Abletec ALC1000 any experience?

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Hi, I went for it and just completed building 2 ALC1000 and 2 ALC0300 amps.
Have only been able to test on old passive speakers, so difficult to say too much about SQ, but it seems promising so far.

My plan is to go active and build some new speakers for this project. But it may take a while.....

Regarding pops and clicks:

Power on: The amplifier itself only give you a relay click after a couple of seconds not audible in the speakers.

Power off: A slight click in the speakers, but IMO it should not be loud enough too damage any connected speakers.
 
And here some pictures for anyone interested:

Abletec w cover.JPG

Abletec wo cover.JPG

Aletec back.JPG

First time attaching pictures, so hope this works....

- Svein
 
Svein,

Your build looks great.

Thanks for your report. The price of these modules is certainly attractive, especially the 0180.

Pops and clicks are bad in my world, as I'm actively amplifying compression drivers. But I have some speaker protection boards that could solve that, and the DC protection issue.

Cheers.
 
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Hi, I went for it and just completed building 2 ALC1000 and 2 ALC0300 amps.

These amplifiers look great. Serious stuff.

The ALC0180 shows also a little sound/buzz when switched on, but it is so little that if you blink your eye (ear?) you will not notice it, and for sure there is no danger for your speakers what-so-ever.
 
The ALC0180 shows also a little sound/buzz when switched on, but it is so little that if you blink your eye (ear?) you will not notice it, and for sure there is no danger for your speakers what-so-ever.

I can confirm that. I tried the ALC0180 with my BMS4592ND.
There is a pop which is hearable but definetely far away from being a serious (technical) issue.

Regards
Matthias
 
Wim: just read your article in AudioXpress both the test and interview (after subscribing which is entirely your fault:)
A lot of good information and a great read.

As far as I could tell you liked the modules after some months of use, but did not compare against any other class-d amps or describe your experience with the SQ in much detail.
Might not be your style, but I found more SQ description in the pragmatik test, and would have enjoyed the same this time around also.

Btw, this is propably because I am very curious how other people have valued these modules besides me. So not really to critizise:)

I have used my Abletec amps quite a bit recently for full range speakers just for fun, and I am quite impressed. Especially with the ALC0300-1300 modules.
They sound very 'natural' and 'well behaved' with great power resources.

Do you know anything about timeline for the AMS based modules from Abletec???

Brgds,
Svein
 
I made a sort of "review" in a conversation with Patrik at anaview about the alc0300 modules that I translated from Swedish when I saw this thread.
I really like the amps so don't read to much into the minor drawbacks, they seem to be more related to other things than the amps.


The amps are playing really god, with a dynamic drive that I'm doubtful to if I have ever heard earlier.
They are picking details in all registers with some sort of confident ease and
they have a musical drive that makes it fun to listen.
I rather sing along then stomp my feet , to the great pleasure of our dog and to my wifes dispaire.
They sometimes have a tendency to be a bit bright/slender but on the other hand they never tip over being to bright .
Female vocalists come across with great energy and it holds together very well.
This comment about bright or slender is on a very small margin and is not really a problem
you just have to be a bit careful about surrounding equipment, cables, preamps and so on.
They have a nice tone and are percived as credible.
A grand piano is percived as a large instrument and not just a collection of keys.
One other example: Pink Floyd ”Bring the boys back home” from ”The wall”.
I have always had a problem liking that track, always seemed absolutly unnessesary on the album.
Just a lot of noice and screaming and that's betwen ”Vera” and ”Comfortably numb” that are true pices of art.
With the setting I have rigth now I can play that ”unnessesary” number at very loud levels and
everything is still noisy and screaming with a lot of energy but now it suddenly makes sense.
At the very end of the song the hair on my neck just stands on its own, I'm thanking you for that :)
To follow a base playing scales is a true pleasure and the amps also have great abillity to articulate
drums and other percussion instruments. If the drummer hits a little bit harder on whatever or if
the baseplayer is slamming the strings it comes across in a very convincing way.
This dynamic style of playing can on occasion be a bit much on really hard piano transients though,
I haven't heard It more than a very few times so it's really not a problem.
Stagepresentation is very good at the back of the stage (drums bass song etc) but can tend to be a
bit vorried at the front of the stage.
I'm quite shure that this is due to the present speakerplacement and it will be adjusted in due time.
It's not an easy task to get a decent setup in my room due to the sloping sealing but I'm slowly getting there.
I'm not getting these nice results if I'm playing directly from the computer/soundcard instead of the main setup,
with the ”Aikido preamp” and the modified Sony scd555es player.
Then it gets to much of poow tjoff and so on, sitting in the sofa blinking wondering when it all will settle down a bit.
Ambience got a little short then as well. Overly controlled, without bounce or square you might call it.
Maybe the soundcard doesn't like the low input impedance or the long cables (7,5m Mogami gold ballanced).
It sounds great over the ”Lars / Gigaworks-dac” as well (preamp still connected).
I havn't tried any other sources besides these but evidently they can make quite a difference.

