So I'll build me one stereo pair of these, first serious amp project. 
Nothing too strenuous here, just after a few opinions. Firstly, cooling: how about these stock Intel LGA775 heatsinks, one per MOSFET? Particularly the one attached, as I've already got two of them, and they are frequently sold second hand cheap, they come bundled with CPUs that often get after market heatsinks.
I'd have them protruding halfway through the top panel, and have a thermistor controlled 120mm silent (6 to 14 dBa) fan driving air in, forcing it out through the 4 heatsinks (and elsewhere if the flow rate makes it too noisy).
The enclosure will be matt black anodised aluminium, extruded and diamond plate.
I've scored 150 25V 2200uF electrolytic polar axial lead caps for $25NZ (that's $3.03 per faradvolt, I think), so they can be the power supply, and I can make 8 cap banks of 39600 uF, plenty enough for this project right? They are gold coloured, so I may make a feature of them, expose them along the front and sides with narrow gaps to actively cool them.
Also, just so I'm clear, a question regarding the input, amping is quite a new field to me.
Balanced being required, and unbalanced being everything I own, It would be wise to build into it a B1 JFET buffer, correct?
Furthermore, as is customary in my other major DIY area, PC Case Modding, a worklog/thread is commonly made to record and show-off progress, so should I make one for this amp, and where should I?
Cheers, Jesse.
Nothing too strenuous here, just after a few opinions. Firstly, cooling: how about these stock Intel LGA775 heatsinks, one per MOSFET? Particularly the one attached, as I've already got two of them, and they are frequently sold second hand cheap, they come bundled with CPUs that often get after market heatsinks.
I'd have them protruding halfway through the top panel, and have a thermistor controlled 120mm silent (6 to 14 dBa) fan driving air in, forcing it out through the 4 heatsinks (and elsewhere if the flow rate makes it too noisy).
The enclosure will be matt black anodised aluminium, extruded and diamond plate.
I've scored 150 25V 2200uF electrolytic polar axial lead caps for $25NZ (that's $3.03 per faradvolt, I think), so they can be the power supply, and I can make 8 cap banks of 39600 uF, plenty enough for this project right? They are gold coloured, so I may make a feature of them, expose them along the front and sides with narrow gaps to actively cool them.
Also, just so I'm clear, a question regarding the input, amping is quite a new field to me.
Balanced being required, and unbalanced being everything I own, It would be wise to build into it a B1 JFET buffer, correct?
Furthermore, as is customary in my other major DIY area, PC Case Modding, a worklog/thread is commonly made to record and show-off progress, so should I make one for this amp, and where should I?
Cheers, Jesse.
Attachments
Pikefish said:
A stock B1 will not give you balanced outputs - you'd have to rework the design as a phase-splitter first. It would be best to execute this as a separate preamp with its own power supply, though it is feasible to add it as a new front end to the amp itself. But if you don't otherwise need a balanced-out preamp, the simplest thing is probably to add good line transformer to the front of each amp.
Yeah, I realise now the B1 doesn't seem to have the right number of plugs for balanced operation. Haven't got the foggiest idea how to rework the design as a phase-splitter, so I'd then run the B1's out through a pair of line transformers, and have the last switch position route to a XLR balanced input, for upgradability. Maybe make it also able to function as an output from the preamp.
Is this then all the volume control I need? Going parts shopping next weekend and can't make another trip for a long time.
Cheers.
Is this then all the volume control I need? Going parts shopping next weekend and can't make another trip for a long time.
Cheers.
gah double post
Another question, regarding the power transformer, could one get away with using a 160VA transformer instead, if the supply caps were 39600uF each? Would also a soft-starter be needed, pointless, or unsufficient?
I'd ask Mike at his blog this sort of thing, but then the answer's not here for the benefit of others.
Cheers, Jesse.
Another question, regarding the power transformer, could one get away with using a 160VA transformer instead, if the supply caps were 39600uF each? Would also a soft-starter be needed, pointless, or unsufficient?
I'd ask Mike at his blog this sort of thing, but then the answer's not here for the benefit of others.
Cheers, Jesse.
Circlomanen, please write to me about the suggested current
and also a supply suggestion.
panzertoo@yahoo.com
You have not opened the thread...reason why go direct to my mail adress.
regards,
Carlos
and also a supply suggestion.
panzertoo@yahoo.com
You have not opened the thread...reason why go direct to my mail adress.
regards,
Carlos
Mind changed because i have those fets... the Ciclomanen ones
FETs are problem here in my home..hard to find them.
I do not appreciate class A, also do not appreciate Fets, but this circuit call my attention because very simple....no CCS, no lamps in series... very simple.
A pitty i will have to use a transformer or phase splitter into the input... i think the circuit will loose the charm to me if i will have the need to install a transformer or another stage as phase splitter.
If needed... i will stop to build immediatelly.
The nice things is that it is simple...if need something into the input...well... will not be simple anymore..will look alike others.
And i use to change my mind... and daily my friend... this means evolution brother!
regards,
Carlos
FETs are problem here in my home..hard to find them.
I do not appreciate class A, also do not appreciate Fets, but this circuit call my attention because very simple....no CCS, no lamps in series... very simple.
A pitty i will have to use a transformer or phase splitter into the input... i think the circuit will loose the charm to me if i will have the need to install a transformer or another stage as phase splitter.
If needed... i will stop to build immediatelly.
The nice things is that it is simple...if need something into the input...well... will not be simple anymore..will look alike others.
And i use to change my mind... and daily my friend... this means evolution brother!
regards,
Carlos
Attachments
Will this works EUVL?
The signal entering the way i have shown into the black and white image posted?
