# Zapco ST Amps



## Offroader5 (Apr 8, 2011)

I've been accused of poor search abilities before, but I haven't noticed any talk about these.

Seems like everyone is jumping on board with "nano" or "mini" class D amps. Some seem too good to be true in terms of power output vs. size.

I was just doing research on new/smaller amps and ran across Zapco's site. They have an ST (Studio) series now...some even with Bluetooth streaming ability. The BT is not really what I'm after, but as an overall amp the ST-D BT's seem very nice. The ST-X's seem to be pretty small for A/B amps.

Zapco's site is a bit shy on info for the ST-D BT's. Anyone have any other info on these?


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## chithead (Mar 19, 2008)

Try them out with me  Maybe we will get some perks for being some of the first ones.


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## Offroader5 (Apr 8, 2011)

chithead said:


> Try them out with me  Maybe we will get some perks for being some of the first ones.


Man....I JUST got done reworking my amp board/wiring and got it re-installed. I need to see about relocating the 8's next and the possible mid relocation to the sail panel area. Last thing I need is to worry about 2 or 3 upgrades at once.


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## chithead (Mar 19, 2008)

It's ironic, I'm selling the Zapco DC amps only because of their size, and had looked at those PPI/Soundstream Class D amps as possible solutions. But after seeing this posting, and talking to a new friend on here, decided to go with those Class D Zapcos instead. 

Love me some Zapco!

Now to decide on a processor. Oh the joys of audio...


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## thehatedguy (May 4, 2007)

Keep it with Zapco and do the DSP8.


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## chithead (Mar 19, 2008)

Hmmm... could hang on to my DRC-SL if went that route. I believe it's compatible with the Z8 processor. 

Good idea!


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## thehatedguy (May 4, 2007)

I don't think you can use the DRC with the Z8.


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## chithead (Mar 19, 2008)

Well poop snacks


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## Offroader5 (Apr 8, 2011)

The more I think about these things, the more I want to give them a try.

I just look at the power you'd get in that smaller package for what I assume should be a fair price. And we're talking true power from a reputable company that preaches about other companies over-rated power numbers.

One thing I see from the pictures is the power/ground/remote looks to be a small plug in lieu of the standard connections.

EDIT: I'll leave this here:
http://zapco.co/wp-content/uploads/2015/01/Zapco_STDBT_sheet.pdf


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## LumbermanSVO (Nov 11, 2009)

I have the ST-1500XM installed, but haven't powered it up yet, it's been to cold to work on the car and I don't have a garage. I leave this weekend for a 3-month work trip. When I get back I need to re-install my horns and then I can fire up the system for a basic test, it'll be awhile.

My RCA connectors were bent into the case when I got the amp, but I was able to fix it after popping off the back cover. The shipping box needs a little extra work to prevent this from happening again.


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## chithead (Mar 19, 2008)

Think I saw your picture of it mounted the other day when browsing Zapco Class D amps ^^^ 

Pretty cool the way it was mounted on the side like that.


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## LumbermanSVO (Nov 11, 2009)

chithead said:


> Think I saw your picture of it mounted the other day when browsing Zapco Class D amps ^^^
> 
> Pretty cool the way it was mounted on the side like that.


Are you referring to me? If so, thanks! 

The idea is to have the subs, amps and processor hidden behind the side interior panels so I can park with the top off the Bronco and not worry about things walking away.


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## chithead (Mar 19, 2008)

LumbermanSVO said:


> Are you referring to me? If so, thanks!
> 
> The idea is to have the subs, amps and processor hidden behind the side interior panels so I can park with the top off the Bronco and not worry about things walking away.


Great idea :thumbsup:


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## LumbermanSVO (Nov 11, 2009)

Yeah, I'll start the panel build when I get back from this trip. I'll have 5-6 weeks home before my next trip, so hopefully I can make some good progress. At the very least it'll be a playable system.

On one hand it's painful to wait so long to hear this thing, but on the other hand, these speakers have been sitting on a shelf for the better part of a decade, so whats a few more months?


