An almost fully modded Autocontruire TA2020

ac2005

Member
2005-07-29 8:19 pm
HK
I am going to heavily mod my Autocontruire TA2020 as I find that it has very good potential.

I am going to replace the unknown power caps with Black Gate FK 2200uf, other electrolytic caps with Black Gate N Series of the same value, all unknown polyester caps with Sonicaps of the same value and two 15 ohms resistors with Mills non-inductance resistors. I will also bybass the input caps with a 0.1uF Sonicap. I want to replace the other 5 metal film resistors too but I am still searching for the replacements.

How does it sound?

I think I am finishing this mod next week. I will post some photos and test report afterward.
 
ac2005 said:
I am going to heavily mod my Autocontruire TA2020 as I find that it has very good potential.

I am going to replace the unknown power caps with Black Gate FK 2200uf, other electrolytic caps with Black Gate N Series of the same value, all unknown polyester caps with Sonicaps of the same value and two 15 ohms resistors with Mills non-inductance resistors. I will also bybass the input caps with a 0.1uF Sonicap. I want to replace the other 5 metal film resistors too but I am still searching for the replacements.

How does it sound?

I think I am finishing this mod next week. I will post some photos and test report afterward.

Hi,

I was just wondering if someone already made some mod to the amp ;)

What would be interesting is that you make the change one by one to see what mode have the most effective impact on the sound. This way, those with less skills or les $$ would know the mods that have the most effect and do only one or two of them.

What do you think ?

Regards,
 
Nuuk,

I have some caps 10 000 mf + 1000 mf + 100 mf that I want to use as a reservoir for my autocostruire TA2020. I just want to be sure that I understand how to connect them. I would connect them in // with the little value closer to the amp (faster reaction).

Also, I have some Solen 0.1 mf teflon film cap and some 0.1 military paper in oil cap. I could use some of these caps in // with the 2.2 uf input caps. What would be the best choice ? I could try both, but I would like to try the best first ;)

Thanks
 
I have some caps 10 000 mf + 1000 mf + 100 mf that I want to use as a reservoir for my autocostruire TA2020. I just want to be sure that I understand how to connect them. I would connect them in // with the little value closer to the amp (faster reaction).

Yes, they would go across the rails, the positive side of the cap towards the 12 volt rail.

Also, I have some Solen 0.1 mf teflon film cap and some 0.1 military paper in oil cap. I could use some of these caps in // with the 2.2 uf input caps. What would be the best choice ? I could try both, but I would like to try the best first

I have no idea which is best so you will just have to try them both with an open mind (not forgetting that it could sound better without either!). ;)
 
Nuuk said:


Yes, they would go across the rails, the positive side of the cap towards the 12 volt rail.



I have no idea which is best so you will just have to try them both with an open mind (not forgetting that it could sound better without either!). ;)

Thanks, I have connected the caps and it measure OK (after a little mistake). I'll try the amp with the Paper in Oil first & see if it make a difference.

Thanks again !
 
ac2005, I am completely sure that I know what you will say after the replacement of the parts: You will find it much better than before.

I think merely replacing parts by identically valued and rated parts, which are "approved high quality" by the high-end community is not real modding. This will rather directly lead you into a psychological trap. Having put a lot of work and money into this change of the system, your mind will tell you that the new configuration must be much better, and your sonic cognition will heavily tempted to confirm this.

Note that if you do not change the values or ratings of the parts, the audible changes, if there are any, will be rather subtle. And using more expensive parts does not automatically mean that the changes will be improvements (even though this is exactly what the people selling the expensive parts are trying to tell us). In order to really figure out if the replacements you are planning will let to better sonic quality (save the criteria are fixed), you have to be very open minded (as Nick already pointed out) and I think there is no way around extensive AB tests of the changed system with a system left in original state.

Mick
 

ac2005

Member
2005-07-29 8:19 pm
HK
Hi all,

Thanks for you guys' response.

My parts are still on the way to my home so I still can do nothing to my TA2020 now.

I will be very careful not to be influenced by the price tags and make an untrue conclusion. It's impossible to do a complete A/B test coz I don't have 2 sets of TA2020. But it's always a bad idea to change all parts in one time coz it's hard to find out where the improvements and problems come from. So I will divide my work into 5 stages.

1. power caps
2. all parts except the input caps
3. as the impedence of my speakers is 4 ohms, I will add 4 x 0.22uf caps to optimize the TA2020 for a pair of 4 ohm speakers
4. change the input caps
5. bypass the input caps with a 0.1uf cap

The total cost of this mod is around US$150. Not too expensive. I hope there will be a big improvement coz the stock parts seem to be quite cheap and not of the high quality.

