How bad is this power supply ringing?

[dowto1000]

Guess I was trying to squeeze a bit more wisdom before I finished wiring up the power supply. This summer I'm taking some time to build a very nice tube amp prototyping board with a bunch of socket boards I picked up and some terminal blocks. That way I can switch out components and move wires around like crazy.

Try to use as few Socket Boards and Terminal Blocks as possible.

Wiring should be done in a 2A3 SET as PTP or CTC, which stands for Point to Point or Component to Component. Lay out and short proper wire is critical. Use the spacing and lengths of the parts, to minimize wire lengths, yet keep fields from interacting.

Most SETs I see do not use heavy enough wiring, wideband wiring, and thus, they lose DYNAMICS, become Tuners, not Amps !!

Dowto1000

 

[Tubeglowpio]

My 2 cents:

If you stay within class A, then the power supply is effectively static with respect to changing conditions coming from each end - mains charging pulses come in one end but effectively don't perturb the other end - and output stage signal currents pass through the filter output cap but don't effectively pass back through the filter to perturb the other end. So chasing power supply filter ringing behaviour is like working on a solution when there is no problem. If your class A is loosing it at peak signal, then you've got other issues to deal with more than the power supply.

If you have a hum level down near the amp's noise floor, then B+ ripple voltage on the output stage may be the dominant hum source, and may be noticeable. If you had a hum 'aim', then it would be to build your amp and work out how to alleviate all the other hum sources to see if you can actually measure and hear the hum from just the B+ ripple - that would then be a good place to start looking further at your B+ supply, and you would be a wiser person for the learning curve taken.

The output stage filter capacitance, although it is part of the power supply, should be located and wired so as to minimise loop area for the output stage signal current path. And as with all filter caps, connect input and output circuits only at the cap terminals.

I'm using a 2 part star ground system, one for the output stage and one for the driver stage. The last amp I built used similar grounding and didn't even use a choke and I could barely hear any hum if I was right next to my 96db speakers.

 

[Tubeglowpio]

Try to use as few Socket Boards and Terminal Blocks as possible.

Wiring should be done in a 2A3 SET as PTP or CTC, which stands for Point to Point or Component to Component. Lay out and short proper wire is critical. Use the spacing and lengths of the parts, to minimize wire lengths, yet keep fields from interacting.

Most SETs I see do not use heavy enough wiring, wideband wiring, and thus, they lose DYNAMICS, become Tuners, not Amps !!

Dowto1000

The socket boards and that will just be to mess around with to get an idea of the next amp I want to build, just to experiment with. This amp that I'm building now will include 16 awg silver plated copper bus wire. 18 awg for both heaters and signal wire and I have some shielded belden wire for the inputs. I learned years ago breadboarding little solid state amps that long high awg wire picks up RF due to the higher resistance.

 

[primosounds]

It's a rh84 amp build so I've heard they need better regulation than most single ended amps, I think it's due to the plate to plate feedback. I think I was going for less than 10mA of ripple for the outputs in that arrangement.

Alex, has worked out the PS design and the number of amps made to his specs number in the hundreds if not thousands. So, no need to reinvent the wheel, even if you can not stay within the components specified, keeping the values close will be ok.
I have made over 10 of this type of amp with different power tube and driver tube combination. All the amps had CLCLC or LCLC type filter supply but No 2 amps had the exact same combo of Choke values. I did not use PSUD on the first 7 amps and they all turned out sounding excellent.

 

[Selmerdave]

Try to use as few Socket Boards and Terminal Blocks as possible.

Wiring should be done in a 2A3 SET as PTP or CTC, which stands for Point to Point or Component to Component. Lay out and short proper wire is critical. Use the spacing and lengths of the parts, to minimize wire lengths, yet keep fields from interacting.

Most SETs I see do not use heavy enough wiring, wideband wiring, and thus, they lose DYNAMICS, become Tuners, not Amps !!

Dowto1000

drlowmu, I presume

 

[Tubeglowpio]

Alex, has worked out the PS design and the number of amps made to his specs number in the hundreds if not thousands. So, no need to reinvent the wheel, even if you can not stay within the components specified, keeping the values close will be ok.
I have made over 10 of this type of amp with different power tube and driver tube combination. All the amps had CLCLC or LCLC type filter supply but No 2 amps had the exact same combo of Choke values. I did not use PSUD on the first 7 amps and they all turned out sounding excellent.

I hear you primo, the few tube amps that I've built so far have sounded good enough to impress family and friends that have heard them, although it's not too hard to beat the sound quality of consumer stereos. Point is I've only used psud2 for quick calculations of voltages, this was the first time I looked for ringing and that and I've had no problems, guess I'm just trying to step it up more this time and be certain to get the best bang for my buck and maybe learn a thing or two. What I ended up doing to see if my power supply design was ok was I actually just modeled the one Alex listed first to see about what I should have going in mine.