Had some friends over and it seems that we agree on most of what I have described so you should be pleased with yourself.

Best regards.
 
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Thank you Dahlberg,

great review/ feedback.

I have sort of similar experience as you regarding SQ, but I have a difficult time to compare against other amps since I only have active speakers.
Therefore I had to test on new speakers without any amp to use as reference.

Good to hear others are happy with these modules. They are very attractive when it comes to price/performance ratio IMO.

Svein
 
Hi Svein,

the connectors shown on my pictures have to be ordered additionally.
You find them at the bottom of the ALC0180 product detail page under "Related parts and parts bought in addition to this item":

ALC-MP133-1.
1.79 EUR per piece :)


Matthias
For the ALC0180-2300, Profusion only supply the multi-way signal in and power out connector/wiring.
Mains power in and 2x speaker out connectors are also required. These are:

Con1 (Mains) JST VHR-3N
(JST (JAPAN SOLDERLESS TERMINALS)|VHR-3N|CRIMP HOUSING, 3WAY, 3.96MM | Farnell United Kingdom)

Con6, Con7 (Speakers) JST VHR-2N
(JST (JAPAN SOLDERLESS TERMINALS)|VHR-2N|CRIMP HOUSING, 2WAY, 3.96MM | Farnell United Kingdom)

Andy
 
Connecting unbalanced outputs to balanced inputs on ALC0180 modules

The ALC0180-2300 modules are Class II double insulated and thus there is no earth (ground) via the mains cable.

I need to connect long coax, unbalanced preamp output cables to the ALC0180 balanced inputs.

I could simply connect the central coax signal wire to the + terminal and the shield to the - terminal. However, I suspect I will have a hum problem with this and potentially an Electrostatic Discharge risk to my inputs.

Am I right in thinking that I do need a mains earth for the ALC0180 which I link to the - inputs and hence the preamp cable shield?

This should remove the hum and ESD risk.

Do I also need to connect the ground to the ALC0180 pcb ground also or can I just leave it floating?

Any guidance much appreciated.

Andy
 
Abletec ALC0240-2300

Here’s my experience with the Abletec ALC0240-2300 module.

This device is marketed as a “plug and play” two channel power amplifier complete with power supply, and it should be a simple matter for the end user to connect up the mains power, input connectors and speaker connectors and start using the amp.

Unfortunately, due to (amongst other things) the deficient instructions provided by Abletec, end users who configure the amp in single-ended mode in accordance with the published Abletec “block diagram” and connect it to unbalanced sources will end up with severe hum in both channels.

The reason for this is that Abletec’s block diagram for single-ended operation with unbalanced sources depicts the + and – inputs of both channels without any ground connections.

In order to prevent or minimise hum, it is necessary to either ground the – input of each channel to a ground pin on the amp (or to the star earth point if the amp is grounded to the chassis), or use shielded two core cable with only the shield grounded at both the preamplifier and the amp.

Sadly, none of this information can be found in any of the documents published by Abletec, and it seems that Abletec just assumes that the end user will know these things. As many hobbyists have only limited technical literacy, Abletec should provide that information, together with clear and unambiguous connection diagrams.

Which raises the next issue I have with Abletec. It is not clear from the Abletec block diagram whether the ground symbols on the block diagram depict internal grounds on the amp PCB or ground connections which need to be made by the end user. For example, Pins 3, 8 and 9 are internally connected on the PCB and it is necessary to make a physical ground connection only if you want to ground the amp to the chassis. All internal PCB grounds should be marked as such in the Abletec block diagram, and external ground connections clearly identified.

Finally, there is the curious absence in Abletec’s specifications for the amp of its input impedance.

In order to avoid pumping of the power supply rails, Abletec has the left channel of the amp connected in non-inverting mode and the right channel in inverting mode.

I measured the input impedance of each channel of the amp (with 8 ohm loads) when configured in single-ended mode in accordance with the Abletec block diagram, with the following results:

Left Channel
Frequency Input Impedance
10Hz 12.44kΩ
1kHz 11.9kΩ
10kHz 8.775kΩ
20kHz 4.74kΩ

Right Channel
Frequency Input Impedance
10Hz 3.75kΩ
1kHz 3.8kΩ
10kHz 3.06kΩ
20kHz 2.3kΩ

There is a marked asymmetry between the input impedances of the two channels, with an unusually low input impedance in the right channel. When the amp is used with a typical vacuum tube preamplifier with capacitor-coupled output, the result will be audible channel imbalance, premature LF roll-off in the right channel and increased distortion (particularly if the preamp does not use a cathode-follower output).

When auditioned in such circumstances, a negative perception of the performance of the Abletec amp will be the likely result.
Abletec should have disclosed the input impedance characteristics of the amp, as this is essential information for the end user.

There are, however, two cures for this problem.

The simplest is to discard the “anti-rail pumping” setup and wire the amp for unbalanced sources as shown in the attached image. Note that this only works with preamps that are compatible with 10k loads. If hum continues to be a problem, just use shielded two-core cable.