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## Offroader5 (Apr 8, 2011)

I wonder if the BT amp case can be rotated...or possibly the logo badge? The way my cable runs are set up in my install is power/ground/remote runs down the passenger side and the signal wires run down the drivers. If they cannot somehow be rotated, I would have to install them upside down or at a minimum (like I have the PPI's) standing vertically.


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## so cal eddie (Oct 1, 2008)

I'm definitely interested in these new BT amps. The power numbers seem a little fishy to me, but it is zapco advertsing them, so they must be accurate. I wish there were more specs available, but I guess we will all have to wait and see. I wonder why there is no mono amp being advertised?? Seems odd to me. I was really considering some other amps, but I will have to hold off and wait for these.


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## HighQman1974 (Jul 20, 2014)

Ive got an ST-4X and an ST-1500xm. Ive 1000% percent happy with my decision to run them!


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## knever3 (Mar 9, 2009)

I really like!! Hiding amps like the factory does is the way to go now in SUV's. It's so hard to take up usable space with amps when someone says the factory one is hidden. Now they need to make a marine grade for all those out there that like to stream music to their boat.


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## chithead (Mar 19, 2008)

Marine Class D that can stream via Bluetooth would be awesome!


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## Offroader5 (Apr 8, 2011)

I was just thinking an awesome thought.

A single 204D.BT and a pair of SI BM MKIV's


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## chithead (Mar 19, 2008)




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## papasin (Jan 24, 2011)

chithead said:


>


Ok, fine, done!   lol


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## LumbermanSVO (Nov 11, 2009)

So, I thought I'd chime in after nearly a year of silence. Sometime after June I finally got enough of the system together to actually turn it on. It sure seems like the ST-1500XM puts out more than rated. With two IDMax 12V3's in a soft top full size Bronco, it is much louder than these same subs were in the same box in a hatchback Mustang on a Directed 1200W class D amp. And by much louder, I mean far more than you should expect to see from a 300 watt difference, especially since the Mustang had the cabin gain advantage.

So far it's been reliable, even after cranking it for hours in the southern heat.

I haven't built the new interior panels yet. Since I first posted in this thread I've been on the road for well over 30 weeks. This weekend I'll be switching my signal chain to all digital from my iPhone to the processor.


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## Bolding220 (Jan 18, 2008)

LumbermanSVO said:


> So, I thought I'd chime in after nearly a year of silence. Sometime after June I finally got enough of the system together to actually turn it on. It sure seems like the ST-1500XM puts out more than rated. With two IDMax 12V3's in a soft top full size Bronco, it is much louder than these same subs were in the same box in a hatchback Mustang on a Directed 1200W class D amp. And by much louder, I mean far more than you should expect to see from a 300 watt difference, especially since the Mustang had the cabin gain advantage.
> 
> So far it's been reliable, even after cranking it for hours in the southern heat.
> 
> I haven't built the new interior panels yet. Since I first posted in this thread I've been on the road for well over 30 weeks. This weekend I'll be switching my signal chain to all digital from my iPhone to the processor.


What ohm do you have the ST-1500XM at?


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## LumbermanSVO (Nov 11, 2009)

1 Ohm.


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## LumbermanSVO (Nov 11, 2009)

My ST-1500XM seems to have died today. I swapped from a pair of ID Max 12's running at 1 ohm to a pair of JBL @15GTI's at 1.5 ohm. After about five minutes of playing it went into protect. It now goes into protect immediately after turning on, even with nothing connected.


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## barracuda777 (Mar 4, 2009)

Checked it with some tecnicien, or waranty if apply.

A friend play with a ST-1500XM at 0.8 ohm, yes...sure, only for a while, and get 1860 watts. Amp still play fine.