 

[Tubeglowpio]

drlowmu, I presume

I'm guessing that is a AK member? Are those the ones that BlueGlow Electronics has shown on his youtube channel? I actually got mine from ebay for 15 bucks each, debated just making them myself with some Belton sockets but had a lot going on so figured why not.

 

[primosounds]

I know that adding both together sounds like the safer route as I would think it would just act like a larger inductor with resistance of course. I was having more trouble getting the two separate choke filter to not ring in the psud2 but your experience with these amps does make me feel better about it. Ive been meaning to ask you about the rh84 schematic as I see each channel actually has their own 10uf cap so I should omit my last cap then. Did you find 10uf for each channel good? I was thinking of using this 400 volt audyn crossover cap, but not sure if it's bad to use a crossover cap in the supply? I might order some solen fast caps but have heard they can sound dry.

A film cap is almost alway better than an electrolytic type. I find that a film cap in the driver B+ supply is very beneficial. I always include a film cap there. You might have some breakin time with that cap.

 

[Tubeglowpio]

A film cap is almost alway better than an electrolytic type. I find that a film cap in the driver B+ supply is very beneficial. I always include a film cap there. You might have some breakin time with that cap.

So crossover caps are ok to use in power supplies? I feel like I read else where that they may not endure the constant 120hz cycles? I'm thinking I could get away with it as that last filter cap wont see much current. I could pick up some Solen fast caps this week which I know have been used plenty in supplies, but a negative of those is I heard they cant sound a bit harsh...

 

[Tubeglowpio]

I am having my open to some new ideas to experiment with. The first tube stereo I ever fixed up then heard was a Magnavox 8601 and was pretty blown away at the time, had a very nice harmonic structure to the sound which I thought was just dominate 2nd harmonics but maybe the transient response had something to do with why I liked the amp as well. Lots to learn and experiment with, I'm sure I will do a lot of this before spending my funds on building the 2A3 amp, I want that thing to be my every night stereo for a while.

 

[primosounds]

So crossover caps are ok to use in power supplies? I feel like I read else where that they may not endure the constant 120hz cycles? I'm thinking I could get away with it as that last filter cap wont see much current. I could pick up some Solen fast caps this week which I know have been used plenty in supplies, but a negative of those is I heard they cant sound a bit harsh...

[Well, if you are just using that cap for the driver tube B+ supply the amount of ripple in the voltage there is small. So it is not a hard duty for that cap. But if it were the first cap after the rectifier that would be a different story.

 

[dowto1000]

Hi,

You write " But if it were the first cap after the rectifier that would be a different story. "

No one should use any capacitor right after a rectifier. No use of a "C", of any size, as the input filter after the rectifier.

A L input filter, is superior......... and the best technique.

L1/C1/L2/C2, all Ls under 10 Ohms DCR. No Cs higher than 56 uF. ( talking SET amps, drawing 70 mA. total ) .

Dowto1000

 

[dowto1000]

So crossover caps are ok to use in power supplies? I feel like I read else where that they may not endure the constant 120hz cycles? I'm thinking I could get away with it as that last filter cap wont see much current. I could pick up some Solen fast caps this week which I know have been used plenty in supplies, but a negative of those is I heard they cant sound a bit harsh...

Solen Film Caps are old technology, were not ever good enough, don't copy common mistakes, Solens are, IMHO, a true waste of money. There are much better cap choices - today, sometimes at Industrial prices, not at fancy costs.

In my DC Type 45, 46 and JJ 2A3-40 SET builds, I exclusively use film caps .......everywhere !!

As a BASIC or " main " film cap, I usually find the new WIMA DC LINK MKP4s, ( in as high a voltage rating as you can afford and fit in ), are the best 2018 cap choice. I would highly recommend them as a " go to " part. Industrially priced, in good amps and in SOTA audio systems, they actually out-perform Blackgate WKZs which are NLA but sell for 20 times the WIMAs. Get FOUR PIN units, only, NOT the two pin units !!

Dowto1000

 

[Tubeglowpio]

[Well, if you are just using that cap for the driver tube B+ supply the amount of ripple in the voltage there is small. So it is not a hard duty for that cap. But if it were the first cap after the rectifier that would be a different story.

OK, that's what I was thinking based on some stuff that I read in the past. I just wanted to confirm because it's hard to find info on that, thank you.

