This schematic is quite close to being finished. 
Remember, R5 is now a series wired composite of a wirewound part and 2 carbon film parts. Connect the wirewound part to the 'X7 anode.
Connect pin 9 on the 12AX7 socket to the junction of the O/P tube heaters. Initially, that "bus" will be connected directly to ground. If, during the debugging process, hum levels are unacceptably large, that "bus" will be grounded for AC, via a cap., and elevated to approx. +60 VDC, by adding a resistive voltage divider between B+ and ground.
Permanently "jumper" pin 1 of each O/P tube socket to the corresponding pin 3. Then, it doesn't matter which O/P tube type is in use, at any particular time. The O/P tube cathode current gets set, at installation time. Recheck the cathode current at approx. 6 month intervals. Tubes are consumables that wear out, over time.
Remember, R5 is now a series wired composite of a wirewound part and 2 carbon film parts. Connect the wirewound part to the 'X7 anode.
Connect pin 9 on the 12AX7 socket to the junction of the O/P tube heaters. Initially, that "bus" will be connected directly to ground. If, during the debugging process, hum levels are unacceptably large, that "bus" will be grounded for AC, via a cap., and elevated to approx. +60 VDC, by adding a resistive voltage divider between B+ and ground.
Permanently "jumper" pin 1 of each O/P tube socket to the corresponding pin 3. Then, it doesn't matter which O/P tube type is in use, at any particular time. The O/P tube cathode current gets set, at installation time. Recheck the cathode current at approx. 6 month intervals. Tubes are consumables that wear out, over time.
Please elaborate this proposal - what should be connected and where?
Do you agree with pcan's proposal about 150 Ohm resistors connected to the ground in the heaters' line? I'm about to update PS schematic. Thank you!
See post #126, where I linked to the 3 parts needed to form the composite. Resistances in series simply add. 100 K + 150 K + 220 K = 470 K 
The idea is using 3 connected pieces to replace a single "lump".
The key point "pcan" made is the need to ground the heater supply, for purposes of hum control. I would use his resistor pair idea, if the filament supply was "6.3" VAC and the winding lacked a center tap (CT). The "bus" connecting 'X7 pin 9 and the junction of the O/P tube heaters I previously described accomplishes the same thing, "synthesizing" a CT for the heater supply. In the "12.6" VAC situation we have, my method uses only wire and saves a few cents.
The idea is using 3 connected pieces to replace a single "lump".The key point "pcan" made is the need to ground the heater supply, for purposes of hum control. I would use his resistor pair idea, if the filament supply was "6.3" VAC and the winding lacked a center tap (CT). The "bus" connecting 'X7 pin 9 and the junction of the O/P tube heaters I previously described accomplishes the same thing, "synthesizing" a CT for the heater supply. In the "12.6" VAC situation we have, my method uses only wire and saves a few cents.
Some "peaking" is good. Lots of "peaking" could be bad. It just "felt" right to use 100 K in the inductive wirewound (WW) position. In turn, the other 2 parts were needed to get the correct total resistance. The part linked for R5 happens to be rated 5 W., not because toughness is needed, but its low cost. The parts linked for R6 & R7 are rated 1 W., which is quite sufficient. Roughly 1 mA. of plate current flows in each 'X7 section. Apply the P = I2R formula, to each of the resistors that make up the 470 Kohm total. Don't forget to leave "breathing room". Maintain a belt & suspenders mindset, to ensure your trousers don't fall. Reliability matters, with both tubes & SS.
There is 1 more small change. For now, simply ground the "bus" that connects pin 9 of the 12AX7 socket to the junction of the power tube heaters.
Added ground to the "bus" and changed the ratings for those resistors. I will start ordering components soon. Is it possible to say what will be changed in the PS and Amp so that I could order components with other possible values? Probably it makes sense to buy 0.5W and 2W resistor kit.
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I'd be very cautious about buying resistor kits. Different resistor types are suited to different roles. There is no "best" resistor type. Best for what job?
