Sandbasser, for the wima film caps I used what I had on hand. I don't think it makes much difference if you used the mks which is what a did and a few mkp. Digikey sells some EPCOS MKT and I used them also.
For resistors, I used 1/2w Vishay Dale, the brown ones CMF55, since they had all the values covered. These are all from Digikey. Yageo resistors should be fine also. Make sure they are 1% tolerance ratings.
Have fun building!
For resistors, I used 1/2w Vishay Dale, the brown ones CMF55, since they had all the values covered. These are all from Digikey. Yageo resistors should be fine also. Make sure they are 1% tolerance ratings.
Have fun building!
About the sound and performance. Today I finally made a comparison between my 1st amp the DX blame st and my 2nd amp a V1.3 Symasym. I used a couple of DPDT switches to switch the speakers between amplifiers on the fly so it is easier to tell any differences.
The results were unanimous for all 3 listeners. The symasym seemed slightly more pressured on our ears at the higher frequencies. Some said the symasym sounded a bit more muffled in the lower frequency range but this may be because the upper was different.
The Blame ST had slightly more clarity then symasym and some comments were also made that the bass was slightly greater.
Overall the Blame ST seemed for all 3 people was more pleasureable to listen too.
Will post a video of the experiment on you tube when I get time.
Regards
SImon
After my experiment today. I think the best way to explain the Blame ST is "Friendly". Friendly and "Pleasurable". Similar to sex I suppose but not quite as good.
@Sandbasser,
from an economic point of view I recommend the use of a 10 µF MKS- or MKT - capacitor (like the EPCOS or the Vishay 1820) as input cap.
Both of them fit perfectly on the PCB.
You may, if you like to, bypass /parallel the MKS or MKT by a small (nF) MKP capacitor to expand the capacitor's capabilities in higher frequencies.
I do not recommend the use of MKP or some fancy Mundorf Silver/Gold capacitors as input C1.
First: it looks ugly since MKPs are normally very big in size and do not fit in this position.
Second: normally the AMP's input signal is already DC-decoupled by the source's (CDP, DAC, PreAMP...) output cap.
The total quality of the caps is then determined by the one having the poorest quality.
If the source uses a "poor" quality cap on its output (like a low-cost PC's soundcard does for example),
you will not be able to compensate this cap's quality by even a Mundorf pure Gold as input to the AMP.
This is what I mean with "economic reasons".
Best regards - Rudi_Ratlos
from an economic point of view I recommend the use of a 10 µF MKS- or MKT - capacitor (like the EPCOS or the Vishay 1820) as input cap.
Both of them fit perfectly on the PCB.
You may, if you like to, bypass /parallel the MKS or MKT by a small (nF) MKP capacitor to expand the capacitor's capabilities in higher frequencies.
I do not recommend the use of MKP or some fancy Mundorf Silver/Gold capacitors as input C1.
First: it looks ugly since MKPs are normally very big in size and do not fit in this position.
Second: normally the AMP's input signal is already DC-decoupled by the source's (CDP, DAC, PreAMP...) output cap.
The total quality of the caps is then determined by the one having the poorest quality.
If the source uses a "poor" quality cap on its output (like a low-cost PC's soundcard does for example),
you will not be able to compensate this cap's quality by even a Mundorf pure Gold as input to the AMP.
This is what I mean with "economic reasons".
Best regards - Rudi_Ratlos
Rudi, recieved the PS boards and caps. Thanks!
Niss Man, thanks for that review. It great to hear that it was preferred over the symassym. Carlos himself said it would better the symassym. I built the Blame ES myself, which is said to be sonically better than the ST.
I have another amp I am putting together. I have the BAKSA boards that Rabbitz generously sent to me. According to him it is 90% of the AKSA, the AKSA is highly regarded amongst audiophiles. I've always wanted to hear the AKSA since its birth but never had the budget to purchase being a young DIY'er. I have a feeling the Blame ES is going to better the BAKSA but want to have a AMP to play with and tweak. I want to learn on how to use a SPICE simulator and experiment on the BAKSA since it is built on a excellent foundation.
