds. Fan modded and in perfect condition smile.gif
post #3187 of 4398
Quote:
Originally Posted by JWagstaff View Post

Usually power ratings are given for 20-20khz, because that is the most typical use and gets higher power than the 2 Hz - 34.2 kHz the LG can do flat. According to the spec sheet it's flat to 2 hz, which is why it's so good for subwoofers. http://labgruppen.com/media/downloads/product/TDS-FP14000.pdf

Even if an amp doesn't do flat below 20 hz it will just slowly roll off, it doesn't just cut off at a certain point. Usually amplifier frequency response looks something like this http://www.circuitstoday.com/wp-content/uploads/2011/12/RC-coupled-amplifier-frequency-response.png

The smaller your room the more room gain you get. it doesn't change the frequency, room gain just makes low frequencies louder. A sub will produce "sound" all the way to 1 hz, but it will usually be very low SPL so you can't hear it or feel it. Room gain will add some SPL to your low frequencies. So if a subwoofer is flat to 20 hz, then room gain will add a certain amount of SPL from 1-40 hz, adding more SPL to the lower frequencies, which will make it flat lower, maybe to 15 hz or something. Room gain is 12 dB per octave as you decrease in frequency. It starts at the longest dimension of your room's half wavelength. Say it's 40 hz (meaning the longest dimension in your room is about 14 ft), then you get 12 dB gain at 20 hz, 24 dB gain at 10 hz, and 36 dB gain at 5 hz.

Wow.. this makes so much sense... now suddenly it's all so clear.. thanks for the great explanations...
post #3188 of 4398
That LG / Clone amp really is a beast! I just wish its reliability was guaranteed (the clone, that is) as it would be a definite buy if it had zero issues frown.gif
post #3189 of 4398
so i got to test one of these clones here are results on a 30a 220v line.
also these amps clip Well before the lights even get close to indicating so.
bypassed all the fuses they blew too easily.




so peak should be double these numbers


2600w / 2x ,4ohm load 10hz, thermal limit 3s, pulling 7.6k watts from wall
1600w / 2x ,8ohm load 10hz, thermal limit 15s, pulling 5.4k watts from wall
5580w / 1x, 4.6ohm, thermal limit 3s, 8.5k watts from wall
4050w / 1x 8.2ohm , thermal limit 8s, 6.9k watts from wall


things to note, this amp is class H.
i was expecting a little more power out of it RMS
it has no roll off till 6hz .
it didn't die while i was testing it.
thd was 1% at the numbers above as i said Clip Lights Are not accurate in any way on mine.
u cant get these numbers with the stock fuses installed they blow at about 4k watts.
so pretty good amp if it wasn't for the reliability.
i would still buy a ipr2-7500, sorry but 5 year warranty is just worth it it also uses 25- 30% less power then the clones do at same power.
if your pushing these hard i would replace the stock power cord mine got very hot didn't seem to be under gauge some type of Chinese trickery going on inside that wire.
post #3190 of 4398
2600 watts at 4ohms.... pretty damn good for $850
post #3191 of 4398
Over 4,000w for 8 seconds at 8.2ohm...dang impressive!
post #3192 of 4398
great work ca!

guys...hit the darn thumbs up button on that post ...
post #3193 of 4398
Cookie - awesome work! I assume the one channel tests were in bridged mode? Also, how much do you think it left on the table when running in 120v config without the fuses bypassed?
post #3194 of 4398
Great job cookie!
post #3195 of 4398
Thread Starter 
Very nice tests, how about some results @ 20hz?

Also, if you're recommending the Peavey, can you post the same tests for that?

As for the clip lights, keep in mind that these will burst higher than your long duration sine wave testing. The output these have shown from your tests at 10 hz is very good.
Edited by notnyt - 8/11/13 at 12:29pm
post #3196 of 4398
Quote:
Originally Posted by cookieattk View Post

these amps clip Well before the lights even get close to indicating so.

At which lights is it clipping at then?


Can you post a graph of power over time? (Say dual 4 @ 20hz)

I run mine on 30a 120v and I've never blown a fuse or popped the breaker.
Only under heavy bass at near full excursion / max SPL do I ever use more than 10% of the watts it produces (-10db), but when you do... the last 90% of the watts gets eaten up pretty quickly.













