I've noted here that this is a contraversial topic so I'd like the forum members to provide their opinions on where the most benefit is likely to be derived when making a mono channel supply for their amps. Below are five examples which could all be considered "mono" powered amps so pick your favorite and state why you expect an audable difference?
1. Everything separate, even the lines to the outlets.
2. Common delivery but separate transfomers, rectifiers and caps.
3. Common transformer but everything separate after that.
4. Common transformer and double bridge but everything separate after that.
5. Hybrid combination based on greatest bang for the buck.
1. Everything separate, even the lines to the outlets.
2. Common delivery but separate transfomers, rectifiers and caps.
3. Common transformer but everything separate after that.
4. Common transformer and double bridge but everything separate after that.
5. Hybrid combination based on greatest bang for the buck.
Hi!
At least in car-hifi, "true" mono supply designs are being used in order to minimize (that is, get entirely rid of) the influences of one channel of the stereo music signal on the other channel -> stability (for example, if a "strong" bass impulse is only heard on one channel, normally the voltage of that channel would drop a little bit because of the needed power, therefore influencing also the power available to the other channel, but if you use separate supplies, only the voltage of the "demanding" channel would drop, while the other stays "stable").
So far I have not used a "true" mono supply, only what you describe under pt. 3 for my P3A (500 VA toroid, but seperate rectification and smoothing). But I'm a student on low money
, so who knows what crazy stuff I would build if I had the money for it... a P3A with 150.000 uF on each rail, built entirely of BG caps... 
Bye,
Arndt
At least in car-hifi, "true" mono supply designs are being used in order to minimize (that is, get entirely rid of) the influences of one channel of the stereo music signal on the other channel -> stability (for example, if a "strong" bass impulse is only heard on one channel, normally the voltage of that channel would drop a little bit because of the needed power, therefore influencing also the power available to the other channel, but if you use separate supplies, only the voltage of the "demanding" channel would drop, while the other stays "stable").
So far I have not used a "true" mono supply, only what you describe under pt. 3 for my P3A (500 VA toroid, but seperate rectification and smoothing). But I'm a student on low money
, so who knows what crazy stuff I would build if I had the money for it... a P3A with 150.000 uF on each rail, built entirely of BG caps... Bye,
Arndt
Cradle22
If the power delivery is the issue, isn't this a function of the size of the transformance as opposed to it being divided?
Peter Daniel
How are you my friend, its been a while and from my reading I can see that you've progressed nicely in your art, Congratulations! Now, is the soundstage improvement better focus or greater size? This is important because what you're hearing may be phase delivery timing issues that appear to increase the soundstage at the expense of resolution.
If the power delivery is the issue, isn't this a function of the size of the transformance as opposed to it being divided?
Peter Daniel
How are you my friend, its been a while and from my reading I can see that you've progressed nicely in your art, Congratulations! Now, is the soundstage improvement better focus or greater size? This is important because what you're hearing may be phase delivery timing issues that appear to increase the soundstage at the expense of resolution.
UrSv
Nice to see you here I wanted to address the points you made earlier in this thread. Wouldn't the spike that gets through one transformer also get through another transformer on the same power line? As I understand it, each transformer is also a source of noise and HF hash so do you still maintain that multiple transformers will sound better?
Nice to see you here
I wanted to address the points you made earlier in this thread. Wouldn't the spike that gets through one transformer also get through another transformer on the same power line? As I understand it, each transformer is also a source of noise and HF hash so do you still maintain that multiple transformers will sound better?i have tried option 2 3 times, even though i assume they are dual mono but sharing mains, a buzzing sound is heard from one side. This doesn't happen if i just connect one side of the amp
(2 monos in one) oppose to the dual mono same chasis and same mains.
Recently i built a real monos-separate chasis and separate trans but sharing the same distribution block for ac mains but 2 power cords are used. i couldnot hear any buzzing at all.
(2 monos in one) oppose to the dual mono same chasis and same mains.
Recently i built a real monos-separate chasis and separate trans but sharing the same distribution block for ac mains but 2 power cords are used. i couldnot hear any buzzing at all.
Hi,
In my amplifiers I use a single mains-connector, then a softstart module, that module has more "output"-connectors. from there each transformer even has it's own mains filter to be (almost) completely shure there's no influence at eachother (don't know if my english is good enough to let you know what I mean)...
Grtz, Joris
P.S. That is #2.
In my amplifiers I use a single mains-connector, then a softstart module, that module has more "output"-connectors. from there each transformer even has it's own mains filter to be (almost) completely shure there's no influence at eachother (don't know if my english is good enough to let you know what I mean)...
Grtz, Joris
P.S. That is #2.
yldouright said:
a single transformer setup has its advantages in real world listening vs. two transformers of 1/2 the capacity.
smaller transformers tend to have higher output impedence. So if a loud passage is being played, the rail voltage will drop more on a small transformer vs. on a large transformer.
It is likely that loud passages don't show up on all channels at exactly the same time for real world music. so when playing such music through an amp powered by one big transformer, the channel handling loud music has more resources to it.
a mono setup has its advantages in channel separation but most amps have pretty good psrr, minimizing the benefits of a mono setup.
and in case of high output impedence devices like batteries, the advantage of having a true mono ps is even less.
millwood
I was thinking more along the lines of each tranformer being a source of noise so if you have less transformers, less noise downstream. I'm also a fan of the single transformer because of the impracticality of matching them. There is also the time/delivery issue aforementioned is really high resolution applications like Peter Daniel's AMP-1 series.
