and thusly we enter the crosstalk discusion...
free your mind, Neo
Honestly, with no ill will or intent I must say, by improving your layout and wiring techniques you'll be well bellow the level of cross talk you have right now with that particular scheme.
I told you how to do achieve both your goals however (use a second pair of bridges and keep each rail fully isolated).
Ah, but that's costly, and is it worth it? Why don't you try it with two first and see what you think? With proper wiring techniques, spacing where required twists as required even so low as common mode chokes your level of crosstalk with will be wholy unaudible and the level of detail, clairity, holography..... you'll have not imagined before.
The mere inductance from the power leads going to each amp (with their OWN grounds) will serve to isolate crosstalk. Just think how the current flows and go with it... for instance you'll see in some app notes where stereo grounds are wired in tandem.... EEEERRRRRRRRR.
In the end the only ground that'll reach your case is that of the input signal shield and earth, with the supply fully floating.... and ditch those ground lift resistors. It'll be a whole new world!
free your mind, Neo
Honestly, with no ill will or intent I must say, by improving your layout and wiring techniques you'll be well bellow the level of cross talk you have right now with that particular scheme.
I told you how to do achieve both your goals however (use a second pair of bridges and keep each rail fully isolated).
Ah, but that's costly, and is it worth it? Why don't you try it with two first and see what you think? With proper wiring techniques, spacing where required twists as required even so low as common mode chokes your level of crosstalk with will be wholy unaudible and the level of detail, clairity, holography..... you'll have not imagined before.
The mere inductance from the power leads going to each amp (with their OWN grounds) will serve to isolate crosstalk. Just think how the current flows and go with it... for instance you'll see in some app notes where stereo grounds are wired in tandem.... EEEERRRRRRRRR.
In the end the only ground that'll reach your case is that of the input signal shield and earth, with the supply fully floating.... and ditch those ground lift resistors. It'll be a whole new world!
Hey Bert,
No, you got it backwards, or sideways. lol. You have a rectifier and cap network. Each of them would if I understand this correctly, would go to each channel. You have 1 transformer with 1 supply per channel.
Ray
No, you got it backwards, or sideways. lol. You have a rectifier and cap network. Each of them would if I understand this correctly, would go to each channel. You have 1 transformer with 1 supply per channel.
Ray
Hi Bert,
Hi Bert,
Actually, if I read this right, each Plus and Minus from the caps go to Plus and Minus of each module. Your grounds would be only at the input RCA's. This actually makes more sense to me because I wasn't quite sure how you would hook it all up with the centertap arrangement.
Ray
Hi Bert,
Actually, if I read this right, each Plus and Minus from the caps go to Plus and Minus of each module. Your grounds would be only at the input RCA's. This actually makes more sense to me because I wasn't quite sure how you would hook it all up with the centertap arrangement.
Ray
Power Supply wiring and its benefits
Hi Robert F,
Ok, so you hook the AC of each bridge to each secondary, Could you please describe verbally the rest of the circuit? Thanks.
Ray
Hi Robert F,
Ok, so you hook the AC of each bridge to each secondary, Could you please describe verbally the rest of the circuit? Thanks.
Ray
Re: Power Supply wiring and its benefits
Hi Ray,
I doubt I can do it better than Chris' schematic in post 1369. Yes there will be shared power supplies between channels that way.
I am currently building an amp using 4 pole Jensens and I use two transformers with dual secondaries, one transformer per channel. I must be a masochist because I have made the bridges from discrete diodes too...
ray bronk said:
Hi Ray,
I doubt I can do it better than Chris' schematic in post 1369. Yes there will be shared power supplies between channels that way.
I am currently building an amp using 4 pole Jensens and I use two transformers with dual secondaries, one transformer per channel. I must be a masochist because I have made the bridges from discrete diodes too...
Ray,
Compromise! I suspect if using 4 poles it will be better to share
the two bridges between channels. I must admit I have not tried the comparison.
Compromise! I suspect if using 4 poles it will be better to share
the two bridges between channels. I must admit I have not tried the comparison.
Hi Robert F,
Was thinking in terms of circuit design using standard caps. If using each secondary hooked up to each bridge, and standard series cap configuration, Bert might be right, just a single supply hooked up to both modules. So not sure, what is the advantage here.
Ray
Was thinking in terms of circuit design using standard caps. If using each secondary hooked up to each bridge, and standard series cap configuration, Bert might be right, just a single supply hooked up to both modules. So not sure, what is the advantage here.
Ray
classd4sure said:
Chris, you'll end up with 2 monoblocks in 1 housing. Money is no issue.
With a 1 transformer design I cannot ditch the groundlift resistors. The whole amp. becomes very unstable, remember my gain is over 60x(35Db). My crosstalk/amps stability is ruined if I ground it differently. (Crosstalk now is -90Db@15khz, that's not bad is it. Highest I've ever got it is -100Db@20khz with an AB amp.)
I've tried this over and over again. Grounding my amp. at the inputs only without groundlift resistors makes it useless/ugly sounding..
with 2 completely separated psu's it might? work. I mean grounding it only at the input connectors.
