Hermano.... he uses CCS to the VAS, and this is exactly what i have removed
in the past, in order to make sonics even better....so....he is really comparing amplifiers in other level or performance...i am afraid, not higher.
There's no doubt he is happy as a morning bird, and i hope he continue happy building, designing, creating and adapting several good amplifiers for here to the ethernity..... also, there's no doubt his amplifier may be sounding very good...well...it is a blameless..and these folks, blameless design and all their variations, are really great!
I hope he goes to the next step...produce lovely layout, even better than the ones he already produced, open a group buy and spread good Blameless designs all over the world.....and for sure, alike mine one, Chinese will make faster, cheaper and better.
saludos,
Carlos
in the past, in order to make sonics even better....so....he is really comparing amplifiers in other level or performance...i am afraid, not higher.
There's no doubt he is happy as a morning bird, and i hope he continue happy building, designing, creating and adapting several good amplifiers for here to the ethernity..... also, there's no doubt his amplifier may be sounding very good...well...it is a blameless..and these folks, blameless design and all their variations, are really great!
I hope he goes to the next step...produce lovely layout, even better than the ones he already produced, open a group buy and spread good Blameless designs all over the world.....and for sure, alike mine one, Chinese will make faster, cheaper and better.
saludos,
Carlos
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Una clarificacion Carlos
I've watched the videos you have posted and what is not clear to me if that instablity you showed, I understan was CCS's VAS floating ??? And it was clear to me the tonal difference in your videos, despite the lack of quality of mpeg file.
Saludos
Felices Fiestas
Cheers
Arturo
I've watched the videos you have posted and what is not clear to me if that instablity you showed, I understan was CCS's VAS floating ??? And it was clear to me the tonal difference in your videos, despite the lack of quality of mpeg file.
Saludos
Felices Fiestas
Cheers
Arturo
Now that my powermad listening tests are over , let me clarify the results (turning on winamp-below 1).
What I compared was a "blame ES like" voltage stage with a TRUE "blameless" compensated with TMC. I said the ES could hold it's own against a much faster blameless (1mhz unity gain point / 75v/us slew). The ES has a natural rolloff and slew limiting thanks to the bootstrapped current source. This gives a natural sound with smoother bass.
Uncle charlie.... Do you know which will stay in my living room ?? .. the "ES" type. Even as the highs are a little more pronounced on the blameless's , I like "mellow". You notice on (pix 2) the BX is different from the ES , even as it probably sounds VERY similar. I actually had to go to the Blame ES schematic to see the order of the 2 bootstrap resistors (smaller one goes to negative rail - pix 2) ... I am not a "bootstrap man" , you are !!
I had 100mv offsets with the larger resistor at the rail. Had to calculate the 2 resistors for 75 volts as well (6.8k
+ 4.7k =11500 75/11500= 6.52 ma VAS). This is another drawback , the "ES" type is not scalable without actual component changes. The CCS'ed "blameless" will hold 6.25ma (AX) from 40 -75v easily.
So each way ...CCS or not , if used properly , has advantages. Both sound AWESOME.
What I compared was a "blame ES like" voltage stage with a TRUE "blameless" compensated with TMC. I said the ES could hold it's own against a much faster blameless (1mhz unity gain point / 75v/us slew). The ES has a natural rolloff and slew limiting thanks to the bootstrapped current source. This gives a natural sound with smoother bass.
Uncle charlie.... Do you know which will stay in my living room ?? .. the "ES" type. Even as the highs are a little more pronounced on the blameless's , I like "mellow". You notice on (pix 2) the BX is different from the ES , even as it probably sounds VERY similar. I actually had to go to the Blame ES schematic to see the order of the 2 bootstrap resistors (smaller one goes to negative rail - pix 2) ... I am not a "bootstrap man" , you are !!
I had 100mv offsets with the larger resistor at the rail. Had to calculate the 2 resistors for 75 volts as well (6.8k+ 4.7k =11500 75/11500= 6.52 ma VAS). This is another drawback , the "ES" type is not scalable without actual component changes. The CCS'ed "blameless" will hold 6.25ma (AX) from 40 -75v easily.
So each way ...CCS or not , if used properly , has advantages. Both sound AWESOME.
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Yes... this is fair....you have 100 percent agreement on that
These amplifiers sounds really good.
