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Presonus eris8 teardown

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Had to take it apart so took some pics along the way, don't really know the names of the components on the board as such so maybe if anyone does maybe they can say so.

As a budget studio monitor goes it is not bad, not the best construction I have seen but certainly not the worst.

Anyways, lets start.

Rear plate amp, all specs can be found here.


IMG_20230523_150857.jpg


First look inside, a little surprised at the sparsity of the components but things are laid out well and given their own space, not a fan of how the amp board is bolted to the heatsink.

IMG_20230523_151422.jpg


Nice cut to size layer of polyfill and one horizontal brace.

IMG_20230523_151452.jpg


Amp plate unplugged and turned to face us.

IMG_20230523_151524.jpg


Close up of the power supply.

IMG_20230523_151545.jpg


Close up of the amp board and the capacitors.

IMG_20230523_151611.jpg


IMG_20230523_151723.jpg


These are op amps(maybe) but not to sure of terminology yet.

IMG_20230523_151753.jpg


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The pre amp board.

IMG_20230523_151918.jpg




IMG_20230523_151934.jpg




IMG_20230523_152001.jpg




IMG_20230523_152006.jpg


More caps and trying to see the text on the mosfets attached to the heatsink.

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The power input plug(fuse is in here I think).

IMG_20230523_152330.jpg


The tweeter had it's own little housing to isolate it from the main body of the cabinet, nice touch I though.

IMG_20230523_152428.jpg


Main 8"driver.

IMG_20230523_152433.jpg


Without the polyfill, the screws around the outer edge were holding the plastic baffle in place so hat to come out to be able to release the driver from the box.

IMG_20230523_152507.jpg


Full frontal :cool:

IMG_20230523_152932.jpg


Baffle off, just four screws for the driver and not very good ones at that.

IMG_20230523_153630.jpg


Rear of the baffle with the tweeter, nice little cooling fins on the rear but was expecting much more magnet than this, ok maybe a neo mag but not much meat on the bone really.

IMG_20230523_153641.jpg


The rear of the driver, magnet size is ok but looks to be a very basic speaker.

IMG_20230523_153855.jpg


Some light shining through the kevlar weave.

IMG_20230523_154308.jpg


Some led's for the power indicator panel.

IMG_20230523_154334.jpg


So I got this speaker for £20 posted off ebay, sold as not working.

I took it apart and nothing was connected inside, I connected everything up and it just works, I had hoped that the 8" driver would be a suitable temporary replacement for my Mackie HR824's but it is just a wee bit to small but for £20 I though the gamble was good enough, If nothing else I have a pretty decent speaker that I can use the plate amp for testing other drivers that I have lined up for other projects or if another e8 comes up I will have a pair.
 

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Last edited:

Doodski

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Some of what you apparently pointed out as OP amps are not OP amps. They include a bridge diode, output amp ICs, voltage regulators etc. :D So don't go replacing them thinking that you will improve the sound by rolling them...LoL.
 
OP
C

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After taking it apart I decided to have a little bit of fun, the plate amp is 75w for the woofer and 65w for the tweeter and a crossover freq of 2k, I think it is an active crossover, I have a Tannoy 2033 woofer with tweeter from an old tannoy 609 that has a crossover frequency of 2k so thought I would make up some wires and drop the woofer in to the presonus box to see how she sounds and if the amp is enough for the drivers etc, mostly just curious, by pure chance two of the mounting holes lined up on the box so took here for a bit of a spin, sounded ok really.

IMG_20230523_154840.jpg



IMG_20230523_183129.jpg


The baffle didn't quite fit.


IMG_20230523_155012.jpg


I took a vid but can't post them here so will drop a youtube link in shortly.
 

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OP
C

Citizen

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Some of what you apparently pointed out as OP amps are not OP amps. They include a bridge diode, output amp ICs, voltage regulators etc. :D So don't go replacing them thinking that you will improve the sound by rolling them...LoL.
Haha, not touching any of that stuff yet, as you point out I need to learn what things are before I do.
 
Last edited:
OP
C

Citizen

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After taking it apart I decided to have a little bit of fun, the plate amp is 75w for the woofer and 65w for the tweeter and a crossover freq of 2k, I think it is an active crossover, I have a Tannoy 2033 woofer with tweeter from an old tannoy 609 that has a crossover frequency of 2k so thought I would make up some wires and drop the woofer in to the presonus box to see how she sounds and if the amp is enough for the drivers etc, mostly just curious, by pure chance two of the mounting holes lined up on the box so took here for a bit of a spin, sounded ok really.

View attachment 288021


View attachment 288023

The baffle didn't quite fit.


View attachment 288022

I took a vid but can't post them here so will drop a youtube link in shortly.
A vid of the result.

 

MaxwellsEq

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Identifying components is not straightforward. A plastic package with 3 legs could be any number of things. Most common are BJT transistors or FETs, but they can also be regulators. If there's anything on the package, Google can be good at identifying parts.

In general, you can sometimes work out what something is by its location in the circuit, e.g. if it's close (physically or electrically), to the transformer, it may be a regulator; near the speakers, it may be a power transistor.
 

wwenze

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This kind of class AB amp without a heatsink at the back is just heat death waiting to happen. The heatsink inside the chassis just isn't sufficient... And it doesn't help to make things cooler for the other components e.g. capacitors
 

mr.k

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Totallly offtopic, but always wanted to ask...on my old TV, one of the capacitors almost caught fire.
TV started to smoke, and I'll never know what would happed if I didn't turned off tv immediately.

Since then, it's always unsettling for me to see capacitors wrapped in a pile of polyfill.

Why do capacitors and polyfill inside speakers not pose a fire risk?
 

wwenze

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Capacitors are generally not heat-producing devices. Which makes sense from an electrical theory standpoint: It only holds and releases charge, without using up energy. (Real capacitors have ESR, dielectric loss blah blah but these are small compared to the amount of current flowing through the capacitor)
 
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