The K20 is even more powerful... and the rumor is that Crown has fixed these issues with the iTech HD 12k.
post #3197 of 4398
Just curious, unfortunately I rent and can't put in a 30A dedicated breaker for my 120v version of the FP14000. Is anyone using it on a regular 15 or 20 amp circuit and if so have you tripped the breaker?
I haven't pushed mine that hard to trip the breaker (20A) but curious what others have experienced. It seems for loud transients there is plenty of juice in the capacitors and the amp doesn't pull as much current for those transients as I expected.

also:

@ Cookieattk, What is "thermal limit" in your tests?
post #3198 of 4398
I've got 2 running on 20A breakers and 2 on 30A, I blast everything down there and no breaker pops as of yet on the 20s!
Edited by N8DOGG - 8/17/13 at 5:13pm
post #3199 of 4398
Quote:
Originally Posted by javi404 View Post

Just curious, unfortunately I rent and can't put in a 30A dedicated breaker for my 120v version of the FP14000. Is anyone using it on a regular 15 or 20 amp circuit and if so have you tripped the breaker?
I haven't pushed mine that hard to trip the breaker (20A) but curious what others have experienced. It seems for loud transients there is plenty of juice in the capacitors and the amp doesn't pull as much current for those transients as I expected.

also:

@ Cookieattk, What is "thermal limit" in your tests?

I've popped breakers on several occasions with my clones on dedicated 20a lines.
post #3200 of 4398
Quote:
Originally Posted by popalock View Post

I've popped breakers on several occasions with my clones on dedicated 20a lines.

Very Nice. I need a dedicated room before I can build something for this amp to punish before I can trip breakers.

Congrats on your home theater of the month BTW, I'm reading through it now.
post #3201 of 4398
Well, it's a miracle. I finally have a working amp. They sent me another power supply minus caps. I had to transfer the caps from my busted one to the new one. This was quite an ordeal. I'm estimating that I put in about 80 hours troubleshooting/fixing the amp over the past 4 months. I have only tested one channel so far, but it appears to be working great. The big question now is, how long will it last? Once I played the Pod Emergence scene from WOW, I told myself it was worth the trouble. biggrin.gif I'm going to enjoy it as much as I can. Now I can finally get to tuning the LMS.
post #3202 of 4398
Quote:
Originally Posted by duc135 View Post

Thanks for mentioning the pots. I measured the output at 198.x and it would continuously power cycle on its own. I started off with the pot on the left as looking from the front of the amp and it did nothing. Like Trike had mentioned on his post, it was all the way clockwise so I returned it to its original position. The pot on the right was also turned all the way clockwise. As soon as I turned it down the amp stabilized. Again, Trike was correct. Breath on it wrong and it will send the voltage rocketing in one direction or the other. After about an hour of fidgeting with it it's been hovering between the high 190.x and low 191.x.

Crossing my fingers that this has fixed my amp. What I do know is that my amp will start power cycling as soon as the voltage goes north of 198V.

Thank you to you and Trike for the help.

I did adjust it like that, but under heavy bass, The amp would reset and power cycle. Because the output voltage kept dropping under heavy load. Sanway told me what I did was an incorrect way to adjust it. Adjusting those two pots requires an oscillioscope.

This is what they sent to me, early in the process on adjusting those pots.
post #3203 of 4398
Quote:
Originally Posted by notnyt View Post


Sorry, let me clarify a little here since I've done this research recently.

Gisen has a completely different unit. They use aluminum heatsinks colored like copper
[snipped]

Right, I'm only going to comment on the heatsinks;

I found the pictures of the two amps cooling very interesting and I studied them carefully. Yes copper is a better material than aluminium for heatsinks (4.01 W/cmK compared to 2.37 W/cmK) but that's not the whole story - the design of the heatsinks is also very important.

Going by your pictures those Sanway 'sinks are a very poor design. The 'fins' make minimal contact with the plates and are very thin (copper is expensive). With my experience of cooling systems I'd say that 75% of the heat is radiated out through the plate rather than the fins - hence the need for relatively massive airflow. 2mm above the plate the fin would be cold.

Conversely the Gisen Aluminium 'sinks are a much better design. They're extruded with the fins rising from the 'plates' with a good thick base so that the heat is conducted up into the fins where the large surface area helps it to dissipate. They look like a far more efficient design - enough to more than make up for the different thermal conductance of the two materials. I would expect the Gisens to only need about half of the airflow that the Sanways need to achieve the same cooling.

Interesting thread, thanks.
post #3204 of 4398
Quote:
Originally Posted by Demidemon View Post

[snipped]

Right, I'm only going to comment on the heatsinks;

I found the pictures of the two amps cooling very interesting and I studied them carefully. Yes copper is a better material than aluminium for heatsinks (4.01 W/cmK compared to 2.37 W/cmK) but that's not the whole story - the design of the heatsinks is also very important.