R2 and R10 are grid stoppers. Being both non-metallic and non-inductive, carbon composition parts are well suited to the role. R1 and R9 are in grid to ground positions. Low noise matters here and metal film parts get the nod. R3, R8, and R12 require 1% precision parts. Again, metal film parts get the nod. Mouser carries Xicon brand metal film resistors, which will give excellent price/performance for all the previously mentioned items. IMO, a 1% precision part is indicated for R4 too and this item fills the requirement.
I'm trying to collect in one place the info scattered across multiple pages. Here is the final schematic for PS and the parts list.
Code:
T1 - Triad N-68X
[URL]https://www.mouser.com/ProductDetail/Triad-Magnetics/N-68X?qs=%2fha2pyFadujgpvvi3%252bprbw33P0KLwfnamaApL%252b8cFew%3d[/URL]
T2 - Triad VPS24-1000
[URL]https://www.mouser.com/ProductDetail/Triad-Magnetics/VPS24-1000?qs=sGAEpiMZZMvwUzoUXIIvydH8%2fj5UF54yTv9IKwPkmq4%3d[/URL]
T3 - Triad C-24X
[URL]https://www.mouser.com/ProductDetail/Triad-Magnetics/C-24X?qs=xrpI9KL%2FXvsp8oLEd8wC%2FQ%3D%3D[/URL]
V1 - OA2
[url=https://www.ebay.com/itm/1PCS-SYLVANIA-OA2-0A2-OA2WA-6626-CV4020-Vacuum-tube-NOS/152620246140?epid=1072830523]1PCS - SYLVANIA OA2 / 0A2 ( OA2WA / 6626 / CV4020) Vacuum tube NOS | eBay[/url]
C1 - 0.01uF 2000V
[URL]https://www.mouser.com/ProductDetail/Cornell-Dubilier-CDE/DPPM20S1K-F?qs=sGAEpiMZZMv1cc3ydrPrFwLJAmLhcfj35IIgJQNHda0%3d[/URL]
C2 - 20uF 400V
[URL]https://www.mouser.com/ProductDetail/United-Chemi-Con/EGXF401ELL200MJ30S?qs=sGAEpiMZZMukHu%252bjC5l7YYOm8CqN7Zj%2foW0GsUvVneI%3d[/URL]
C3, C4 - 180uF 250V
[URL]https://www.mouser.com/ProductDetail/Nichicon/UCY2E181MHD6?qs=sGAEpiMZZMtZ1n0r9vR22awqI6nzE%2fsTPmyizGVpPNg%3d[/URL]
C5 - 82uF 400V
[URL]https://www.mouser.com/ProductDetail/Panasonic/EEU-EE2G820?qs=sGAEpiMZZMtZ1n0r9vR22dN7zJS18SGV4uFjDxRrTxw%3d[/URL]
C6 - 0.068uF 400V
[URL]https://www.mouser.com/ProductDetail/WIMA/MKP1G026804C00KF00?qs=sGAEpiMZZMv1cc3ydrPrF2CPLAojp4yWTme4nl3ONOM%3d[/URL]
D1, D2 - UF4007GP-TP
[URL]https://www.mouser.com/ProductDetail/Micro-Commercial-Components-MCC/UF4007GP-TP?qs=sGAEpiMZZMtbRapU8LlZDzWSnAblitvPZLDaoGuk%2f10%3d[/URL]
L1 - CL-140 Inrush Current Limiter
[URL]https://www.mouser.com/ProductDetail/Amphenol-Advanced-Sensors/CL-140?qs=sGAEpiMZZMuqZeNK75brD9Lrm4Ls3H6A27r%252bQtFpb38%3d[/URL]
R1, R2, R3, R4 - ?Here is the amp schematic and the parts list:
Code:
T1 - GXSE15-5K
[URL="https://www.edcorusa.com/gxse15-8-5k"]EDCOR - GXSE15-8-5K[/URL]
V1 - 12AX7
[URL="https://www.ebay.com/itm/Sino-12AX7B-Preamp-Vacuum-Tube/152759915406"]Sino 12AX7B Preamp Vacuum Tube | eBay[/URL]
