[nwboater]

Hi,

Does anyone here have any experience or knowledge of the TK2050 Class D amp boards available on Ebay by hifimediy. There is a huge thread on the DIY Audio forum about them. At less than $50 (Without power supply) they certainly qualify as 'Cheap'. But are they 'Cheerful'?

I have been seriously looking at the $175 Class D Amp thread here and are quite interested in them. Perhaps comparing these two amps is unfair, but I'd like to. Anyone have experience with both?

Thanks.

In Cheerful Anticipation,
Rod

[wushuliu]

I have not heard them (just the modded Sure versions some time ago) but given the high quality parts used and the fact that the designers are going for sq first, not money, I am sure they sound very very good. For the money they are a steal. No other pre-assembled TK2050 kits come that cheap with that high a quality. I believe they are working on a 2x mono w/ PS kit as well.

As for comparing to ClassDaudio kits, since they use complete different chips you would just have to compare yourself. It's all in the implementation. The Classduadio give you more power and probably easier to assemble for beginners.

You can't go wrong w/ either.

[avionic]

  I have 2 of the tk2050 from hifimediy,the 4 ohm and the 8 ohm version. The sound quality is very ,very good. All you need is a power supply and you are up and running. The size of the board is only 3"x5" which is another bonus.
   I also have had the class d audio amps for quite some time. They also sound incredibly good. A little more work to get running but def. more power than the 2050. Not saying the 2050's are weak at all, just not as much power as the class d.
  Either way you cant go wrong. $50.00 shipped for 80 or so watts a side = no brainer for the hifimediy amp. I use the tk2050's for running some monitors and I am in the process of building a 5 channel class d audio amp with SMPS that will fit in a 12"x16" case.
   In the end I guess I would say take your pick you'll be happy either way.



                 

[nwboater]

wushuliu & avionic,

Thanks very much for the informative replies. Good to have some positive feedback on these amps.

Avionic - I take it that your new 5 channel amp is using the 'Class D' brand amps. I'm curious if you chose those over the tk2050 for SQ or the higher power. Especially with 5 channels there's a good chunk of price difference.

Rod

[parodielin]

Am I correct that all I need is the amp board and the power supply?

So V2.0 (2*100W) board + Meanwell 27V SMPS. (~$100 shipped total)

I have to do the wiring, add power switch, RCA jacks, ...

[wushuliu]

Am I correct that all I need is the amp board and the power supply?

So V2.0 (2*100W) board + Meanwell 27V SMPS. (~$100 shipped total)

I have to do the wiring, add power switch, RCA jacks, ...

That sounds about right. Although I would wait a couple weeks as they are finalizing a dual mono block and PS design which will probably be very well-priced and would be a smarter choice amp-wise (depending on your speakers, anyway) than a single board. Very exciting time for diy audio!

[nwboater]

That sounds about right. Although I would wait a couple weeks as they are finalizing a dual mono block and PS design which will probably be very well-priced and would be a smarter choice amp-wise (depending on your speakers, anyway) than a single board. Very exciting time for diy audio!

How do you see the new dual mono amps comparing to the existing offerings? And would you mind elaborating on why and with what kind of system you would see these as a better choice?

Thanks,
Rod

[wushuliu]

How do you see the new dual mono amps comparing to the existing offerings? And would you mind elaborating on why and with what kind of system you would see these as a better choice?

Thanks,
Rod

My assessment is purely based on the watts provided (and I'm speaking specifically of the Hifimediy here, not the classdaudio). With the dual mono you will be able to provide more power and cleaner audio to your speakers, also I believe they are working on a pretty good design for the PS. As to the second half of your question that's pretty broad and I couldn't answer that without more info except to say that the TK2050 is effectively more like 2x70w, not 100w. 100w would be with high distortion. So depending on your speakers' efficiency 70w may or may not be enough for your needs.