Going by your pictures those Sanway 'sinks are a very poor design. The 'fins' make minimal contact with the plates and are very thin (copper is expensive). With my experience of cooling systems I'd say that 75% of the heat is radiated out through the plate rather than the fins - hence the need for relatively massive airflow. 2mm above the plate the fin would be cold.

Conversely the Gisen Aluminium 'sinks are a much better design. They're extruded with the fins rising from the 'plates' with a good thick base so that the heat is conducted up into the fins where the large surface area helps it to dissipate. They look like a far more efficient design - enough to more than make up for the different thermal conductance of the two materials. I would expect the Gisens to only need about half of the airflow that the Sanways need to achieve the same cooling.

Interesting thread, thanks.
so who's gonna be the first to buy and test the gisen? biggrin.gif
post #3205 of 4398
On Gisen website, the FP14000 has 4 fans with same sizes.
If someone uses the Gisen Fp14000, please let me know the ratings of the capacitors they use.
Also the brand and part no of the IGBTs.
Thank you.
post #3206 of 4398
Quote:
Originally Posted by cookieattk View Post

so i got to test one of these clones here are results on a 30a 220v line.
also these amps clip Well before the lights even get close to indicating so.
bypassed all the fuses they blew too easily.




so peak should be double these numbers


2600w / 2x ,4ohm load 10hz, thermal limit 3s, pulling 7.6k watts from wall
1600w / 2x ,8ohm load 10hz, thermal limit 15s, pulling 5.4k watts from wall
5580w / 1x, 4.6ohm, thermal limit 3s, 8.5k watts from wall
4050w / 1x 8.2ohm , thermal limit 8s, 6.9k watts from wall


things to note, this amp is class H.
i was expecting a little more power out of it RMS
it has no roll off till 6hz .
it didn't die while i was testing it.
thd was 1% at the numbers above as i said Clip Lights Are not accurate in any way on mine.
u cant get these numbers with the stock fuses installed they blow at about 4k watts.
so pretty good amp if it wasn't for the reliability.
i would still buy a ipr2-7500, sorry but 5 year warranty is just worth it it also uses 25- 30% less power then the clones do at same power.
if your pushing these hard i would replace the stock power cord mine got very hot didn't seem to be under gauge some type of Chinese trickery going on inside that wire.




So basically, ~1 more decibel per channel than my $650 3 year warranteed Crown.

Beautiful.

thanks for the data.

James
post #3207 of 4398
^ Well, not exactly. Those tests were done at 10hz, the crowns output will be significantly diminished at that point. Most of crown's specs are done at 1KHz - I own a few of these amps as well. wink.gif
post #3208 of 4398
^ I've seen no evidence of that...at least not with ALL models. What Crown "specs" and what they deliver are two different things and all of the XTI's (and most of their newer amps, as far as I can recollect) are 20hz to 20 khz.

Matter of fact, I started a thread about it and someone found testing to the contrary...it's around here (AVS) somewhere. I get 100+ db 10hz output in my room with a test tone so I'm pretty much convinced my consumption of the "crowns don't reproduce down low" kool-aid was errant. They produce dozens and dozens of models so I won't speak for all of them, but I'm very confident with the xti 4002.

James
Edited by mastermaybe - 8/21/13 at 8:26am
post #3209 of 4398
1,600w per channel at 8ohm (10hz!!) for 15 seconds, and 4,050w in an 8ohm bridge for 8 seconds is insane power. The 4002 can't touch those numbers at any frequency, not even half in the 8ohm stereo category.
post #3210 of 4398
^ I don't understand...what exactly do you mean by "the 4002 can't touch those numbers"?

If you simply mean it's rated for less power, then, well, sure, I suppose. But "can't touch" sounds a bit hyperbolic to me...especially with the "not even half" quip which is really is close enough to half to still mean a 3db difference.

The 4002 is rated for 2400 watts into 8 ohms, bridged. So the output difference is less than 3 decibels, there. But this is prolly a numbers game not about practical output, so then, yep, for 30-50% more cash, decreased reliability, no warranty, and the inability to drive dual 2 ohm loads, the Sanway destroys the wimpy Crown. confused.gif

James
Edited by mastermaybe - 8/21/13 at 8:32am
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: DIY Speakers and Subs

Gear mentioned in this thread:

AVS › AVS Forum › Audio › DIY Speakers and Subs › Lab Gruppen FP14000 clone amplifiers