So says you.
I say unscientific terminology is meaningless - such as
and
They are the true total BS.
1/ You won't die from getting 600V DC on any part of your hand or leg, but it will arc and burn you, and isn't fun.
(I have had quite a few nasty moments).
What will kill you is getting it from one hand to the other - which essentially seizes your heart muscle when it's DC, across you from one side to the other.
(AC gives you a second chance)..
This is of course the reason why you NEVER EVER use more than one hand when handling high voltages.
I read here unending unscientific BS, about all sorts "precious" ideas.
Take a little look at what proper manufacturers like UTC did in the past.
They did special series S28-S34 I have quite a few of them.
Brilliant stuff, especially their swinging chokes, so those guys from the 60s did know their stuff, a lot of which was used for broadcast and studio audio.
Do you actually know the difference between a swinging choke and a normal one I have to ask?
ie.
If you want to know about PSU for SE amplifiers you want to talk to Electraprint.
Jack Elliano would laugh at the discussions on here, as he is a world authority on power supplies, IMD and chokes.
I've had a few energetic chats with him, and what he doesn't know you couldn't write on the end of pin....70yrs and counting.
You ignore knowledge like that at your peril.
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I purchased the CDE 947D caps which are 350uF for C2. Should get them in 3 days.
I have a pair of Coleman Bias Regulators. I have yet to try these for fixed bias on the 45B tubes. The 45Bs should have a bias of 60-80Vdc. My challenge is that the only source for Vac is from my power transformer which also supplies B+ and heater voltage. This power transformer has a spare 70Vac secondary that I could use with the Coleman Bias regulators. Although I recall Rod telling me that ideally using a separate transformer for the B+ and Bias are recommended. Do you foresee any issues using the 70V secondary tap for the Bias Supply? BTW: this 70Vac tap will run thru a rectifier circuit to get the DC, then into Coleman's regulator. Is the fixed bias method really that much better than the AC cathode bias that I am currently using?
BTW: The attached photo is my power transformer that I had made from Monolith. Very nice product.
I have a pair of Coleman Bias Regulators. I have yet to try these for fixed bias on the 45B tubes. The 45Bs should have a bias of 60-80Vdc. My challenge is that the only source for Vac is from my power transformer which also supplies B+ and heater voltage. This power transformer has a spare 70Vac secondary that I could use with the Coleman Bias regulators. Although I recall Rod telling me that ideally using a separate transformer for the B+ and Bias are recommended. Do you foresee any issues using the 70V secondary tap for the Bias Supply? BTW: this 70Vac tap will run thru a rectifier circuit to get the DC, then into Coleman's regulator. Is the fixed bias method really that much better than the AC cathode bias that I am currently using?
BTW: The attached photo is my power transformer that I had made from Monolith. Very nice product.
Attachments
The 845 molybd. sound warmer / more lush than the graphite (which I have here as well...Thomas was giving me a good incentive to try both). Not better. Different. Very Similar to Gm70 Copper or Iron vs. Graphite (Foton). The graphite gives more focus / deeper space more 3d, the molyb or Copper give more tone, very fluent...its more a question of taste.
BTW...the Elrog are build in a way I never saw on any other tubes... they are really beauties. Like Bentleys. Unbelievable built quality. I will never sell them.
The ultrapath setting is still a compromise. I tried that as well, but it looses against a normal fixed bias setting through the secondary of the IT. The signature of the ultrapath cap is still too dominate. Try simply to avoid all caps in the signal path and reduce resistors to the minimum...each component is audible. Especially on the cathodes. The two resistors to generate a ground path are really a bad idea...tried that as well. Rod coleman advised against that and he is soooo right.
So, yes ..use this secondary 70V...it will be worth it. I dont see an issue. The only thing which is important: The neg. bias must be there before HV is there...I use a EZ80, as I dont want silicon in my amp, so i needed a separate transformer which I switch on before HV hits the Endtriodes...maybe u want to use a directly heated tube rectifier there or silicon to avoid this.
BTW...the Elrog are build in a way I never saw on any other tubes... they are really beauties. Like Bentleys. Unbelievable built quality. I will never sell them.
