IndianEars, i don't think regulating the B+ supplies to mV level has any sonic advantages. No doubt it could reduce some "hum" though. It depends how the regulation of the B+ is achieved - high value chokes / high value capacitor or an active device. I would rather use a low value choke/ capacitor and have better dynamic response to music impulses than worry about small amount of ripple.
In the future, I will double shunt G2 ( and the Ra's B+) if that is the question you are asking me. On a monoblock, one has room to do this. I will also always double L/C ( using hash choke Ls ) G2 and the Ra, from now on, in any monoblock and/or stereo amp.
On a stereo amp that is built for high performance ( why do it any other way ? ), this " quadruple " topology must be done in my opinion today, due to the shared supply. I have listened all day off and on to quad filtering of the Ra and of G2, and frankly from what I am hearing of my reference music selections, I "must" now have an amp done this way. The inner detail of the double shunting, combined with the "quietness" of a double hash choke L/C, is hard to not to have as part of a high performance amplifier design, once heard.
I am now hearing what I want to hear, performance-wise, from the power supply configuration of the new 6005 amplifier. It is superb actually. There is a lot of work ahead of me. I will design a bigger chassis, and put the parts you saw in this amp, in a finished chassis with less crowding, a big rebuild. I also have a lot of work to do, to experiment and find the right combinations of multiple film cap bypassing, so the amp plays a large variety of musical instruments properly.
Over the last three weeks, I have methodically determined and optimized the driver tubes' ( higher ) operating voltages, and as of today, fully determined the amp's overall needed power supply. Achieving both of these optimizations, is very satisfactory to me - having accomplished both makes me happy. The remaining work is to design and carefully lay out a new larger chassis, and experiment with multiple film cap bypassing, to make the most of things.
IndianEars, i don't think regulating the B+ supplies to mV level has any sonic advantages. No doubt it could reduce some "hum" though. It depends how the regulation of the B+ is achieved - high value chokes / high value capacitor or an active device. I would rather use a low value choke/ capacitor and have better dynamic response to music impulses than worry about small amount of ripple.
That is a brilliant response. I understand from often repeated direct experiences, what you are saying. Others may not !!
Probably, only 2-3% of all power amp designs are regulated. A form of passive regulation, the way we two might execute it, will outperform active regulation, on the basis of our passive methods being far more dynamic, and having less noise, from the ( often used ) solid state parts in an active regulator.
Shunt regulation works quite well as passive regulators though at expense of heat, but has advantages of lower noise IME. I have tried lowering ripple a bit by added extra capacitors. Each time I did that, I lost dynamic response and the music sounded more sterile and lifeless to my ears.
In the strictest sense, we might say a shunt is not a regulator.
But who cares, the real point is, Hari, you and I use it, and to great effect.
It is rarely seen, in the schematics I preview.
A design may use a shunt R, to " bleed / discharge the capacitors " for safety reasons upon turn-off, but it is very very seldom used to improve the sonics of an amplifier one would seriously listen to. As far as I can tell, only Thomas Meyer ( of Germany ) uses an very mild shunt, maybe 1/4th the value of what we do, and I do not recall seeing it anywhere else. (1)
Yes, the double hash chokes and small film caps ( L1/C1, L2/C2 ) helps to remove power supply B+ noise. It keeps this unwanted noise from polluting any of the most sensitive stages in an amplifier. It removes " the frizzies ", or unwanted artifacts, and it stabilizes the B+ supply a bit.
In all my years of audio and amp building, I have never heard the listening result one can obtain ( in 2021 ), by double ( series ) hash choke filtering combined with double series shunting, of a tube amp's sensitive B+ rail. This effective technique is presently used and exclusive to only two people I am aware of. All others it seems, in the vast audio world, are oblivious to this.
Enjoy your amps Hari !! " The proof of the pudding " is in the eating .
drlowmu
(1) Correction, one exception I recall. The 22K 3 watt resistor in Nobu Shishido's "RW" 2A3 DC amp acts as a mild SHUNT, of sorts, and that amp's full schematic is on this page .
NO Combination of Resistors and or Capacitors and or inductors - No Matter How elaborate that configuration - can ever be a Voltage regulator.
The output voltage of ANY such combination will ALWAYS be a ratio of the / dependent on the input voltage.
The Fundamental Characteristic of a Voltage regulator is that its Output voltage must remain be Fixed and independent of any input voltage fluctuations.
No Sachin, you are quite incorrect. Allow me to explain please.
