QUASI Amplifier for Beginners

[AndrewT]

With +-47.5Vdc (which varies markedly with mains voltage variations) expect maximum output voltage to be ~40Vpk.

40Vpk into 8r0 is equivalent to 100W into 8r0.

 

[apexaudio]

With +-47.5Vdc (which varies markedly with mains voltage variations) expect maximum output voltage to be ~40Vpk.

40Vpk into 8r0 is equivalent to 100W into 8r0.

With 2x47.5V AC maximum output power is 240W into 8R or 480W into 4R...

 

[AndrewT]

47.5-0-47.5 volts

I read that as DC voltage available from the PSU.
You read that as AC voltage from the transformer.
Which?

 

[apexaudio]

@AudioSenseCD
What is DC rail voltage on your PSU or what is AC voltage on your transformer?

 

[AudioSenseCD]

ac rail voltage sir is 47.5-0-47.5 ac 1kva traffo

 

[AudioSenseCD]

dc rail voltage sir is 66.975 i mean 67-0-67 volts dc

 

[AudioSenseCD]

@apex sir can i use tip41c and tip42c for the drivers

 

[djk]

No, they are only 100V.

The design requires 150V parts for ±67V.

 

[AudioSenseCD]

@jdk thanks sir for the info and what will the other substitute for the driver mje15031/mje15030 its to expensive here in out country $5 us dollar each PHP200 pesos

 

[apexaudio]

LED VU

 

[AudioSenseCD]

@ apex sir do you have a pcb design, placement parts ,layout TY...

and sir what is the other final predrivers for mje15031/30?

regards

 

[AudioSenseCD]

@apex sir i got an alternative for mje 15031/30

a1941/c5198

datasheet

Technical/Catalog Information 2SA1941-O(Q,T)
Vendor Toshiba
Category Discrete Semiconductor Products
Transistor Type PNP
Voltage - Collector Emitter Breakdown (Max) 140V
Current - Collector (Ic) (Max) 10A
Power - Max 100W
DC Current Gain (hFE) (Min) @ Ic, Vce 80 @ 1A, 5V
Vce Saturation (Max) @ Ib, Ic 2V @ 700mA, 7A
Frequency - Transition 30MHz
Current - Collector Cutoff (Max) -
Mounting Type Through Hole
Package / Case TO-3P-3, SC-65-3
Packaging Tube
Lead Free Status Lead Free
RoHS Status RoHS Compliant
Other Names 2SA1941 O Q,T
2SA1941OQ,T

Datasheets 2SC5198
Standard Package 50
Category Discrete Semiconductor Products
Family Transistors (BJT) - Single
Series -
Transistor Type NPN
Current - Collector (Ic) (Max) 10A
Voltage - Collector Emitter Breakdown (Max) 140V
Vce Saturation (Max) @ Ib, Ic 2V @ 700mA, 7A
Current - Collector Cutoff (Max) -
DC Current Gain (hFE) (Min) @ Ic, Vce 80 @ 1A, 5V
Power - Max 100W
Frequency - Transition 30MHz
Mounting Type Through Hole
Package / Case TO-3P-3, SC-65-3
Supplier Device Package TO-3P(N)
Packaging Tube

 

[mihailo]

You can also use 2SC2073/2SA940 ( 150W 1,5A 20W ) instead of MJE15030/31. I had used it in AX-14 Apex project, and it works nice. Its very cheap transistor. You can find it in tv services.

 

[djk]

AudioSenseCD, I like your idea of the TO-3P driver transistors.

 

[AudioSenseCD]

@jdk thank you sir for compliments i will gladly help....

@mihailo hard to find in my area sir and i greatly study the drivers and predrivers so i got stock of 2cs5198 & 2sa1941 and i use both i hope it will help others

regards

 

[AudioSenseCD]

still going....

please enlighten me master 's of diyaudio

 

[apexaudio]

Nice progres.
Pcb from post #1 have mistake, check your pcb.

 

[apexaudio]

TO220 (TIP41C/42C) and TO126 (MJE340/350) have different (revert BCE-ECB) pins.

 

[AudioSenseCD]

yes sir i already cut the line and jump thx again for info about tip

 

[djk]

You cannot use the TIP41C/42C to replace the MJE340/350 unless the rails are under ±50V.

Also, the TIP are 3Mhz parts vs the MJE are 15Mhz~60Mhz (depending on the operating current).