The ultrapath setting is still a compromise. I tried that as well, but it looses against a normal fixed bias setting through the secondary of the IT. The signature of the ultrapath cap is still too dominate. Try simply to avoid all caps in the signal path and reduce resistors to the minimum...each component is audible. Especially on the cathodes. The two resistors to generate a ground path are really a bad idea...tried that as well. Rod coleman advised against that and he is soooo right.
So, yes ..use this secondary 70V...it will be worth it. I dont see an issue. The only thing which is important: The neg. bias must be there before HV is there...I use a EZ80, as I dont want silicon in my amp, so i needed a separate transformer which I switch on before HV hits the Endtriodes...maybe u want to use a directly heated tube rectifier there or silicon to avoid this.
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I have Jack Elliotts OPt for Kr520 here...from my Welbourne labs Apollo 2 times...lame ducks compared to any of the Amplimo or Monolith...let alone Alexanders stuff...Jacks stuff sound really 2nd class in direct comparison in the same circuit. Tried that as I had high hopes, but reality is different. His mantra on Hib is wrong.
I still try to convince Alexander though to go from Copper OCC (which even Monolith is NOT using) to silver OCC...I think Jack has there a point.
And yes, we know swinging chokes...you are boring...I fall asleep...goood night.
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On the CDE 947D ...they need a burn in of 7 day /24h, during this time they change quiet a bit through multiple phases of different sounds...in the end u know what you have in front of you...I would be surprised if they disappoint you...Let me know.
Silver, probably in the long future, Frank! The investment for an OPT would be insanely expensive!
My advise is to start with the smaller transformers first. From experience, we lately compared a silver vs copper input tranny with the other materials like core and insulation being kept the same. It was enough to make a total system sound overhaul.
My advise is to start with the smaller transformers first. From experience, we lately compared a silver vs copper input tranny with the other materials like core and insulation being kept the same. It was enough to make a total system sound overhaul.
50AE, are you suggesting silver throughout: OPT, IT? Also, chokes? I am using Duelund silver 3 silver foil hook-up wire. I love it!
I would recommend you silver coat your speaker drivers first - with a few micron vapour deposition - and swap out all the cross-over caps for silver mica, and swap all the inductors for silver plated copper - that will definitely get some liveliness and snap in to the sound stage. Speakers are where the best benefit ratio is achieved.
My comment was more on the different magnetic properties of silver vs. copper.
From Jack Elliotts page (electra print):
"Copper wire is used to wind transformers due to it being one of the lowest Direct Current Resistance (DCR) of all the metals used to create a magnetic field. Copper is also used to receive the flux variations in the secondary windings. If silver wire is used for the primary, it will create the same field due to the same amount of turns is needed as the copper. The only difference is a lower DCR than the equivalent copper primary, a costly decision for no performance increase.
Silver wire used for the secondary it will be about 200% more sensitive than copper. If the primary has very low level flux motion from higher harmonic content sounds, silver wire will reproduce it. This is the only increase in performance offered by silver wire when used as a secondary."
This effect was reported by many others like Menno v.d.Veen (Amplimo), AE Europe etc.
And further:
"Recently the price of silver has increased to a point that the cost would be prohibitive for many to consider amps delivering the precious metal sound. Electra-Print Audio performed a test to see if the transformer secondary winding needed to be pure silver wire to achieve the sound difference. They determined that partial silver wire or silver plated multi-strand wire was found to be equal to using solid silver wire. The amount of silver needed is just 20% to achieve the improvement in the sound".
from Step Into the Eddie Current Listening Lounge! – Eddie Current
So maybe its not as prohibitive expensive as it initially appears...i would start with an IT to see what happens...
From Jack Elliotts page (electra print):
"Copper wire is used to wind transformers due to it being one of the lowest Direct Current Resistance (DCR) of all the metals used to create a magnetic field. Copper is also used to receive the flux variations in the secondary windings. If silver wire is used for the primary, it will create the same field due to the same amount of turns is needed as the copper. The only difference is a lower DCR than the equivalent copper primary, a costly decision for no performance increase.
Silver wire used for the secondary it will be about 200% more sensitive than copper. If the primary has very low level flux motion from higher harmonic content sounds, silver wire will reproduce it. This is the only increase in performance offered by silver wire when used as a secondary."
This effect was reported by many others like Menno v.d.Veen (Amplimo), AE Europe etc.