The first time i have listened to them i dislike a lot....i do think i have made some mistake...was several years ago.
Then i tried once again.... going over my own prejudices about and i was very surprised... was the amplifier i was searching my whole life... the answer for my deep prays.... was a moment of enormous emotion.... so long time searching for "the sound"..... then i changed to the bootstrapp and found it even more sweet....but the original is more precise..better to measurements...maybe better to treble as you said.... congratulations by your amplifiers.... make them available to our forum friends....offer them as kits or boards...then you will feel even better watching them happy with your amplifiers....will be good to all of us to see them listening these good amplifiers.
Merry Christmas Pete.
regards,
Carlos
These amplifiers sounds really good.
The first time i have listened to them i dislike a lot....i do think i have made some mistake...was several years ago.
Then i tried once again.... going over my own prejudices about and i was very surprised... was the amplifier i was searching my whole life... the answer for my deep prays.... was a moment of enormous emotion.... so long time searching for "the sound"..... then i changed to the bootstrapp and found it even more sweet....but the original is more precise..better to measurements...maybe better to treble as you said.... congratulations by your amplifiers.... make them available to our forum friends....offer them as kits or boards...then you will feel even better watching them happy with your amplifiers....will be good to all of us to see them listening these good amplifiers.
Merry Christmas Pete.
regards,
Carlos
Thank you , Hugh ... and Carlo's, too.
In the spirit of the season , I would thank Capt'n GROGG (member) ( pix 1 - parts ) he will get my unused trafo and old PCB's (hopefully 1/1/11 - out of $$ now).As far as a CCS , they hold the Vbe to "tighter" tolerances , making for less Xover distortion. they also react much better with TMC and can negotiate 40 to 80v rail changes. Carlo's was right , upon actually using TMC on the bootstrapped blame .. I actually had some parasitic oscillation and a WARM zobel.
All fixed - tmc feedback (Rtmc = 1k) and the cap ratio of over 1:4 68p/470p ,, along with trimming the LTP degeneration a bit (47R to 100R - like the ES , BTW).I remember that , you wanted to shoot the amps with a double barreled shotgun before hitting the junk bin. Blameless = BAD
that was when we had disagreements. I don't want that again , we are doing the same thing , we need to build .. BUILD , build .. to really get the best. you are right about the blameless/CCS as a wonderful test amp (notice - pix 2 again "blameless" testing a PB250).(last attachment - 10th power board.. for neighbor) Simulation is nice , but you have to build to get the final "bugs" out , both electrically and soundwise.
BTW , 12 OPS boards (6 stereo pairs) , 6 power supplies and softstarts ,14 bx/ax's .. 1 1/2 gallon HCL 1/2 gal H2O2 8cu.ft FR-4 and 2000 freakin' holes later .. lots of amps ... MERRY christmas , Hugh and Charlie
I will unleash these tested and wonderful things soon with pictures,current/ voltage readings (45 -75v). They have every "trick" in the DIYA land thrown into them ... reliable, over rated and safe.EDIT :
only on AX .. I do it both ways . Charlie... can swap them in 30 seconds
OS
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Well.... all this is fair...but Hugh forgot he sent me Maya
and i have listened the Maya years ago, i do have them here and they sound very good.
It is one of the best audio amplifiers i have listened.... i have pointed some lack of treble....maybe this is what you have fixed replacing bootstrap by CCS.
I will tweak my amplifiers next year.... once again.... trying to tune the TMC once again... despite Brazilians asked me three different models to use as subwoofer amplifier.... i will work the Troyan next year too... they want new group buy...boards for Troyan.
I do think we can feed our people with different amplifiers...will keep the bootstrap to the Dx Blame models...and OS can offer CCS and TMC version.... you may offer CCS only....well...i do not know how you're doing your amplifiers now a days Hugh..but for sure they may be sounding great...the way they ever sounded.... with your unbeatable sound stage due to your copyrigthed secrets.
Maya has much better sound stage and better bass than the Dx Blame ST...mine one is my prefered because more ballanced to my personnal taste, but cannot beat in all amplifiers characteristics...beat this one in the treble, loose to that other in dinamics...beat that other one in focus and transparency and loose to another one in the voice ranges...well... it is the very best i have ever listened to..but this does not means that others cannot beat it someway.
