Search found 8881 matches

by Paul Barker
Thu Dec 29, 2011 9:23 pm
Forum: Valves
Topic: SRPP Series Shunt Reg Anyone?
Replies: 56
Views: 22694

In the still pic, the three 75v VR tubes are in the little chassis in forground the 830b on the wooden breadboard. In the first video this version which has 100mA shunted by the 830b is playing. In the second video the two british VR tubes are doing all the shunt work. In both cases the mechanism by...
by Paul Barker
Thu Dec 29, 2011 8:26 pm
Forum: Valves
Topic: SRPP Series Shunt Reg Anyone?
Replies: 56
Views: 22694

By the way the last cap shouldn't be necessary if you shunt as much current as your amp demands. I did manage to breadboard a power supply capable of providing for an output stage of 260v 50mA using two of the venerable old British 4 pin regulators pulling about 50mA. I just chopped and changed the ...
by Paul Barker
Thu Dec 29, 2011 8:14 pm
Forum: Valves
Topic: SRPP Series Shunt Reg Anyone?
Replies: 56
Views: 22694

The 5k6 resistor you got the idea from the plate load of the error amplifier in a conventional series pass design. It is without purpose here. Unless you are using it to strike the VR tubes. This is not necessary. The 6080 when it heats up will pull sufficient current to strike the VR's and plenty t...
by Paul Barker
Tue Dec 27, 2011 9:06 pm
Forum: Valves
Topic: Shunt Reg Using a 13E1 as Shunt Element
Replies: 70
Views: 30645

Just mulling this over, the 12E1 Triode connected would have a max g2 voltage 300 max current 100 mA max dissipation 35 Watts. Be less hungry for filament and less likely to create the problems Nick experienced. Colomore used to have bucket loads of these and tried touting them as TT22 alternatives...
by Paul Barker
Tue Dec 27, 2011 9:06 pm
Forum: Valves
Topic: Shunt Reg Using a 13E1 as Shunt Element
Replies: 70
Views: 30645

Just mulling this over, the 12E1 Triode connected would have a max g2 voltage 300 max current 100 mA max dissipation 35 Watts. Be less hungry for filament and less likely to create the problems Nick experienced. Colomore used to have bucket loads of these and tried touting them as TT22 alternatives...
by Paul Barker
Sat Dec 24, 2011 3:12 pm
Forum: Valves
Topic: Shunt Reg Using a 13E1 as Shunt Element
Replies: 70
Views: 30645

Anyway I have just thought of a brilliant plan. Build an output stage of 12e1 with a 75c1 as it's cathode bias and complement that with a shunt valve the same. So either side of the transformer primary two identical setups will see saw. But for simplicity of construction the power supply will be LCL...
by Paul Barker
Sat Dec 24, 2011 3:06 pm
Forum: Valves
Topic: Shunt Reg Using a 13E1 as Shunt Element
Replies: 70
Views: 30645

How come you need 360v? Is your amp direct coupled?
by Paul Barker
Sat Dec 24, 2011 2:59 pm
Forum: Valves
Topic: Shunt Reg Using a 13E1 as Shunt Element
Replies: 70
Views: 30645

I wish it wasn't so blinking cold on the top floor of my house or I would go up there and breadboard the shunt element to let you know what current it pulls from a 360v B+. i am just really worn out after working away long time doing 12 hr days and am at last home body has gone into a metabolic rate...
by Paul Barker
Sat Dec 24, 2011 2:56 pm
Forum: Speakers
Topic: OB Picture Gallery and Design Philosophy Discussion Thread
Replies: 153
Views: 54573

Your room demonstrates a serious listener. I can't figure out how you get bass with no effective baffle. What is the trick?
by Paul Barker
Sat Dec 24, 2011 2:48 pm
Forum: Valves
Topic: Shunt Reg Using a 13E1 as Shunt Element
Replies: 70
Views: 30645

You see Steve the beauty is that the shunt section will try to pull down the voltage but you have the series section to adjust the voltage back up. Once you have your desired voltage the shunt section will assist the series section in holding it tight.
by Paul Barker
Sat Dec 24, 2011 2:45 pm
Forum: Valves
Topic: Shunt Reg Using a 13E1 as Shunt Element
Replies: 70
Views: 30645

see my edit.
by Paul Barker
Sat Dec 24, 2011 2:42 pm
Forum: Valves
Topic: Shunt Reg Using a 13E1 as Shunt Element
Replies: 70
Views: 30645

You could leave that regulator in position. Pop the 12e14 and 75c1 in place adjust the series pass reg to provide the output stage B+ you require and just take whatever the 12e14 does as a bonus. Report back what it does and if it improves the sound.

I can send you a 75c1.
by Paul Barker
Sat Dec 24, 2011 2:18 pm
Forum: Valves
Topic: Shunt Reg Using a 13E1 as Shunt Element
Replies: 70
Views: 30645

Oh bum.
by Paul Barker
Sat Dec 24, 2011 10:53 am
Forum: Valves
Topic: Shunt Reg Using a 13E1 as Shunt Element
Replies: 70
Views: 30645

Might just fall into place. I think Steve has some 12e1's, if not I can send some. One consideration of the SP 211 amp is the use of 211 to return ac. We so often neglect to realise that the other (b+) side of the opt in a se amp has as much influence on Sound . Same valve as output valve makes sense.
by Paul Barker
Sat Dec 24, 2011 10:47 am
Forum: Valves
Topic: Shunt Reg Using a 13E1 as Shunt Element
Replies: 70
Views: 30645

Might just fall into place. I think Steve has some 12e1's, if not I can send some. One consideration of the SP 211 amp is the use of 211 to return ac. We so often neglect to realise that the other (b+) side of the opt in a se amp has as much influence on Sound . Same valve as output valve makes sens...