This I'll have to try(before going on a holiday for nearly a month😀 ).
Just have to find 2 of 40V(x2) toroids(250VA) and redo the TNET PCB's.
I'll make 2 sep. 1's.
circuit diagram
Hi Bert,
Let me revise the circuit I presented earlier.
Each bridge get a secondary winding. No centertap. Let's take one channel. Plus from bridge goes to bplus of cap, minus of bridge goes to minus of cap. Those two caps, floating ground and connect to the module's ground. The 2 Plus and Minus points, to connect the wires which go to Plus and Minus of a module, are from the Plus/Plus and Minus/Minus bridge/cap junction
Rather than the centertap being the junction, it is only the single ground point from the 2 caps coming off the bridge.
Now with the attempt to keep this simple, using 2 caps, 10000 MF per rail for each module. That's it.
Ray.
Hi Bert,
Let me revise the circuit I presented earlier.
Each bridge get a secondary winding. No centertap. Let's take one channel. Plus from bridge goes to bplus of cap, minus of bridge goes to minus of cap. Those two caps, floating ground and connect to the module's ground. The 2 Plus and Minus points, to connect the wires which go to Plus and Minus of a module, are from the Plus/Plus and Minus/Minus bridge/cap junction
Rather than the centertap being the junction, it is only the single ground point from the 2 caps coming off the bridge.
Now with the attempt to keep this simple, using 2 caps, 10000 MF per rail for each module. That's it.
Ray.
circuit diagram
Hi Bert,
What chris was suggesting is to get another set of rectifiers. Since you have 8 caps, if I understand you correctly, all you are doing is the hookup the 2nd bridge parallel to each bridge/2ndary winding, and hook up the caps as stated in the last post. All you are doing is to parallel the whole thing. You are doubling up the rectification, as well as adding more capacitance. You don't need a 2nd transformer. Then to get the ground, you just ground at the input without your 10ohm resistor. The caps ground are just floating and again hook up to the ground on the module.
Ray
Hi Bert,
What chris was suggesting is to get another set of rectifiers. Since you have 8 caps, if I understand you correctly, all you are doing is the hookup the 2nd bridge parallel to each bridge/2ndary winding, and hook up the caps as stated in the last post. All you are doing is to parallel the whole thing. You are doubling up the rectification, as well as adding more capacitance. You don't need a 2nd transformer. Then to get the ground, you just ground at the input without your 10ohm resistor. The caps ground are just floating and again hook up to the ground on the module.
Ray
Ray,
Its like a dual mono setup.
Just to test 1 channel reveals very little. I want the whole soundstage picture.
I will build a 2 transformer, 2 rect. per toroid, 2 Tnets per toroid setup.
Like true mono amps but than dual. The 0V goes to the power amp. sep. and the only ground will be at the input.
Cannot draw a schematic where I am now. Will be home on sunday and show you the schematic.
Have got the needed parts by monday(hope) and will just make an amp than.(if time allows it or whatever would disturb my intensions).
Time is not always on your side.
Its like a dual mono setup.
Just to test 1 channel reveals very little. I want the whole soundstage picture.
I will build a 2 transformer, 2 rect. per toroid, 2 Tnets per toroid setup.
Like true mono amps but than dual. The 0V goes to the power amp. sep. and the only ground will be at the input.
Cannot draw a schematic where I am now. Will be home on sunday and show you the schematic.
Have got the needed parts by monday(hope) and will just make an amp than.(if time allows it or whatever would disturb my intensions).
Time is not always on your side.
Hi Bert, What your're doing is not totally necessary. Try it with the verbal schematic I posted. If you got two more bridges, then just wire up the other 2 bridge/cap network the same way, and parallel them with one transformer. Try that first. Hate to see you go and get a new transformer and case and all that. One step at a time.
Ray
Ray
Ray,
I've 4 caps. in total. Can you draw how you would wire it up(if possible and you liking to do it). From what I understand you want 1 bridge rect. per winding(2 off on the toroid) Connect the sec. side of the bridges for the 0V point - feed the amps - ground only at input. Correct?
You than have 2 amps. on 1 physical PSU.
Crosstalk will not be optimal but you can hear the difference.....is this what you mean.
I can try that but it will not be so optimal to compare it to my ref. optimal made stereo amp. which has a huge soundstage.
BTW ordered the toroids already. Casing/housings I have enough off in a lot of sizes. I just do not have the toroids. Am waiting for SMPS's really.
I've 4 caps. in total. Can you draw how you would wire it up(if possible and you liking to do it). From what I understand you want 1 bridge rect. per winding(2 off on the toroid) Connect the sec. side of the bridges for the 0V point - feed the amps - ground only at input. Correct?
You than have 2 amps. on 1 physical PSU.
Crosstalk will not be optimal but you can hear the difference.....is this what you mean.
I can try that but it will not be so optimal to compare it to my ref. optimal made stereo amp. which has a huge soundstage.
BTW ordered the toroids already. Casing/housings I have enough off in a lot of sizes. I just do not have the toroids. Am waiting for SMPS's really.
circuit diagram
Hi Bert,
At this point in time, you have all you need.