And further:
"Recently the price of silver has increased to a point that the cost would be prohibitive for many to consider amps delivering the precious metal sound. Electra-Print Audio performed a test to see if the transformer secondary winding needed to be pure silver wire to achieve the sound difference. They determined that partial silver wire or silver plated multi-strand wire was found to be equal to using solid silver wire. The amount of silver needed is just 20% to achieve the improvement in the sound".
from Step Into the Eddie Current Listening Lounge! – Eddie Current
So maybe its not as prohibitive expensive as it initially appears...i would start with an IT to see what happens...
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Definitely not, you'll probably need to sell your house for that 😀
I would recommend what I call "material poisoning", it is the addition of some silver material in your system. An input transformers has a few grams only and does wonders.
I'm not convinced yet you need a full silver system.
Me neither. But a silver-plated OCC-copper wire which fulfills the 20% from above on the secondaries ? Should be affordable. Or a mix of some layers Copper and combined with some layer silver ?
BTW...What is the weight of an IT secondary only ? 100gr ? 150 gr ? Right now the silver price is like 1 gr = 1 Euro.
But, hey, this was just an idea...I will stop now...
BTW...What is the weight of an IT secondary only ? 100gr ? 150 gr ? Right now the silver price is like 1 gr = 1 Euro.
But, hey, this was just an idea...I will stop now...
quote: the negative bias must be there before the HV is there
Yes, with HV on and zero bias Volt on grid, you would destroy the output tubes !
With a (quick on) direct heated rectifier (5Z3) for HV psu do not use a soft start indirect heated rectifier for the minus bias voltage. The HV would be first on.
For a soft start on HV psu you could insert a TV-damper diode (6DA4 / 6DM4) after the 5Z3 before the first LC.
Or, remove the 5Z3 and use two tv-dampers rectifiers for full wave - they sound good.
Other: SiC Schottky diodes for minus bias psu. The Infineon SiC diodes are best. The Cree SiC are not so good.
Yes, with HV on and zero bias Volt on grid, you would destroy the output tubes !
With a (quick on) direct heated rectifier (5Z3) for HV psu do not use a soft start indirect heated rectifier for the minus bias voltage. The HV would be first on.
For a soft start on HV psu you could insert a TV-damper diode (6DA4 / 6DM4) after the 5Z3 before the first LC.
Or, remove the 5Z3 and use two tv-dampers rectifiers for full wave - they sound good.
Other: SiC Schottky diodes for minus bias psu. The Infineon SiC diodes are best. The Cree SiC are not so good.
TV-Damper diodes I tried as well many different types, somewith Copper, some with Nickel plates. Sound OK, but not more than that...if you want an elcheapo solution in general...not comparable really to nice 5u4g or 866.,,,and we are back to Half-wave...so two are needed at least...
So, Sic or germanium diodes I would say as well...the later sound quiet like a tube rectifier. Maybe I will move to those one day as well.
So, Sic or germanium diodes I would say as well...the later sound quiet like a tube rectifier. Maybe I will move to those one day as well.
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Of your AMCC100 interstages, approximately 450g per secondary per transformer.
I'm skeptical about silver plated copper.
Um, no. His designs are recycled circa 1927 Loftin/White.
I actually built an amp like his was. sounded sweet but the harmonic distortion values I measured were really too much.
Switching to Lundahl chokes reduced harmonic distortion values considerably. Lundahl filament chokes can be used with their regular power chokes to create a fly-wheel supply. It works quite well.
But you can also simply build a LCLC supply the old-school way. Harmonic distortion was just as low. Less fiddling with PSU-II simulations and tuning that 1st cap.
Lesson learned: Those cheap chokes he uses are cheap for a reason.
Been there, done that. I use cap multipliers for low powered amps, pre-amps, etc.
This matches my experience. I took his advise as well more like an inspiration for going after reasonably low RDC chokes, which indeed is a good advise.