I guess GTI had a lower impedance running than Image


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## LumbermanSVO (Nov 11, 2009)

Yeah, turns out one of my GTI's had a bad coil, it measured at .5ohms. If my math is correct, the amp saw a .15 ohm load. Also, I had an issue with the charging circuit and it stopped charging. I'll be gone for work for 5 months, so I'll fix the charging issue when I get back and see if the amp was going into protect due to low voltage, or if the .15 ohm killed it.


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## gstokes (Apr 20, 2014)

Offroader5 said:


> Seems like everyone is jumping on board with "nano" or "mini" class D amps. Some seem too good to be true in terms of power output vs. size.


I wouldn't say everybody is jumping on board but if size is a concern then Class D mini amps are the way to go..


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## jonah1810 (Apr 16, 2015)

I have both the st-1500xm and the st-4x SQ. both are great amps that also look Slick. The only thing I've found i didn't like was the knobs on the st-4x are kinda not very solid. However in the st-1500xm they are. So it's probably only that specific model That has the weak gain and crossover knobs. 

But if your considering using them, i highly recommend it! I beleive they have some bluetooth st models out that are insane power for their size. Can't speak on those ones though


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## rimshot (May 17, 2005)

I just bought a st 1000xm II to replace a jbl 5001.will report back when I install wednesday, im excited. My first zapco amp and its not made in the US  , i still trust their testing standards however.


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## RRizz (Sep 4, 2012)

Thoughts on that St 1000??? Im considering the same move, from the Jbl msa5001 as well.......


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## barracuda777 (Mar 4, 2009)

RRizz said:


> Thoughts on that St 1000??? Im considering the same move, from the Jbl msa5001 as well.......


What kind of thought are you looking for?

Enough power?
Does it sounds good?
Is it a good value for my money?

I can answer that. Yes for all, definitely a great entry level amplifier.


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## RRizz (Sep 4, 2012)

I was looking for that exact info, but in direct comparison to the jbl msa5001..


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## barracuda777 (Mar 4, 2009)

RRizz said:


> I was looking for that exact info, but in direct comparison to the jbl msa5001..


Sorry about the jbl. I got no idea sir.:mean:


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## rimshot (May 17, 2005)

I took a sabbatical, but the Zapco was far, far better sounding/performing than the jbl. In another class, and I liked the jbl. I also agree that it is underrated. I have the xm1000II and at 1 ohm it had more than enough power for a CSS SDX12.


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## FNcrazy (Jul 1, 2016)

Wasn't there a forum member or website that could get good prices on Zapco stuff? 

Sent from my SM-G935V using Tapatalk


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## SkizeR (Apr 19, 2011)

FNcrazy said:


> Wasn't there a forum member or website that could get good prices on Zapco stuff?
> 
> Sent from my SM-G935V using Tapatalk


zapco doesnt do that. gotta see a local dealer or buy from woofers etc


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## FNcrazy (Jul 1, 2016)

SkizeR said:


> zapco doesnt do that. gotta see a local dealer or buy from woofers etc


Oh, OK. I thought one of their dealers was on here and helped us out. 

The best products any local dealer I have sells JL Audio... Which is good of course, but I can't try any of this exotic stuff. 

But I digress... 

Sent from my SM-G935V using Tapatalk


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## SkizeR (Apr 19, 2011)

FNcrazy said:


> Oh, OK. I thought one of their dealers was on here and helped us out.
> 
> The best products any local dealer I have sells JL Audio... Which is good of course, but I can't try any of this exotic stuff.
> 
> ...


Woofers etc is the only authorized way of getting zapco shipped to you

Sent from my SM-G920V using Tapatalk


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## 1sty (Jun 24, 2009)

Anyone know if the ST-X zapco amps are prone to turn on and off pops?


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## RRizz (Sep 4, 2012)

I have the st 1000xm and the st 4x sq, and they are quiet on and off. Unlike my 2 Pioneer PRS 800D's, whose relays can be heard 2 blocks away in heavy traffic, and in a thunderstorm..lol I have actually opened the cases and covered them with dynamat, and its still like someones slapping a bongo in the rear hatch.