Here is part of the dual mono.

http://www.diyaudio.com/forums/class-d/164274-new-tk2050-board-45.html

[nwboater]

My assessment is purely based on the watts provided (and I'm speaking specifically of the Hifimediy here, not the classdaudio). With the dual mono you will be able to provide more power and cleaner audio to your speakers, also I believe they are working on a pretty good design for the PS. As to the second half of your question that's pretty broad and I couldn't answer that without more info except to say that the TK2050 is effectively more like 2x70w, not 100w. 100w would be with high distortion. So depending on your speakers' efficiency 70w may or may not be enough for your needs.

Here is part of the dual mono.

http://www.diyaudio.com/forums/class-d/164274-new-tk2050-board-45.html

Thanks for your elaboration. I'm in the process of going active with my old Klipschorns and changing them from 3 way to 2 way. Being very efficient they don't need gobs of power, but I believe some extra headroom on the bass bins is not a bad thing. And these speakers are very revealing - low distortion is quite important!

Think I'll wait for the new dual mono amps to be out for awhile before making a move in their direction. But I'm still wondering about the 'Class D' amps. I may just get one so I can compare with the hifimediy amp. I will be using a Behringer DCX-2496 for crossover so may go to the Class D SDS-254 kit because it has balanced inputs. Quite a price difference to the hififmediy amps!

I'm setting up a 5.1 Active system so need quite a few amps. That's why I'm keeping a good look at pricing.

Rod

[Barry_NJ]

That sounds about right. Although I would wait a couple weeks as they are finalizing a dual mono block and PS design which will probably be very well-priced and would be a smarter choice amp-wise (depending on your speakers, anyway) than a single board. Very exciting time for diy audio!

Looks like it's available now...

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=130420520248

[wushuliu]

Looks like it's available now...

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=130420520248

That was fast. They are on a roll. 300 Watts! for $100. Accepts both DC and AC.  Wow. That looks pretty dang cool. Somebody has to get one and report back!

[Barry_NJ]

That was fast. They are on a roll. 300 Watts! for $100. Accepts both DC and AC.  Wow. That looks pretty dang cool. Somebody has to get one and report back!

Well the 300 Watt rating is into a 4 Ohm load, so 150 is a more realistic number...

[wushuliu]

Well the 300 Watt rating is into a 4 Ohm load, so 150 is a more realistic number...

I run 4 ohms...

[srb]

I run 4 ohms...

Me too.
 
They say on the ebay page that the PSU board can accept either a SMPS feeding DC or an AC source.  Would there be any reason to use an SMPS other than to possibly save some energy as well as lower component cost from not having to buy a more expensive torroid?
 
If AC is supplied, is the only component needed an AC transformer?  They say the AC range is 22V-35V and DC is 30-50V.  Are these amp boards not using a + and - power supply rail like the Class D Audio amps, and therefore only a single 35VAC secondary transformer would be required?
 
Lastly, any idea what the storage capacitance of the PSU board is, and could a separate PSU board be used for each amp board?  I would like to build a complete dual mono with 2 transformers and 2 PSU boards, even if it isn't necessary because of the low cost of component parts.
 
Steve

[wushuliu]

Me too.
 
They say on the ebay page that the PSU board can accept either a SMPS feeding DC or an AC source.  Would there be any reason to use an SMPS other than to possibly save some energy as well as lower component cost from not having to buy a more expensive torroid?
 
If AC is supplied, is the only component needed an AC transformer?  They say the AC range is 22V-35V and DC is 30-50V.  Are these amp boards not using a + and - power supply rail like the Class D Audio amps, and therefore only a single 35VAC secondary transformer would be required?
 
Lastly, any idea what the storage capacitance of the PSU board is, and could a separate PSU board be used for each amp board?  I would like to build a complete dual mono with 2 transformers and 2 PSU boards, even if it isn't necessary because of the low cost of component parts.
 
Steve

Hey Steve, you may want to ask them direct via ebay or diyaudio, but I'm pretty sure it's a dual rail and therefore the toroids used for the classdaudio amps would suffice (I think they use Antek, you can get them at antekinc.com). Only the toroid is needed, the rest is assembled. Last I read the PS only has 4x4700uf, so it would be recommended to increase that amount for toroid use (but should be sufficient for smps use). The  recommended SMPS, I think is a holdover from the Sure TK2050 craze and that SMPS was what everyone used for it and it was highly recommended. You'll want to check on that though... Don't know much else.