V2 - 6P15P-EV
[URL="https://www.ebay.com/itm/6P15P-EV-4Pcs-Russian-Military-Long-LIFE-Vacuum-Pentode-tube-OTK-same-year-EL83/292276425741"]6P15P-EV 4Pcs Russian Military Long LIFE Vacuum Pentode tube OTK same year EL83 | eBay[/URL]
C1 - 0.082uF 400V
[URL="https://www.mouser.com/ProductDetail/EPCOS-TDK/B32642B6823J?qs=sGAEpiMZZMv1cc3ydrPrFzRLALvOkyF1xqwV3JmB0SfGtnllqjsKTw%3d%3d"]B32642B6823J EPCOS / TDK | Mouser[/URL]
C2 - 0.1uF 400V
[URL]https://www.mouser.com/ProductDetail/EPCOS-TDK/B32671L4104J000?qs=sGAEpiMZZMtI26rxh1qzjhCu5rOhviVHVa96FMB1%252bC8%3d[/URL]
C3 - 680uF 16V
[URL]https://www.mouser.com/ProductDetail/Nichicon/LKG1E681MESYCK?qs=sGAEpiMZZMtZ1n0r9vR22d%252blFeYd%252bH4EB5OPpYC2i4g%3d[/URL]
C4 - 180pF 1kV
[URL]https://www.mouser.com/ProductDetail/Vishay-Cera-Mite/561R10TCCT18?qs=sGAEpiMZZMt1mVBmZSXTPFXppOBlV6Pk7PmGGS9GNQY%3d[/URL]
R1 - 100 kOhm 0.5W
[URL]https://www.mouser.com/ProductDetail/Xicon/293-100K-RC?qs=sGAEpiMZZMukHu%252bjC5l7YQs4PzqcsJEK1gKCm%252btXr3E%3d[/URL]
R2, R12 - 100 Ohm 0.5W
[URL]https://www.mouser.com/ProductDetail/Vishay-Semiconductors/TZX3V6A-TR?qs=sGAEpiMZZMui8icXhU1dEupM5jfX%252bQnA[/URL]
R3 - 820 Ohm 0.5W 1%
[URL]https://www.mouser.com/ProductDetail/Welwyn-Components-TT-Electronics/MFR4-820RFI?qs=sGAEpiMZZMukHu%252bjC5l7YRDwiouGrKBmwSsVuz94HuQ%3d[/URL]
R4 -150 kOhm 2W
[URL]https://www.mouser.com/ProductDetail/Vishay-Dale/CPF2150K00FKE14?qs=sGAEpiMZZMu61qfTUdNhGz34irntT%2fJFIKWZR%2fBAcb0%3d[/URL]
R5 - 100k 5W wirewound
[URL]https://www.mouser.com/ProductDetail/Xicon/280-PRM5-100K-RC?qs=sGAEpiMZZMtbXrIkmrvidHiKlRtT248Uj8xqXsZy2zA%3d[/URL]
R6 - 150 Kohm carbon film 1W
[URL]https://www.mouser.com/ProductDetail/Xicon/294-150K-RC?qs=sGAEpiMZZMu61qfTUdNhG3GWZmU6PwDPWeAE%2fkNyxUU%3d[/URL]
R7 - 220 Kohm carbon film 1W
[URL]https://www.mouser.com/ProductDetail/Xicon/294-220K-RC?qs=%2fha2pyFaduiRHRkVJgnDOB3vlddufLrLIToe7QaFR9Q%3d[/URL]
R8, R10 - 10 kOhm 0.5W
[URL]https://www.mouser.com/ProductDetail/Vishay-Dale/CMF5510K000BEEA?qs=sGAEpiMZZMukHu%252bjC5l7YWGhjK80auj0pDzGU6krlXY%3d[/URL]
R9 - 470 kOhm 0.5W
[URL]https://www.mouser.com/ProductDetail/Xicon/293-470K-RC?qs=sGAEpiMZZMukHu%252bjC5l7YTF6je7BkLxK9noGLdhjO%252bM%3d[/URL]
R11 - 150 Ohm 0.5W
[URL]https://www.mouser.com/ProductDetail/Bourns/3362P-1-151?qs=sGAEpiMZZMs26uXuX7MLMQDudKPvZ1vl[/URL]
Recommended speakers 3" 8 Ohm 91 dB:
[URL]https://www.parts-express.com/faitalpro-3fe25-3-professional-full-range-woofer-8-ohm--294-1104?AID=1457483&PID=7598510[/URL]There are errors in the signal BoM.