 

[Tubeglowpio]

Hi,

You write " But if it were the first cap after the rectifier that would be a different story. "

No one should use any capacitor right after a rectifier. No use of a "C", of any size, as the input filter after the rectifier.

A L input filter, is superior......... and the best technique.

L1/C1/L2/C2, all Ls under 10 Ohms DCR. No Cs higher than 56 uF. ( talking SET amps, drawing 70 mA. total ) .

Dowto1000

I don't think the chokes I have on hand would work with a lclc filter but I will most likely go that route with the 2A3 amp.

 

[Tubeglowpio]

Solen Film Caps are old technology, were not ever good enough, don't copy common mistakes, Solens are a huge waste of money. There are much better cap choices - today,

In my DC Type 45, 46 and JJ 2A3-40 SETs, I exclusively use film caps .......everywhere !!

As a BASIC or " main " film cap, I usually find the new WIMA DC LINK MKP4s, ( in as high a voltage rating as you can afford and fit in ), are the best 2018 cap choice. I would highly recommend them as a " go to " part. Industrially priced, in good amps and in SOTA audio systems, they actually out-perform Blackgate WKZs which are NLA but sell for 20 times the WIMAs. Get FOUR PIN units, only, NOT the two pin units !!

Dowto1000

I have heard enough negative things and this add to that so I will stay away. I did actually try one once but only had it clipped in while I compared it between a polypropylene in oil run cap and a f and t electrolytic. None were given burn in time but to me the f&t actually sounded better than the solen and the run cap was the best sounding. I have used wima caps before, I think I have tried mkp10 and mkp4, I thought they sounded pretty neutral, nothing really stood out with them to me, they were used as coupling caps though not power supply caps.

 

[dowto1000]

The socket boards and that will just be to mess around with to get an idea of the next amp I want to build, just to experiment with. This amp that I'm building now will include 16 awg silver plated copper bus wire. 18 awg for both heaters and signal wire and I have some shielded belden wire for the inputs. I learned years ago breadboarding little solid state amps that long high awg wire picks up RF due to the higher resistance.

Whoah !!! After 36 years of DHT amp building, in 2018, I would not use the AWGs you are thinking of, at all. One must maintain high transfer efficiency, inside the SET amp !!. Or else it will be boring dynamically, like most all tube amps today are. Most of the wire I DIY-use is m22759/11, look it up.

I use 12 AWG on the primary leads of the Power Transformer, and to the AC switching and fuses. 20 Amp Hubbell IECs, no 15 A. IECs. On the Power Transformer Secondary, I use 16 AWG on the ENDS of the HV secondary, UNTWISTED to the tube rectifier,....( sounds better untwisted ) and 12 AWG as the HV winding's center tap lead-out to a star ground.

My 5 VCT ( 5U4GB or 5V43A ) rectifier winding is 14 AWG on ends, and the rectifier center tap, feeding the B+ filter, gets doubled-up 14 AWG ( effectively 11 AWG ) to L1. L1 and L2 are usually the same size and value. I always replace stock Hammond choke lead-outs with doubled up 16 AWG . In 2018, I favor Hammond Ls such as the 159ZB ( 7.85 Ohms ) and the 159ZA ( 6 Ohms ) for monoblocks using 2A3 Finals, etc etc. PSUD them as 425 mHY and 400 mHY respectively.

The B+ filter, is almost always ( 5U4GB, 5V3A ) a directly heated rectifier, they can do 4.6 A. and 6.6 A. instantaneous per plate. L1 as above, C1 is a WIMA DC LINK 4 Pin up to about 35 uF total / maximum , L2 as above, and C2 is typically about 50 to 56 uF as a total "C" amount. Maybe, for C2, a 50 uF WIMA DC LINK MKP4 and several paralleled film caps, to get precisely what I want, aurally from the filter ( wide band response and superb Dynamic contrasting - are my main build goals.)

At the C1 and C2 filter location ( to the DHT Finals ), since 4-2016, I bypass these two main caps with a 5 uF film cap that is rated at / shows an " I Max" or maximum current capability of 1570 Amperes. In these A1 circuits, this is KILLER for getting the leading edge of all musical transients, like no one has ever heard before in the tube audio universe. These same caps are in my speaker crossover - VOTT a7-800s.,

Now, this cap type, with the specific use of heavier m22759/11 wideband wire must make some sense to you.

Have fun, I do.

Dowto1000

OK, have I given you enough to digest?? Have fun, I do. Did you see the following post, from yesterday ??

http://audiokarma.org/forums/index....leads-of-audiotransformers-and-chokes.824731/

Best wishes.