[Barry_NJ]

I run 4 ohms...

Me too.

Fair enough guys. I guess I'm used to commercial amp manufacturers usually giving power ratings into an 8 Ohm load, so when comparing, I like to try to keep things as equal as possible. When I read that an amp has 300 Watts/Channel I assume that is into an 8 Ohm load. Then I do some research and find out that spec is into 4 Ohms, and it's rating of 150 into 8 Ohms is a bit of a let-down to me.

[srb]

Fair enough guys. I guess I'm used to commercial amp manufacturers usually giving power ratings into an 8 Ohm load, so when comparing, I like to try to keep things as equal as possible. When I read that an amp has 300 Watts/Channel I assume that is into an 8 Ohm load. Then I do some research and find out that spec is into 4 Ohms, and it's rating of 150 into 8 Ohms is a bit of a let-down to me.

I agree they should be rated at 8 ohms, like most all amplifiers traditionally have been rated.  I think this 4 ohm rating for class D amplifiers started with Hypex UCD and B&O ICEPower, and now every other class D maker feels they have to also spec at 4 ohms so their products will be comparable and competitive.  Never should have happened.
 
Steve

[parodielin]

I don't really mind them rating at 4 ohm.  For one most my speakers are 4 ohm and for two most amps capable of 8 ohm load are not necessarily capable for 4 ohm load or the power would not have doubled, for example, 150 8 ohm perhaps 200 4 ohm instead of 300.

So what would be a reasonably cost transformer to use with this one?  It seems like it could be done within $150.

And make it even better, add a Pass B1 preamp for another $150 (including a Hammond case), it could be a killer combo for $300. 

I agree they should be rated at 8 ohms, like most all amplifiers traditionally have been rated.  I think this 4 ohm rating for class D amplifiers started with Hypex UCD and B&O ICEPower, and now every other class D maker feels they have to also spec at 4 ohms so their products will be comparable and competitive.  Never should have happened.
 
Steve

[Steidl Guitars]

Parodielin asked:  So what would be a reasonably cost transformer to use with this one?  It seems like it could be done within $150.

I was wondering the same thing, so if someone who knows would be willing to chime in, I'd sure appreciate it.

In the meantime, I assume that any of these in the 24v to 30v range with sufficient current might be okay:

http://www.antekinc.com/gview.php

Maybe something like this?:  http://www.antekinc.com/details.php?p=79    which is 28 v and 7 amps.

Thanks...

[srb]

most amps capable of 8 ohm load are not necessarily capable for 4 ohm load or the power would not have doubled, for example, 150 8 ohm perhaps 200 4 ohm instead of 300.

Although some solid state Class A, Class AB and Class A/AB power amplifiers double their power rating at 4ohms, the majority do not.  Here are some examples:
 
Bryston 4BSST² :  300W @ 8ohm and 500W @ 4ohm
McCormack DNA-250:  250W @ 8ohm and 400W @ 4ohm
Parasound Halo A21:  250W @ 8ohm and 400W @ 4ohm
 
My own present amplifier, an Audio Refinement Multi-5, is rated at 125W @ 8ohm and 200W @ 4ohm and is used to drive my 4ohm speakers.
 
These are all high quality popular mainstream amplifiers that can run continuously at 4ohms with absolute stability.
 
The majority of Class D amplifiers are rated at double the power @ 4ohms, and include B&O ICEPower, Hypex UCD, Class D Audio (with the exception of the CDA/SDS-258), Virtue (Tripath) and the Hifimediy Tripath amps in this thread.
 
If you are looking for a transformer to run the Hifimediy T3 mono amps, a 700VA transformer is recommended for 2 T3 amplifier boards to reach the 300W @ 4ohm rating (or if constructing a dual mono, 350VA for each).  An Antek AN-8430 800VA/30V transformer sells for $84.00.
 
Steve