pcb's are done, capacitors are connected together p2p.. now, i am rethinking how to put everything on a mdf board, connect it and turn it on...
the transformer is huge, heatsinks are not small also so it will be a huge amplifier (AGAIN!!!
)... WAF will be low here
anyway - the dimension of the amplifier will be 45*50cm (W*D)..
everything mentioned is fine - the only thing i am worried about is if it will be working - because of that problem of mirrored pcb's, human mistake factor and other stuff...
hopefully it will be fine...
...
the transformer is huge, heatsinks are not small also so it will be a huge amplifier (AGAIN!!!
)... WAF will be low here anyway - the dimension of the amplifier will be 45*50cm (W*D)..
everything mentioned is fine - the only thing i am worried about is if it will be working - because of that problem of mirrored pcb's, human mistake factor and other stuff...
hopefully it will be fine...
...
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
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Yesterday I have checked for the last time my PCB's... They seem to be o.k... Parts seem to be where they have to be. Transistor orientation also. So, I am ready to mount them on heatsinks.
Few days ago I started to put the "monster" together on a piece of mdf board...
It will not look nice but hopefully it will sound nice - as I have said before, this is not a project for pleasure and to look nice but rather a project out of need from parts "out of my junkbox" to have something to listen too...
From what I can say right now, I suspect it will probably sound better than anything I have had at my home related DIY - let's hope it will be like that... Pictures are on the way as soon as possible....
Few days ago I started to put the "monster" together on a piece of mdf board...
It will not look nice but hopefully it will sound nice - as I have said before, this is not a project for pleasure and to look nice but rather a project out of need from parts "out of my junkbox" to have something to listen too...
From what I can say right now, I suspect it will probably sound better than anything I have had at my home related DIY - let's hope it will be like that
... Pictures are on the way as soon as possible....
It will sound delicious and you will feel satisfied and happy
Your construction, good ideas to the supply, huge condensers, for sure will contribute to the final result.
Observing your heatsinks. i feel they will manage to cool down your power transistors.
Mirrored boards may induce you to errors....but you will find them all.
regards,
Carlos
Your construction, good ideas to the supply, huge condensers, for sure will contribute to the final result.
Observing your heatsinks. i feel they will manage to cool down your power transistors.
Mirrored boards may induce you to errors....but you will find them all.
regards,
Carlos
O.K. i have connected it yesterday into the system. First few notes were not that good - the sound was not open enough, the magic was not there... It was like playing through the curtain. So, i decided to simply cut of the big capacitors (39.000uF - one for each rail) i had in the filtering. The sound was better - a lot better... Than, i decided to cut down the bias current from 870mA down to 230mA... And that was it - magic was there, soundstage, details, realistic voice - very very good. I am impressed...
Still, i have to change rectifier bridge if possible (to change Semikron industrial bridge with ultrafast diodes (if i find enough of them - i think i have only 3 pieces that are 2*10A)....
I only regret that it is not full power (50W/8ohm) but o.k....
.......
Regarding sound... It is, from what i could hear while my son was sleeping, the best thing i have ever made... It is few steps better than Studio i had before... Better details, bass is smaller in scale but very good, soundstage is also very nice - not a huge difference but very notable one. Not hard to recognize it...
When playing near class A (and with those big cap's connected also) it was sounding really not that good. I suspect that in class A it will not need filtering capacitors that big like single ended amplifiers need - i was having around 13.000uF per rail when i disconnected those big ones - not much and hum was barely noticable. So, PSRR seems also to be really good.
What can i say Carlos - really a good amplifier. I would like to make another one with full power (not this smaller scale version) and to put it inside the box and finish the story...
Carlos - congratulations.. very nice job, very nice amplifier... I will have to change the title of this page to "class AB" since it is not working in class A at all
(pictures can be found on my home page - not to upload them twice)....
Still, i have to change rectifier bridge if possible (to change Semikron industrial bridge with ultrafast diodes (if i find enough of them - i think i have only 3 pieces that are 2*10A)....
I only regret that it is not full power (50W/8ohm) but o.k....
.......
Regarding sound... It is, from what i could hear while my son was sleeping, the best thing i have ever made... It is few steps better than Studio i had before... Better details, bass is smaller in scale but very good, soundstage is also very nice - not a huge difference but very notable one. Not hard to recognize it...
When playing near class A (and with those big cap's connected also) it was sounding really not that good. I suspect that in class A it will not need filtering capacitors that big like single ended amplifiers need - i was having around 13.000uF per rail when i disconnected those big ones - not much and hum was barely noticable. So, PSRR seems also to be really good.
What can i say Carlos - really a good amplifier. I would like to make another one with full power (not this smaller scale version) and to put it inside the box and finish the story...
Carlos - congratulations.. very nice job, very nice amplifier... I will have to change the title of this page to "class AB" since it is not working in class A at all
(pictures can be found on my home page - not to upload them twice)....