The difference we can have when make comparison between good amplifiers are not so huge... there are details only that allow us to pick the winner....but the advantage, sometimes, remembers me a horse race. when a horse have beated the other by a nose.
When comparing the Dx Blame ES with your Maya.... 2 of my testers, my close friends in the total of 8, voted to Maya as being the best...you see..was not unanimous..... these ones still prefer the Maya and they bother me a lot asking me to give them these boards.
regards,
Carlos
and i have listened the Maya years ago, i do have them here and they sound very good.
It is one of the best audio amplifiers i have listened.... i have pointed some lack of treble....maybe this is what you have fixed replacing bootstrap by CCS.
I will tweak my amplifiers next year.... once again.... trying to tune the TMC once again... despite Brazilians asked me three different models to use as subwoofer amplifier.... i will work the Troyan next year too... they want new group buy...boards for Troyan.
I do think we can feed our people with different amplifiers...will keep the bootstrap to the Dx Blame models...and OS can offer CCS and TMC version.... you may offer CCS only....well...i do not know how you're doing your amplifiers now a days Hugh..but for sure they may be sounding great...the way they ever sounded.... with your unbeatable sound stage due to your copyrigthed secrets.
Maya has much better sound stage and better bass than the Dx Blame ST...mine one is my prefered because more ballanced to my personnal taste, but cannot beat in all amplifiers characteristics...beat this one in the treble, loose to that other in dinamics...beat that other one in focus and transparency and loose to another one in the voice ranges...well... it is the very best i have ever listened to..but this does not means that others cannot beat it someway.
The difference we can have when make comparison between good amplifiers are not so huge... there are details only that allow us to pick the winner....but the advantage, sometimes, remembers me a horse race. when a horse have beated the other by a nose.
When comparing the Dx Blame ES with your Maya.... 2 of my testers, my close friends in the total of 8, voted to Maya as being the best...you see..was not unanimous..... these ones still prefer the Maya and they bother me a lot asking me to give them these boards.
regards,
Carlos
I have tried all the different CCS's , each will have a different sound especially when used on the LTP. RED LED or double diode is nice , but will be offset by poor PSRR. Double transistor CCS's have the best simplicity to performance ratio. With a 2 resistor feed/cap (below 1/ #1 - R9/10 - C5) , 70db or more PSRR is available. When combined with even a first order capacitor multiplier , stereo separation is quite stellar
. R8 ("R") on the AX CCS is the one that doug self said to eliminate , it does increase distortion slightly but decreases H3 and adds H2 at 3.3ma tail current , also it allows a handy measurement point to adjust the CCS (CCS adj.) , 7.5V / 2200 = 3.4ma (my suggested setting).(#2- pix 1) is a fully separate high gain 2 device CCS for JUST the VAS. This really drops the THD in simulation to make even a un-TMC'ed amp have .3ppm
at 1k /50w. Both these CCS's are fed from the negative rail cap multiplier , I have seen no more than a couple uV ripple in the sources while going full out nuclear with the Mongrel PB250/AX combo ... truely a "lab amp".
I have scoped the left channel while blasting the right , NO wave at all , even at the uVolt CRO setting. Some would do the fancy regulator , this would improve things ,but would you hear it ??? A couple uV's versus .01uV @ .001R output impedance ???
I will explore this with my setup also (pix 2 - A/B) Those are separate taps (clip jumper 1 and 2).Imagine dual 80v salas shunt regulators running the AX or BX - one PURE amp "sippin' on some clean "juice". LABAMP , for sure.
Oh carlo's .. a suggestion , Add some "flyback diodes" to your amps (MUR - 460 3A -PIX 3), a nice safety factor , especially for woofers with massive magnets/ voicecoils
The "supercharged" running 4R massive woofers would benefit greatly.edit: , as far as a lack of trebel w/ bootstrap , the TYPE of bootstrap cap is VERY important , a cheap chinese 63v/100uF vs a panasonic ultra low ESR EE series can be easily heard. I'd love to try a "blackgate" , but they are discontinued , and i will not use obsolete parts in my amps
.OS
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Carlos,
I have moved on from my original Maya. The latest uses an output stage in open loop and a very different input stage. Only the VAS is the same, though with CCS.