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## 1sty (Jun 24, 2009)

could that be a result of your DEX?
My 1000Xm sounds like a gun shot with most turn offs and some turn on's via the subwoofers.


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## DC/Hertz (Nov 27, 2011)

Add a relay in the remote wire


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## RRizz (Sep 4, 2012)

DC/Hertz said:


> Add a relay in the remote wire


Tried that, no Bueno. Pulled amps out, and tried on bench with no input signal ... still there. Contacted pioneer directly, and had conversation with tech about my options to reduce or eliminate it, and they told me there was no fix.
Its not a signal issue, its the actual relay inside clicking on and off. I have considered changing the relays inside, but honestly, its not worth the effort.


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## RRizz (Sep 4, 2012)

1sty said:


> could that be a result of your DEX?
> My 1000Xm sounds like a gun shot with most turn offs and some turn on's via the subwoofers.


 No, because the Zapcos and the pioneers are in the same car. One of the zapcos is on my sub. quiet as a mouse.
I should add that it is not popping through my speakers, just the relays in the amp clamping down.
So far I have used amps from Zapco, Soundstream, pioneer, and JBL with my p99, and never had issues with speaker popping.


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## 1sty (Jun 24, 2009)

adding to the pantheon of weird crap that only happens to me. My sub amplifier is measuring 0.4 ohms between the negative speaker terminal and ground.
This is with no speaker wire connected.


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## barracuda777 (Mar 4, 2009)

Pop On and OFF is a the result of a chain "turn on and Off " problem.
Sometimes extra relays on this chains are the problems. Or secondary remote signals (processors for examples.)
With all the STX past to my hands and friends, NONE, absolutely none did a pop, including with Pioneer head units

Did you turn on and turn off your sound from the head unit or directly through ignition key?


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## MoparMike (Feb 14, 2012)

I'm running the ST-2X, 4Xp and 1000XMII and have zero issues with them, including any turn on pop. I don't use relays but the remote chain runs through a JL Fix processor before going into a TWK processor and then out to the amps. That helps to stagger out the power cycling in relation to the car turning on.


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## 1sty (Jun 24, 2009)

measuring 0.4 ohms between the negative speaker terminal and the ground connection doesn't bother anyone?


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## TxHouse (Nov 7, 2010)

Can anyone tell me which amp would provide better sound quality to a set of krx2 components. The st-4xp or the st-4d. I know the st-4d has the headroom but I'll take less headroom if it means better sound quality. 

Sent from my FRD-L04 using Tapatalk


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## DC/Hertz (Nov 27, 2011)

Take the headroom. That is a big part of sound quality.


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## SkizeR (Apr 19, 2011)

TxHouse said:


> Can anyone tell me which amp would provide better sound quality to a set of krx2 components. The st-4xp or the st-4d. I know the st-4d has the headroom but I'll take less headroom if it means better sound quality.
> 
> Sent from my FRD-L04 using Tapatalk


The st-4xsq version would be better than the two 

Sent from my VS988 using Tapatalk


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## papasin (Jan 24, 2011)

SkizeR said:


> The st-4xsq version would be better than the two
> 
> Sent from my VS988 using Tapatalk



Based on...?


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## SkizeR (Apr 19, 2011)

papasin said:


> Based on...?


Well ive used all 3 (Well, the xp and sq 4 channel and the normal 2 channel) within the past few weeks including in my own car. I'm not shooting blind

Sent from my VS988 using Tapatalk


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## papasin (Jan 24, 2011)

SkizeR said:


> Well ive used all 3 (Well, the xp and sq 4 channel and the normal 2 channel) within the past few weeks including in my own car. I'm not shooting blind
> 
> Sent from my VS988 using Tapatalk



Ok, so you admit not testing them in a blind test.


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## bonesb (Sep 19, 2017)

What do you guys think of the zapco st-204d.bt


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## barracuda777 (Mar 4, 2009)

bonesb said:


> What do you guys think of the zapco st-204d.bt


Would be better to open a special thread on it, no? This way you can receive better rand more answers.


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