Niss Man, thanks for that review. It great to hear that it was preferred over the symassym. Carlos himself said it would better the symassym. I built the Blame ES myself, which is said to be sonically better than the ST.
I have another amp I am putting together. I have the BAKSA boards that Rabbitz generously sent to me. According to him it is 90% of the AKSA, the AKSA is highly regarded amongst audiophiles. I've always wanted to hear the AKSA since its birth but never had the budget to purchase being a young DIY'er. I have a feeling the Blame ES is going to better the BAKSA but want to have a AMP to play with and tweak. I want to learn on how to use a SPICE simulator and experiment on the BAKSA since it is built on a excellent foundation.
No problems to use Wima capacitors...also you can use
special resistances if you want them.
regards,
Carlos
special resistances if you want them.
regards,
Carlos
Baksa may sound with more bass than Aksa.
There are some secrets in the Aksa circuit that results in wonderfull sound stage and awsome highs.
Are these Baksa from Greg Erskine?.... if made by Greg, or Rabbitz..for sure is a good thing..because they are good guys..skilled... they know what they're doing.
regards,
Carlos
There are some secrets in the Aksa circuit that results in wonderfull sound stage and awsome highs.
Are these Baksa from Greg Erskine?.... if made by Greg, or Rabbitz..for sure is a good thing..because they are good guys..skilled... they know what they're doing.
regards,
Carlos
Carlos, the boards are Greg Erkine's boards. Rabbitz had an extra pair so he generously sent them to me.
I do understand that there are secrets that are not revealed, so these BAKSA won't be a true AKSA.
Any updates on the MKII's?
Thanks!
I do understand that there are secrets that are not revealed, so these BAKSA won't be a true AKSA.
Any updates on the MKII's?
Thanks!
Thanks Rudi.. Visay 1820 is out of stock in Farnell which is my source of parts.
Regards,
C0olet
Regards,
C0olet
Yes...they are suitable too.
About secrets, not to tell secrets?
Because secrets are secrets.... and we do not tell secrets.
regards,
Carlos
About secrets, not to tell secrets?
Because secrets are secrets.... and we do not tell secrets.
regards,
Carlos
Gentlemen,
Would it be a problem, if I use 1 transformer (>300VA) to power 2 PSUs, or do I need separate transformers for each PSU?
Regards,
Nikolay
Would it be a problem, if I use 1 transformer (>300VA) to power 2 PSUs, or do I need separate transformers for each PSU?
Regards,
Nikolay
Not a problem. My prototype worked very well under this condition. Try it and evaluate the results.
Cheers,
Max.
if you have two amplifiers in the same box, then at some point both amplifiers must eventually connect to Safety Earth.
How you wire up the transformers and PSUs and amplifiers must take account of the Safety Earth connection.
A dual secondary transformer will perform differently from a centre tapped transformer and in turn both will behave differently from 4 isolated secondaries (two dual secondary transformers or a quad secondary transformer behave the same in this scenario).
The final option is two centre tapped transformers.
Each of those 4 options require to be studied in detail and the grounding adjusted to suit each option.
I have not found a universal solution that can be applied to all four transformer options.
How you wire up the transformers and PSUs and amplifiers must take account of the Safety Earth connection.
A dual secondary transformer will perform differently from a centre tapped transformer and in turn both will behave differently from 4 isolated secondaries (two dual secondary transformers or a quad secondary transformer behave the same in this scenario).
The final option is two centre tapped transformers.
Each of those 4 options require to be studied in detail and the grounding adjusted to suit each option.
I have not found a universal solution that can be applied to all four transformer options.
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It is all rigth to use a single transformer..no problems
But better results while using two separated transformers to avoid interactions.
Better audio separation, better sound stage is the result of two transformers.