R1, R9, and R12 should be metal film, not carbon film.
R2 and R10 should be carbon composition. Use this and this.
A 0.1% tolerance part for R8 is costly overkill. Use this. The price is nice and KOA/Speer's reputation is solid.
A 1/2 W. rated part is cutting things too fine, for R11. Use this. "Better to be looking at it, than looking for it."
To put it mildly, coupling caps. are a subject of considerable "debate". With some exceptions, my preferences are discrete polypropylene film/metal foil and Soviet surplus K40 paper in oil (PIO) parts. Polyester exhibits some electrical quirks and (for the most part) metalized film is "meh". This part gets my nod for C2. We now come to subject of C1. Polystyrene is easily as good electrically as polypropylene, but it's heat sensitive. C1 is not nearly as thermally "exposed" as C2. So, this is what I suggest for C1. Don't loose sleep over the WVDC rating. Plate to grid shorts/arcs in small signal triodes are RARE occurrences.
R1, R9, and R12 should be metal film, not carbon film.
R2 and R10 should be carbon composition. Use this and this.
A 0.1% tolerance part for R8 is costly overkill. Use this. The price is nice and KOA/Speer's reputation is solid.
A 1/2 W. rated part is cutting things too fine, for R11. Use this. "Better to be looking at it, than looking for it."
To put it mildly, coupling caps. are a subject of considerable "debate". With some exceptions, my preferences are discrete polypropylene film/metal foil and Soviet surplus K40 paper in oil (PIO) parts. Polyester exhibits some electrical quirks and (for the most part) metalized film is "meh". This part gets my nod for C2. We now come to subject of C1. Polystyrene is easily as good electrically as polypropylene, but it's heat sensitive. C1 is not nearly as thermally "exposed" as C2. So, this is what I suggest for C1. Don't loose sleep over the WVDC rating. Plate to grid shorts/arcs in small signal triodes are RARE occurrences.
Not really. Buy Belton sockets if you want to. Personally, I fine Chinese sockets work well enough if you don't do a lot of "tube rolling", but I prefer NOS Soviet parts.
7 pin: 10PC 7PIN B7A Chassis Mount Vacuum Tube Sockets For 6Z4 6J1 6J2 6J5 6X4 6K7 EAA9 | eBay
9 pin : 9 Pin Vacuum Tube Sockets For 12AX7 6DJ8 5670 EL84 ECC83 Bottom Chassis Mountx10 | eBay
I find GDparts to be reputable. Never had any issues, but of course you might want to buy them from the USA instead of China.
If you like, I can sell you the 4 sockets you need to save you money. I should be able to mail them to you for 10$ inclusive depending on the weight an size of the pack.
7 pin: 10PC 7PIN B7A Chassis Mount Vacuum Tube Sockets For 6Z4 6J1 6J2 6J5 6X4 6K7 EAA9 | eBay
9 pin : 9 Pin Vacuum Tube Sockets For 12AX7 6DJ8 5670 EL84 ECC83 Bottom Chassis Mountx10 | eBay
I find GDparts to be reputable. Never had any issues, but of course you might want to buy them from the USA instead of China.
If you like, I can sell you the 4 sockets you need to save you money. I should be able to mail them to you for 10$ inclusive depending on the weight an size of the pack.
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