BTW, kanaddict, what is the result of your mod?
 
ac2005 said:

BTW, kanaddict, what is the result of your mod?

Hi,

I'm currently on vacation and don't have much time to write. To make my comments short I will say :

1- Both the Solen film cap and the paper in oil cap improve the sound;
2- With Solen cap, the sound is softer without loosing details (compare to the stock board). The bass is more present (easy to hear).
3- With the paper in oil cap, the bass went back to were it was with the stock board, but the dynamic ...WOW ! It also provide a little bit more details.
4- Both caps provided a better separation. Instrument are more well define.

No bypass cap sound better then the other, just different & depending on what you like some may prefer one to the other. The sound with the paper in oil cap is more spectacular, but I think that on a long term, I would be more happy with the Solen. I'll have to live a few weeks with each one before making a final decision :smash:

So, I now wonder how the amp. would sound if I would replace the 2,2 uf with some quality cap ? Better then it do with some bypass cap ??

I also think about trying a .22 uf in // with the .33uf
This would give a Q of about 9 and I suspect that the effect on the bass would be very interesting.

Regards,

Daniel
 

ac2005

Member
2005-07-29 8:19 pm
HK
Some of my parts have arrived. I have replaced the power caps with Black Gate FK 2200uF and Cpump with Black Gate NX 1uF The result seems good. The silence is more silence. I can hear more details. The sound is softer. The bass has more details and is more bouncy.

Is it worth $50? Hard to say. If you are a perfectionist like me, you would probably love this upgrade. If you aren't, you can try some much cheaper power caps like Elna or Panasonic. The result might not be a big difference.

IMG_3691.jpg



More parts to go
IMG_3693.jpg
 
Finnegann said:
Have you noticed that Tripath no longer has the TA2020 on their list of available IC's? It's actually marked as "not recommended" on their complete product list?

http://www.tripath.com/data.htm


Not Recommended :xeye:

Funny :clown:

How they can explain that they were selling it as good stuff and now no longer recommend it :confused:
All the comments I read about the autocostruire TA2020 were very good. I started to modify mind and it sound as good as I was expecting it to sound.

Maybe the Autocostruire TA2020 was too good and some big $$$ amp. company like Audioresearch complained about that....who know !
 
You don't have to worry about that ... it simply means that Tripath is going sooner or later to introduce a similar product with some added feature or a slightly lower cost ;) ! And possibly with a similar pinout (maybe a replacement will be possible).

The same is happening on their 4 channel chips, but the new ones, as far as I can see, are very similar to the previous ones, they simply cost less.
The chip makersare working for the big numbers ... and this means that there are still very large lots of ta2020 chips available from the resellers.
In my opinion sourcing the ta2020 won't be a problem for a long time.

An finally, given that you say that the kit is sounding very good (and I agree with that), can we say using a similar approach that also the NAD 3020 is actually "not recommended"?
Of course it is, it has been out of production for decades, yet it remains a very successful amplifier and it's still much requested on ebay sales .... :D

Have a good time listening!
 

ac2005

Member
2005-07-29 8:19 pm
HK
I am finally done with my mod. But I first have to say I happened to discover a major drawback of the Black Gate FK caps. The sound is too soft and you can't feel the strength of music, especially rock music. The bass is like an old man with asthma. So I finally added back one stock power cap in parallel to those Black Gate. Oh, the strength was back again! I have tried Elna for Audio 4700uF and Nichicon Great Supply 6700uF. Neither one was as good as the stock one. It seems that the stock power caps are not bad at all, though not as silent and the details are not as rich as Black Gate.

Sonicaps are rich in details, airy and bright. After having changed all caps except the input caps to Sonicaps, there were real improvements over the stocks caps. You can hear more details better seperation and richer soundstage. You can feel even more air and more details after replacing the input caps with Sonicaps. But it seems that I made a mistake here. It's not a good idea to replace all the caps with one brand. Now maybe there is too much air; the sound is too bright. The treble is a little bit strident and the vocal is not rich enough. So I think it should be a good idea to replace the input caps with Jensen copper foil in oil or Jupiter Beewax caps to get richer vocal and suppress the strident treble a little bit. Somebody says he has a good result by adding a pair of Sprague Vitamin Q 1uF paper oil caps as speaker output crossovers to have warmer vocal and less bright treble. Maybe I will try that too.

