Hi,
This is my 1st message to this huge forum.
I am currently busy with making the so called "Killatone" speakers to complement my current 2.1 monitoring system.
I have already built a "kit" chip amp (what I could use for the speakers), but I like to go for something nicer.
Originally I have considered to build the Zen V4, but as far as I understand the V9 is better.
1st of all I like to know what should I build?
Next: once decided what to build I like to aks you ladies and gens for help, guidances how to realize succesfully this project.
Currently the enclosure is already in design phase = 2 rather big coolblocks on the sides, fully metal enclosure.
Any help and good word is welcome.
trif.
This is my 1st message to this huge forum.
I am currently busy with making the so called "Killatone" speakers to complement my current 2.1 monitoring system.
I have already built a "kit" chip amp (what I could use for the speakers), but I like to go for something nicer.
Originally I have considered to build the Zen V4, but as far as I understand the V9 is better.
1st of all I like to know what should I build?
Next: once decided what to build I like to aks you ladies and gens for help, guidances how to realize succesfully this project.
Currently the enclosure is already in design phase = 2 rather big coolblocks on the sides, fully metal enclosure.
Any help and good word is welcome.
trif.
Start with Z1? hm, is it really the way to go? Can I not imeediately go with V4 or V9?
I remember when i studied physics at the univ we still had to know very well tubes, although at that time some chip amps were already coming into the market.
I would go for a tube amp, push-pull with Lundahl trafo, but I do not want to work with the high voltages (as I do not have so much expirience, although the concept is very elegant, and I believe the sound is also nice).
So, therefore my interest is in the ZENs or any other solid state amp.
trif.
I remember when i studied physics at the univ we still had to know very well tubes, although at that time some chip amps were already coming into the market.
I would go for a tube amp, push-pull with Lundahl trafo, but I do not want to work with the high voltages (as I do not have so much expirience, although the concept is very elegant, and I believe the sound is also nice).
So, therefore my interest is in the ZENs or any other solid state amp.
trif.
OK.
It will be ZV4. In one enclosure 2 channels.
I am currently busy with the enclosure design/preparation for manufacturing.
Is it better to go for 2 transformers (one per channel)?
I like to have some GUIDANCES on that, because the enclosure size will be mainly determined by the number of transformers (1 or 2).
Currently I have one nice torroid trafo.
trif.
It will be ZV4. In one enclosure 2 channels.
I am currently busy with the enclosure design/preparation for manufacturing.
Is it better to go for 2 transformers (one per channel)?
I like to have some GUIDANCES on that, because the enclosure size will be mainly determined by the number of transformers (1 or 2).
Currently I have one nice torroid trafo.
trif.
OK. I am going to include into the enclosure design several (extra) holes (kind of universal bottom plate of the enclosure) for 1 or 2 trafo scenario. Yes, I know I could drill any extra holes if it is required, but I like to go for a "clean" approach, so any input on this is welcome.
On the coolblocks: I see on the Z4V sechamatics, that the PCB is grounded via the R20, 22Ohm/3W rezistor. Do I have to forseen a grounding point on the coolblock for this rezistor, or not (or on the bottom plate). If yes, is its position important, or can be anywhere on the coolblock?
trif.
On the coolblocks: I see on the Z4V sechamatics, that the PCB is grounded via the R20, 22Ohm/3W rezistor. Do I have to forseen a grounding point on the coolblock for this rezistor, or not (or on the bottom plate). If yes, is its position important, or can be anywhere on the coolblock?
trif.
trifidmaster said:
I do not exactly know why R20.
But, I believe that Nelson Pass always thinks of the "safety first" for all diyers. The ground line of the circuit is to be connected to the chassis (the protective earth). By the way, the ground line is quite long so that the line could have any problem in the middle of the line. Therefore, it seems that the right end (PSU side) ground point is connected to the chassis with the bridge diode, meanwhile the left end (the inputside) ground point is also connected to the chassis but this time with R20. Double safety . . .
R20 is to be connected from the left end ground point to any place of chassis.
Regards
As decided my "1st" amp will be the ZV4.
Do I need to consider venting holes/perforation in the bottom plate/top plate?
I have seen in several projects, that conically shaped metal legs are used for the enclosures. Is there a reason for that other than astetics? What material should I use for these legs?
trif.
Do I need to consider venting holes/perforation in the bottom plate/top plate?
I have seen in several projects, that conically shaped metal legs are used for the enclosures. Is there a reason for that other than astetics? What material should I use for these legs?
trif.
OK. I will design into the bottom plate 2 rows of venting holes, and perhaps 4 rows on the the top plate.
New design will follow.
Orginally I planned to do the front/bak/top/bottom plates from steanless steal, but I will go for aluminum for the whole enclosure. I will brush the plates, and anodize them (natural color). I know anodization is a rather good insluator. So, I like to know what places should I leave not anodized on the plates.
trif.
New design will follow.
