OLD THREAD Simplistic Mosfet HV Shunt (The Simpler Simplistic Design by Salas)

[Salas]

Not attached. But if you are talking about a UL KT88 SE amp that I have seen discussed in the forum sometimes, then do your experiments, but the SSHV has not been used on heavier things than phones tube amps, and I am afraid you are pushing the envelope. Power amp OPTs, UL, heavy primary inductances, 390V, heavy current swing, a brave man. But it can simply be not applicable in the end, and save it for something else. Good luck, let us know.

P.S. Maybe the current went trough LEDs and drain to gate fast before the RC time could bias up the cap, and skipped war.

 

[DIYspaceW]

PCB Group buy, round 2. Please Update the list yourselves when you type:

Note
1Pcb have: 2 SSHV + 2 filament!

1. kstlfido = 2 pcb
2. Sorr = 1 1/2 pcb
3. ksnider1 = 2 pcb
4. fredlock = 1 pcb
5. pinholer = 1 pcb
6. j45yip = 1 pcb
7. Skylar = 1 pcb
8. DIYspaceW = 1pcb

 

[regal]

The heatsink is supposed to be 100 W, I applied first to a resistor, managed to adjust the voltage and everything was OK. Then I tried with the amp, but I did not pre-heat the filaments, so I guess that at startup there was no load. Voltage raised and first BUM (I guess the led) then smoke. From what I see R1 and R2 are gone and one of the leds. I suppose that also the semiconductors will not be so happy. What would you unsolder first, to check if they are fried ?

D.

Would a tube rectifier like the 5AR4 be best in that it ramps up slowly giving the tubes a chance to warm up?


I'm planning on a similiar application to a SE OPT but is is much lower current (20mA load.)

 

[Skylar]

quanghao,

Should we go ahead and pay now or wait for an invoice from you?
Thanks.

 

[neskor]

PCB Group buy, round 2. Please Update the list yourselves when you type:

Note
1Pcb have: 2 SSHV + 2 filament!

1. kstlfido = 2 pcb
2. Sorr = 1 1/2 pcb
3. ksnider1 = 2 pcb
4. fredlock = 1 pcb
5. pinholer = 1 pcb
6. j45yip = 1 pcb
7. Skylar = 1 pcb
8. DIYspaceW = 1pcb
9. neskor = 1 pcb

 

[damohpi]

PCB Group buy, round 2. Please Update the list yourselves when you type:

Note
1Pcb have: 2 SSHV + 2 filament!

1. kstlfido = 2 pcb
2. Sorr = 1 1/2 pcb
3. ksnider1 = 2 pcb
4. fredlock = 1 pcb
5. pinholer = 1 pcb
6. j45yip = 1 pcb
7. Skylar = 1 pcb
8. DIYspaceW = 1pcb
9. neskor = 1 pcb
10. damohpi = 2 pcb

 

[mach1]

PCB Group buy, round 2. Please Update the list yourselves when you type:

Note
1Pcb have: 2 SSHV + 2 filament!

1. kstlfido = 2 pcb
2. Sorr = 1 1/2 pcb
3. ksnider1 = 2 pcb
4. fredlock = 1 pcb
5. pinholer = 1 pcb
6. j45yip = 1 pcb
7. Skylar = 1 pcb
8. DIYspaceW = 1pcb
9. neskor = 1 pcb
10. damohpi = 2 pcb
11. mach1 = 2 pcb

 

[Quark]

PCB Group buy, round 2. Please Update the list yourselves when you type:

Note
1Pcb have: 2 SSHV + 2 filament!

1. kstlfido = 2 pcb
2. Sorr = 1 1/2 pcb
3. ksnider1 = 2 pcb
4. fredlock = 1 pcb
5. pinholer = 1 pcb
6. j45yip = 1 pcb
7. Skylar = 1 pcb
8. DIYspaceW = 1pcb
9. neskor = 1 pcb
10. damohpi = 2 pcb
11. mach1 = 2 pcb
12. Quark = 2 pcb

 

[bucurb]

questions

I'm new in this Group Buys.
What is the price for one PCB, please?
How can I pay one PCB, please?
Pay Pall it's ok, please?

Thank you

 

[wendell c]

PCB Group buy, round 2. Please Update the list yourselves when you type:

Note
1Pcb have: 2 SSHV + 2 filament!

1. kstlfido = 2 pcb
2. Sorr = 1 1/2 pcb
3. ksnider1 = 2 pcb
4. fredlock = 1 pcb
5. pinholer = 1 pcb
6. j45yip = 1 pcb
7. Skylar = 1 pcb
8. DIYspaceW = 1pcb
9. neskor = 1 pcb
10. damohpi = 2 pcb
11. mach1 = 2 pcb
12. Quark = 2 pcb
13. wendell c = 1pcb

 

[regal]

What are the specs for the 1n41742A, I can't find a datasheet for it and it isn't sold in the USA

 

[regal]

Also MPSA94 not available at digikey,

Is ZTX958 an Ok substitute?

http://www.diodes.com/datasheets/ZTX958.pdf

 

[Salas]

The pin order is different. The characteristics look compatible. Beyond that, nobody have used it, nobody knows more. Its a candidate Jacob says.

 

[Salas]

What are the specs for the 1n41742A, I can't find a datasheet for it and it isn't sold in the USA

Just any 12V half Watt or one Watt Zener you can easily get does the job fine.

 

[Salas]

The pin order is different. The characteristics look compatible. Beyond that, nobody have used it, nobody knows more. Its a candidate Jacob says.

P.S. Nikon1975 have used NEC 2SA1626 as 400V PNP which is pin order compatible to MJE350. It worked. But you can carefuly twist pins if you get something else to test. Its a matter of easy access to parts foremostly.

 

[regal]

Thanks,

I'm right on the edge, 310 in and about 285V out, I'll probably try the MJE350 first.

 

[quanghao]

Thanks,

I'm right on the edge, 310 in and about 285V out, I'll probably try the MJE350 first.

Hi regal and Hi all!
This image I was measure V-in and v-out SSHV for my amli.
My amli need 330V and 89 mA. I fix SSHV 110mA at 330v- Vout, V-in at 340V.
Use Mje 350!
You can see int the image!

Or See this link please:
http://www.diyaudio.com/forums/tube...ll-tube-dht-amli-26-45-2a3-3.html#post2193915

 

[Nikon1975]

Quanghao,

do you pre-heat the tubes before switching on the regulators ?

D.

 

[quanghao]

Quanghao,

do you pre-heat the tubes before switching on the regulators ?

D.

No! they turn one time!

 

[jameshillj]

QuangHao.
Could you let me know what's happening with the "shunt for Dac" pcbs, please?