London Power ad

[-]
Search the Forum








(Advanced Search)

SV2-M36 Voltages
#10
Hi Kevin,

Using your Va/Vs terminology, my latest full-PS loaded readings are:
1. W1-1 = Va input = B+ from standby: 331 V
2. W2-1 = Vs input = B2: 321 V
3. W1-2 = Va output = OT centre tap: ~325.6 V
Direct measured W1-1 → W1-2 loss = 5.37 V
4. W2-2 = Vs output = second scaled rail: ~317 V
So the input difference Va − Vs is about 10 V, while at full PS the two regulator losses are approximately:
Va side: 5.4 V
Vs side: 4 V
Output valve plates are then about 322 V and screens about 314 V after their respective winding/resistor drops.
I have not replaced M2 on this SV2. The earlier large loss disappeared after reducing R5 to about 270 kΩ as you suggested.
Best,
Steve
Reply


Messages In This Thread
SV2-M36 Voltages - by Steve Ward - 09-17-2026, 01:48 PM
RE: SV2-M36 Voltages - by K O'Connor - 09-17-2026, 02:49 PM
RE: SV2-M36 Voltages - by Steve Ward - 09-17-2026, 03:45 PM
RE: SV2-M36 Voltages - by Steve Ward - 09-17-2026, 07:28 PM
RE: SV2-M36 Voltages - by K O'Connor - 09-17-2026, 07:34 PM
RE: SV2-M36 Voltages - by Steve Ward - 09-17-2026, 07:43 PM
RE: SV2-M36 Voltages - by K O'Connor - 09-17-2026, 07:46 PM
RE: SV2-M36 Voltages - by Steve Ward - 09-18-2026, 11:49 AM
RE: SV2-M36 Voltages - by K O'Connor - 09-18-2026, 12:33 PM
RE: SV2-M36 Voltages - by Steve Ward - 09-18-2026, 04:08 PM
RE: SV2-M36 Voltages - by K O'Connor - 09-18-2026, 08:40 PM

Forum Jump:

[-]
Come in where it's warm!
A warm welcome to tube amp modding fans and those interested in hi-fi audio! Readers of Kevin O'Connor's The Ultimate Tone (TUT) book series form a part of our population. Kevin O'Connor is the creator of the popular Power Scaling methodology for amplifiers.
Please remember these three principles: respect, sharing, community.
Not familiar with The Ultimate Tone book series? See discussion topics, or click here to visit London Power/Power Press Publishing.

[-]
Tube Amp Forum Hosted by London Power
London Power logo