Cheap amp performance? What you think?

jol50 · 8th April 2008, 01:26 AM

Has anyone here into audio actually run/tried one of these cheap amps? I had a pyramid way back in early 90s that worked ok actually, but no cheap amps since that I used in a car I drove except this current sort of cheap kicker. I have a couple I got blown now, ultra linear, pyramid, etc...going to put some parts in them new/used whatever (so I don't invest more than they are worth...that might be a challenge) and get them going...I will try them and see.

I'm just (seriously) curious. I have a few sets of good amps to try when I swap amps soon here like alpine/SS/etc...so I'm going to lay wires in the trunk so I can swap and figure hey why not compare some junk. I know they fall apart faster but how about sound? Will they be ok if they are huge amps so they stay away from clipping....or not?

I will be using them full range off my crossover. I like quality sound a little loud sometimes and do not have DSP in this car.

If you have (or not) run any, what do you think will happen?

Clipped · 8th April 2008, 03:36 AM

ive used bigger cheap amps to run fullrange and they work really well...the ones i use usually have 2 x tip35/36 per channel (4+4 total).

if the amp is strong enough, the speakers will distort before the amp.

only gripes are low slope crossovers and a bit less extension of detail.

where a good quality amp will carry more detaillllllllllllllllllllllllllllllllllll a cheaper amp will carry less detailllllllllllllll.

but youd never know the difference unless you A/B'ed the amps in comparison.

aznboi3644 · 9th April 2008, 07:41 AM

I've used a Profile Baja HA1000

I put that thing through a beating...It put out some decent power...a lot better than other cheap brands.

I even had the amp wrapped in a fleece blanket wedged between the back of the box and the back of the rear bench seat. The blanket was to prevent vibration because I was lazy and didn't mount the amp.

I'm sure I was clipping the crap out of the amp. It got hot as hell but never even shut down or go into protection...just kept on pumping out power.

jol50 · 9th April 2008, 04:12 PM

I may be able to put TIPs in this UL, it has 6+6 outputs...the factory transistors are too expensive. I saw where someone bought one new for ~80 on ebay lol. The other ones are only 2+2 except a 4 ch but have not looked at it closely yet. And I have an insignia that is 360rms bridged, even has a fan in it, plus a blitz that I think is around 75-100/ch x2. What a collection.

I need 400rms minimum for my 4 12s so will only run them on highs, unless the UL actually can do half of 900rms at 4ohms bridged. Even then I'd rather a class D for power reasons but I may test it just to further our quest for possibly useless knowledge .

Clipped · 9th April 2008, 04:31 PM

if you can find what the part numbers are for the trans...i can look them up in my master replacement guide if you cant find them online.

some of the KIA parts are hard to find crosses for....if it starts with something like 2skXXXX its probably a toshiba part.

heres one of the ghetto amps i used, but with 6+6 trans:
(i sold this actual amp to the ampguts contributor, it got hot as fark)

http://ampguts.realmofexcursion.com/...00/inside1.jpg

it was hooked up 2 ohms per channel (2 channel amp) four 6.5" components with tweets through the passive...it worked really good for mid/hi's...as long as you use a bigger amp than necessary, cheap amps work good for hipass duty.

jol50 · 9th April 2008, 04:42 PM

http://www.digchip.com/datasheets/pa...413/2SB817.php
2SB817 and 2SD1047 come up as sanyo, I think base resistor is 3.3ohm. PS is Fairchild 50N06, they are not so bad to get unless they are upgradable too, have not looked. Strange too is that on the board it lists B688A/D718A for outputs not what is in it. Don't think they have been replaced.

The insignia look a lot like the one you listed. This is the UL: http://www.savinglots.com/lotprod.asp?item=UL3200D It is longer/slimmer than photo looks.

jol50 · 9th April 2008, 05:30 PM

ul3200d. Rail caps are 2200uf 50v. The outputs do not say '2S' on them, just the big K.

Clipped · 9th April 2008, 05:54 PM

the B688A/D718A are :
140volt 12 amp 100 watt devices /current gain 60 min

TIP35/36 are :
100 volt 25 amp 125 watt devices /current gain 15min-75 max

the fets can be upgraded but with the output trans used, there may not be much difference in performance.

Philip's cross for B688A/D718A are ECG36/37

jol50 · 9th April 2008, 09:59 PM

I guess I don't care if it performs any better, some more reliability and maybe quality sound would be preferable....but mostly something cheap and as good/better. I looked up some other matches and they too were hard to locate.

jol50 · 10th April 2008, 04:23 PM

Lol, I ripped into this insignia that was sitting here got two of them. One has blown channel ok, second tests ok/works but freaks out gets loud when bridged. I look and RCA has ground broken hmmm and why two channels difference like that? I pull board out and one rectifier stays on sink....turns out second rectifier and over half the fets have broken legs from assembly on that side, it also has PS for each channel. They are crooked and all clamps were factory glued. Common practice it seems but even a cheap amp can't work well if it is not put together all the way, it never worked right from day one.