Any single powerful resistor from the B+ to ground, provides a shunt, or current drawing action. It takes however : two resistors and a capacitor, to make it a working shunt . One resistor is needed as a series ( dropping ) resistor, and the other resistor is the actual shunt resistor to ground, with a capacitor across it to provide extra filtering for the additional current being drawn.
The combination of these three parts creates a shunt. It is technically not a regulator, as I pointed out earlier in this thread.
These three simple passive parts accomplish wonderful results in the circuit. Particularly when repeated, one after another, or two shunt sections in series.
A shunt section's three part combination, depending upon the current drawn, VS the current drawn by the tube, acts to lower the impedance of the circuit. As a result, a stage having a shunt ( or two in series as I whole-heartedly suggest - and now do ) will sound far better, than no shunt at all.
The whole point of my post is getting lost. There is no need to get bogged down in textbook definitions.
How many of you contributing here in this thread ( other than Hari Iyer ) have ever built and listened to a double series shunt in a tube amp?? Probably none of you posting, would be my guess.
I am providing any interested and open minded DIY tube amp builder, a proven way to improve their equipment's performance, and that is the point of my posting such information herein. The reason to post is to help others build higher performance tube amps !!
Instead of worrying about precise textbook definitions, I would suggest designing and building a double series shunt, which supplies the B+ to your tube amplifier's Input stage, and give that a listen. IndianEars, if he builds tube amps, should be the first person to design and try it. He will hear and benefit with the results he obtains. I am doing this double series shunting now, since mid-2019, and I want to freely share it with others, so they may try it out !! Very simple to employ, no definition, or o'scope measurements are needed !
Earlier in this thread, you were provided with all the better brands of R-Shunt power resistors I am aware of, to order and use.
Design it, build it, listen to it. Then post you listening results up here, to assist others.
+1 to that @drlowmu . Nobody really cares too much about theory. We are not going to appear for any university exams here to prove theory Vs practical . What matters to me is just the outcome - have adding a resistor or two no matter how with a capacitor has positively benefited me in terms of SQ. Moreover implementation will cost not more than $3/-. So nothing to loose either money wise.
+1 to that @drlowmu . Nobody really cares too much about theory. We are not going to appear for any university exams here to prove theory Vs practical . What matters to me is just the outcome - have adding a resistor or two no matter how with a capacitor has positively benefited me in terms of SQ. Moreover implementation will cost not more than $3/-. So nothing to loose either money wise.
It would be better to say that two Shunt sections will cost less than $100.00 USD. We use good parts !! The cost of quality multiple film caps , in the second Shunt stage, directly feeding the load, add up.
Who cares about these terms, from a textbook, not I.
I am mainly interested in learning how to build a good sounding amp.
I don't use things like a zener diodes in a tube circuit. Others may, but not me.
No Sachin, you are quite incorrect. Allow me to explain please.
Any single powerful resistor from the B+ to ground, provides a shunt, or current drawing action. It takes however : two resistors and a capacitor, to make it a working shunt . One resistor is needed as a series ( dropping ) resistor, and the other resistor is the actual shunt resistor to ground, with a capacitor across it to provide extra filtering for the additional current being drawn.
The combination of these three parts creates a shunt. It is technically not a regulator, as I pointed out earlier in this thread.
These three simple passive parts accomplish wonderful results in the circuit. Particularly when repeated, one after another, or two shunt sections in series.
A shunt section's three part combination, depending upon the current drawn, VS the current drawn by the tube, acts to lower the impedance of the circuit. As a result, a stage having a shunt ( or two in series as I whole-heartedly suggest - and now do ) will sound far better, than no shunt at all.
The whole point of my post is getting lost. There is no need to get bogged down in textbook definitions.
How many of you contributing here in this thread ( other than Hari Iyer ) have ever built and listened to a double series shunt in a tube amp?? Probably none of you posting, would be my guess.
I am providing any interested and open minded DIY tube amp builder, a proven way to improve their equipment's performance, and that is the point of my posting such information herein. The reason to post is to help others build higher performance tube amps !!
Instead of worrying about precise textbook definitions, I would suggest designing and building a double series shunt, which supplies the B+ to your tube amplifier's Input stage, and give that a listen. IndianEars, if he builds tube amps, should be the first person to design and try it. He will hear and benefit with the results he obtains. I am doing this double series shunting now, since mid-2019, and I want to freely share it with others, so they may try it out !! Very simple to employ, no definition, or o'scope measurements are needed !