I found this image and have readed Nelson Pass text entirelly and felt sad.... maybe will not work my way.
Interesting.... damn simulators!...worked into the simulator... will it work real life?
Do not be sad because i have not accepted your past idea EUVL.... be friendly and inform me if will work or not.
The amplifier may be good or not good... with your pointing it or without you pointing it.
You are not an amplifier, so, do not feel bad or sad...you are human.
regards,
Carlos
The signal entering the way i have shown into the black and white image posted?
I found this image and have readed Nelson Pass text entirelly and felt sad.... maybe will not work my way.
Interesting.... damn simulators!...worked into the simulator... will it work real life?
Do not be sad because i have not accepted your past idea EUVL.... be friendly and inform me if will work or not.
The amplifier may be good or not good... with your pointing it or without you pointing it.
You are not an amplifier, so, do not feel bad or sad...you are human.
regards,
Carlos
Attachments
Audio is subjective, good for me may be bad for you
Depends home, speakers, ears, musical taste, presence or absence of absortion materials, reflective materials and so on.
I want to try the amplifier, but for sure will not be playing for ever in my home...just to listen, to evaluate by myself, as a research.
Too much hot to my place....today here is 31 degrées celsius...no wind..awfull temperature...imagine now a 55 degrées celsius heatsinks here!
The construction is stopped for a while...could be ready to go today, but waiting forum folks informations about this Balanced and unbalanced input.
Can i use the way shown into the black and white image posted folks?
thank you in advance by your kindness.
regards,
Carlos
Depends home, speakers, ears, musical taste, presence or absence of absortion materials, reflective materials and so on.
I want to try the amplifier, but for sure will not be playing for ever in my home...just to listen, to evaluate by myself, as a research.
Too much hot to my place....today here is 31 degrées celsius...no wind..awfull temperature...imagine now a 55 degrées celsius heatsinks here!
The construction is stopped for a while...could be ready to go today, but waiting forum folks informations about this Balanced and unbalanced input.
Can i use the way shown into the black and white image posted folks?
thank you in advance by your kindness.
regards,
Carlos
Attachments
I have assembled and found it good
Treble is not so mufled as the DOZ and others class A i have in my home.
Do not pick radio frequency when we put finger into the input
Was stable and easy to adjust... a pitty, too much hot... increased current to 1.5 A each side and i felt the unit would melt...poor transistors very hot to the touch.
I found sound nice, excelent bandwidth, clear treble, mids and bass...nice..very nice.
And i have tried several input circuits, transformers, inverters using transformers, transistors inverting, direct plugged..well..tried many ways... and i found good in many ways... some very small noise into wrong ways but audio remains nice.
I think the unit will sound great when using the good pre amplifier to match the unit.
I would be happy with a sligtly bigger high end...yes, have tried headphones and different speakers.. and with those speakers and headphones i have some class AB here that produces more treble, better high end... despite the difference is not so big.
I felt distortion very low...very good..but when you increase the input audio..then, while clipping, into this moment distorts awfully.... of course!
Will be dismounted...to much hot to my home... was a nice experience
thank you the attention (not so big)
There's a video into youtube... the unit was playing.
http://www.youtube.com/watch?v=OhcuGzPg1qc
regards,
Carlos
Treble is not so mufled as the DOZ and others class A i have in my home.
Do not pick radio frequency when we put finger into the input
Was stable and easy to adjust... a pitty, too much hot... increased current to 1.5 A each side and i felt the unit would melt...poor transistors very hot to the touch.
I found sound nice, excelent bandwidth, clear treble, mids and bass...nice..very nice.
And i have tried several input circuits, transformers, inverters using transformers, transistors inverting, direct plugged..well..tried many ways... and i found good in many ways... some very small noise into wrong ways but audio remains nice.
I think the unit will sound great when using the good pre amplifier to match the unit.
I would be happy with a sligtly bigger high end...yes, have tried headphones and different speakers.. and with those speakers and headphones i have some class AB here that produces more treble, better high end... despite the difference is not so big.
I felt distortion very low...very good..but when you increase the input audio..then, while clipping, into this moment distorts awfully.... of course!
Will be dismounted...to much hot to my home... was a nice experience
thank you the attention (not so big)
There's a video into youtube... the unit was playing.
http://www.youtube.com/watch?v=OhcuGzPg1qc
regards,
Carlos
Attachments
Well, back from RMAF. The show was fun, but every five years or so is enough for me. I'll tend to email, etc. over the next few days, and the "Antimatter" boards will be measured this weekend. Thanks for your patience.
I'm a fairly quiet person and not prone to schmoozing, but I did stop by to see the Parts Express guys and I made a strong appeal for them to offer us some heatsinks in their catalog. They seemed receptive.
Mike
I'm a fairly quiet person and not prone to schmoozing, but I did stop by to see the Parts Express guys and I made a strong appeal for them to offer us some heatsinks in their catalog. They seemed receptive.
Mike
There are two parts to the article: the first is the article, and the second has complete details on the build, including a parts list, sources and lots of pictures. Be sure to check it out if you haven't already.
I purchased my heatsinks from Newark. Digikey offers a similar profile, but they charge twice as much for it.
The T-slot profile used is also offered as a standard profile by many of the manufacturers. I'm hoping to convince Parts Express to offer it in a few different lengths as it would be useful for many of the PassDIY projects, and depending on configuration, you don't even need to drill and tap holes.
I purchased my heatsinks from Newark. Digikey offers a similar profile, but they charge twice as much for it.
The T-slot profile used is also offered as a standard profile by many of the manufacturers. I'm hoping to convince Parts Express to offer it in a few different lengths as it would be useful for many of the PassDIY projects, and depending on configuration, you don't even need to drill and tap holes.