8th April 2008, 01:26 AM	#1
jol50 diyAudio Member Join Date: Nov 2007	Cheap amp performance? What you think? Has anyone here into audio actually run/tried one of these cheap amps? I had a pyramid way back in early 90s that worked ok actually, but no cheap amps since that I used in a car I drove except this current sort of cheap kicker. I have a couple I got blown now, ultra linear, pyramid, etc...going to put some parts in them new/used whatever (so I don't invest more than they are worth...that might be a challenge) and get them going...I will try them and see. I'm just (seriously) curious. I have a few sets of good amps to try when I swap amps soon here like alpine/SS/etc...so I'm going to lay wires in the trunk so I can swap and figure hey why not compare some junk. I know they fall apart faster but how about sound? Will they be ok if they are huge amps so they stay away from clipping....or not? I will be using them full range off my crossover. I like quality sound a little loud sometimes and do not have DSP in this car. If you have (or not) run any, what do you think will happen?

9th April 2008, 04:42 PM	#6
jol50 diyAudio Member Join Date: Nov 2007	ultra http://www.digchip.com/datasheets/pa...413/2SB817.php 2SB817 and 2SD1047 come up as sanyo, I think base resistor is 3.3ohm. PS is Fairchild 50N06, they are not so bad to get unless they are upgradable too, have not looked. Strange too is that on the board it lists B688A/D718A for outputs not what is in it. Don't think they have been replaced. The insignia look a lot like the one you listed. This is the UL: http://www.savinglots.com/lotprod.asp?item=UL3200D It is longer/slimmer than photo looks.

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8th April 2008, 03:36 AM	#2
Clipped diyAudio Member Join Date: Mar 2005 Location: home	ive used bigger cheap amps to run fullrange and they work really well...the ones i use usually have 2 x tip35/36 per channel (4+4 total). if the amp is strong enough, the speakers will distort before the amp. only gripes are low slope crossovers and a bit less extension of detail. where a good quality amp will carry more detaillllllllllllllllllllllllllllllllllll a cheaper amp will carry less detailllllllllllllll. but youd never know the difference unless you A/B'ed the amps in comparison.

9th April 2008, 07:41 AM	#3
aznboi3644 diyAudio Member Join Date: Dec 2007	I've used a Profile Baja HA1000 I put that thing through a beating...It put out some decent power...a lot better than other cheap brands. I even had the amp wrapped in a fleece blanket wedged between the back of the box and the back of the rear bench seat. The blanket was to prevent vibration because I was lazy and didn't mount the amp. I'm sure I was clipping the crap out of the amp. It got hot as hell but never even shut down or go into protection...just kept on pumping out power.

9th April 2008, 04:12 PM	#4
jol50 diyAudio Member Join Date: Nov 2007	I may be able to put TIPs in this UL, it has 6+6 outputs...the factory transistors are too expensive. I saw where someone bought one new for ~80 on ebay lol. The other ones are only 2+2 except a 4 ch but have not looked at it closely yet. And I have an insignia that is 360rms bridged, even has a fan in it, plus a blitz that I think is around 75-100/ch x2. What a collection. I need 400rms minimum for my 4 12s so will only run them on highs, unless the UL actually can do half of 900rms at 4ohms bridged. Even then I'd rather a class D for power reasons but I may test it just to further our quest for possibly useless knowledge .

9th April 2008, 04:31 PM	#5
Clipped diyAudio Member Join Date: Mar 2005 Location: home	if you can find what the part numbers are for the trans...i can look them up in my master replacement guide if you cant find them online. some of the KIA parts are hard to find crosses for....if it starts with something like 2skXXXX its probably a toshiba part. heres one of the ghetto amps i used, but with 6+6 trans: (i sold this actual amp to the ampguts contributor, it got hot as fark) http://ampguts.realmofexcursion.com/...00/inside1.jpg it was hooked up 2 ohms per channel (2 channel amp) four 6.5" components with tweets through the passive...it worked really good for mid/hi's...as long as you use a bigger amp than necessary, cheap amps work good for hipass duty.

9th April 2008, 05:30 PM	#7
jol50 diyAudio Member Join Date: Nov 2007	ul3200d. Rail caps are 2200uf 50v. The outputs do not say '2S' on them, just the big K.

9th April 2008, 05:54 PM	#8
Clipped diyAudio Member Join Date: Mar 2005 Location: home	the B688A/D718A are : 140volt 12 amp 100 watt devices /current gain 60 min TIP35/36 are : 100 volt 25 amp 125 watt devices /current gain 15min-75 max the fets can be upgraded but with the output trans used, there may not be much difference in performance. Philip's cross for B688A/D718A are ECG36/37

9th April 2008, 09:59 PM	#9
jol50 diyAudio Member Join Date: Nov 2007	I guess I don't care if it performs any better, some more reliability and maybe quality sound would be preferable....but mostly something cheap and as good/better. I looked up some other matches and they too were hard to locate.

10th April 2008, 04:23 PM	#10
jol50 diyAudio Member Join Date: Nov 2007	Lol, I ripped into this insignia that was sitting here got two of them. One has blown channel ok, second tests ok/works but freaks out gets loud when bridged. I look and RCA has ground broken hmmm and why two channels difference like that? I pull board out and one rectifier stays on sink....turns out second rectifier and over half the fets have broken legs from assembly on that side, it also has PS for each channel. They are crooked and all clamps were factory glued. Common practice it seems but even a cheap amp can't work well if it is not put together all the way, it never worked right from day one.