I really like that 4D32 design.
i have one in the works....
Attachments
Attachments
-
367B35E8-30F2-49ED-A879-9FF3855AD76F.JPG244.8 KB · Views: 216
-
F4280629-0545-4DCB-BBEA-BC0A1EDBC86B.JPG665.2 KB · Views: 352
-
9CECDC40-CE49-478A-A156-E0B00B6D35DA.JPG386.1 KB · Views: 365
-
30BA8949-EA5F-4C95-A843-DFBDC32ED7C4.JPG384.7 KB · Views: 233
-
ACB1457A-4515-4608-91A9-C17198815275.JPG396 KB · Views: 613
-
4092C8A3-24EE-4072-84E5-B2ED313FFFC8.JPG223.7 KB · Views: 325
-
015AB161-ED0C-4A0F-9437-E2D532D2F88F.JPG535.9 KB · Views: 299
-
193FEA46-DE67-435A-B682-6743F9209C74.JPG335.6 KB · Views: 220
-
148B205B-3744-4FD2-A2D2-5F1C080C5392.JPG321.8 KB · Views: 339
-
6A8C6923-34C3-4902-91DF-08CDC21B87A9.JPG732.9 KB · Views: 323
Attachments
-
4742BBBA-11A1-4F25-8DB2-5E9B44FCB3A2.JPG358.8 KB · Views: 184
-
37E6F090-015A-45BC-A085-35278F7DCDBC.JPG314.3 KB · Views: 193
-
05E71C9F-E812-4849-9C1E-0663331C0443.JPG310.4 KB · Views: 203
-
967A2843-EB8B-41C2-A304-E5A155DCE810.JPG438 KB · Views: 118
-
B1A1ED9B-DD26-4149-AEE3-236FCDE4191E.JPG545.8 KB · Views: 121
-
1FB0A6CE-D2FA-4627-8C5B-70ECBD9F0B9C.JPG564.2 KB · Views: 174
-
8DD1F469-1827-4494-91B1-EC2FCE9E1898.JPG254.7 KB · Views: 122
-
6F8ED62D-3364-4EBD-83B8-2FC1FE37C5D4.JPG376 KB · Views: 200
-
D3047439-259E-498B-9717-8BDF381A6C33.JPG399.3 KB · Views: 194
-
BE201A68-9056-4E7E-AA70-58BC8134C172.JPG97.4 KB · Views: 175
+
Attachments
-
0672F586-6C04-4BAC-AD01-29D6D8DAAC5F.JPG259.5 KB · Views: 138
-
80934A1F-B695-4F55-9679-FBC0AD3B36D9.JPG264.6 KB · Views: 223
-
1A0E3676-751F-437F-A6D3-F0FEF468B442.JPG670.5 KB · Views: 171
-
E9F6C344-4570-4B19-9D69-15D16D1CF36C.JPG133.9 KB · Views: 107
-
CDC340BE-C3EF-4DDD-9F09-AFFCB8511EA8.JPG423.3 KB · Views: 197
-
28468A2D-5709-4624-A15A-A9819503757A.JPG416.3 KB · Views: 203
-
63641D58-3D4D-448C-9735-2573ECCBEAF0.JPG285.7 KB · Views: 213
-
507E0AC6-C34B-4D5E-A9CC-45BBAEAAA50B.JPG255.6 KB · Views: 196
-
87B5B5A0-9165-42EB-9478-ED803F3BBED1.JPG287.6 KB · Views: 227
They're feeding the 40KD6 heaters directly off the mains in that OTL !
Best regards!
Let's say is an old design from the 90´s
As always, Safety First!
Prevent the "Surviving Spouse Syndrome"
A general statement that filaments and cathodes should be tied together by a 'recommended' resistor (not just the 40KD6 tubes), depending on the circuit topology, can have both safety and performance implications.
A few Newbies might be confused, and might build either an Un-Safe circuit, or a Low Performance circuit, or both at the same time.
Please, tell me I am missing some important point . . .
If you start with a concertina phase splitter stage, and then tie the heater to the cathode with the recommended 10k or 20k Ohm resistor, the Concertina performance will be degraded.
It will be true, whether the filament is AC or DC powered, if the filaments share a common supply.
And, if you start with an LTP phase splitter, and then tie the heater to the cathode with the recommended 10k or 20k Ohm resistor, then that phase splitter performance will be degraded.
It will be true, whether the filament is AC or DC powered, if the filaments share a common supply.
With a single AC or DC powered filament supply all the cathodes will be resistively tied together by the suggested filament to cathode resistances.
Floating Cathodes will no longer be floating, and many circuit topologies Require 'floating' cathodes that are not tied to another circuit by a 10k or 20k resistor.
Just my 2 pennies worth.
