To me it seems tht there is a market for extremely good phono stages that cost a lot. Not a big market but that is probably not what you want either as you do not have that many components.
If I were in your shoes, I would try to make something that is "above" CTC-standards, and skip the BT milled case,
and make it an all-out phono stage that will give you an A-rating.
Try to find a good mechanical designer that also has experience in industrial design, so the case will look good and has some resemblance of your previous products.
Use some exotic PCB-material and PCB-treatment. If you can't make your own layout, get the best designer you can. Pay them by giving them a phono stage.
You seem to have exotic parts and maybe you can use that to fund some of the cost.
Sigurd
If I were in your shoes, I would try to make something that is "above" CTC-standards, and skip the BT milled case,
and make it an all-out phono stage that will give you an A-rating.
Try to find a good mechanical designer that also has experience in industrial design, so the case will look good and has some resemblance of your previous products.
Use some exotic PCB-material and PCB-treatment. If you can't make your own layout, get the best designer you can. Pay them by giving them a phono stage.
You seem to have exotic parts and maybe you can use that to fund some of the cost.
Sigurd
john curl said:Thanks for the info, Rick. I have not seen that issue, yet.
Also, thanks for your offer, Joshua_G. I would take you up on it, if I could see how it could be done.
Right now, I am at a crossroads. I have a new phono stage, made to Vendetta Research or CTC standards, but I don't see any actual customers who are willing to buy it, if I put it into production.
This design will be competitive with Nelson Pass, Einstein, etc. , and I can only make a few hundred units over the lifetime of the product, with the available (and still best) parts. I doubt that I would want to build any more than that, in any case.
The problems in this industry, for me, is customers, almost completely, and of course, capitalization. I literally go from month-to-month, hoping for some royalties to pay the bills, and it is even tough for Parasound at the moment, even with great reviews. I can understand how many established hi enders like Nelson Pass can sell, as he has an established customer base through his excellent reputation and dealer base, but I have only one or two dealers that I can rely on. Most would rather that I go away, as they have too many different products on their shelf than they can sell successfully today.
We have to decide whether to reduce the case cost to something within reason, or go all out in order to compete with Nelson, Roland, etc. Reducing the case cost WILL reduce the shielding and the WAF. What to do?(I know, sell the Porsche) No that is not a solution, so don't try it again, you turkeys!
PMA said:
Pavel, I really tried to find it, but I have no idea which circuit this was measured in, what were the conditions (signal level, load impedance, I assume it was an amplifier?). Where was it measured, in a ground loopp? Signal ground wire?
You have to make up your mind, what you want to do with these erratic posts. I can't imagine you want to spend time and effort to throw up curves and nobody has any idea how to apply them.
Jan Didden
Hi Jan,
yes, this thread is growing extremely fast
The image was here
http://www.diyaudio.com/forums/showthread.php?postid=1742951#post1742951
1st measurement is with load return connected to PWRGND, 2nd to SIGGND. It is a high-bias amplifier, above 1A idle. Voltage measured accross load (4R), Y scale in V, i.e. 5.0e-04 means 0.5mV. Due to high idle current there is a high ripple on PSU caps, the ripple is on board as well and ripple current through on-board 500uF filtration caps makes troubles on wire impedance between SIGGND and PWRGND. Hope I am clear enough.
yes, this thread is growing extremely fast
The image was here
http://www.diyaudio.com/forums/showthread.php?postid=1742951#post1742951
1st measurement is with load return connected to PWRGND, 2nd to SIGGND. It is a high-bias amplifier, above 1A idle. Voltage measured accross load (4R), Y scale in V, i.e. 5.0e-04 means 0.5mV. Due to high idle current there is a high ripple on PSU caps, the ripple is on board as well and ripple current through on-board 500uF filtration caps makes troubles on wire impedance between SIGGND and PWRGND. Hope I am clear enough.
PMA said:Hi Jan,
yes, this thread is growing extremely fast
The image was here
http://www.diyaudio.com/forums/showthread.php?postid=1742951#post1742951
1st measurement is with load return connected to PWRGND, 2nd to SIGGND. It is a high-bias amplifier, above 1A idle. Voltage measured accross load (4R), Y scale in V, i.e. 5.0e-04 means 0.5mV. Due to high idle current there is a high ripple on PSU caps, the ripple is on board as well and ripple current through on-board 500uF filtration caps makes troubles on wire impedance between SIGGND and PWRGND. Hope I am clear enough.
Yes, very clear, thanks.
It's not anything that would come as a surprise if you have been battling these things, but it is nice again to be made aware of it.
BTW, my personal opinion is that these issues are much more important in tracking down audible differences between amps than the brand of the wire, to mention just one random issue...
Jan Didden
PMA said:
Absolutely! I agree too.
Interesting observation regarding a way to observe the effect...
But what about after you've got these sorts of issues straightened out. And you've gotten some speakers that are also lower than average in their own distortions? Then what? Might one then begin to hear the alleged "differences" between high quality caps (eg. one brand of polypropylene cap vs another brand?), or even "wire"?? Is it possible?
And, what percentage of commercial amps suffer from "ground pollution"? By extension, what % of home systems then are suffering sonic deficits as a result??
Glen, apologize for mispeeling your name. Glad that you hear differences between your amps (think you said that). Wouldn't it have been faster and simpler to just say that in the first place?
_-_-bear
janneman said:
You are correct in asking for more details. Every EMC problem is always specific although there are some generic approaches in solving the problems.
This is a classical problem of ground loop coupling. The ground system is there to bring back the currents to the potential sources that generated them. These will create voltage drops in the ground system. If a voltage drop created by another current is in serie with the input we have coupling. It is the case here if the load is connected to power ground.
But it is not the end. The board ground can be separated between low current signal ground and high current signal ground( the output transistors and on board large capacitor).
It is sometimes good to keep the two grounds separated by a resistor to avoid coupling generated by the large output currents.
It is interesting to hear, like PMA has done, some aural experience, where this trick has shown to be usefull. Or perhaps understand that it is not very usefull, or that it can be wrong in some topologies.
The same for the problematic af ground loops created because of the safety ground. Which kind of ground breaker is the best in the presence of hum in the ground and in the presence of RFI.
The same for common mode noise created by different grounding.
Do we have a different effect with a serie or shunt feedback topology at the input? This from an aural point of view.
These effects are real and can cause different aural experiences IMHO.
JPV
john curl said:
That sounds interesting.
Questions:
1) Are you saying that they turn in place ('spinning in their graves') or that they are able to move past one another ('a milling crowd')?
2) Does a current through the specimen have any effect? (Now, that would open multiple cans of worms...)
In any event, I'd think there'd be an effect at the crystal boundaries due to the motion. Increased noise, I'd think.
SY,
Give it a rest. Your post says what it says. People can make up their own minds. Either I'm a terrible person who has willfully misinterpreted your words or I'm someone who happened to remember a post wherein you said you heard something that wasn't easily explained.
Just take the 'out' I left you (you were swayed by 'group think') and let it go. That way you'd be back safely within the boundaries of politically correct engineering practice and all would be well.
Or you could admit that it was interesting and try to follow up.
Your choice.
Grey
- Status
- Not open for further replies.