Anybody has other good idea?

BTW, I have also added 4 x 0.22uF caps to optimize this little amp for 4 ohm speakers. The bass is a little bit richer. But other improvement is not quite noticeable. Maybe the caps need burn in. I am now using Holco resistors but it looks like coil resistors are the best. I have ordered some Welwyn coil resistors. They are much cheaper than Mills and people say they sound almost identical.

Sonicaps are so big so the case and pcb are quite congested. The little holes on the pcb are very very fragile. I have damaged over 10 and sometimes had to solder the parts directly to where they should go according to the schematics or the tests by the multimetre. So be careful.
IMG_3701.jpg


IMG_3702.jpg
 
I can have an explanation about what you found ...

Tripath suggests to use "low ESR" capacitors on the supply lines. They must supply strong impulsive currents, so their internal resistence must be low, they suggest Panasonic FC types (actually the only ones with a declared low ESR value ...).

But what about the "other" capacitors, the ones that you find at your local shop or even other Panasonic types?

Well, I recently acquired a tester of capacitor's ESR (equivalent series resistance), the Atlas ESR 60. I think it's the only way to understand which capacitor is good and which is not ... and I performed some measurements.

The stock capacitors on the Autocostruire kit are actually quite good. Their ESR is extremely low, comparable or better as the one of the Panasonic FC types.

So maybe they look poor, yet they do their job very well. Maybe "hi-end" capacitors are more appropriate in other kind of circuits, here we need something that is capable of doing a "hard" job.

Bye.
 

KT

Member
2003-10-11 4:37 pm
USA
ac2005 said:
I am finally done with my mod. But I first have to say I happened to discover a major drawback of the Black Gate FK caps. The sound is too soft and you can't feel the strength of music, especially rock music. The bass is like an old man with asthma.

AC2005,

Very nice that you're modifying the Audioconstruire kit.

I just wanted to throw this into the mix - that Blackgate caps can often take a long (I mean looooong...) time to burn in and they can often sound suprisingly bad until that time.

I have not used the FK model in a D-class amp on the power rails, but when I used Blackgate Standard, Blackgate N, FK and PK in a DAC, I thought I about selling the DAC because it sounded muddled, confused, flat, and also a little stiff at the same time.

Then about a month or more later, the sound opened up and the pacing became much, much better, and everything just sounded relaxing and right. Now it is the best DAC I have. Even better when I used BG N as the ouput cap.

Also, when I used BG Standard in a 300B single ended amp, it took a while before the sound became focused and musical.

It may be different in your application, but for what I used them for it took some time before the Blackgates sounded right.

Anyway, it's just a thought to consider.

Keep us updated as the unit burns in.

Best,
KT
 
KT said:

I just wanted to throw this into the mix - that Blackgate caps can often take a long (I mean looooong...) time to burn in and they can often sound suprisingly bad until that time.
KT

Hi,

I wondedr if there is a way to make the burn-in before the installation in the amp ? I suppose that if we apply some low current (ex: 12V) to the caps for a few weeks, this could lead to the same results.

What do you think ?
 
ac2005 said:

BTW, I have also added 4 x 0.22uF caps to optimize this little amp for 4 ohm speakers. The bass is a little bit richer. But other improvement is not quite noticeable.

Your bord is now heavy moded :eek:
I don't think I will ever modify mid as much as you have ;)
I was planning to order some 2.2uf Sonicaps to replace the input caps (I actualy use some 0.1 Solen film cap in // with the stock 2.2uf ) and some 0.22uf to optimize the amp for my 4 ohm speakers. I was not sure of the brand I would use for the 0.22uf. Do you used Sonicap for the 0.22uf ?

Thanks for sharing you work with us !
 

BWRX

diyAudio Moderator Emeritus
2005-01-17 5:29 am
Pennsylvania
ac2005 said:
The little holes on the pcb are very very fragile. I have damaged over 10 and sometimes had to solder the parts directly to where they should go according to the schematics or the tests by the multimetre. So be careful.

This is one aspect where the AMP3 is better as it has a PCB that can withstand quite a bit of soldering and desoldering! I speak from experience... Of the three or four times I installed and removed a few different supply caps on the one board I managed to only lift one of the pads. By that time I had fried the amp because of a tiny solder blob that managed to short two pins on the chip.

starn02 said:
they suggest Panasonic FC types (actually the only ones with a declared low ESR value ...).

Actually, the Panasonic FM and Nichicon HE series are also very low ESR types that are cheaper than the FC's.