The other, more complex, alternative is a construct a high quality two channel unity gain buffer and interpose it between the input sockets and the input pins of the amp. This method permits the “anti-rail pumping” setup to be used without disadvantage.

I opted for the “simplest” cure and found that the amp performs very well indeed when connected to my home-built vacuum tube preamp (which uses 6DJ8 cathode-followers with both sections of each output tube connected in parallel).
 

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SMD opamp choice Abletec ALC0180-2300

I did replace the original MC33078 opamp (SMD) on my Abletec ALC0180-2300 board. I did change it for the OPA2604 (SMD). I have some experience with different opamps and the OPA2604 (SMD) is a safe and good choice.
The LM4562 and equiv. are not-my-cup-of-tea.

If you have the tools and experience do change the opamp, to my opinion the sound improved a lot.

Wim.
 
Abletec based IRS20955 based amplifier

Just wanted to point that the Abletec modules are using International Rectifer's IRS20955 / IRS20957 based Class D IC.

They use a dedicated IC which is not available to the DIY market, which allows them to use the IC in an optimum way. The Abletec modules are a self-oscillating design.
 
ALC0180-2300 Mains Rectifiers

I have two ALC0180-2300s of which I'm making changes to one so I can compare it with the other. Eventually these will be a pair of bridges for the final amp but I'm using them singly while experimenting.

I've ordered a set of OPA2604s as Wim suggests; however, before inserting those, I have a mod which I always find worthwhile before any signal component changes - namely the mains cable to oxygen free copper and the replacement of the cheap rectifiers with Schottky devices.

The idea is to avoid introducing RF noise at the mains input due to the reversing voltage switch-off spikes in the rectifiers. Schottky rectifiers are fine for simple transformer/rectifier/capacitor supplies as the reverse voltage is usually not too high for them. When it comes to switch-mode supplies, there is a little more to it.

The ALC0180s have four secondary diode rectifiers type ES3B with a fast 20nsec recovery time. Added to this, there is a RC snubber across each one. Clearly the designer was considering RF interference from these. However, other than cost, what I can't understand is why the mains input voltage rectifier is a 'Bog-Standard' GBL06 bridge type with no snubbers.

The GBL06 has no figures specified for its switch off time and can thus be assumed to not have that parameter optimised for low RF emission.

Mains voltage (230v in the UK) is far too much for a Schottky rectifier so I've searched out a fast, soft recovery type to use - namely Fairchild's FFPF04S60STU (Farnell 188-5724). Of course 4 of these TO-220F packaged devices are needed to be squeezed in where the bridge was but it is possible with care.

The result: The original was good, clear and revealing but slightly shouty and up front. The modified version sounds more relaxed and analogue-like.

Give it a try and post your impressions of the mod. (And don't touch anything with a mains voltage on it!).

Andy

'Bridge' rectifier picture attached.
 

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Changing MC33078 to OPA2604 on ALC0180-2300

I did replace the original MC33078 opamp (SMD) on my Abletec ALC0180-2300 board. I did change it for the OPA2604 (SMD). I have some experience with different opamps and the OPA2604 (SMD) is a safe and good choice.
The LM4562 and equiv. are not-my-cup-of-tea.

If you have the tools and experience do change the opamp, to my opinion the sound improved a lot.

Wim.

Following on from my posting on 11th April 2012, I've now changed the MC33078 op-amps on one of my two ALC0180s to OPA2604 as suggested by Wim.

Using an acoustic recording with plenty of space around the instruments (track 6, Crooked Still, Shaken by a Low Sound), I've tried again and again to hear any difference between the ALC0180s with the MC33078 and OPA2604.

Listening for any kind of detail or spacing of instruments or anything else, I can't honestly say I can hear any difference between the op-amps.

Having changed the high-voltage rectifier diodes first, the op-amps might have sounded different had I not done this; however, I'm not going to take them out!

Conclusion? I'll stick to upgrading the rectifiers first.

I'd be glad to hear of others' similar experiences.

Andy
 
Some info...

ALC1000

Mains connector
Pin 1= AC_N (Neutral)
Pin2= AC_L (Live)
Pin3= PE (protective Earth same as earth. Not needed).

Be careful pressing the contact.

PCB has contacts on the backside as well....
If you wish to connect balanced (with XLR) then Input+ to pin9 (IN+) at CON1 and signal- to pin10 (IN-) at CON1 and finally the signal to signal GND to pin8 (GND) at CON1. If you do single ended connect signal to pin9 and gnd to pin10+pin8.


ALC0300

Mains connectors
CON2= AC_L (Live)
CON3= AC_N (Neutral)
(No earth)

Balanced signal (with XLR) to input skal connect your signal+ to pin9 (IN+) at CON1 and signal- to pin10 (IN-) at CON1 and finally your signal GND to pin8 (GND) at CON1. If you do single ended connect signal to pin9 and gnd to pin10+pin8.

Hope this helps.

I did get better documentation by contacting Abletec directly, but can unforunately not find it at the moment.

Svein
 
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