I dont have any pcb design for 30W version.
Show me the circuit.
I will make it for 30W with TO-3 devices. https://www.onsemi.com/pub/Collateral/MJ21193-D.PDF
regards
Prasi
Show me the circuit.
I will make it for 30W with TO-3 devices. https://www.onsemi.com/pub/Collateral/MJ21193-D.PDF
regards
Prasi
Nice music thimios!
Guys i have a concern about bias and dc offset, mine is so sensitive to adjust. I have it set at 0.6a bias but my dc offset seems to change when cold and warm, but it changes? Whats is acceptable for the dc offset? 0-10ma?
I have to add that i have 1k adjustable potentiometers so i can play with different bias settings and this seems to also affect the value of the dc offset. I could set the dc offset to 0v but when i try to adjust the bias to get it to where i want it either throws my dc offset off.
Guys i have a concern about bias and dc offset, mine is so sensitive to adjust. I have it set at 0.6a bias but my dc offset seems to change when cold and warm, but it changes? Whats is acceptable for the dc offset? 0-10ma?
I have to add that i have 1k adjustable potentiometers so i can play with different bias settings and this seems to also affect the value of the dc offset. I could set the dc offset to 0v but when i try to adjust the bias to get it to where i want it either throws my dc offset off.
I had the same problem with mine, I set up the bias 0.9A at warm up (about 20 minutes from startup) but after 2-3 hours later it crawls all the way up to 1.5A.
I had a large heatsink it could handle the heat but still not normal behavior. The DC offset was fine max 25 mV movement between cold and warm.
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After a short listening i must share my finding.
What is the used transistors.
J1=2sk246
J2=J103
T1=bc550c
T2=bc560c
T3=2sa1837
T4=2sc4793
T5=MJL3281A
T6=MJL1302A
R3=2k2//1k multi turn
R4=2k2//1k multi turn
I have test other transistor combination BUT stay away from high voltage transistors as ksa992, ksc1845 for the ccs, T1, T2.
I spend all the day trying to understand why one chanel playing so different, no bass.
Now i know... T1, T2 bc550, 560.
What is the used transistors.
J1=2sk246
J2=J103
T1=bc550c
T2=bc560c
T3=2sa1837
T4=2sc4793
T5=MJL3281A
T6=MJL1302A
R3=2k2//1k multi turn
R4=2k2//1k multi turn
I have test other transistor combination BUT stay away from high voltage transistors as ksa992, ksc1845 for the ccs, T1, T2.
I spend all the day trying to understand why one chanel playing so different, no bass.
Now i know... T1, T2 bc550, 560.
Hiraga 8w
I don't know why this amplifier hate capacitive multiplier.
I have a huge 12v toroidal.
I have add a second secondary for 2x12v configuration.
Two separate secondary,two separate diode bridges and two caps banks.
Nice dynamic powerful listening but with hum.
Any attempt for cap.multiplier was BIG disappointment,even when huge capacitor bank(80000uf) was used after the capacitor multiplier.
I don't know why this amplifier hate capacitive multiplier.
I have a huge 12v toroidal.
I have add a second secondary for 2x12v configuration.
Two separate secondary,two separate diode bridges and two caps banks.
Nice dynamic powerful listening but with hum.
Any attempt for cap.multiplier was BIG disappointment,even when huge capacitor bank(80000uf) was used after the capacitor multiplier.
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I think this is the circuit.
If it possible draw for the two possibility TO247-TO-3
Best Regards.
Thimios
Sorry my friend, I forgot all about the promise I made you.
here is it, just a rough sketch.
regards
prasi
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A flying lightspeed attenuator.
IMO a very good solution for volume control.
can you draw the circuit for this?
I can make it as a panel mount attenuation for any amplifier.
I have been intrigued by this amp for years ... finally time to attempt a build! I am planning on putting this in a Dissipante 3U case. I tried to keep the PS as close to the original design as possible with CDE 380LX lytic, KEMET FS supercap and KEMET SMR PPS caps. The amp will have provisions for AC or battery power with a 4P ON-OFF-ON switch.
Part subs will be:
- JFET - Linear Systems matched 170/74 B-grade quad
- 1st Stage - BC550/560
- 2nd Stage - BC327/337
- Output - NJW0281G/0302G
- 5W - Ohmite TA
Being a PCB Designer by trade, I chose to put the whole amp on a single PCB that will bolt to the baseplate of the Dissipante. The PT and connections will be to the rear of the PCB. Due to part cost, I'd like some feedback before I order anything. Go ahead ... tear it up!
PS - In the original design, Hiraga used an 11V supercap and cautioned not to exceed 13.8V ... I was curious if anyone has pushed the modern supercaps (KEMET FS) past their rated voltage?
Part subs will be:
- JFET - Linear Systems matched 170/74 B-grade quad
- 1st Stage - BC550/560
- 2nd Stage - BC327/337
- Output - NJW0281G/0302G
- 5W - Ohmite TA
Being a PCB Designer by trade, I chose to put the whole amp on a single PCB that will bolt to the baseplate of the Dissipante. The PT and connections will be to the rear of the PCB. Due to part cost, I'd like some feedback before I order anything. Go ahead ... tear it up!
PS - In the original design, Hiraga used an 11V supercap and cautioned not to exceed 13.8V ... I was curious if anyone has pushed the modern supercaps (KEMET FS) past their rated voltage?
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Nice to see this topic still actual.
I almost finished my own little monster after years of delay.
I designed a very tiny switch on/off circuit which also controls the batteries to switch on when the voltage over the second part of capacitors rises above 13,2 V and only when the batteries are connected
The pink on the photo is actual clear blue to the human eye: a number of blue LEDs embedded in the frontpanel will give it a blue "ambilight" when on..
The wooden covers, on and below the 15mm thick aluminium middleframe will be made from American Black walnut..
Kees
I almost finished my own little monster after years of delay.
I designed a very tiny switch on/off circuit which also controls the batteries to switch on when the voltage over the second part of capacitors rises above 13,2 V and only when the batteries are connected
The pink on the photo is actual clear blue to the human eye: a number of blue LEDs embedded in the frontpanel will give it a blue "ambilight" when on..
The wooden covers, on and below the 15mm thick aluminium middleframe will be made from American Black walnut..
Kees