Vigier
Sounds like you went far up the mono trail but is there an audable/measurable difference and if so, how much improvement did you get for your effort?
NickC
This sounds like you were able to resolve a ground loop or stray inductance problem with separate tranformers and enclosures. From your reply, I'm unsure if you ever tried feeding all the amps from one transformer.
UrSv
Yes, you're right but would he end up with a better sounding amp if he did? I'm still waiting for you to give your opinion on the last questions directed to you
I was thinking more along the lines of each tranformer being a source of noise so if you have less transformers, less noise downstream. I'm also a fan of the single transformer because of the impracticality of matching them. There is also the time/delivery issue aforementioned is really high resolution applications like Peter Daniel's AMP-1 series.
Vigier
Sounds like you went far up the mono trail but is there an audable/measurable difference and if so, how much improvement did you get for your effort?
NickC
This sounds like you were able to resolve a ground loop or stray inductance problem with separate tranformers and enclosures. From your reply, I'm unsure if you ever tried feeding all the amps from one transformer.
UrSv
Yes, you're right but would he end up with a better sounding amp if he did? I'm still waiting for you to give your opinion on the last questions directed to you
yldouright said:UrSv
Nice to see you here
AFAIK the transformer itself is not a source of "RF and hash" but it will transfer these things via inductive or capacitive coupling. I would also assume it is also bandwidth limited which means that "RF and hash" sourced from one place will get attenuated passing through one transformer to another one.
My summary is that I would not even consider using one transformer to provide 32 A to a set of amplifers as virtually everything is MUCH worse. Ripple, conduction angle generated noise, likelyhood od rectifier or cap failure, start-up handling and so forth. Secondly I can not understand why one would even thnk about mathcing transformers for this application. Surely it must irrelevant at best? Minor differences (as expected here) should have absolutely NO effect on the performance of the different amplifiers. Sure, if the rails differ by 0.5 V at 12 V rails then you might get 3 W less or more from one or the other. And? The gain is the same and it does not affect anything I can see would make a difference.
As for Cradle22 ending up with a better amp if he did there is not a single doubt in my mind as the PSU, IMHO, would be better in every aspect providing the amps with cleaner and better supply in every aspect of the concept. I would assume that this is why dual mono is the desired topology of most amplifier manufacturers. Or so it seems to me.
UrSv
True, the ripple is a function of the current drawn but each additional amplifier will divide the current draw if it has its own leg. The total ripple seen by the amp capacitance bank is the same if you use four transformers outputting 8A or one outputting 32A/4 amplifiers. Speaking to JOE DIRT® and other members on this forum has led me to the conclusion that matching transformers is not at all irrelevent. The issue of capacitance failure can be made to equal the four transformer scheme if each amp has its own bank of capacitors instead of pooling the entire capacitance at the beginning for all the amplifiers.
As always one has to make one's mind up on what one thinks about one's matters. The question is who to believe. You have checked with Mr Dirt and some others. That's fine. Are they right? I am trying to respond here but I am doing so with the conviction that most people with a lot of knowledge refrain from responding due to the very obvious hopeless case they would be making since the idea of running it with one transformer is extremely bad and definitely a bad option. This is of course my view on things.
What on earth would make a difference in this application if the transformers were slightly different (which I think would be fairly unlikely)? It would be interesting to know.
What on earth would make a difference in this application if the transformers were slightly different (which I think would be fairly unlikely)? It would be interesting to know.
if I may interject here....both of you have good arguments and this discussion has its merits.
every design becomes a hurdle to overcome when doing anything as you all know,there are different approaches to building anything,what it comes down to is the best way for your application....(I try to tell my students that).....every design has its pitfalls so we must compensate in other areas.....the difference in rail voltage is insignificant but the current demands are important. I wish I had more time because this is interesting as I use to be into this quite alot years back
DIRT®
every design becomes a hurdle to overcome when doing anything as you all know,there are different approaches to building anything,what it comes down to is the best way for your application....(I try to tell my students that).....every design has its pitfalls so we must compensate in other areas.....the difference in rail voltage is insignificant but the current demands are important. I wish I had more time because this is interesting as I use to be into this quite alot years back
DIRT®
one opinion here
Onthis page in the Class A site of Geoff Moss there is an detailed evolution from an original JLH amp to the 2003 version.
Expert comments by an experienced musician about the influence each modificiation had.
One of the most notible had been the introducion of a separate power supply for each channel.
I'm not sure if it's been the case of just "doubling" all components or creating two psu with 'half' transformer / buffer capacity.
I personally cannot compare single / double psu's as I build two project both with two psu's from scratch. (the second set a bit larger than the first)
Onthis page in the Class A site of Geoff Moss there is an detailed evolution from an original JLH amp to the 2003 version.
Expert comments by an experienced musician about the influence each modificiation had.
One of the most notible had been the introducion of a separate power supply for each channel.
I'm not sure if it's been the case of just "doubling" all components or creating two psu with 'half' transformer / buffer capacity.
I personally cannot compare single / double psu's as I build two project both with two psu's from scratch. (the second set a bit larger than the first)
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