I am convinced that any topology can be made to sound very good. And more convinced than ever that THD is just one aspect of the design; you can change sound with minor changes that hardly influence THD at all, and this is what identifies a good from an outstanding amp.
Art and science, it's a damn nuisance.....
How are you feeling after your op, Carlos, much better now?
Hugh
I have moved on from my original Maya. The latest uses an output stage in open loop and a very different input stage. Only the VAS is the same, though with CCS.
I am convinced that any topology can be made to sound very good. And more convinced than ever that THD is just one aspect of the design; you can change sound with minor changes that hardly influence THD at all, and this is what identifies a good from an outstanding amp.
Art and science, it's a damn nuisance.....
How are you feeling after your op, Carlos, much better now?
Hugh
Yep....you are right...you was always rigth
I'm 33 kilos less heavy...feeling much better.
Well, i thank you both by the kind attention, but i will go away to take care of my threads and amplifiers...when you are more than enought to take care of yours.
My presence may interrupy the dinamics and sequence,... and as Ed La Fontaine said...will create doubts about what to build...and this is not good.
au revoir...uncle Charlie gone!
Carlos
I'm 33 kilos less heavy...feeling much better.
Well, i thank you both by the kind attention, but i will go away to take care of my threads and amplifiers...when you are more than enought to take care of yours.
My presence may interrupy the dinamics and sequence,... and as Ed La Fontaine said...will create doubts about what to build...and this is not good.
au revoir...uncle Charlie gone!
Carlos
Yes , and damn hard work... too
Different capacitors , a small change in the tail resistance , FET or CFP input pair , even (secret) nested feedback in the input stage. All small changes , all done so easily and gracefully on a modular system. I have actually pulled off over a dozen circuit changes and listened to them in a hour.
These won't alter total THD in any big way , but look at the 10K FFT (H2-11) and "cause and effect" will show itself bigtime.
All this experience and knowledge at DIYA has been wonderful , but one must make his own path. Setup of an output stage is both exciting and worrisome . There is the "lightbulb method" or just the "cross your fingers and hope for the best" method. In (PIX 1) , I start with a known good voltage stage (A BX in this instance) and mount the main drivers ( PIX 1 - A/B - mje15034/35) , attaching small temporary heatsinks to "keep things together" . I also halve the main driver Re (100R = 2X 47R) and tack the 2 - 1/4 watt 47R's from the driver emitter rails to the output rail (PIX 1- C and D) . This creates a small 10 watt AB amplifier capable of driving a small speaker or headphones w/ a 220r resistor.
I also Fuse the bridge rectifier (PIX 2) with 2 1/4 watt 10R resistors , these can even be used as a safety factor with the "1 pair output test" (main outputs). You can also set your V BIAS (Vbe) until you reach + and - 550 millivolts (pix 3) in preperation for the first pair main outputs, this will bring most outputs into an unbiased, (class B) state.
At this point you are ready for 1 pair of main outputs .... stuff them and attach to a temporary heatsink (larger of course). After doing the steps above , you should be slightly below the class AB point (Class B) ... 0 mv/ma. A couple turns on your Vbe you should see a millivolt or two across your .22/.27R emitter resistor(s). I bias to 17-18mv on my .27R's and 15mV on any .22R ouput stages. From here , I stuff all my output devices (after doing a Hfe test for a "raw" match. On my 8 device boards , Re readings within a millivolt on all 8 devices assure me of good current sharing. The basic Vbe operation can be tested in "test mode" with a lighter.. 1/2 second "flick of the bic"
, should drastically reduce the bias ... blowing on the Vbe tranny will bring it back up just as fast. A final test on the permanent heatsink is simple , After thermal greasing and running/inspecting the amp ... run a hairdryer on the heatsink. 60+ C is a good upper limit and If you live in a cold climate , put the whole amp outside in the subzero (-10C). The PB250 in the pix will stay between 15 -18mv per Re ALL THE WAY from 15C to 60C. When heating from the hairdryer it will "overshoot" 17mv Re then go back to 15-16 as the hairdryer brings it up to 60C. A much worse scenerio than anything in the home or even what the great outdoors could subject it to. When I last listened to the old PB250's , they were at 17mV Re .. the same as I set them to 4 months ago. Thermal issues and durability are among the most important issues , NO burning amps around here !!
