DCB1 PSU was tried some years back for T-amp with good results. DCB1 is family but has some differences and bigger power MOSFETS. There are stronger TO-220s for 1.1 though.
http://www.diyaudio.com/forums/power-supplies/153484-using-hypnotize-general-shunt-reg-pcb.html
read posts #20-29
http://www.diyaudio.com/forums/power-supplies/153484-using-hypnotize-general-shunt-reg-pcb.html
read posts #20-29
Salas...with your help, I am able to use your sslv 1.1 to filament bias my 26 tube line amp. with great happiness !!! It turned my 26 into a church mouse !!!
Do TA 2024 or TA 2020 need more current??
I am sure you have a way to solve this problem if in deed it is one!
Do TA 2024 or TA 2020 need more current??
I am sure you have a way to solve this problem if in deed it is one!
Salas....I have read through what you have suggested, but still a bit confused......with V1, V2, DCB1...etc...etc...
Appreciate if you could summarize what is now best PSU for T-2024 or T-2020 please......thankyou.
1.1 with IRF9640 in both MOSFET positions for the positive polarity branch and big sinks when the amplifier's peak power current draw just before clipping has been measured (or having asked the manufacturer) and the CCS setting covers it with say at least 100mA spare. Also oscilloscope rail check for interference on the rail from the amp's chips when in four wire mode to determine if its better to use it in two wire mode.
I'm having problems with the left channel regs. The output reaches 24V at about 85% on the variac and turning the trimmer in either direction has no affect. This is the same on both positive and negative regs. All LEDs light up.
Vdrop=.05
ground to source pin at Q201=20v
VGS=2.9
Vdrop=.05
ground to source pin at Q201=20v
VGS=2.9
Let it come up at 100% mains first then measure drop on R101 & R201 as well as Q101 & Q201 VGS. Make sure you aren't using too high R103-R203. Your dummy load should be calculated for drawing at least 20mA less than the CCS can provide.
Measurements
Now only one positive reg won't adjust. Here are the measurements I took at 100% mains on all four regs:
Right Channel
Positive:
Output = 24V
R101 Vdrop = .32
V Ground to Scource = 28.6V
Q101 VGS = 9.7V
Negative
Output = 24V
R201 Vdrop = .25
V Ground to Scource = 28.5V
Q101 VGS = 5V
Left Channel
Positive ** This is the reg that won’t adjust
Output = 29V
R101 Vdrop = .05
V Ground to Scource = 26.5
Q101 VGS = 10.4
Negative
Output = 24V
R101 Vdrop = .28
V Ground to Scource = 25
Q201 VGS = 5V
Now only one positive reg won't adjust. Here are the measurements I took at 100% mains on all four regs:
Right Channel
Positive:
Output = 24V
R101 Vdrop = .32
V Ground to Scource = 28.6V
Q101 VGS = 9.7V
Negative
Output = 24V
R201 Vdrop = .25
V Ground to Scource = 28.5V
Q101 VGS = 5V
Left Channel
Positive ** This is the reg that won’t adjust
Output = 29V
R101 Vdrop = .05
V Ground to Scource = 26.5
Q101 VGS = 10.4
Negative
Output = 24V
R101 Vdrop = .28
V Ground to Scource = 25
Q201 VGS = 5V
Shows from the very small Vdrop in the problematic one. It will probably need a new q101. Also the q101 vgs is unusually high in both positives. Maybe you got a dodgy batch of 9610s?
I'm sorry Salas the question is about C101,201 & 301, I'm using MKP 10uF and the question is what's the min /max value using MKP for this position?
Right, I somehow thought about the termination. No problem to use >10uF then, filters better for some less noise. Don't use <4.7uF either, not to decrease the filtering too low. Its a matter of fitting the size of a film cap.
Replaced Q101, same results. I've had 9610s in the circuit from two different sources with same results.
The only physical difference in the problematic one is where I melted the side of the output capacitor taking mosfets in and out. Could this be the problem?