 

[Tubeglowpio]

Whoah !!! After 36 years of DHT amp building, in 2018, I would not use the AWGs you are thinking of, at all. One must maintain high transfer efficiency, inside the SET amp !!. Or else it will be boring dynamically, like most all tube amps today are. Most of the wire I DIY-use is m22759/11, look it up.

I use 12 AWG on the primary leads of the Power Transformer, and to the AC switching and fuses. 20 Amp Hubbell IECs, no 15 A. ones. On the Power Transformer Secondary, I use 16 AWG on the ENDS of the HV secondary, UNTWISTED to the tube rectifier,....( sounds better untwisted ) and 12 AWG as the HV winding's center tap lead-out to star ground. My 5 VCT ( 5U4GB or 5V43A ) rectifier winding is 14 AWG on ends, and the rectifier center tap, feeding the B+ filter, gets doubled-up 14 AWG ( effectively 11 AWG ) to L1. L1 and L2 are usually the same size and value. I always replace stock Hammond choke lead-outs with doubled up 14 AWG . In 2018, I favor Hammond Ls such as the 159ZB ( 7.8 Ohms ) and the 159ZA ( 6 Ohms ) for monoblocks using 2A3 Finals, etc etc.

The B+ filter, is almost always ( 5U4GB, 5V3A ) directly heated rectifiers that can do 4.6 A. and 6.6 A. instantaneous. L1 as above, C1 is a WIMA DC LINK 4 Pin up to about 35 uF total / maximum , L2 as above, and C2 is typically about 50 to 56 uF as a total "C" amount. Maybe a 50 uF WIMA DC LINK MKP4 and several paralleled film caps, to get precisely what I want, aurally from the filter ( wide band response and superb Dynamic contrasting are my main build goals.)

At the C1 and C2 filter location ( to my DHT Finals ), I bypass these two main caps with a 5 uF film cap that is rated at / shows an " I Max" or maximum current capability of 1570 Amperes. In these A1 circuits, this is KILLER for getting the leading edge of all musical transients, like no one has ever heard before in the tube audio universe. Same caps are in my speaker crossover - VOTT a7-800s., Now, this cap type, and my specific use of heavier m22759/11 wideband wire must make some sense to you.

Have fun, I do.

Dowto1000

OK, have I given you enough to digest?? Have fun, I do. Did you see this post from yesterday, of mine ??

http://audiokarma.org/forums/index....leads-of-audiotransformers-and-chokes.824731/

Im all for well built or even over built amps as I do plan on my 2A3 amps to be overbuilt. The problem I find is that the nine pin Belton sockets really can't fit more than 18 gauge wire. Plus there are people using smaller gauge wire up to 22 awg for signal wire. 18 awg copper running an inch or two shouldn't be a problem but I do agree that even larger wire could only improve things, maybe I'll use some 12 gauge silver plated copper throughout someday with all film caps and non inductive resistors, lclc filter, and make it dual mono blocks too with hashimoto output transformers. Anyways I enjoyed your posts and will check out the wire you mention and your other post and I will indeed have fun.

 

[dowto1000]

Im all for well built or even over built amps as I do plan on my 2A3 amps to be overbuilt. The problem I find is that the nine pin Belton sockets really can't fit more than 18 gauge wire. Plus there are people using smaller gauge wire up to 22 awg for signal wire. 18 awg copper running an inch or two shouldn't be a problem but I do agree that even larger wire could only improve things, maybe I'll use some 12 gauge silver plated copper throughout someday with all film caps and non inductive resistors, lclc filter, and make it dual mono blocks too with hashimoto output transformers. Anyways I enjoyed your posts and will check out the wire you mention and your other post and I will indeed have fun.

Hi,

You should likely AVOID adding wire lengths to any tube socket, leading off to a terminal board.

Wire the Ra and Rk directly to one end of the socket ON the tube Pin.

Less is more !!! Less solder joints, less wire, shorter lead lengths, better transfer efficiency, less chance to degrade complex signal and dynamics. This is better sonically.

Give much thought, fore thought as to how to lay out and build an amplifier !!!

Use quality heavy wire between components, starting by replacing most lead outs, coming in and out of the winding, where you can exert some control. Think B+ leads, ground leads.

This following post, from today, is of value, I feel this guy builds the #1 SET amp in the history of this world, Just IMHO.

https://www.audioasylum.com/forums/tubediy/messages/26/262835.html


Dowto1000

 

[Tubeglowpio]

I guess when I wrote that I was mostly thinking about the heater wire as I don't need much wire in this project, as I played out so components leads are long enough to use. I read your link and made me rethink how bad of an idea it was to build this amp on a Hammond steel chassis, I normally use aluminum but liked that this one had the black powder coat. Hope I don't have the power transformer hum.