But this does not mean the amplifier will not perform fine with a single transformer.
Single transformer is a cheap solution we use to apply... also you can see products using a single transformer to reduce the cost of production.
We use to search for good amplifiers to obtain better performance than these things we find in the market.... so... two transformers are better idea..and two rectifiers and two bank of condensers naturally.... you can use one, and in the future you can change this if you want.
What happens when you use a single transformer, and single rectifier and single bank of condensers?
The same voltage, the same supply will feed left and rigth amplifiers... now imagine the rigth channel have a strong bass pulse...while the left channel has bells and wistles...something soft there.... the voltage will drop because the bass pulse..and this reduction of voltage will modulate the audio you have in the left channel.... you see?.. interaction!..something we do all we can to avoid.....
Having separated supplies...one to each channel...what happens in the rigth channel will not mess with the left channel.... the easy analogy is independent suspensions in automobiles..if you have linke supensions connected by a big long axel, them what happens in the rigth wheel will move and shake the automobile left side..while independent suspensions does not do that.
regards,
Carlos
But better results while using two separated transformers to avoid interactions.
Better audio separation, better sound stage is the result of two transformers.
But this does not mean the amplifier will not perform fine with a single transformer.
Single transformer is a cheap solution we use to apply... also you can see products using a single transformer to reduce the cost of production.
We use to search for good amplifiers to obtain better performance than these things we find in the market.... so... two transformers are better idea..and two rectifiers and two bank of condensers naturally.... you can use one, and in the future you can change this if you want.
What happens when you use a single transformer, and single rectifier and single bank of condensers?
The same voltage, the same supply will feed left and rigth amplifiers... now imagine the rigth channel have a strong bass pulse...while the left channel has bells and wistles...something soft there.... the voltage will drop because the bass pulse..and this reduction of voltage will modulate the audio you have in the left channel.... you see?.. interaction!..something we do all we can to avoid.....
Having separated supplies...one to each channel...what happens in the rigth channel will not mess with the left channel.... the easy analogy is independent suspensions in automobiles..if you have linke supensions connected by a big long axel, them what happens in the rigth wheel will move and shake the automobile left side..while independent suspensions does not do that.
regards,
Carlos
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MKII will be released together the Supercharged, only in December,24
Do not wait...i am not sure it will be released or not..some folks in Brazilian forum give up to build the Dx Blame ST because the new models...so..i am thinking to cancell the new models sending them to release July 2011.
Dx Blame ST, Dx Blame MKII and Dx Blame Supercharged will be almost the same amplifier with specific features only...same sound..different input impedance and customized to difficult loads (MKII) and the Dx Blame with steróids to the powerholics or people that have non efficient speakers.
Will not offer upgrade as i want people to listen the ST first, to be sure they will not have any sonic advantage, these new models are for special cases..as i said.
Prototypes are beeing tested..a will continue to be till December, 24.
There's a lot of things running at same time here.
regards,
Carlos
Do not wait...i am not sure it will be released or not..some folks in Brazilian forum give up to build the Dx Blame ST because the new models...so..i am thinking to cancell the new models sending them to release July 2011.
Dx Blame ST, Dx Blame MKII and Dx Blame Supercharged will be almost the same amplifier with specific features only...same sound..different input impedance and customized to difficult loads (MKII) and the Dx Blame with steróids to the powerholics or people that have non efficient speakers.
Will not offer upgrade as i want people to listen the ST first, to be sure they will not have any sonic advantage, these new models are for special cases..as i said.
Prototypes are beeing tested..a will continue to be till December, 24.
There's a lot of things running at same time here.
regards,
Carlos
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Hi, would a 500VA dual secondary (18-0),(18-0) transformer be ok for a stereo amp?
My speakers are 4Ohm and quite efficient (94dB), so some reduction of power is ok.
My speakers are 4Ohm and quite efficient (94dB), so some reduction of power is ok.
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