Take a piece of paper, and I'll describe it to you.
First, this is not! ment to be as the optimum layout. It is just to be for an understanding of how to set this power supply up.
transformer at back of page, power supply towards you and modules on left and right sides of paper.
Now, we have this wiring scheme off the transformer. It too won't be the correct one. I am just using colors to identify the transformer leads.
We'll assume for sake of being brief, haha, the primary is already connected to its IEC terminals, and not! plugged in.
Yellow and black, and red and orange are the two secondaries.
Red and black would normally be the two grounds for the secondaries.
So Yellow and black hook up to AC sides of bridge, and red and orange hook up to the other bridge.
Plus of left bridge goes to plus of cap.
Minus of left bridge goes to minus of cap. Repeat process for the right bridge.
Now, at the junction of the plus and minus of cap and bridge (left bridge) is hooked up a wire which will go to the plus and minus of left module. You then hook a wire up to each plus and Minus Junction on the right bridge so it too will go to the right module.
On the left bridge/cap bank, you take the other ends of the two caps and hook them together to create ground. That ground is connected to the left module. Repeat process for the right bridge.
Now for the actual ground which is created at the input. Everything else is floating. You'll have to ask Chris how to use a second rectifier, using the 4 caps you have.
Hope that's clear. You have taken the reference point from the centertap and left it with just each of the 2 caps being connected together at the Plus and Minus points. If I understand correctly, you now have more current draw.
Anything further, ask Chris.
Ray
Hi Bert,
At this point in time, you have all you need.
Take a piece of paper, and I'll describe it to you.
First, this is not! ment to be as the optimum layout. It is just to be for an understanding of how to set this power supply up.
transformer at back of page, power supply towards you and modules on left and right sides of paper.
Now, we have this wiring scheme off the transformer. It too won't be the correct one. I am just using colors to identify the transformer leads.
We'll assume for sake of being brief, haha, the primary is already connected to its IEC terminals, and not! plugged in.
Yellow and black, and red and orange are the two secondaries.
Red and black would normally be the two grounds for the secondaries.
So Yellow and black hook up to AC sides of bridge, and red and orange hook up to the other bridge.
Plus of left bridge goes to plus of cap.
Minus of left bridge goes to minus of cap. Repeat process for the right bridge.
Now, at the junction of the plus and minus of cap and bridge (left bridge) is hooked up a wire which will go to the plus and minus of left module. You then hook a wire up to each plus and Minus Junction on the right bridge so it too will go to the right module.
On the left bridge/cap bank, you take the other ends of the two caps and hook them together to create ground. That ground is connected to the left module. Repeat process for the right bridge.
Now for the actual ground which is created at the input. Everything else is floating. You'll have to ask Chris how to use a second rectifier, using the 4 caps you have.
Hope that's clear. You have taken the reference point from the centertap and left it with just each of the 2 caps being connected together at the Plus and Minus points. If I understand correctly, you now have more current draw.
Anything further, ask Chris.
Ray
Ray,
So you use 1 winding per amp.?You than create a virtual ground with 2 caps? Very confusing. Is this for your 0V point of the amp.?
I will make a schematic to see if I got the picture right and post it here tomorrow(I don't have the possibility right now to go to my ftp).
As far as I know you'll need 4 windings, 2 rect., 4caps.to properly set up a stereo amp. Having a floating ground is bit of a risc.
So you use 1 winding per amp.?You than create a virtual ground with 2 caps? Very confusing. Is this for your 0V point of the amp.?
I will make a schematic to see if I got the picture right and post it here tomorrow(I don't have the possibility right now to go to my ftp).
As far as I know you'll need 4 windings, 2 rect., 4caps.to properly set up a stereo amp. Having a floating ground is bit of a risc.
circuit diagram
Hi Bert,
First, off, don't need two transformers, or 4 windings. Just take the schematic the way I described it to you. If the caps are 10K Mf each, it will be 10K per rail. the ground hooks up to the ground on each module. Both supplies are totally separate except for the core on the transformer. If you have any questions, email me. This isn't hard to understand. You only need just! 2 windings on 1 transformer. Try this supply first before you deal with adding the 2nd tier of rectifiers/caps.
Ray
Hi Bert,
First, off, don't need two transformers, or 4 windings. Just take the schematic the way I described it to you. If the caps are 10K Mf each, it will be 10K per rail. the ground hooks up to the ground on each module. Both supplies are totally separate except for the core on the transformer. If you have any questions, email me. This isn't hard to understand. You only need just! 2 windings on 1 transformer. Try this supply first before you deal with adding the 2nd tier of rectifiers/caps.
Ray
+/- 12V supply for UCD400
Hi,
I built my own PSU for the UCD400's. Now I'd like to try supplying
clean 12V to the AD8620. Has anyone got experience building
a simple external +/- voltage source based on regulators
for the UCD?
Thanks,
Mike
Hi,
I built my own PSU for the UCD400's. Now I'd like to try supplying
clean 12V to the AD8620. Has anyone got experience building
a simple external +/- voltage source based on regulators
for the UCD?
Thanks,
Mike
- Status
- Not open for further replies.