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I've been going the rounds with my headphone amp constantly.
Wow, this sounds awesome, inspiring, beautiful, emotional!
Okay, I changed something, clarity is better, I can hear more stuff...
Okay, I changed something else and it's clearer, but it sounds like crap...
OMG, this sound makes me want to puke (good instrument separation though...)
Hey, it sounds good again...
etc.
Lacking a science for this is sad, because I don't know what improves and why, and sometimes the change is a dubious one that I wouldn't trust expensive headphones with.
OT, but I got an awesome laserdisc player. I am SO happy. I got a laserdisc titled "Lee Ritenour and Dave Grusin, Live from the Record Plant". AMAZING. It's a Pioneer CLD-1030, from 1989, I demo'd all the other players and this was clearly the best... For $20, in fine condition!!! So even if I lack good laserdiscs, it is still a CD player, which costed half as much the players at walmart but is many times more valuable. Now I need to get my Soraya working. Hugh, are the TO92's important or can I use the KSC1845/A992 for the Soraya boards you gave me?
- keantoken
Wow, this sounds awesome, inspiring, beautiful, emotional!
Okay, I changed something, clarity is better, I can hear more stuff...
Okay, I changed something else and it's clearer, but it sounds like crap...
OMG, this sound makes me want to puke (good instrument separation though...)
Hey, it sounds good again...
etc.
Lacking a science for this is sad, because I don't know what improves and why, and sometimes the change is a dubious one that I wouldn't trust expensive headphones with.
OT, but I got an awesome laserdisc player. I am SO happy. I got a laserdisc titled "Lee Ritenour and Dave Grusin, Live from the Record Plant". AMAZING. It's a Pioneer CLD-1030, from 1989, I demo'd all the other players and this was clearly the best... For $20, in fine condition!!! So even if I lack good laserdiscs, it is still a CD player, which costed half as much the players at walmart but is many times more valuable. Now I need to get my Soraya working. Hugh, are the TO92's important or can I use the KSC1845/A992 for the Soraya boards you gave me?
- keantoken
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Yes , KT .. the sim can't predict sound. My 2.2k tail resistor was a audible change that the sim did not predict fully. the failure of both my CX and initially my BX w/ TMC .. blew me away !!
By playing with the BX , a single miller of 68p give magical sound (strong emotions , anyone ) .... listen for hours. The AX went as predicted , i just had to decrease the TMC feedback a little and go for a 1:4.7 ratio (100/470p) . your old AX I gave you , can be made to match my new one exactly , just put in your 2 caps/560-820R resistor ... WOW WOW ... what an amp. It has the clearest, non-fatiquing sound one could ask for. Oh , you have soraya's , bet the TMC'ed AX's can match them..
HEY - OS....... Ya gotta have a couple of little fires every now and again. You live in the Great Smoky Mountains and we get a lot of tourist that wanna see "Smoky Mountains". Well - that and whiskey stills, "Mountain Men", and maybe a little Bluegrass or County & Western music being played at the local ho-down.
Sooooo - smoke a couple of amps and open up a tourist spot!!
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The last few weeks I have been following the treads here on the Forum in order to build an Amplifier
First it was the Goldmund tread then I order the boards in the hope that there are some people build these Amplifiers so that I could learn something from you all here to build this Amplifier.
Now I follow this tread of OS and hope that there will now a final product comes, so that we can order here the printed circuit boards.
As I have already reported I am not an Electro engineer but with a little help from you all for example, how I should measure the circuit, surely it should be feasible in order to build this amplifier myself.
It seems to me in any case a challenge to build this amplifier.
There are several designs but my feeling says that this should be THE Amplifier.
I also build the Shigaclone CD Transport myself with a little help from other diyers.
Hopefully there will soon be a group sales made, to order these boards.
Regards,
Rudy
P.s. Sorry for my bad English
First it was the Goldmund tread then I order the boards in the hope that there are some people build these Amplifiers so that I could learn something from you all here to build this Amplifier.
Now I follow this tread of OS and hope that there will now a final product comes, so that we can order here the printed circuit boards.
As I have already reported I am not an Electro engineer but with a little help from you all for example, how I should measure the circuit, surely it should be feasible in order to build this amplifier myself.
It seems to me in any case a challenge to build this amplifier.