Orginally I planned to do the front/bak/top/bottom plates from steanless steal, but I will go for aluminum for the whole enclosure. I will brush the plates, and anodize them (natural color). I know anodization is a rather good insluator. So, I like to know what places should I leave not anodized on the plates.
trif.
Emm, since the design of that chassis is quite conventional - I'm not quite sure how come you have so many un-closed issues about it?
It's smart to use some vent openings, it's smart to anodize the chassis to black (for higher heat "radiation"), the legs won't hurt (if the amp is a bit higher from the bottom surface - the air convection is a bit better) ... the end of story ...
Oh, about ground - make sure you'll have 1 ground point on the chassis - not several points ... Ususally it's somewhere close to the IEC AC connector ...
Also it's quite important to make a good star ground for the PSU. You can see here an example of a star ground in my MiniA. With such ground no hum or buzz at all ...
Check diy gallery in mr. NP's diy site - there a lot of very very good ideas for chassis contruction ...
About the trannie - use single trannie - but with separated windings for left and right channel (eg.: 0-38V 0-38V) and I think 450-500VA will be more than adequate for the job. Zen v4 "eats" around 200W to produce around 2x30W of pure music pleasure. Ofcourse - you can crank up bias a bit (but then again with around 45W disipating at each power device - you're allready quite high) and so add some more pwr consumption - but I don't think you'll need it ...
So 1 good trannie with 450-500VA will be more than enough ...
You can see the interior of my Zen v4 here and the front view here
Btw - my intention is not to insult you or something like that - just to help you - and from my own experineces I think you make to big problems with stuff, you'll have to experiment anyway ... Because you'll see in practice when the amp will be half made (functioning circuitry but with chassis not finished yet) - that some stuff must be solved at that time ...
So I think it's better not to finalize the chassis untill the amp will operate ...
It's smart to use some vent openings, it's smart to anodize the chassis to black (for higher heat "radiation"), the legs won't hurt (if the amp is a bit higher from the bottom surface - the air convection is a bit better) ... the end of story ...
Oh, about ground - make sure you'll have 1 ground point on the chassis - not several points ... Ususally it's somewhere close to the IEC AC connector ...
Also it's quite important to make a good star ground for the PSU. You can see here an example of a star ground in my MiniA. With such ground no hum or buzz at all ...
Check diy gallery in mr. NP's diy site - there a lot of very very good ideas for chassis contruction ...
About the trannie - use single trannie - but with separated windings for left and right channel (eg.: 0-38V 0-38V) and I think 450-500VA will be more than adequate for the job. Zen v4 "eats" around 200W to produce around 2x30W of pure music pleasure. Ofcourse - you can crank up bias a bit (but then again with around 45W disipating at each power device - you're allready quite high) and so add some more pwr consumption - but I don't think you'll need it ...
So 1 good trannie with 450-500VA will be more than enough ...
You can see the interior of my Zen v4 here and the front view here
Btw - my intention is not to insult you or something like that - just to help you - and from my own experineces I think you make to big problems with stuff, you'll have to experiment anyway ... Because you'll see in practice when the amp will be half made (functioning circuitry but with chassis not finished yet) - that some stuff must be solved at that time ...
So I think it's better not to finalize the chassis untill the amp will operate ...
Stabist,
Thank you for your valuable comments.
I know what you mean by:
"So I think it's better not to finalize the chassis untill the amp will operate ..."
Perhaps I am affected with my professional life and I want to make the amp according to my standards.
Since the electronics of the Z4 is "rather" obvious I did not consider it as a problematic part in this project. That is all behind my "open" questions.
Currently I am waiting for the PCBs.
trif.
Thank you for your valuable comments.
I know what you mean by:
"So I think it's better not to finalize the chassis untill the amp will operate ..."
Perhaps I am affected with my professional life and I want to make the amp according to my standards.
Since the electronics of the Z4 is "rather" obvious I did not consider it as a problematic part in this project. That is all behind my "open" questions.
Currently I am waiting for the PCBs.
trif.
The PCBs (for my Zen4) are with me but before soldering I have just figured out the following:
I have ordered from DigiKey the high power metal film resistors, and they have sent me METAL OXIDE type of resistors.
Strangly enough the DigiKey P/N numbers are correct.
As far as I know both type of rezistors are made by the same technique, but the metal oxide is better for higher temp/power.
So far so good.
But the metal oxide has more noise compared to the metal film.
So, is it necessary top use metal films for the high power resiztors?
Any input on this is welcome.
trif.
I have ordered from DigiKey the high power metal film resistors, and they have sent me METAL OXIDE type of resistors.
Strangly enough the DigiKey P/N numbers are correct.
As far as I know both type of rezistors are made by the same technique, but the metal oxide is better for higher temp/power.
So far so good.
But the metal oxide has more noise compared to the metal film.
So, is it necessary top use metal films for the high power resiztors?
Any input on this is welcome.
trif.
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