Prevent the "Surviving Spouse Syndrome"
A general statement that filaments and cathodes should be tied together by a 'recommended' resistor (not just the 40KD6 tubes), depending on the circuit topology, can have both safety and performance implications.
A few Newbies might be confused, and might build either an Un-Safe circuit, or a Low Performance circuit, or both at the same time.
Please, tell me I am missing some important point . . .
If you start with a concertina phase splitter stage, and then tie the heater to the cathode with the recommended 10k or 20k Ohm resistor, the Concertina performance will be degraded.
It will be true, whether the filament is AC or DC powered, if the filaments share a common supply.
And, if you start with an LTP phase splitter, and then tie the heater to the cathode with the recommended 10k or 20k Ohm resistor, then that phase splitter performance will be degraded.
It will be true, whether the filament is AC or DC powered, if the filaments share a common supply.
With a single AC or DC powered filament supply all the cathodes will be resistively tied together by the suggested filament to cathode resistances.
Floating Cathodes will no longer be floating, and many circuit topologies Require 'floating' cathodes that are not tied to another circuit by a 10k or 20k resistor.
Just my 2 pennies worth.
Last edited:
They're feeding the 40KD6 heaters directly off the mains in that OTL !
Best regards!
perhaps, they found that 100vac was not lethal enough.....but that is one practice i will never copy....
Attachments
-
B4641F30-006D-4E33-BC18-306B5DC78A70.JPG528.6 KB · Views: 307
-
CA95715A-144D-4C7E-A43D-9F306C75F213.JPG294.4 KB · Views: 320
-
414F10C9-38AB-403A-A2A6-6441357AEBAF.JPG473.8 KB · Views: 322
-
23FB1BAD-91C6-4446-BBF0-007A47F344A3.JPG255 KB · Views: 326
-
4813211E-ED6B-4DBF-87CB-4966FF0A27CF.JPG606.4 KB · Views: 191
-
3CE9FB51-EA3B-436D-AE80-FA6DF0A27973.JPG457.9 KB · Views: 183
-
36956018-C1F2-4D58-B13D-D6686F19AA13.JPG314.6 KB · Views: 185
-
0C1398B5-07EA-400A-A998-23A838F33A77.JPG255.4 KB · Views: 186
-
31F7F529-D6D2-4D06-94A8-AF59197EC046.JPG315.1 KB · Views: 201
-
FF056B5F-F8CC-4E8C-84D5-5E78943BA1B1.JPG251.9 KB · Views: 121
Attachments
-
0E787C8A-8A84-40DE-ADA8-3ECFD9B88B62.JPG323.6 KB · Views: 146
-
CDCA707A-486C-4947-B4D9-E63188C8442E.JPG261.9 KB · Views: 163
-
4050F3DA-C94F-43E8-91F6-3596F0BF0011.JPG381.9 KB · Views: 180
-
9E6E4E88-7443-4497-95DF-7EAECDC5AE25.JPG397 KB · Views: 160
-
EDF10BB2-62DF-464E-863F-46AE3F43DC78.JPG219.4 KB · Views: 99
-
17A35E32-6609-49BC-B8A6-FFF73B9733A3.JPG562.1 KB · Views: 133
-
0A677C8C-BCE7-4127-8164-425F00717EA1.JPG594 KB · Views: 141
-
3B11C021-1A68-4F96-AAA2-54E8B22CA264.JPG324.6 KB · Views: 178
-
938AB584-BB8B-4143-B181-740543F4AE62.JPG110.1 KB · Views: 179
-
76E9C458-97BA-4525-B63A-86FB20D03D07.JPG126.3 KB · Views: 150
どうもありがとうございます
Domo arigato gozaimasu
to Old Radio Boy from Japan and Diyers Friends
for all schematics sharing and contributions
Peace and Joy to All Merry Christmas
Domo arigato gozaimasu
to Old Radio Boy from Japan and Diyers Friends
for all schematics sharing and contributions
Peace and Joy to All Merry Christmas
Attachments
-
0D73E321-6D91-4F20-B03D-346E4BB8937D.JPG163 KB · Views: 74
-
6B3A2AA7-0ACC-43C0-9E4D-02552DB821A8.JPG478.2 KB · Views: 142
-
1BB3611B-240A-4953-A0D3-12D167629A38.JPG381.7 KB · Views: 191
-
1A87C10C-DBFE-46D1-9EF6-E3B5252E412D.JPG642.4 KB · Views: 196
-
786BE11A-C4BD-489C-8704-DE10B1BCA6DA.JPG345.7 KB · Views: 193
-
87B64D37-8238-44E2-9BD7-163D0F0A96D1.JPG459.7 KB · Views: 176
-
5B2038F3-2284-4DC8-A97A-D864450DDC32.JPG54.1 KB · Views: 82
- Home
- Amplifiers
- Tubes / Valves
- Gold mine of DI¥ audio tubes schematics from Japan