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Class T Audio Amplifiers

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TDA8920 module: happy customer several months onward

Just thought I'd mention I'm a happy user of one of the ConnexElectronics TDA8920 modules (which I got from Col).. very nice sound with my EconoWave speakers. And even though I'm using quite high efficiency compression drivers the amp is very quiet (after I got my grounding set up properly).

Also I measured the power usage with one of the Jaycar power meters.. 6-7W at normal listening volume, essentially 0 when silent.. I can leave it on 24/7 and not worry about power use. my preamp uses more power than my power amp.
 
Connex TA3020 amps.. what is the key differences between 3a, 3b, 3c

Hi,

Col visited a few days ago and we compared his ConnexElectronics TA3020 amp (V1) with DIY PSU including 4 x 10,000 uF filter caps.. VERY impressive, it has noticeably firmer bass and more detail than my "reference" amp, a class AB ART SLA-1 studio power amp - driving my "econowave" style speakers.

Listening to "South Of The Line" by NZ dub band Pitch Black I could hear more fine detail I hadn't heard before, and better bass, as my current amps must have been struggling to put out the power to reproduce the fine detail and deliver the low end bass lines in this track at the same time.

Anyway, looking on the Connex site I can see 3A, 3B and 3C models.. what are the key differences between these models? I can see the 3C has the filter caps on board, while I am guessing with 3A and 3B I would get an extra linear PSU (PS10K63, PS10K80, or even PS18K71) to deliver the power - which would be best? I don't listen at very high volumes - but I often listen to very bass driven music, and it was very apparent the extra control and detail with the cnx ta3020 v1 in some of my favourite bass heavy tracks.

Measuring the power draw (with jaycar power meter) I can see the v1 uses about 13W idle or at low volumes, and only up to 22-28W at deafening volume levels in my house. This is a lot better than the ART SLA-1, but not quite as efficient as the my cnx TDA8920 (essentially 0 watts idle) - are the versions 3A, 3B or 3C any different with their idle power consumption?
(Note in standby mode the v1 does use zero power, unlike some bits of gear I have!)

I've had some good results with my Connex TDA8920 amp (though it has a strange sonic artifact with piano sounds I just noticed) and my ART SLA-1 but the improvement in trying out the TA3020 was quite noticible - and there are quite a few options to run with implementing one on the Connex web site.
 
more TA3020 questions: input connectors

I can see the v1 and v2 use a screw in terminal header for the inout connections while the 3a and 3c use a plug in connector - I found this plug in connector a bit hard to work with when I was boxing up my TDA8920, is there any advantage to this connector? I can't see what kind of connector the 3b uses but am i right in assuming its not a screw in terminal header?
 
TA3020 v3c with softstart and 500VA toroid

Here's my very simple implementation of the v3c in a spare steel box I found in recycling, but already had some of the mains wiring and EMI filter and is the perfect size.

Ugly but I think I managed to get a good layout internally.

Sounds very good.. low power use (about 11W idle).

Can hear faint white noise if I put my ear next to the waveguide (high efficiency compression driver), but not audible away from the horn.

When I had the amp module bolted to the chassis with metal nuts and bolts it caused some ground loop noise. Replacing the metal nuts and bolts with polycarbonate ones and the sound went away. Soft start is still bolted down with metal nuts.

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nice amp zog:)

ive got 4 3020v3c modules coming (with all optional extras), with 4 smps1000 power supplies (again with all optional extras) in a couple of weeks :D

this is to run my stereo (bi-amped and mono) and my surround system (bi-amped center speaker) and 1 channel each for the rear speakers.

i want to run the full 200wrms @8 ohm out of each channel, unless there is any reason not to?? i know it requires a small modification for this- anyone have the details for this?

and i would like to try bridgeing the amps -to see if i find it any different/better.

this is my attempt at the ultimate power amp for my needs, and hopefully a perminant fixture. so im open to any modifications or setup advice anyone can give me:)

thanks all.

ps- having spent some time now with the sure t2050 amp, im soooo excited about this!!!!
 
cristi,
could you identify the rectifyer bridge that needs to be bypassed in order to get the full 400 w rms out of the ta3020v3c with a photo or diescription and exactly what needs to be done- is it just removed or do i bridge the soled pads with some wire?

does this need to be done if the amplifier is run in BTL mode?

thanks.
 
the rectifier bridge is between the speaker protection relay and the heatsink, and the connections which have to be bridged are the AC1 with V+ and the AC2 with V-, which are the closest ones. the rectifier bridge must be bypassed ONLY when the board is supplied with DC voltage. the TA3020v3c amplifier can be used in BTL mode with or without the rectifier bridge bypassed.
 
nice amp zog:)

ive got 4 3020v3c modules coming (with all optional extras), with 4 smps1000 power supplies (again with all optional extras) in a couple of weeks :D

QUOTE]

Other than a box and connectors is anything else needed to build a two channel amp besides the 3010v3c and a smps1000? Is this the optimal way to build this amp? Thinking about my first build and am curious as to how involved it is.
 
nice amp zog:)

ive got 4 3020v3c modules coming (with all optional extras), with 4 smps1000 power supplies (again with all optional extras) in a couple of weeks :D

QUOTE]

Other than a box and connectors is anything else needed to build a two channel amp besides the 3010v3c and a smps1000? Is this the optimal way to build this amp? Thinking about my first build and am curious as to how involved it is.

Also does any of the 3 power approaches outlined in the owners manual result in better sonic performance?
 
Very Good Info Zogg666. Would the following transformer be a good fit?

Primaries: 115/230V 50/60Hz
Secondaries: 0-16V 1A, 13V-0-13V 1A, x2 40V 12A

I will have to find some experienced help to bring it all together in the end. I certainly will not hit the power switch until a pro checks it all out. :p
 
The 2x40V AC at 12A secondaries of the transformer are enough to supply the TA3020v3c amplifier board. in fact the transformer, if can supply 12A continuous, can be used to power two amplifier boards. after rectifier and filtering, you will get about +-56V DC, and the amplifier will deliver about 250W per channel for the STW34NB20 version or 300W per channel for the IRFP4228 version.
 
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