But this mantra of near zero ohm and consequently low inductance has other effects and sounded wrong to me as well (fizzling, no tonal fundament). The more Rdc, the more warmth and the slower, uninvolving, less dynamic the music becomes...we talk here about 150ohm for a HV choke for example. 20 to 35 ohn sound just right to me.Lower and it is for my taste to thin sounding. The flywheel I could not find any goods on that except another choke in the PSU which is not my philosophy. I try to avoid any unnecessary components if possible.KISS. And yes, thos Hammond chokes sound...brrrrrr
But this mantra of near zero ohm and consequently low inductance has other effects and sounded wrong to me as well (fizzling, no tonal fundament). The more Rdc, the more warmth and the slower, uninvolving, less dynamic the music becomes...we talk here about 150ohm for a HV choke for example. 20 to 35 ohn sound just right to me.Lower and it is for my taste to thin sounding. The flywheel I could not find any goods on that except another choke in the PSU which is not my philosophy. I try to avoid any unnecessary components if possible.KISS. And yes, thos Hammond chokes sound...brrrrrr
Thanks for all the feedback. I want to use my existing Slagle interstage transformer and the monolith SX-11 OPT. So, I am thinking about the suggestion below, in order of priority.
1. COMPLETED: Replace Kemet (550uF) with Cornell Dubilier 947D Series Film Capacitors (350uF) in the C2 position. The caps have been ordered and I should have results later this week.
2. Eliminate the 2x50 ohm resistors on the 45B filaments and use fixed bias on the 45B tube. I may need some help with a schematic for this. I do have a used 70Vac secondary on my power transformer and can rectify the 70Vac. I would prefer a very simple, passive solution if possible. Need help here.
3. Replace RCA 5Z3 and 83 rectifiers with a Telefunken RGN2004 or possibly 2 x HW 866 mercury
4. Eventually, replace the existing PS chokes (L1 and L2) to lower DCR: 10H 25 ohms
5. Replace C3g driver with silver input transformer 1:8 + 801A
6. Eventually, if I need more watts, replace the 45B with the KR842 or Philips 814A
Constructive thoughts are always encouraged. Including re-prioritization of the list above.
Thanks!
1. COMPLETED: Replace Kemet (550uF) with Cornell Dubilier 947D Series Film Capacitors (350uF) in the C2 position. The caps have been ordered and I should have results later this week.
2. Eliminate the 2x50 ohm resistors on the 45B filaments and use fixed bias on the 45B tube. I may need some help with a schematic for this. I do have a used 70Vac secondary on my power transformer and can rectify the 70Vac. I would prefer a very simple, passive solution if possible. Need help here.
3. Replace RCA 5Z3 and 83 rectifiers with a Telefunken RGN2004 or possibly 2 x HW 866 mercury
4. Eventually, replace the existing PS chokes (L1 and L2) to lower DCR: 10H 25 ohms
5. Replace C3g driver with silver input transformer 1:8 + 801A
6. Eventually, if I need more watts, replace the 45B with the KR842 or Philips 814A
Constructive thoughts are always encouraged. Including re-prioritization of the list above.
Thanks!
1. Give it one week of burn in...it changes from open, but a bit light to more close and warm and settle after a week right in the middle.
2.
I can send you a schematic for the passive supply, you dont need the coleman regs for such a low gain tube, a passive supply is sufficient. But you can see the logic how not to use the 2 50ohm resistors.
3. Try a rg1064 first...but tfk mesh. the rgn2004 is 200 Euro. Lets start smaller. The rgn2004 sounds the same, just a but stiffer.
4. Maybe try to parallel your existing chokes ?
5. Input transformer is a difficult chapter...no Lundahls, please. Get a highlevel DAC. Maybe a second 801 A stage is the better option(which I use).
6. The 814 has a nice high gain and needs only half of the swing of the 45.
2.
I can send you a schematic for the passive supply, you dont need the coleman regs for such a low gain tube, a passive supply is sufficient. But you can see the logic how not to use the 2 50ohm resistors.
3. Try a rg1064 first...but tfk mesh. the rgn2004 is 200 Euro. Lets start smaller. The rgn2004 sounds the same, just a but stiffer.
4. Maybe try to parallel your existing chokes ?
5. Input transformer is a difficult chapter...no Lundahls, please. Get a highlevel DAC. Maybe a second 801 A stage is the better option(which I use).
6. The 814 has a nice high gain and needs only half of the swing of the 45.
your current circuit is on post #99 ? You don't have -61V on the 45 grid if the IT secondary is grounded. nope. That does not happen.
Did anyone else mention this? There are other things I see in the schematic that don't make sense to me, but is this running?
What is the voltage at the top of the 1k Ohm cathode resistor?
Ian
Did anyone else mention this? There are other things I see in the schematic that don't make sense to me, but is this running?
What is the voltage at the top of the 1k Ohm cathode resistor?
Ian
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