Earlier in this thread, you were provided with all the better brands of R-Shunt power resistors I am aware of, to order and use.
Design it, build it, listen to it. Then post you listening results up here, to assist others.
I do not usually like to give out schematics, for people to copy, after I have done all the work to develop an effective topology.
But to make this thread crystal clear, I am attaching what I call a " Master Schematic " for any FM / interested DIY person to view and grasp .
Notice please, three things :
1) No specific parts values are given - for people to copy with out thought
2) I had no capability to make a " squiggly " resistor symbol, so when I added-on to this master schematic, I used a hexagon shape, to denote a resistor symbol .
3) Use of this quadruple filter topology, or a variation thereof, in any commercial product, is strictly prohibited, without obtaining my prior written consent. ( C )
( C )
You can see, this was done as of 2-16-2021, representing my latest ideas. Have fun building and hearing this !! I am.
Left out the "g" in spelling aligned above, sorry. Circuit - associated circles are similarly color coded.
Singular reference makes me guess its their Power Transformer, not a pair of Output Transformers. They do use R Cores. "Dogpile" search engine, often is a useful resource.
I hope to do R-Core business with your local Silchar Technologies soon. I am designing a Universal Filament transformer, 5 VCT, for tube rectifiers - optimizing 5U4Gs, etc. A separate R-Core used there, properly designed, makes for an audible improvement.
In Post #31 I had mentioned that R Core is not uncommon (as a Mains Transformer) Just that I had never come across its use as an output transformer in Tube amps
The McIntoch MA6000 seems to use it as a Power transformer, .... and unfortunately, going by reviews... it is not too good high drive levels ....
I suspect they have cut corners in the design to meet a relatively low (For McIntoch ) price point
In Post #31 I had mentioned that R Core is not uncommon (as a Mains Transformer) Just that I had never come across its use as an output transformer in Tube amps
The McIntoch MA6000 seems to use it as a Power transformer, .... and unfortunately, going by reviews... it is not too good high drive levels ....
I suspect they have cut corners in the design to meet a relatively low (For McIntoch ) price point
You are welcome. What if McIntosh uses R-Cores in most, if not all of their new designs? We don't know that, but I could call the company and ask, if I wanted to do so. Can we attribute a poor review to their use of an R-Core power transformer, as you seem to deduce ? Not really, IMHO.
Softone has had Kitamura-Kiden, the 1978 R-Core originator, build a line of S.E. and Push-Pull Softone R-Core output transformers - for at least twenty years now. There are typically many theorist-types, will look at one or two narrow specifications or measurements, and dismiss a design. Here, as an example, is a " Audio Asylum " Forum discussion in 2001, 20 years ago, of the RW-20, which does this " narrow theoretical dismissal " perfectly :
Audio Asylum - Audio Asylum Thread Printer - Get a view of an entire thread on one page
www.audioasylum.com
The common denominator, among all these 2001 theorists ( who are all very smart ) is that not a single one of them has any direct experience using and listening to the device !!! You are included in that bunch, as being very smart, but having absolutely no specific direct experience.
" Mikey", who owned Magnequest Transformers, posted in the above-referenced thread a whole series of impressive calculations. Guess what my friends, I personally now own and also have heard Mikey's highly-rated MQ-DS-025, versus a $120.00 USD RW-20 in 2019. There was no comparison between the two at all. The Softone's music playback far-excelled Mikey's E-I output transformer, by a very large margin ... audibly lower in distortion, more introspection into the music. ( with $19,000 USD 2A3 SE amps ) .
Unlike all the smart people posting above, I do have direct experience. ( 2019 and 2021 ). In my listening experiences, and for my needs with efficient ( over 100 dB horn loaded speakers ) the RW-20 is by far, the best output transformer, of a Single Ended variety, I have ever heard.
All I need is about one Watt or so, with my ALTEC VOTT A7-8s. I seriously doubt that any other S.E. transformer type, available today, at any cost, will match the RW-20's overall sonic performance. Especially once the RW-20 is fully broken in ( 400 hours ).
The many unique advantages of a R-Core transformer, ( lower distortion, cooler running, less fields, etc, etc ) also applies directly to it's use - as a power transformer. I am presently working on a design specification for my new 6005 amp, to convert from it's Hammond E-I power transformer, to a custom-designed Shilchar Technologies R-Core.
All of these observations, and my own opinion, comes about as a result of experiencing a Kitamura-Kiden R-Core product, as an output transformer, directly.