There are several designs but my feeling says that this should be THE Amplifier.
I also build the Shigaclone CD Transport myself with a little help from other diyers.
Hopefully there will soon be a group sales made, to order these boards.
Regards,
Rudy
P.s. Sorry for my bad English
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Both BX and AX (wow!!) are approved. (winners and losers)
I have both final (new PB250-H) channels done (PIX-1). Yesterday I ran my AX/BX's on one old one and the one new one.
I don't care if carlo's (DX) gets mad on this one , but the current sourced, TMC'ed blameless's really exceed any "ES" style amp. In other word , the mighty AX blows the "ES" away ..
Don't get me wrong , but the BX/ES was tried with multiple compensations , I can even adjust the tail current while in operation. Matched pair with .5mv offset BEFORE adjustment , faster devices...
They scoped perfect , no ringing or errata ... and they sound better than any symasym or even the luxman clone. All these VB's sound better than my discrete OEM receiver (I still have one ) , but the bootstrap restricts slew , (amp is slower by design). A strange thing about the bootstrap , it sounded better after it was ran hard ( bedding down ?? )
Me and a few musician friends (lots of them in pigeon forge , tenn.) listened to the BX's with a variety of music (classic , classic rock , jazz) for hours. they had "strong emotions" and wanted to buy some..
I said "wait !" ... screwed the AX's in and cranked it up AGAIN. WOW !!!
was the response. They were astounded that the same amp could even sound better. I told them these were the idea of a dead english guy (Baxandall) , who had his papers released by another english author (D. Self).
So , as an audiophile , and designer who has built them all (pokemon) , the AX is the "holy grail" .... it's sound won't just give "strong emotions" but will absolutely "knock your socks off". I "fine tuned" TMC to MY amp (100/470p - 820R{Rtmc} ) , the bass is even better than the BX/ES now. (absolute final schema below - PIX 2).
I really like the BX's (PIX 3) , they will go to the "doghouse" (barn/lab) hooked into the NEW 2XPB60 (dual modular 60w test board) , I still have "strong emotions" for these ... but they can't match the AX. Another thing , the AX really ran away With the ball at high volumes (massive sound stage - impressive bass) , this must be TMC correction.
I will work hard now to turn all this work into concise projects , a few updates are required since these are REAL now.
OS
I have both final (new PB250-H) channels done (PIX-1). Yesterday I ran my AX/BX's on one old one and the one new one.
I don't care if carlo's (DX) gets mad on this one , but the current sourced, TMC'ed blameless's really exceed any "ES" style amp. In other word , the mighty AX blows the "ES" away
..Don't get me wrong , but the BX/ES was tried with multiple compensations , I can even adjust the tail current while in operation. Matched pair with .5mv offset BEFORE adjustment , faster devices...
They scoped perfect , no ringing or errata ... and they sound better than any symasym or even the luxman clone. All these VB's sound better than my discrete OEM receiver (I still have one
) , but the bootstrap restricts slew , (amp is slower by design). A strange thing about the bootstrap , it sounded better after it was ran hard ( bedding down ?? )Me and a few musician friends (lots of them in pigeon forge , tenn.) listened to the BX's with a variety of music (classic , classic rock , jazz) for hours. they had "strong emotions" and wanted to buy some..
I said "wait !" ... screwed the AX's in and cranked it up AGAIN. WOW !!!
was the response. They were astounded that the same amp could even sound better. I told them these were the idea of a dead english guy (Baxandall) , who had his papers released by another english author (D. Self).
So , as an audiophile , and designer who has built them all (pokemon) , the AX is the "holy grail" .... it's sound won't just give "strong emotions" but will absolutely "knock your socks off". I "fine tuned" TMC to MY amp (100/470p - 820R{Rtmc} ) , the bass is even better than the BX/ES now. (absolute final schema below - PIX 2).
I really like the BX's (PIX 3) , they will go to the "doghouse" (barn/lab) hooked into the NEW 2XPB60 (dual modular 60w test board) , I still have "strong emotions" for these ... but they can't match the AX. Another thing , the AX really ran away With the ball at high volumes (massive sound stage - impressive bass) , this must be TMC correction.
I will work hard now to turn all this work into concise projects , a few updates are required since these are REAL now.
OS
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