You are the first one that make it class A..and i am glad you have tested
I trust in your evaluation and i respect your skills..so..what you are saying is the real truth and people can trust and use your thougths as reference to their own decisions.
I am very happy you have appreciated...i was not sure about sonics, as i have never tried it in class A...was only simulated and looked good...but..simulator does not sound!
Thank you very much by your detailed explanations, there are folks that goes to my personnal email inbox asking things about class A...you know these amplifiers have special appeal to a lot of guys.
My amplifier will be producing sound in your home, and this is very good to my heart..you are a very old friend..we use to have good conversations since 2004.... i am honored with my amplifier playing inside your home.
Enjoy and let us know your further improvements and decisions taken..... then, please, visit the Dx Blame builders thread if you keep it in class AB, to give them, the AB addicted folks, informations about your progress.
regards,
Carlos
I trust in your evaluation and i respect your skills..so..what you are saying is the real truth and people can trust and use your thougths as reference to their own decisions.
I am very happy you have appreciated...i was not sure about sonics, as i have never tried it in class A...was only simulated and looked good...but..simulator does not sound!
Thank you very much by your detailed explanations, there are folks that goes to my personnal email inbox asking things about class A...you know these amplifiers have special appeal to a lot of guys.
My amplifier will be producing sound in your home, and this is very good to my heart..you are a very old friend..we use to have good conversations since 2004.... i am honored with my amplifier playing inside your home.
Enjoy and let us know your further improvements and decisions taken..... then, please, visit the Dx Blame builders thread if you keep it in class AB, to give them, the AB addicted folks, informations about your progress.
regards,
Carlos
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Carlos - for sure - it will stay in class AB.. it simply sounds better to me in my system....
i will rethink maybe to put it further down - maybe down to 100mA bias.... not sure - i am thinking to do that....
what needs to be done here now is to change the rectifier bridge for a set of ultrafast softrecovery diodes... 20A each.
this would be very good thing to do...
and as I said - i would really like to build it to full power one day as i think with full power it will show it's best ....
so, guys - i can say for sure - go for the original full power version - forget class A here... class AB sounds better to me in my system...
***********
my system where i am listening Blame right now:
Shigaclone - cd player,
Caliente - 12B4A preamplifier,
Blame ST - scaled down version - down to +/-21Vdc and 230mA of bias current,
Rega Ara - speakers...
cables are:
Siltech ST-G48 G3, Kimber Cable Silver Streak, Klotz MC5000 - interconnect cables,
Oelbach LS214 - speaker cable
i will rethink maybe to put it further down - maybe down to 100mA bias.... not sure - i am thinking to do that....
what needs to be done here now is to change the rectifier bridge for a set of ultrafast softrecovery diodes... 20A each.
this would be very good thing to do...
and as I said - i would really like to build it to full power one day as i think with full power it will show it's best ....
so, guys - i can say for sure - go for the original full power version - forget class A here... class AB sounds better to me in my system...
***********
my system where i am listening Blame right now:
Shigaclone - cd player,
Caliente - 12B4A preamplifier,
Blame ST - scaled down version - down to +/-21Vdc and 230mA of bias current,
Rega Ara - speakers...
cables are:
Siltech ST-G48 G3, Kimber Cable Silver Streak, Klotz MC5000 - interconnect cables,
Oelbach LS214 - speaker cable
Zen Mod, thanks for participating here - my schematic is not exactly like the one you posted and it is not final - it is now a leftover from what had to be a class A amplifier... right now it is working in class AB and it will need to be retuned but i don't have time to do it unfortunately... also the inductors are a leftover from what was suposed to be a class A power supply... probably it would be better to remove them i agree... but, time is limited so it will also have to wait... Carlos also suggested some mods man, i would need a 48 hours day heheheheheheheh
anyway, i will return to the amplifier after a while to tune it better...
those 39kuF were really a problem - also in soem previous amps i made... they are really slow sounding - don't know why i put them here - they were bypassed with smaller caps and also some small Cerafines but it didn't help ... anyway, they are out now ... no need for them...
- my schematic is not exactly like the one you posted and it is not final - it is now a leftover from what had to be a class A amplifier... right now it is working in class AB and it will need to be retuned but i don't have time to do it unfortunately... also the inductors are a leftover from what was suposed to be a class A power supply... probably it would be better to remove them i agree... but, time is limited so it will also have to wait... Carlos also suggested some mods man, i would need a 48 hours day heheheheheheheh anyway, i will return to the amplifier after a while to tune it better...
those 39kuF were really a problem - also in soem previous amps i made... they are really slow sounding - don't know why i put them here - they were bypassed with smaller caps and also some small Cerafines but it didn't help ... anyway, they are out now
... no need for them...- Status
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